Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "First pull request for this merge window, there will also be a
  followup request with some stragglers.

  This pull request contains:

   - Fix for a thundering heard issue in the wbt block code (Anchal
     Agarwal)

   - A few NVMe pull requests:
      * Improved tracepoints (Keith)
      * Larger inline data support for RDMA (Steve Wise)
      * RDMA setup/teardown fixes (Sagi)
      * Effects log suppor for NVMe target (Chaitanya Kulkarni)
      * Buffered IO suppor for NVMe target (Chaitanya Kulkarni)
      * TP4004 (ANA) support (Christoph)
      * Various NVMe fixes

   - Block io-latency controller support. Much needed support for
     properly containing block devices. (Josef)

   - Series improving how we handle sense information on the stack
     (Kees)

   - Lightnvm fixes and updates/improvements (Mathias/Javier et al)

   - Zoned device support for null_blk (Matias)

   - AIX partition fixes (Mauricio Faria de Oliveira)

   - DIF checksum code made generic (Max Gurtovoy)

   - Add support for discard in iostats (Michael Callahan / Tejun)

   - Set of updates for BFQ (Paolo)

   - Removal of async write support for bsg (Christoph)

   - Bio page dirtying and clone fixups (Christoph)

   - Set of bcache fix/changes (via Coly)

   - Series improving blk-mq queue setup/teardown speed (Ming)

   - Series improving merging performance on blk-mq (Ming)

   - Lots of other fixes and cleanups from a slew of folks"

* tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits)
  blkcg: Make blkg_root_lookup() work for queues in bypass mode
  bcache: fix error setting writeback_rate through sysfs interface
  null_blk: add lock drop/acquire annotation
  Blk-throttle: reduce tail io latency when iops limit is enforced
  block: paride: pd: mark expected switch fall-throughs
  block: Ensure that a request queue is dissociated from the cgroup controller
  block: Introduce blk_exit_queue()
  blkcg: Introduce blkg_root_lookup()
  block: Remove two superfluous #include directives
  blk-mq: count the hctx as active before allocating tag
  block: bvec_nr_vecs() returns value for wrong slab
  bcache: trivial - remove tailing backslash in macro BTREE_FLAG
  bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section
  bcache: set max writeback rate when I/O request is idle
  bcache: add code comments for bset.c
  bcache: fix mistaken comments in request.c
  bcache: fix mistaken code comments in bcache.h
  bcache: add a comment in super.c
  bcache: avoid unncessary cache prefetch bch_btree_node_get()
  bcache: display rate debug parameters to 0 when writeback is not running
  ...

Documentation/ABI/testing/procfs-diskstats

@@ -5,6 +5,7 @@ Description:
 		The /proc/diskstats file displays the I/O statistics
 		of block devices. Each line contains the following 14
 		fields:
+
 		 1 - major number
 		 2 - minor mumber
 		 3 - device name
@@ -19,4 +20,13 @@ Description:
 		12 - I/Os currently in progress
 		13 - time spent doing I/Os (ms)
 		14 - weighted time spent doing I/Os (ms)
+
+		Kernel 4.18+ appends four more fields for discard
+		tracking putting the total at 18:
+
+		15 - discards completed successfully
+		16 - discards merged
+		17 - sectors discarded
+		18 - time spent discarding
+
 		For more details refer to Documentation/iostats.txt

Documentation/admin-guide/cgroup-v2.rst

@@ -51,6 +51,9 @@ v1 is available under Documentation/cgroup-v1/.
      5-3. IO
        5-3-1. IO Interface Files
        5-3-2. Writeback
+       5-3-3. IO Latency
+         5-3-3-1. How IO Latency Throttling Works
+         5-3-3-2. IO Latency Interface Files
      5-4. PID
        5-4-1. PID Interface Files
      5-5. Device
@@ -1314,17 +1317,19 @@ IO Interface Files
 	Lines are keyed by $MAJ:$MIN device numbers and not ordered.
 	The following nested keys are defined.
 
-	  ======	===================
+	  ======	=====================
 	  rbytes	Bytes read
 	  wbytes	Bytes written
 	  rios		Number of read IOs
 	  wios		Number of write IOs
-	  ======	===================
+	  dbytes	Bytes discarded
+	  dios		Number of discard IOs
+	  ======	=====================
 
 	An example read output follows:
 
-	  8:16 rbytes=1459200 wbytes=314773504 rios=192 wios=353
-	  8:0 rbytes=90430464 wbytes=299008000 rios=8950 wios=1252
+	  8:16 rbytes=1459200 wbytes=314773504 rios=192 wios=353 dbytes=0 dios=0
+	  8:0 rbytes=90430464 wbytes=299008000 rios=8950 wios=1252 dbytes=50331648 dios=3021
 
   io.weight
 	A read-write flat-keyed file which exists on non-root cgroups.
@@ -1446,6 +1451,85 @@ writeback as follows.
 	vm.dirty[_background]_ratio.
 
 
+IO Latency
+~~~~~~~~~~
+
+This is a cgroup v2 controller for IO workload protection.  You provide a group
+with a latency target, and if the average latency exceeds that target the
+controller will throttle any peers that have a lower latency target than the
+protected workload.
+
+The limits are only applied at the peer level in the hierarchy.  This means that
+in the diagram below, only groups A, B, and C will influence each other, and
+groups D and F will influence each other.  Group G will influence nobody.
+
+			[root]
+		/	   |		\
+		A	   B		C
+	       /  \        |
+	      D    F	   G
+
+
+So the ideal way to configure this is to set io.latency in groups A, B, and C.
+Generally you do not want to set a value lower than the latency your device
+supports.  Experiment to find the value that works best for your workload.
+Start at higher than the expected latency for your device and watch the
+avg_lat value in io.stat for your workload group to get an idea of the
+latency you see during normal operation.  Use the avg_lat value as a basis for
+your real setting, setting at 10-15% higher than the value in io.stat.
+
+How IO Latency Throttling Works
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+io.latency is work conserving; so as long as everybody is meeting their latency
+target the controller doesn't do anything.  Once a group starts missing its
+target it begins throttling any peer group that has a higher target than itself.
+This throttling takes 2 forms:
+
+- Queue depth throttling.  This is the number of outstanding IO's a group is
+  allowed to have.  We will clamp down relatively quickly, starting at no limit
+  and going all the way down to 1 IO at a time.
+
+- Artificial delay induction.  There are certain types of IO that cannot be
+  throttled without possibly adversely affecting higher priority groups.  This
+  includes swapping and metadata IO.  These types of IO are allowed to occur
+  normally, however they are "charged" to the originating group.  If the
+  originating group is being throttled you will see the use_delay and delay
+  fields in io.stat increase.  The delay value is how many microseconds that are
+  being added to any process that runs in this group.  Because this number can
+  grow quite large if there is a lot of swapping or metadata IO occurring we
+  limit the individual delay events to 1 second at a time.
+
+Once the victimized group starts meeting its latency target again it will start
+unthrottling any peer groups that were throttled previously.  If the victimized
+group simply stops doing IO the global counter will unthrottle appropriately.
+
+IO Latency Interface Files
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+  io.latency
+	This takes a similar format as the other controllers.
+
+		"MAJOR:MINOR target=<target time in microseconds"
+
+  io.stat
+	If the controller is enabled you will see extra stats in io.stat in
+	addition to the normal ones.
+
+	  depth
+		This is the current queue depth for the group.
+
+	  avg_lat
+		This is an exponential moving average with a decay rate of 1/exp
+		bound by the sampling interval.  The decay rate interval can be
+		calculated by multiplying the win value in io.stat by the
+		corresponding number of samples based on the win value.
+
+	  win
+		The sampling window size in milliseconds.  This is the minimum
+		duration of time between evaluation events.  Windows only elapse
+		with IO activity.  Idle periods extend the most recent window.
+
 PID
 ---
 

Documentation/block/null_blk.txt

@@ -85,3 +85,10 @@ shared_tags=[0/1]: Default: 0
   0: Tag set is not shared.
   1: Tag set shared between devices for blk-mq. Only makes sense with
      nr_devices > 1, otherwise there's no tag set to share.
+
+zoned=[0/1]: Default: 0
+  0: Block device is exposed as a random-access block device.
+  1: Block device is exposed as a host-managed zoned block device.
+
+zone_size=[MB]: Default: 256
+  Per zone size when exposed as a zoned block device. Must be a power of two.

Documentation/block/stat.txt

@@ -31,28 +31,32 @@ write ticks     milliseconds  total wait time for write requests
 in_flight       requests      number of I/Os currently in flight
 io_ticks        milliseconds  total time this block device has been active
 time_in_queue   milliseconds  total wait time for all requests
+discard I/Os    requests      number of discard I/Os processed
+discard merges  requests      number of discard I/Os merged with in-queue I/O
+discard sectors sectors       number of sectors discarded
+discard ticks   milliseconds  total wait time for discard requests
 
-read I/Os, write I/Os
-=====================
+read I/Os, write I/Os, discard I/0s
+===================================
 
 These values increment when an I/O request completes.
 
-read merges, write merges
-=========================
+read merges, write merges, discard merges
+=========================================
 
 These values increment when an I/O request is merged with an
 already-queued I/O request.
 
-read sectors, write sectors
-===========================
+read sectors, write sectors, discard_sectors
+============================================
 
-These values count the number of sectors read from or written to this
-block device.  The "sectors" in question are the standard UNIX 512-byte
-sectors, not any device- or filesystem-specific block size.  The
-counters are incremented when the I/O completes.
+These values count the number of sectors read from, written to, or
+discarded from this block device.  The "sectors" in question are the
+standard UNIX 512-byte sectors, not any device- or filesystem-specific
+block size.  The counters are incremented when the I/O completes.
 
-read ticks, write ticks
-=======================
+read ticks, write ticks, discard ticks
+======================================
 
 These values count the number of milliseconds that I/O requests have
 waited on this block device.  If there are multiple I/O requests waiting,

Documentation/iostats.txt

@@ -31,6 +31,9 @@ Here are examples of these different formats::
       3    0   hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160
       3    1   hda1 35486 38030 38030 38030
 
+   4.18+ diskstats:
+      3    0   hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160 0 0 0 0
+
 On 2.4 you might execute ``grep 'hda ' /proc/partitions``. On 2.6+, you have
 a choice of ``cat /sys/block/hda/stat`` or ``grep 'hda ' /proc/diskstats``.
 
@@ -101,6 +104,18 @@ Field 11 -- weighted # of milliseconds spent doing I/Os
     last update of this field.  This can provide an easy measure of both
     I/O completion time and the backlog that may be accumulating.
 
+Field 12 -- # of discards completed
+    This is the total number of discards completed successfully.
+
+Field 13 -- # of discards merged
+    See the description of field 2
+
+Field 14 -- # of sectors discarded
+    This is the total number of sectors discarded successfully.
+
+Field 15 -- # of milliseconds spent discarding
+    This is the total number of milliseconds spent by all discards (as
+    measured from __make_request() to end_that_request_last()).
 
 To avoid introducing performance bottlenecks, no locks are held while
 modifying these counters.  This implies that minor inaccuracies may be

block/Kconfig

@@ -149,6 +149,18 @@ config BLK_WBT
 	dynamically on an algorithm loosely based on CoDel, factoring in
 	the realtime performance of the disk.
 
+config BLK_CGROUP_IOLATENCY
+	bool "Enable support for latency based cgroup IO protection"
+	depends on BLK_CGROUP=y
+	default n
+	---help---
+	Enabling this option enables the .latency interface for IO throttling.
+	The IO controller will attempt to maintain average IO latencies below
+	the configured latency target, throttling anybody with a higher latency
+	target than the victimized group.
+
+	Note, this is an experimental interface and could be changed someday.
+
 config BLK_WBT_SQ
 	bool "Single queue writeback throttling"
 	default n
@@ -177,6 +189,10 @@ config BLK_DEBUG_FS
 	Unless you are building a kernel for a tiny system, you should
 	say Y here.
 
+config BLK_DEBUG_FS_ZONED
+       bool
+       default BLK_DEBUG_FS && BLK_DEV_ZONED
+
 config BLK_SED_OPAL
 	bool "Logic for interfacing with Opal enabled SEDs"
 	---help---

block/Makefile

@@ -9,7 +9,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \
 			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
 			blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
 			genhd.o partition-generic.o ioprio.o \
-			badblocks.o partitions/
+			badblocks.o partitions/ blk-rq-qos.o
 
 obj-$(CONFIG_BOUNCE)		+= bounce.o
 obj-$(CONFIG_BLK_SCSI_REQUEST)	+= scsi_ioctl.o
@@ -17,6 +17,7 @@ obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o
 obj-$(CONFIG_BLK_DEV_BSGLIB)	+= bsg-lib.o
 obj-$(CONFIG_BLK_CGROUP)	+= blk-cgroup.o
 obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o
+obj-$(CONFIG_BLK_CGROUP_IOLATENCY)	+= blk-iolatency.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
 obj-$(CONFIG_IOSCHED_DEADLINE)	+= deadline-iosched.o
 obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o
@@ -34,4 +35,5 @@ obj-$(CONFIG_BLK_MQ_RDMA)	+= blk-mq-rdma.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
+obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o

block/bfq-iosched.c

@@ -634,7 +634,7 @@ static bool bfq_differentiated_weights(struct bfq_data *bfqd)
  * The following function returns true if every queue must receive the
  * same share of the throughput (this condition is used when deciding
  * whether idling may be disabled, see the comments in the function
- * bfq_bfqq_may_idle()).
+ * bfq_better_to_idle()).
  *
  * Such a scenario occurs when:
  * 1) all active queues have the same weight,
@@ -742,8 +742,9 @@ inc_counter:
  * See the comments to the function bfq_weights_tree_add() for considerations
  * about overhead.
  */
-void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_entity *entity,
-			     struct rb_root *root)
+void __bfq_weights_tree_remove(struct bfq_data *bfqd,
+			       struct bfq_entity *entity,
+			       struct rb_root *root)
 {
 	if (!entity->weight_counter)
 		return;
@@ -759,6 +760,43 @@ reset_entity_pointer:
 	entity->weight_counter = NULL;
 }
 
+/*
+ * Invoke __bfq_weights_tree_remove on bfqq and all its inactive
+ * parent entities.
+ */
+void bfq_weights_tree_remove(struct bfq_data *bfqd,
+			     struct bfq_queue *bfqq)
+{
+	struct bfq_entity *entity = bfqq->entity.parent;
+
+	__bfq_weights_tree_remove(bfqd, &bfqq->entity,
+				  &bfqd->queue_weights_tree);
+
+	for_each_entity(entity) {
+		struct bfq_sched_data *sd = entity->my_sched_data;
+
+		if (sd->next_in_service || sd->in_service_entity) {
+			/*
+			 * entity is still active, because either
+			 * next_in_service or in_service_entity is not
+			 * NULL (see the comments on the definition of
+			 * next_in_service for details on why
+			 * in_service_entity must be checked too).
+			 *
+			 * As a consequence, the weight of entity is
+			 * not to be removed. In addition, if entity
+			 * is active, then its parent entities are
+			 * active as well, and thus their weights are
+			 * not to be removed either. In the end, this
+			 * loop must stop here.
+			 */
+			break;
+		}
+		__bfq_weights_tree_remove(bfqd, entity,
+					  &bfqd->group_weights_tree);
+	}
+}
+
 /*
  * Return expired entry, or NULL to just start from scratch in rbtree.
  */
@@ -1344,18 +1382,30 @@ static bool bfq_bfqq_update_budg_for_activation(struct bfq_data *bfqd,
 		 * remain unchanged after such an expiration, and the
 		 * following statement therefore assigns to
 		 * entity->budget the remaining budget on such an
-		 * expiration. For clarity, entity->service is not
-		 * updated on expiration in any case, and, in normal
-		 * operation, is reset only when bfqq is selected for
-		 * service (see bfq_get_next_queue).
+		 * expiration.
 		 */
 		entity->budget = min_t(unsigned long,
 				       bfq_bfqq_budget_left(bfqq),
 				       bfqq->max_budget);
 
+		/*
+		 * At this point, we have used entity->service to get
+		 * the budget left (needed for updating
+		 * entity->budget). Thus we finally can, and have to,
+		 * reset entity->service. The latter must be reset
+		 * because bfqq would otherwise be charged again for
+		 * the service it has received during its previous
+		 * service slot(s).
+		 */
+		entity->service = 0;
+
 		return true;
 	}
 
+	/*
+	 * We can finally complete expiration, by setting service to 0.
+	 */
+	entity->service = 0;
 	entity->budget = max_t(unsigned long, bfqq->max_budget,
 			       bfq_serv_to_charge(bfqq->next_rq, bfqq));
 	bfq_clear_bfqq_non_blocking_wait_rq(bfqq);
@@ -3233,11 +3283,21 @@ void bfq_bfqq_expire(struct bfq_data *bfqd,
 	ref = bfqq->ref;
 	__bfq_bfqq_expire(bfqd, bfqq);
 
+	if (ref == 1) /* bfqq is gone, no more actions on it */
+		return;
+
 	/* mark bfqq as waiting a request only if a bic still points to it */
-	if (ref > 1 && !bfq_bfqq_busy(bfqq) &&
+	if (!bfq_bfqq_busy(bfqq) &&
 	    reason != BFQQE_BUDGET_TIMEOUT &&
-	    reason != BFQQE_BUDGET_EXHAUSTED)
+	    reason != BFQQE_BUDGET_EXHAUSTED) {
 		bfq_mark_bfqq_non_blocking_wait_rq(bfqq);
+		/*
+		 * Not setting service to 0, because, if the next rq
+		 * arrives in time, the queue will go on receiving
+		 * service with this same budget (as if it never expired)
+		 */
+	} else
+		entity->service = 0;
 }
 
 /*
@@ -3295,7 +3355,7 @@ static bool bfq_may_expire_for_budg_timeout(struct bfq_queue *bfqq)
  * issues taken into account are not trivial. We discuss these issues
  * individually while introducing the variables.
  */
-static bool bfq_bfqq_may_idle(struct bfq_queue *bfqq)
+static bool bfq_better_to_idle(struct bfq_queue *bfqq)
 {
 	struct bfq_data *bfqd = bfqq->bfqd;
 	bool rot_without_queueing =
@@ -3528,19 +3588,19 @@ static bool bfq_bfqq_may_idle(struct bfq_queue *bfqq)
 }
 
 /*
- * If the in-service queue is empty but the function bfq_bfqq_may_idle
+ * If the in-service queue is empty but the function bfq_better_to_idle
  * returns true, then:
  * 1) the queue must remain in service and cannot be expired, and
  * 2) the device must be idled to wait for the possible arrival of a new
  *    request for the queue.
- * See the comments on the function bfq_bfqq_may_idle for the reasons
+ * See the comments on the function bfq_better_to_idle for the reasons
  * why performing device idling is the best choice to boost the throughput
- * and preserve service guarantees when bfq_bfqq_may_idle itself
+ * and preserve service guarantees when bfq_better_to_idle itself
  * returns true.
  */
 static bool bfq_bfqq_must_idle(struct bfq_queue *bfqq)
 {
-	return RB_EMPTY_ROOT(&bfqq->sort_list) && bfq_bfqq_may_idle(bfqq);
+	return RB_EMPTY_ROOT(&bfqq->sort_list) && bfq_better_to_idle(bfqq);
 }
 
 /*
@@ -3559,8 +3619,14 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd)
 
 	bfq_log_bfqq(bfqd, bfqq, "select_queue: already in-service queue");
 
+	/*
+	 * Do not expire bfqq for budget timeout if bfqq may be about
+	 * to enjoy device idling. The reason why, in this case, we
+	 * prevent bfqq from expiring is the same as in the comments
+	 * on the case where bfq_bfqq_must_idle() returns true, in
+	 * bfq_completed_request().
+	 */
 	if (bfq_may_expire_for_budg_timeout(bfqq) &&
-	    !bfq_bfqq_wait_request(bfqq) &&
 	    !bfq_bfqq_must_idle(bfqq))
 		goto expire;
 
@@ -3620,7 +3686,7 @@ check_queue:
 	 * may idle after their completion, then keep it anyway.
 	 */
 	if (bfq_bfqq_wait_request(bfqq) ||
-	    (bfqq->dispatched != 0 && bfq_bfqq_may_idle(bfqq))) {
+	    (bfqq->dispatched != 0 && bfq_better_to_idle(bfqq))) {
 		bfqq = NULL;
 		goto keep_queue;
 	}
@@ -4582,8 +4648,7 @@ static void bfq_completed_request(struct bfq_queue *bfqq, struct bfq_data *bfqd)
 		 */
 		bfqq->budget_timeout = jiffies;
 
-		bfq_weights_tree_remove(bfqd, &bfqq->entity,
-					&bfqd->queue_weights_tree);
+		bfq_weights_tree_remove(bfqd, bfqq);
 	}
 
 	now_ns = ktime_get_ns();
@@ -4637,15 +4702,39 @@ static void bfq_completed_request(struct bfq_queue *bfqq, struct bfq_data *bfqd)
 	 * or if we want to idle in case it has no pending requests.
 	 */
 	if (bfqd->in_service_queue == bfqq) {
-		if (bfqq->dispatched == 0 && bfq_bfqq_must_idle(bfqq)) {
-			bfq_arm_slice_timer(bfqd);
+		if (bfq_bfqq_must_idle(bfqq)) {
+			if (bfqq->dispatched == 0)
+				bfq_arm_slice_timer(bfqd);
+			/*
+			 * If we get here, we do not expire bfqq, even
+			 * if bfqq was in budget timeout or had no
+			 * more requests (as controlled in the next
+			 * conditional instructions). The reason for
+			 * not expiring bfqq is as follows.
+			 *
+			 * Here bfqq->dispatched > 0 holds, but
+			 * bfq_bfqq_must_idle() returned true. This
+			 * implies that, even if no request arrives
+			 * for bfqq before bfqq->dispatched reaches 0,
+			 * bfqq will, however, not be expired on the
+			 * completion event that causes bfqq->dispatch
+			 * to reach zero. In contrast, on this event,
+			 * bfqq will start enjoying device idling
+			 * (I/O-dispatch plugging).
+			 *
+			 * But, if we expired bfqq here, bfqq would
+			 * not have the chance to enjoy device idling
+			 * when bfqq->dispatched finally reaches
+			 * zero. This would expose bfqq to violation
+			 * of its reserved service guarantees.
+			 */
 			return;
 		} else if (bfq_may_expire_for_budg_timeout(bfqq))
 			bfq_bfqq_expire(bfqd, bfqq, false,
 					BFQQE_BUDGET_TIMEOUT);
 		else if (RB_EMPTY_ROOT(&bfqq->sort_list) &&
 			 (bfqq->dispatched == 0 ||
-			  !bfq_bfqq_may_idle(bfqq)))
+			  !bfq_better_to_idle(bfqq)))
 			bfq_bfqq_expire(bfqd, bfqq, false,
 					BFQQE_NO_MORE_REQUESTS);
 	}

block/bfq-iosched.h

@@ -827,8 +827,11 @@ struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic);
 void bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq);
 void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_entity *entity,
 			  struct rb_root *root);
-void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_entity *entity,
-			     struct rb_root *root);
+void __bfq_weights_tree_remove(struct bfq_data *bfqd,
+			       struct bfq_entity *entity,
+			       struct rb_root *root);
+void bfq_weights_tree_remove(struct bfq_data *bfqd,
+			     struct bfq_queue *bfqq);
 void bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 		     bool compensate, enum bfqq_expiration reason);
 void bfq_put_queue(struct bfq_queue *bfqq);

block/bfq-wf2q.c

@@ -499,9 +499,6 @@ static void bfq_active_insert(struct bfq_service_tree *st,
 	if (bfqq)
 		list_add(&bfqq->bfqq_list, &bfqq->bfqd->active_list);
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
-	else /* bfq_group */
-		bfq_weights_tree_add(bfqd, entity, &bfqd->group_weights_tree);
-
 	if (bfqg != bfqd->root_group)
 		bfqg->active_entities++;
 #endif
@@ -601,10 +598,6 @@ static void bfq_active_extract(struct bfq_service_tree *st,
 	if (bfqq)
 		list_del(&bfqq->bfqq_list);
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
-	else /* bfq_group */
-		bfq_weights_tree_remove(bfqd, entity,
-					&bfqd->group_weights_tree);
-
 	if (bfqg != bfqd->root_group)
 		bfqg->active_entities--;
 #endif
@@ -799,7 +792,7 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
 		if (prev_weight != new_weight) {
 			root = bfqq ? &bfqd->queue_weights_tree :
 				      &bfqd->group_weights_tree;
-			bfq_weights_tree_remove(bfqd, entity, root);
+			__bfq_weights_tree_remove(bfqd, entity, root);
 		}
 		entity->weight = new_weight;
 		/*
@@ -971,7 +964,7 @@ static void bfq_update_fin_time_enqueue(struct bfq_entity *entity,
  * one of its children receives a new request.
  *
  * Basically, this function updates the timestamps of entity and
- * inserts entity into its active tree, ater possibly extracting it
+ * inserts entity into its active tree, after possibly extracting it
  * from its idle tree.
  */
 static void __bfq_activate_entity(struct bfq_entity *entity,
@@ -1015,6 +1008,16 @@ static void __bfq_activate_entity(struct bfq_entity *entity,
 		entity->on_st = true;
 	}
 
+#ifdef BFQ_GROUP_IOSCHED_ENABLED
+	if (!bfq_entity_to_bfqq(entity)) { /* bfq_group */
+		struct bfq_group *bfqg =
+			container_of(entity, struct bfq_group, entity);
+
+		bfq_weights_tree_add(bfqg->bfqd, entity,
+				     &bfqd->group_weights_tree);
+	}
+#endif
+
 	bfq_update_fin_time_enqueue(entity, st, backshifted);
 }
 
@@ -1541,12 +1544,6 @@ struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd)
 		entity = sd->next_in_service;
 		sd->in_service_entity = entity;
 
-		/*
-		 * Reset the accumulator of the amount of service that
-		 * the entity is about to receive.
-		 */
-		entity->service = 0;
-
 		/*
 		 * If entity is no longer a candidate for next
 		 * service, then it must be extracted from its active
@@ -1664,8 +1661,7 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 	bfqd->busy_queues--;
 
 	if (!bfqq->dispatched)
-		bfq_weights_tree_remove(bfqd, &bfqq->entity,
-					&bfqd->queue_weights_tree);
+		bfq_weights_tree_remove(bfqd, bfqq);
 
 	if (bfqq->wr_coeff > 1)
 		bfqd->wr_busy_queues--;

block/bio-integrity.c

@@ -159,28 +159,6 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
 }
 EXPORT_SYMBOL(bio_integrity_add_page);
 
-/**
- * bio_integrity_intervals - Return number of integrity intervals for a bio
- * @bi:		blk_integrity profile for device
- * @sectors:	Size of the bio in 512-byte sectors
- *
- * Description: The block layer calculates everything in 512 byte
- * sectors but integrity metadata is done in terms of the data integrity
- * interval size of the storage device.  Convert the block layer sectors
- * to the appropriate number of integrity intervals.
- */
-static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
-						   unsigned int sectors)
-{
-	return sectors >> (bi->interval_exp - 9);
-}
-
-static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
-					       unsigned int sectors)
-{
-	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
-}
-
 /**
  * bio_integrity_process - Process integrity metadata for a bio
  * @bio:	bio to generate/verify integrity metadata for

block/bio.c

@@ -28,9 +28,11 @@
 #include <linux/mempool.h>
 #include <linux/workqueue.h>
 #include <linux/cgroup.h>
+#include <linux/blk-cgroup.h>
 
 #include <trace/events/block.h>
 #include "blk.h"
+#include "blk-rq-qos.h"
 
 /*
  * Test patch to inline a certain number of bi_io_vec's inside the bio
@@ -156,7 +158,7 @@ out:
 
 unsigned int bvec_nr_vecs(unsigned short idx)
 {
-	return bvec_slabs[idx].nr_vecs;
+	return bvec_slabs[--idx].nr_vecs;
 }
 
 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
@@ -644,83 +646,6 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
 }
 EXPORT_SYMBOL(bio_clone_fast);
 
-/**
- * 	bio_clone_bioset - clone a bio
- * 	@bio_src: bio to clone
- *	@gfp_mask: allocation priority
- *	@bs: bio_set to allocate from
- *
- *	Clone bio. Caller will own the returned bio, but not the actual data it
- *	points to. Reference count of returned bio will be one.
- */
-struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
-			     struct bio_set *bs)
-{
-	struct bvec_iter iter;
-	struct bio_vec bv;
-	struct bio *bio;
-
-	/*
-	 * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
-	 * bio_src->bi_io_vec to bio->bi_io_vec.
-	 *
-	 * We can't do that anymore, because:
-	 *
-	 *  - The point of cloning the biovec is to produce a bio with a biovec
-	 *    the caller can modify: bi_idx and bi_bvec_done should be 0.
-	 *
-	 *  - The original bio could've had more than BIO_MAX_PAGES biovecs; if
-	 *    we tried to clone the whole thing bio_alloc_bioset() would fail.
-	 *    But the clone should succeed as long as the number of biovecs we
-	 *    actually need to allocate is fewer than BIO_MAX_PAGES.
-	 *
-	 *  - Lastly, bi_vcnt should not be looked at or relied upon by code
-	 *    that does not own the bio - reason being drivers don't use it for
-	 *    iterating over the biovec anymore, so expecting it to be kept up
-	 *    to date (i.e. for clones that share the parent biovec) is just
-	 *    asking for trouble and would force extra work on
-	 *    __bio_clone_fast() anyways.
-	 */
-
-	bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
-	if (!bio)
-		return NULL;
-	bio->bi_disk		= bio_src->bi_disk;
-	bio->bi_opf		= bio_src->bi_opf;
-	bio->bi_write_hint	= bio_src->bi_write_hint;
-	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
-	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
-
-	switch (bio_op(bio)) {
-	case REQ_OP_DISCARD:
-	case REQ_OP_SECURE_ERASE:
-	case REQ_OP_WRITE_ZEROES:
-		break;
-	case REQ_OP_WRITE_SAME:
-		bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
-		break;
-	default:
-		bio_for_each_segment(bv, bio_src, iter)
-			bio->bi_io_vec[bio->bi_vcnt++] = bv;
-		break;
-	}
-
-	if (bio_integrity(bio_src)) {
-		int ret;
-
-		ret = bio_integrity_clone(bio, bio_src, gfp_mask);
-		if (ret < 0) {
-			bio_put(bio);
-			return NULL;
-		}
-	}
-
-	bio_clone_blkcg_association(bio, bio_src);
-
-	return bio;
-}
-EXPORT_SYMBOL(bio_clone_bioset);
-
 /**
  *	bio_add_pc_page	-	attempt to add page to bio
  *	@q: the target queue
@@ -1661,10 +1586,8 @@ void bio_set_pages_dirty(struct bio *bio)
 	int i;
 
 	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (page && !PageCompound(page))
-			set_page_dirty_lock(page);
+		if (!PageCompound(bvec->bv_page))
+			set_page_dirty_lock(bvec->bv_page);
 	}
 }
 EXPORT_SYMBOL_GPL(bio_set_pages_dirty);
@@ -1674,19 +1597,15 @@ static void bio_release_pages(struct bio *bio)
 	struct bio_vec *bvec;
 	int i;
 
-	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (page)
-			put_page(page);
-	}
+	bio_for_each_segment_all(bvec, bio, i)
+		put_page(bvec->bv_page);
 }
 
 /*
  * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
  * If they are, then fine.  If, however, some pages are clean then they must
  * have been written out during the direct-IO read.  So we take another ref on
- * the BIO and the offending pages and re-dirty the pages in process context.
+ * the BIO and re-dirty the pages in process context.
  *
  * It is expected that bio_check_pages_dirty() will wholly own the BIO from
  * here on.  It will run one put_page() against each page and will run one
@@ -1704,78 +1623,70 @@ static struct bio *bio_dirty_list;
  */
 static void bio_dirty_fn(struct work_struct *work)
 {
-	unsigned long flags;
-	struct bio *bio;
+	struct bio *bio, *next;
 
-	spin_lock_irqsave(&bio_dirty_lock, flags);
-	bio = bio_dirty_list;
+	spin_lock_irq(&bio_dirty_lock);
+	next = bio_dirty_list;
 	bio_dirty_list = NULL;
-	spin_unlock_irqrestore(&bio_dirty_lock, flags);
+	spin_unlock_irq(&bio_dirty_lock);
 
-	while (bio) {
-		struct bio *next = bio->bi_private;
+	while ((bio = next) != NULL) {
+		next = bio->bi_private;
 
 		bio_set_pages_dirty(bio);
 		bio_release_pages(bio);
 		bio_put(bio);
-		bio = next;
 	}
 }
 
 void bio_check_pages_dirty(struct bio *bio)
 {
 	struct bio_vec *bvec;
-	int nr_clean_pages = 0;
+	unsigned long flags;
 	int i;
 
 	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (PageDirty(page) || PageCompound(page)) {
-			put_page(page);
-			bvec->bv_page = NULL;
-		} else {
-			nr_clean_pages++;
-		}
+		if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page))
+			goto defer;
 	}
 
-	if (nr_clean_pages) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&bio_dirty_lock, flags);
-		bio->bi_private = bio_dirty_list;
-		bio_dirty_list = bio;
-		spin_unlock_irqrestore(&bio_dirty_lock, flags);
-		schedule_work(&bio_dirty_work);
-	} else {
-		bio_put(bio);
-	}
+	bio_release_pages(bio);
+	bio_put(bio);
+	return;
+defer:
+	spin_lock_irqsave(&bio_dirty_lock, flags);
+	bio->bi_private = bio_dirty_list;
+	bio_dirty_list = bio;
+	spin_unlock_irqrestore(&bio_dirty_lock, flags);
+	schedule_work(&bio_dirty_work);
 }
 EXPORT_SYMBOL_GPL(bio_check_pages_dirty);
 
-void generic_start_io_acct(struct request_queue *q, int rw,
+void generic_start_io_acct(struct request_queue *q, int op,
 			   unsigned long sectors, struct hd_struct *part)
 {
+	const int sgrp = op_stat_group(op);
 	int cpu = part_stat_lock();
 
 	part_round_stats(q, cpu, part);
-	part_stat_inc(cpu, part, ios[rw]);
-	part_stat_add(cpu, part, sectors[rw], sectors);
-	part_inc_in_flight(q, part, rw);
+	part_stat_inc(cpu, part, ios[sgrp]);
+	part_stat_add(cpu, part, sectors[sgrp], sectors);
+	part_inc_in_flight(q, part, op_is_write(op));
 
 	part_stat_unlock();
 }
 EXPORT_SYMBOL(generic_start_io_acct);
 
-void generic_end_io_acct(struct request_queue *q, int rw,
+void generic_end_io_acct(struct request_queue *q, int req_op,
 			 struct hd_struct *part, unsigned long start_time)
 {
 	unsigned long duration = jiffies - start_time;
+	const int sgrp = op_stat_group(req_op);
 	int cpu = part_stat_lock();
 
-	part_stat_add(cpu, part, ticks[rw], duration);
+	part_stat_add(cpu, part, ticks[sgrp], duration);
 	part_round_stats(q, cpu, part);
-	part_dec_in_flight(q, part, rw);
+	part_dec_in_flight(q, part, op_is_write(req_op));
 
 	part_stat_unlock();
 }
@@ -1834,6 +1745,9 @@ again:
 	if (!bio_integrity_endio(bio))
 		return;
 
+	if (bio->bi_disk)
+		rq_qos_done_bio(bio->bi_disk->queue, bio);
+
 	/*
 	 * Need to have a real endio function for chained bios, otherwise
 	 * various corner cases will break (like stacking block devices that
@@ -2042,6 +1956,30 @@ EXPORT_SYMBOL(bioset_init_from_src);
 
 #ifdef CONFIG_BLK_CGROUP
 
+#ifdef CONFIG_MEMCG
+/**
+ * bio_associate_blkcg_from_page - associate a bio with the page's blkcg
+ * @bio: target bio
+ * @page: the page to lookup the blkcg from
+ *
+ * Associate @bio with the blkcg from @page's owning memcg.  This works like
+ * every other associate function wrt references.
+ */
+int bio_associate_blkcg_from_page(struct bio *bio, struct page *page)
+{
+	struct cgroup_subsys_state *blkcg_css;
+
+	if (unlikely(bio->bi_css))
+		return -EBUSY;
+	if (!page->mem_cgroup)
+		return 0;
+	blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup,
+				     &io_cgrp_subsys);
+	bio->bi_css = blkcg_css;
+	return 0;
+}
+#endif /* CONFIG_MEMCG */
+
 /**
  * bio_associate_blkcg - associate a bio with the specified blkcg
  * @bio: target bio
@@ -2064,6 +2002,24 @@ int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
 }
 EXPORT_SYMBOL_GPL(bio_associate_blkcg);
 
+/**
+ * bio_associate_blkg - associate a bio with the specified blkg
+ * @bio: target bio
+ * @blkg: the blkg to associate
+ *
+ * Associate @bio with the blkg specified by @blkg.  This is the queue specific
+ * blkcg information associated with the @bio, a reference will be taken on the
+ * @blkg and will be freed when the bio is freed.
+ */
+int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
+{
+	if (unlikely(bio->bi_blkg))
+		return -EBUSY;
+	blkg_get(blkg);
+	bio->bi_blkg = blkg;
+	return 0;
+}
+
 /**
  * bio_disassociate_task - undo bio_associate_current()
  * @bio: target bio
@@ -2078,6 +2034,10 @@ void bio_disassociate_task(struct bio *bio)
 		css_put(bio->bi_css);
 		bio->bi_css = NULL;
 	}
+	if (bio->bi_blkg) {
+		blkg_put(bio->bi_blkg);
+		bio->bi_blkg = NULL;
+	}
 }
 
 /**

block/blk-cgroup.c

@@ -27,6 +27,7 @@
 #include <linux/atomic.h>
 #include <linux/ctype.h>
 #include <linux/blk-cgroup.h>
+#include <linux/tracehook.h>
 #include "blk.h"
 
 #define MAX_KEY_LEN 100
@@ -50,6 +51,8 @@ static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
 
 static LIST_HEAD(all_blkcgs);		/* protected by blkcg_pol_mutex */
 
+static bool blkcg_debug_stats = false;
+
 static bool blkcg_policy_enabled(struct request_queue *q,
 				 const struct blkcg_policy *pol)
 {
@@ -564,6 +567,7 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
 		[BLKG_RWSTAT_WRITE]	= "Write",
 		[BLKG_RWSTAT_SYNC]	= "Sync",
 		[BLKG_RWSTAT_ASYNC]	= "Async",
+		[BLKG_RWSTAT_DISCARD]	= "Discard",
 	};
 	const char *dname = blkg_dev_name(pd->blkg);
 	u64 v;
@@ -577,7 +581,8 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
 			   (unsigned long long)atomic64_read(&rwstat->aux_cnt[i]));
 
 	v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) +
-		atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]);
+		atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]) +
+		atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_DISCARD]);
 	seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
 	return v;
 }
@@ -954,30 +959,77 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
 
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
 		const char *dname;
+		char *buf;
 		struct blkg_rwstat rwstat;
-		u64 rbytes, wbytes, rios, wios;
+		u64 rbytes, wbytes, rios, wios, dbytes, dios;
+		size_t size = seq_get_buf(sf, &buf), off = 0;
+		int i;
+		bool has_stats = false;
 
 		dname = blkg_dev_name(blkg);
 		if (!dname)
 			continue;
 
+		/*
+		 * Hooray string manipulation, count is the size written NOT
+		 * INCLUDING THE \0, so size is now count+1 less than what we
+		 * had before, but we want to start writing the next bit from
+		 * the \0 so we only add count to buf.
+		 */
+		off += scnprintf(buf+off, size-off, "%s ", dname);
+
 		spin_lock_irq(blkg->q->queue_lock);
 
 		rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
 					offsetof(struct blkcg_gq, stat_bytes));
 		rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
 		wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+		dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
 
 		rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
 					offsetof(struct blkcg_gq, stat_ios));
 		rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
 		wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
+		dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
 
 		spin_unlock_irq(blkg->q->queue_lock);
 
-		if (rbytes || wbytes || rios || wios)
-			seq_printf(sf, "%s rbytes=%llu wbytes=%llu rios=%llu wios=%llu\n",
-				   dname, rbytes, wbytes, rios, wios);
+		if (rbytes || wbytes || rios || wios) {
+			has_stats = true;
+			off += scnprintf(buf+off, size-off,
+					 "rbytes=%llu wbytes=%llu rios=%llu wios=%llu dbytes=%llu dios=%llu",
+					 rbytes, wbytes, rios, wios,
+					 dbytes, dios);
+		}
+
+		if (!blkcg_debug_stats)
+			goto next;
+
+		if (atomic_read(&blkg->use_delay)) {
+			has_stats = true;
+			off += scnprintf(buf+off, size-off,
+					 " use_delay=%d delay_nsec=%llu",
+					 atomic_read(&blkg->use_delay),
+					(unsigned long long)atomic64_read(&blkg->delay_nsec));
+		}
+
+		for (i = 0; i < BLKCG_MAX_POLS; i++) {
+			struct blkcg_policy *pol = blkcg_policy[i];
+			size_t written;
+
+			if (!blkg->pd[i] || !pol->pd_stat_fn)
+				continue;
+
+			written = pol->pd_stat_fn(blkg->pd[i], buf+off, size-off);
+			if (written)
+				has_stats = true;
+			off += written;
+		}
+next:
+		if (has_stats) {
+			off += scnprintf(buf+off, size-off, "\n");
+			seq_commit(sf, off);
+		}
 	}
 
 	rcu_read_unlock();
@@ -1191,6 +1243,14 @@ int blkcg_init_queue(struct request_queue *q)
 	if (preloaded)
 		radix_tree_preload_end();
 
+	ret = blk_iolatency_init(q);
+	if (ret) {
+		spin_lock_irq(q->queue_lock);
+		blkg_destroy_all(q);
+		spin_unlock_irq(q->queue_lock);
+		return ret;
+	}
+
 	ret = blk_throtl_init(q);
 	if (ret) {
 		spin_lock_irq(q->queue_lock);
@@ -1288,6 +1348,13 @@ static void blkcg_bind(struct cgroup_subsys_state *root_css)
 	mutex_unlock(&blkcg_pol_mutex);
 }
 
+static void blkcg_exit(struct task_struct *tsk)
+{
+	if (tsk->throttle_queue)
+		blk_put_queue(tsk->throttle_queue);
+	tsk->throttle_queue = NULL;
+}
+
 struct cgroup_subsys io_cgrp_subsys = {
 	.css_alloc = blkcg_css_alloc,
 	.css_offline = blkcg_css_offline,
@@ -1297,6 +1364,7 @@ struct cgroup_subsys io_cgrp_subsys = {
 	.dfl_cftypes = blkcg_files,
 	.legacy_cftypes = blkcg_legacy_files,
 	.legacy_name = "blkio",
+	.exit = blkcg_exit,
 #ifdef CONFIG_MEMCG
 	/*
 	 * This ensures that, if available, memcg is automatically enabled
@@ -1547,3 +1615,209 @@ out_unlock:
 	mutex_unlock(&blkcg_pol_register_mutex);
 }
 EXPORT_SYMBOL_GPL(blkcg_policy_unregister);
+
+/*
+ * Scale the accumulated delay based on how long it has been since we updated
+ * the delay.  We only call this when we are adding delay, in case it's been a
+ * while since we added delay, and when we are checking to see if we need to
+ * delay a task, to account for any delays that may have occurred.
+ */
+static void blkcg_scale_delay(struct blkcg_gq *blkg, u64 now)
+{
+	u64 old = atomic64_read(&blkg->delay_start);
+
+	/*
+	 * We only want to scale down every second.  The idea here is that we
+	 * want to delay people for min(delay_nsec, NSEC_PER_SEC) in a certain
+	 * time window.  We only want to throttle tasks for recent delay that
+	 * has occurred, in 1 second time windows since that's the maximum
+	 * things can be throttled.  We save the current delay window in
+	 * blkg->last_delay so we know what amount is still left to be charged
+	 * to the blkg from this point onward.  blkg->last_use keeps track of
+	 * the use_delay counter.  The idea is if we're unthrottling the blkg we
+	 * are ok with whatever is happening now, and we can take away more of
+	 * the accumulated delay as we've already throttled enough that
+	 * everybody is happy with their IO latencies.
+	 */
+	if (time_before64(old + NSEC_PER_SEC, now) &&
+	    atomic64_cmpxchg(&blkg->delay_start, old, now) == old) {
+		u64 cur = atomic64_read(&blkg->delay_nsec);
+		u64 sub = min_t(u64, blkg->last_delay, now - old);
+		int cur_use = atomic_read(&blkg->use_delay);
+
+		/*
+		 * We've been unthrottled, subtract a larger chunk of our
+		 * accumulated delay.
+		 */
+		if (cur_use < blkg->last_use)
+			sub = max_t(u64, sub, blkg->last_delay >> 1);
+
+		/*
+		 * This shouldn't happen, but handle it anyway.  Our delay_nsec
+		 * should only ever be growing except here where we subtract out
+		 * min(last_delay, 1 second), but lord knows bugs happen and I'd
+		 * rather not end up with negative numbers.
+		 */
+		if (unlikely(cur < sub)) {
+			atomic64_set(&blkg->delay_nsec, 0);
+			blkg->last_delay = 0;
+		} else {
+			atomic64_sub(sub, &blkg->delay_nsec);
+			blkg->last_delay = cur - sub;
+		}
+		blkg->last_use = cur_use;
+	}
+}
+
+/*
+ * This is called when we want to actually walk up the hierarchy and check to
+ * see if we need to throttle, and then actually throttle if there is some
+ * accumulated delay.  This should only be called upon return to user space so
+ * we're not holding some lock that would induce a priority inversion.
+ */
+static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay)
+{
+	u64 now = ktime_to_ns(ktime_get());
+	u64 exp;
+	u64 delay_nsec = 0;
+	int tok;
+
+	while (blkg->parent) {
+		if (atomic_read(&blkg->use_delay)) {
+			blkcg_scale_delay(blkg, now);
+			delay_nsec = max_t(u64, delay_nsec,
+					   atomic64_read(&blkg->delay_nsec));
+		}
+		blkg = blkg->parent;
+	}
+
+	if (!delay_nsec)
+		return;
+
+	/*
+	 * Let's not sleep for all eternity if we've amassed a huge delay.
+	 * Swapping or metadata IO can accumulate 10's of seconds worth of
+	 * delay, and we want userspace to be able to do _something_ so cap the
+	 * delays at 1 second.  If there's 10's of seconds worth of delay then
+	 * the tasks will be delayed for 1 second for every syscall.
+	 */
+	delay_nsec = min_t(u64, delay_nsec, 250 * NSEC_PER_MSEC);
+
+	/*
+	 * TODO: the use_memdelay flag is going to be for the upcoming psi stuff
+	 * that hasn't landed upstream yet.  Once that stuff is in place we need
+	 * to do a psi_memstall_enter/leave if memdelay is set.
+	 */
+
+	exp = ktime_add_ns(now, delay_nsec);
+	tok = io_schedule_prepare();
+	do {
+		__set_current_state(TASK_KILLABLE);
+		if (!schedule_hrtimeout(&exp, HRTIMER_MODE_ABS))
+			break;
+	} while (!fatal_signal_pending(current));
+	io_schedule_finish(tok);
+}
+
+/**
+ * blkcg_maybe_throttle_current - throttle the current task if it has been marked
+ *
+ * This is only called if we've been marked with set_notify_resume().  Obviously
+ * we can be set_notify_resume() for reasons other than blkcg throttling, so we
+ * check to see if current->throttle_queue is set and if not this doesn't do
+ * anything.  This should only ever be called by the resume code, it's not meant
+ * to be called by people willy-nilly as it will actually do the work to
+ * throttle the task if it is setup for throttling.
+ */
+void blkcg_maybe_throttle_current(void)
+{
+	struct request_queue *q = current->throttle_queue;
+	struct cgroup_subsys_state *css;
+	struct blkcg *blkcg;
+	struct blkcg_gq *blkg;
+	bool use_memdelay = current->use_memdelay;
+
+	if (!q)
+		return;
+
+	current->throttle_queue = NULL;
+	current->use_memdelay = false;
+
+	rcu_read_lock();
+	css = kthread_blkcg();
+	if (css)
+		blkcg = css_to_blkcg(css);
+	else
+		blkcg = css_to_blkcg(task_css(current, io_cgrp_id));
+
+	if (!blkcg)
+		goto out;
+	blkg = blkg_lookup(blkcg, q);
+	if (!blkg)
+		goto out;
+	blkg = blkg_try_get(blkg);
+	if (!blkg)
+		goto out;
+	rcu_read_unlock();
+
+	blkcg_maybe_throttle_blkg(blkg, use_memdelay);
+	blkg_put(blkg);
+	blk_put_queue(q);
+	return;
+out:
+	rcu_read_unlock();
+	blk_put_queue(q);
+}
+EXPORT_SYMBOL_GPL(blkcg_maybe_throttle_current);
+
+/**
+ * blkcg_schedule_throttle - this task needs to check for throttling
+ * @q - the request queue IO was submitted on
+ * @use_memdelay - do we charge this to memory delay for PSI
+ *
+ * This is called by the IO controller when we know there's delay accumulated
+ * for the blkg for this task.  We do not pass the blkg because there are places
+ * we call this that may not have that information, the swapping code for
+ * instance will only have a request_queue at that point.  This set's the
+ * notify_resume for the task to check and see if it requires throttling before
+ * returning to user space.
+ *
+ * We will only schedule once per syscall.  You can call this over and over
+ * again and it will only do the check once upon return to user space, and only
+ * throttle once.  If the task needs to be throttled again it'll need to be
+ * re-set at the next time we see the task.
+ */
+void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay)
+{
+	if (unlikely(current->flags & PF_KTHREAD))
+		return;
+
+	if (!blk_get_queue(q))
+		return;
+
+	if (current->throttle_queue)
+		blk_put_queue(current->throttle_queue);
+	current->throttle_queue = q;
+	if (use_memdelay)
+		current->use_memdelay = use_memdelay;
+	set_notify_resume(current);
+}
+EXPORT_SYMBOL_GPL(blkcg_schedule_throttle);
+
+/**
+ * blkcg_add_delay - add delay to this blkg
+ * @now - the current time in nanoseconds
+ * @delta - how many nanoseconds of delay to add
+ *
+ * Charge @delta to the blkg's current delay accumulation.  This is used to
+ * throttle tasks if an IO controller thinks we need more throttling.
+ */
+void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta)
+{
+	blkcg_scale_delay(blkg, now);
+	atomic64_add(delta, &blkg->delay_nsec);
+}
+EXPORT_SYMBOL_GPL(blkcg_add_delay);
+
+module_param(blkcg_debug_stats, bool, 0644);
+MODULE_PARM_DESC(blkcg_debug_stats, "True if you want debug stats, false if not");

block/blk-core.c

@@ -42,7 +42,7 @@
 #include "blk.h"
 #include "blk-mq.h"
 #include "blk-mq-sched.h"
-#include "blk-wbt.h"
+#include "blk-rq-qos.h"
 
 #ifdef CONFIG_DEBUG_FS
 struct dentry *blk_debugfs_root;
@@ -715,6 +715,35 @@ void blk_set_queue_dying(struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_set_queue_dying);
 
+/* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */
+void blk_exit_queue(struct request_queue *q)
+{
+	/*
+	 * Since the I/O scheduler exit code may access cgroup information,
+	 * perform I/O scheduler exit before disassociating from the block
+	 * cgroup controller.
+	 */
+	if (q->elevator) {
+		ioc_clear_queue(q);
+		elevator_exit(q, q->elevator);
+		q->elevator = NULL;
+	}
+
+	/*
+	 * Remove all references to @q from the block cgroup controller before
+	 * restoring @q->queue_lock to avoid that restoring this pointer causes
+	 * e.g. blkcg_print_blkgs() to crash.
+	 */
+	blkcg_exit_queue(q);
+
+	/*
+	 * Since the cgroup code may dereference the @q->backing_dev_info
+	 * pointer, only decrease its reference count after having removed the
+	 * association with the block cgroup controller.
+	 */
+	bdi_put(q->backing_dev_info);
+}
+
 /**
  * blk_cleanup_queue - shutdown a request queue
  * @q: request queue to shutdown
@@ -762,9 +791,13 @@ void blk_cleanup_queue(struct request_queue *q)
 	 * make sure all in-progress dispatch are completed because
 	 * blk_freeze_queue() can only complete all requests, and
 	 * dispatch may still be in-progress since we dispatch requests
-	 * from more than one contexts
+	 * from more than one contexts.
+	 *
+	 * No need to quiesce queue if it isn't initialized yet since
+	 * blk_freeze_queue() should be enough for cases of passthrough
+	 * request.
 	 */
-	if (q->mq_ops)
+	if (q->mq_ops && blk_queue_init_done(q))
 		blk_mq_quiesce_queue(q);
 
 	/* for synchronous bio-based driver finish in-flight integrity i/o */
@@ -780,30 +813,7 @@ void blk_cleanup_queue(struct request_queue *q)
 	 */
 	WARN_ON_ONCE(q->kobj.state_in_sysfs);
 
-	/*
-	 * Since the I/O scheduler exit code may access cgroup information,
-	 * perform I/O scheduler exit before disassociating from the block
-	 * cgroup controller.
-	 */
-	if (q->elevator) {
-		ioc_clear_queue(q);
-		elevator_exit(q, q->elevator);
-		q->elevator = NULL;
-	}
-
-	/*
-	 * Remove all references to @q from the block cgroup controller before
-	 * restoring @q->queue_lock to avoid that restoring this pointer causes
-	 * e.g. blkcg_print_blkgs() to crash.
-	 */
-	blkcg_exit_queue(q);
-
-	/*
-	 * Since the cgroup code may dereference the @q->backing_dev_info
-	 * pointer, only decrease its reference count after having removed the
-	 * association with the block cgroup controller.
-	 */
-	bdi_put(q->backing_dev_info);
+	blk_exit_queue(q);
 
 	if (q->mq_ops)
 		blk_mq_free_queue(q);
@@ -1180,6 +1190,7 @@ out_exit_flush_rq:
 		q->exit_rq_fn(q, q->fq->flush_rq);
 out_free_flush_queue:
 	blk_free_flush_queue(q->fq);
+	q->fq = NULL;
 	return -ENOMEM;
 }
 EXPORT_SYMBOL(blk_init_allocated_queue);
@@ -1641,7 +1652,7 @@ void blk_requeue_request(struct request_queue *q, struct request *rq)
 	blk_delete_timer(rq);
 	blk_clear_rq_complete(rq);
 	trace_block_rq_requeue(q, rq);
-	wbt_requeue(q->rq_wb, rq);
+	rq_qos_requeue(q, rq);
 
 	if (rq->rq_flags & RQF_QUEUED)
 		blk_queue_end_tag(q, rq);
@@ -1748,7 +1759,7 @@ void __blk_put_request(struct request_queue *q, struct request *req)
 	/* this is a bio leak */
 	WARN_ON(req->bio != NULL);
 
-	wbt_done(q->rq_wb, req);
+	rq_qos_done(q, req);
 
 	/*
 	 * Request may not have originated from ll_rw_blk. if not,
@@ -1982,7 +1993,6 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
 	int where = ELEVATOR_INSERT_SORT;
 	struct request *req, *free;
 	unsigned int request_count = 0;
-	unsigned int wb_acct;
 
 	/*
 	 * low level driver can indicate that it wants pages above a
@@ -2040,7 +2050,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
 	}
 
 get_rq:
-	wb_acct = wbt_wait(q->rq_wb, bio, q->queue_lock);
+	rq_qos_throttle(q, bio, q->queue_lock);
 
 	/*
 	 * Grab a free request. This is might sleep but can not fail.
@@ -2050,7 +2060,7 @@ get_rq:
 	req = get_request(q, bio->bi_opf, bio, 0, GFP_NOIO);
 	if (IS_ERR(req)) {
 		blk_queue_exit(q);
-		__wbt_done(q->rq_wb, wb_acct);
+		rq_qos_cleanup(q, bio);
 		if (PTR_ERR(req) == -ENOMEM)
 			bio->bi_status = BLK_STS_RESOURCE;
 		else
@@ -2059,7 +2069,7 @@ get_rq:
 		goto out_unlock;
 	}
 
-	wbt_track(req, wb_acct);
+	rq_qos_track(q, req, bio);
 
 	/*
 	 * After dropping the lock and possibly sleeping here, our request
@@ -2700,13 +2710,13 @@ EXPORT_SYMBOL_GPL(blk_rq_err_bytes);
 void blk_account_io_completion(struct request *req, unsigned int bytes)
 {
 	if (blk_do_io_stat(req)) {
-		const int rw = rq_data_dir(req);
+		const int sgrp = op_stat_group(req_op(req));
 		struct hd_struct *part;
 		int cpu;
 
 		cpu = part_stat_lock();
 		part = req->part;
-		part_stat_add(cpu, part, sectors[rw], bytes >> 9);
+		part_stat_add(cpu, part, sectors[sgrp], bytes >> 9);
 		part_stat_unlock();
 	}
 }
@@ -2720,7 +2730,7 @@ void blk_account_io_done(struct request *req, u64 now)
 	 */
 	if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) {
 		unsigned long duration;
-		const int rw = rq_data_dir(req);
+		const int sgrp = op_stat_group(req_op(req));
 		struct hd_struct *part;
 		int cpu;
 
@@ -2728,10 +2738,10 @@ void blk_account_io_done(struct request *req, u64 now)
 		cpu = part_stat_lock();
 		part = req->part;
 
-		part_stat_inc(cpu, part, ios[rw]);
-		part_stat_add(cpu, part, ticks[rw], duration);
+		part_stat_inc(cpu, part, ios[sgrp]);
+		part_stat_add(cpu, part, ticks[sgrp], duration);
 		part_round_stats(req->q, cpu, part);
-		part_dec_in_flight(req->q, part, rw);
+		part_dec_in_flight(req->q, part, rq_data_dir(req));
 
 		hd_struct_put(part);
 		part_stat_unlock();
@@ -2751,9 +2761,9 @@ static bool blk_pm_allow_request(struct request *rq)
 		return rq->rq_flags & RQF_PM;
 	case RPM_SUSPENDED:
 		return false;
+	default:
+		return true;
 	}
-
-	return true;
 }
 #else
 static bool blk_pm_allow_request(struct request *rq)
@@ -2980,7 +2990,7 @@ void blk_start_request(struct request *req)
 		req->throtl_size = blk_rq_sectors(req);
 #endif
 		req->rq_flags |= RQF_STATS;
-		wbt_issue(req->q->rq_wb, req);
+		rq_qos_issue(req->q, req);
 	}
 
 	BUG_ON(blk_rq_is_complete(req));
@@ -3053,6 +3063,10 @@ EXPORT_SYMBOL_GPL(blk_steal_bios);
  *     Passing the result of blk_rq_bytes() as @nr_bytes guarantees
  *     %false return from this function.
  *
+ * Note:
+ *	The RQF_SPECIAL_PAYLOAD flag is ignored on purpose in both
+ *	blk_rq_bytes() and in blk_update_request().
+ *
  * Return:
  *     %false - this request doesn't have any more data
  *     %true  - this request has more data
@@ -3200,7 +3214,7 @@ void blk_finish_request(struct request *req, blk_status_t error)
 	blk_account_io_done(req, now);
 
 	if (req->end_io) {
-		wbt_done(req->q->rq_wb, req);
+		rq_qos_done(q, req);
 		req->end_io(req, error);
 	} else {
 		if (blk_bidi_rq(req))
@@ -3763,9 +3777,11 @@ EXPORT_SYMBOL(blk_finish_plug);
  */
 void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
 {
-	/* not support for RQF_PM and ->rpm_status in blk-mq yet */
-	if (q->mq_ops)
+	/* Don't enable runtime PM for blk-mq until it is ready */
+	if (q->mq_ops) {
+		pm_runtime_disable(dev);
 		return;
+	}
 
 	q->dev = dev;
 	q->rpm_status = RPM_ACTIVE;

block/blk-ioc.c

@@ -278,7 +278,7 @@ int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node)
 	atomic_set(&ioc->nr_tasks, 1);
 	atomic_set(&ioc->active_ref, 1);
 	spin_lock_init(&ioc->lock);
-	INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC | __GFP_HIGH);
+	INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC);
 	INIT_HLIST_HEAD(&ioc->icq_list);
 	INIT_WORK(&ioc->release_work, ioc_release_fn);
 

block/blk-iolatency.c

@@ -0,0 +1,955 @@
+/*
+ * Block rq-qos base io controller
+ *
+ * This works similar to wbt with a few exceptions
+ *
+ * - It's bio based, so the latency covers the whole block layer in addition to
+ *   the actual io.
+ * - We will throttle all IO that comes in here if we need to.
+ * - We use the mean latency over the 100ms window.  This is because writes can
+ *   be particularly fast, which could give us a false sense of the impact of
+ *   other workloads on our protected workload.
+ * - By default there's no throttling, we set the queue_depth to UINT_MAX so
+ *   that we can have as many outstanding bio's as we're allowed to.  Only at
+ *   throttle time do we pay attention to the actual queue depth.
+ *
+ * The hierarchy works like the cpu controller does, we track the latency at
+ * every configured node, and each configured node has it's own independent
+ * queue depth.  This means that we only care about our latency targets at the
+ * peer level.  Some group at the bottom of the hierarchy isn't going to affect
+ * a group at the end of some other path if we're only configred at leaf level.
+ *
+ * Consider the following
+ *
+ *                   root blkg
+ *             /                     \
+ *        fast (target=5ms)     slow (target=10ms)
+ *         /     \                  /        \
+ *       a        b          normal(15ms)   unloved
+ *
+ * "a" and "b" have no target, but their combined io under "fast" cannot exceed
+ * an average latency of 5ms.  If it does then we will throttle the "slow"
+ * group.  In the case of "normal", if it exceeds its 15ms target, we will
+ * throttle "unloved", but nobody else.
+ *
+ * In this example "fast", "slow", and "normal" will be the only groups actually
+ * accounting their io latencies.  We have to walk up the heirarchy to the root
+ * on every submit and complete so we can do the appropriate stat recording and
+ * adjust the queue depth of ourselves if needed.
+ *
+ * There are 2 ways we throttle IO.
+ *
+ * 1) Queue depth throttling.  As we throttle down we will adjust the maximum
+ * number of IO's we're allowed to have in flight.  This starts at (u64)-1 down
+ * to 1.  If the group is only ever submitting IO for itself then this is the
+ * only way we throttle.
+ *
+ * 2) Induced delay throttling.  This is for the case that a group is generating
+ * IO that has to be issued by the root cg to avoid priority inversion. So think
+ * REQ_META or REQ_SWAP.  If we are already at qd == 1 and we're getting a lot
+ * of work done for us on behalf of the root cg and are being asked to scale
+ * down more then we induce a latency at userspace return.  We accumulate the
+ * total amount of time we need to be punished by doing
+ *
+ * total_time += min_lat_nsec - actual_io_completion
+ *
+ * and then at throttle time will do
+ *
+ * throttle_time = min(total_time, NSEC_PER_SEC)
+ *
+ * This induced delay will throttle back the activity that is generating the
+ * root cg issued io's, wethere that's some metadata intensive operation or the
+ * group is using so much memory that it is pushing us into swap.
+ *
+ * Copyright (C) 2018 Josef Bacik
+ */
+#include <linux/kernel.h>
+#include <linux/blk_types.h>
+#include <linux/backing-dev.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/memcontrol.h>
+#include <linux/sched/loadavg.h>
+#include <linux/sched/signal.h>
+#include <trace/events/block.h>
+#include "blk-rq-qos.h"
+#include "blk-stat.h"
+
+#define DEFAULT_SCALE_COOKIE 1000000U
+
+static struct blkcg_policy blkcg_policy_iolatency;
+struct iolatency_grp;
+
+struct blk_iolatency {
+	struct rq_qos rqos;
+	struct timer_list timer;
+	atomic_t enabled;
+};
+
+static inline struct blk_iolatency *BLKIOLATENCY(struct rq_qos *rqos)
+{
+	return container_of(rqos, struct blk_iolatency, rqos);
+}
+
+static inline bool blk_iolatency_enabled(struct blk_iolatency *blkiolat)
+{
+	return atomic_read(&blkiolat->enabled) > 0;
+}
+
+struct child_latency_info {
+	spinlock_t lock;
+
+	/* Last time we adjusted the scale of everybody. */
+	u64 last_scale_event;
+
+	/* The latency that we missed. */
+	u64 scale_lat;
+
+	/* Total io's from all of our children for the last summation. */
+	u64 nr_samples;
+
+	/* The guy who actually changed the latency numbers. */
+	struct iolatency_grp *scale_grp;
+
+	/* Cookie to tell if we need to scale up or down. */
+	atomic_t scale_cookie;
+};
+
+struct iolatency_grp {
+	struct blkg_policy_data pd;
+	struct blk_rq_stat __percpu *stats;
+	struct blk_iolatency *blkiolat;
+	struct rq_depth rq_depth;
+	struct rq_wait rq_wait;
+	atomic64_t window_start;
+	atomic_t scale_cookie;
+	u64 min_lat_nsec;
+	u64 cur_win_nsec;
+
+	/* total running average of our io latency. */
+	u64 lat_avg;
+
+	/* Our current number of IO's for the last summation. */
+	u64 nr_samples;
+
+	struct child_latency_info child_lat;
+};
+
+#define BLKIOLATENCY_MIN_WIN_SIZE (100 * NSEC_PER_MSEC)
+#define BLKIOLATENCY_MAX_WIN_SIZE NSEC_PER_SEC
+/*
+ * These are the constants used to fake the fixed-point moving average
+ * calculation just like load average.  The call to CALC_LOAD folds
+ * (FIXED_1 (2048) - exp_factor) * new_sample into lat_avg.  The sampling
+ * window size is bucketed to try to approximately calculate average
+ * latency such that 1/exp (decay rate) is [1 min, 2.5 min) when windows
+ * elapse immediately.  Note, windows only elapse with IO activity.  Idle
+ * periods extend the most recent window.
+ */
+#define BLKIOLATENCY_NR_EXP_FACTORS 5
+#define BLKIOLATENCY_EXP_BUCKET_SIZE (BLKIOLATENCY_MAX_WIN_SIZE / \
+				      (BLKIOLATENCY_NR_EXP_FACTORS - 1))
+static const u64 iolatency_exp_factors[BLKIOLATENCY_NR_EXP_FACTORS] = {
+	2045, // exp(1/600) - 600 samples
+	2039, // exp(1/240) - 240 samples
+	2031, // exp(1/120) - 120 samples
+	2023, // exp(1/80)  - 80 samples
+	2014, // exp(1/60)  - 60 samples
+};
+
+static inline struct iolatency_grp *pd_to_lat(struct blkg_policy_data *pd)
+{
+	return pd ? container_of(pd, struct iolatency_grp, pd) : NULL;
+}
+
+static inline struct iolatency_grp *blkg_to_lat(struct blkcg_gq *blkg)
+{
+	return pd_to_lat(blkg_to_pd(blkg, &blkcg_policy_iolatency));
+}
+
+static inline struct blkcg_gq *lat_to_blkg(struct iolatency_grp *iolat)
+{
+	return pd_to_blkg(&iolat->pd);
+}
+
+static inline bool iolatency_may_queue(struct iolatency_grp *iolat,
+				       wait_queue_entry_t *wait,
+				       bool first_block)
+{
+	struct rq_wait *rqw = &iolat->rq_wait;
+
+	if (first_block && waitqueue_active(&rqw->wait) &&
+	    rqw->wait.head.next != &wait->entry)
+		return false;
+	return rq_wait_inc_below(rqw, iolat->rq_depth.max_depth);
+}
+
+static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
+				       struct iolatency_grp *iolat,
+				       spinlock_t *lock, bool issue_as_root,
+				       bool use_memdelay)
+	__releases(lock)
+	__acquires(lock)
+{
+	struct rq_wait *rqw = &iolat->rq_wait;
+	unsigned use_delay = atomic_read(&lat_to_blkg(iolat)->use_delay);
+	DEFINE_WAIT(wait);
+	bool first_block = true;
+
+	if (use_delay)
+		blkcg_schedule_throttle(rqos->q, use_memdelay);
+
+	/*
+	 * To avoid priority inversions we want to just take a slot if we are
+	 * issuing as root.  If we're being killed off there's no point in
+	 * delaying things, we may have been killed by OOM so throttling may
+	 * make recovery take even longer, so just let the IO's through so the
+	 * task can go away.
+	 */
+	if (issue_as_root || fatal_signal_pending(current)) {
+		atomic_inc(&rqw->inflight);
+		return;
+	}
+
+	if (iolatency_may_queue(iolat, &wait, first_block))
+		return;
+
+	do {
+		prepare_to_wait_exclusive(&rqw->wait, &wait,
+					  TASK_UNINTERRUPTIBLE);
+
+		if (iolatency_may_queue(iolat, &wait, first_block))
+			break;
+		first_block = false;
+
+		if (lock) {
+			spin_unlock_irq(lock);
+			io_schedule();
+			spin_lock_irq(lock);
+		} else {
+			io_schedule();
+		}
+	} while (1);
+
+	finish_wait(&rqw->wait, &wait);
+}
+
+#define SCALE_DOWN_FACTOR 2
+#define SCALE_UP_FACTOR 4
+
+static inline unsigned long scale_amount(unsigned long qd, bool up)
+{
+	return max(up ? qd >> SCALE_UP_FACTOR : qd >> SCALE_DOWN_FACTOR, 1UL);
+}
+
+/*
+ * We scale the qd down faster than we scale up, so we need to use this helper
+ * to adjust the scale_cookie accordingly so we don't prematurely get
+ * scale_cookie at DEFAULT_SCALE_COOKIE and unthrottle too much.
+ *
+ * Each group has their own local copy of the last scale cookie they saw, so if
+ * the global scale cookie goes up or down they know which way they need to go
+ * based on their last knowledge of it.
+ */
+static void scale_cookie_change(struct blk_iolatency *blkiolat,
+				struct child_latency_info *lat_info,
+				bool up)
+{
+	unsigned long qd = blk_queue_depth(blkiolat->rqos.q);
+	unsigned long scale = scale_amount(qd, up);
+	unsigned long old = atomic_read(&lat_info->scale_cookie);
+	unsigned long max_scale = qd << 1;
+	unsigned long diff = 0;
+
+	if (old < DEFAULT_SCALE_COOKIE)
+		diff = DEFAULT_SCALE_COOKIE - old;
+
+	if (up) {
+		if (scale + old > DEFAULT_SCALE_COOKIE)
+			atomic_set(&lat_info->scale_cookie,
+				   DEFAULT_SCALE_COOKIE);
+		else if (diff > qd)
+			atomic_inc(&lat_info->scale_cookie);
+		else
+			atomic_add(scale, &lat_info->scale_cookie);
+	} else {
+		/*
+		 * We don't want to dig a hole so deep that it takes us hours to
+		 * dig out of it.  Just enough that we don't throttle/unthrottle
+		 * with jagged workloads but can still unthrottle once pressure
+		 * has sufficiently dissipated.
+		 */
+		if (diff > qd) {
+			if (diff < max_scale)
+				atomic_dec(&lat_info->scale_cookie);
+		} else {
+			atomic_sub(scale, &lat_info->scale_cookie);
+		}
+	}
+}
+
+/*
+ * Change the queue depth of the iolatency_grp.  We add/subtract 1/16th of the
+ * queue depth at a time so we don't get wild swings and hopefully dial in to
+ * fairer distribution of the overall queue depth.
+ */
+static void scale_change(struct iolatency_grp *iolat, bool up)
+{
+	unsigned long qd = blk_queue_depth(iolat->blkiolat->rqos.q);
+	unsigned long scale = scale_amount(qd, up);
+	unsigned long old = iolat->rq_depth.max_depth;
+	bool changed = false;
+
+	if (old > qd)
+		old = qd;
+
+	if (up) {
+		if (old == 1 && blkcg_unuse_delay(lat_to_blkg(iolat)))
+			return;
+
+		if (old < qd) {
+			changed = true;
+			old += scale;
+			old = min(old, qd);
+			iolat->rq_depth.max_depth = old;
+			wake_up_all(&iolat->rq_wait.wait);
+		}
+	} else if (old > 1) {
+		old >>= 1;
+		changed = true;
+		iolat->rq_depth.max_depth = max(old, 1UL);
+	}
+}
+
+/* Check our parent and see if the scale cookie has changed. */
+static void check_scale_change(struct iolatency_grp *iolat)
+{
+	struct iolatency_grp *parent;
+	struct child_latency_info *lat_info;
+	unsigned int cur_cookie;
+	unsigned int our_cookie = atomic_read(&iolat->scale_cookie);
+	u64 scale_lat;
+	unsigned int old;
+	int direction = 0;
+
+	if (lat_to_blkg(iolat)->parent == NULL)
+		return;
+
+	parent = blkg_to_lat(lat_to_blkg(iolat)->parent);
+	if (!parent)
+		return;
+
+	lat_info = &parent->child_lat;
+	cur_cookie = atomic_read(&lat_info->scale_cookie);
+	scale_lat = READ_ONCE(lat_info->scale_lat);
+
+	if (cur_cookie < our_cookie)
+		direction = -1;
+	else if (cur_cookie > our_cookie)
+		direction = 1;
+	else
+		return;
+
+	old = atomic_cmpxchg(&iolat->scale_cookie, our_cookie, cur_cookie);
+
+	/* Somebody beat us to the punch, just bail. */
+	if (old != our_cookie)
+		return;
+
+	if (direction < 0 && iolat->min_lat_nsec) {
+		u64 samples_thresh;
+
+		if (!scale_lat || iolat->min_lat_nsec <= scale_lat)
+			return;
+
+		/*
+		 * Sometimes high priority groups are their own worst enemy, so
+		 * instead of taking it out on some poor other group that did 5%
+		 * or less of the IO's for the last summation just skip this
+		 * scale down event.
+		 */
+		samples_thresh = lat_info->nr_samples * 5;
+		samples_thresh = div64_u64(samples_thresh, 100);
+		if (iolat->nr_samples <= samples_thresh)
+			return;
+	}
+
+	/* We're as low as we can go. */
+	if (iolat->rq_depth.max_depth == 1 && direction < 0) {
+		blkcg_use_delay(lat_to_blkg(iolat));
+		return;
+	}
+
+	/* We're back to the default cookie, unthrottle all the things. */
+	if (cur_cookie == DEFAULT_SCALE_COOKIE) {
+		blkcg_clear_delay(lat_to_blkg(iolat));
+		iolat->rq_depth.max_depth = UINT_MAX;
+		wake_up_all(&iolat->rq_wait.wait);
+		return;
+	}
+
+	scale_change(iolat, direction > 0);
+}
+
+static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio,
+				     spinlock_t *lock)
+{
+	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+	struct blkcg *blkcg;
+	struct blkcg_gq *blkg;
+	struct request_queue *q = rqos->q;
+	bool issue_as_root = bio_issue_as_root_blkg(bio);
+
+	if (!blk_iolatency_enabled(blkiolat))
+		return;
+
+	rcu_read_lock();
+	blkcg = bio_blkcg(bio);
+	bio_associate_blkcg(bio, &blkcg->css);
+	blkg = blkg_lookup(blkcg, q);
+	if (unlikely(!blkg)) {
+		if (!lock)
+			spin_lock_irq(q->queue_lock);
+		blkg = blkg_lookup_create(blkcg, q);
+		if (IS_ERR(blkg))
+			blkg = NULL;
+		if (!lock)
+			spin_unlock_irq(q->queue_lock);
+	}
+	if (!blkg)
+		goto out;
+
+	bio_issue_init(&bio->bi_issue, bio_sectors(bio));
+	bio_associate_blkg(bio, blkg);
+out:
+	rcu_read_unlock();
+	while (blkg && blkg->parent) {
+		struct iolatency_grp *iolat = blkg_to_lat(blkg);
+		if (!iolat) {
+			blkg = blkg->parent;
+			continue;
+		}
+
+		check_scale_change(iolat);
+		__blkcg_iolatency_throttle(rqos, iolat, lock, issue_as_root,
+				     (bio->bi_opf & REQ_SWAP) == REQ_SWAP);
+		blkg = blkg->parent;
+	}
+	if (!timer_pending(&blkiolat->timer))
+		mod_timer(&blkiolat->timer, jiffies + HZ);
+}
+
+static void iolatency_record_time(struct iolatency_grp *iolat,
+				  struct bio_issue *issue, u64 now,
+				  bool issue_as_root)
+{
+	struct blk_rq_stat *rq_stat;
+	u64 start = bio_issue_time(issue);
+	u64 req_time;
+
+	/*
+	 * Have to do this so we are truncated to the correct time that our
+	 * issue is truncated to.
+	 */
+	now = __bio_issue_time(now);
+
+	if (now <= start)
+		return;
+
+	req_time = now - start;
+
+	/*
+	 * We don't want to count issue_as_root bio's in the cgroups latency
+	 * statistics as it could skew the numbers downwards.
+	 */
+	if (unlikely(issue_as_root && iolat->rq_depth.max_depth != UINT_MAX)) {
+		u64 sub = iolat->min_lat_nsec;
+		if (req_time < sub)
+			blkcg_add_delay(lat_to_blkg(iolat), now, sub - req_time);
+		return;
+	}
+
+	rq_stat = get_cpu_ptr(iolat->stats);
+	blk_rq_stat_add(rq_stat, req_time);
+	put_cpu_ptr(rq_stat);
+}
+
+#define BLKIOLATENCY_MIN_ADJUST_TIME (500 * NSEC_PER_MSEC)
+#define BLKIOLATENCY_MIN_GOOD_SAMPLES 5
+
+static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now)
+{
+	struct blkcg_gq *blkg = lat_to_blkg(iolat);
+	struct iolatency_grp *parent;
+	struct child_latency_info *lat_info;
+	struct blk_rq_stat stat;
+	unsigned long flags;
+	int cpu, exp_idx;
+
+	blk_rq_stat_init(&stat);
+	preempt_disable();
+	for_each_online_cpu(cpu) {
+		struct blk_rq_stat *s;
+		s = per_cpu_ptr(iolat->stats, cpu);
+		blk_rq_stat_sum(&stat, s);
+		blk_rq_stat_init(s);
+	}
+	preempt_enable();
+
+	parent = blkg_to_lat(blkg->parent);
+	if (!parent)
+		return;
+
+	lat_info = &parent->child_lat;
+
+	/*
+	 * CALC_LOAD takes in a number stored in fixed point representation.
+	 * Because we are using this for IO time in ns, the values stored
+	 * are significantly larger than the FIXED_1 denominator (2048).
+	 * Therefore, rounding errors in the calculation are negligible and
+	 * can be ignored.
+	 */
+	exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1,
+			div64_u64(iolat->cur_win_nsec,
+				  BLKIOLATENCY_EXP_BUCKET_SIZE));
+	CALC_LOAD(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean);
+
+	/* Everything is ok and we don't need to adjust the scale. */
+	if (stat.mean <= iolat->min_lat_nsec &&
+	    atomic_read(&lat_info->scale_cookie) == DEFAULT_SCALE_COOKIE)
+		return;
+
+	/* Somebody beat us to the punch, just bail. */
+	spin_lock_irqsave(&lat_info->lock, flags);
+	lat_info->nr_samples -= iolat->nr_samples;
+	lat_info->nr_samples += stat.nr_samples;
+	iolat->nr_samples = stat.nr_samples;
+
+	if ((lat_info->last_scale_event >= now ||
+	    now - lat_info->last_scale_event < BLKIOLATENCY_MIN_ADJUST_TIME) &&
+	    lat_info->scale_lat <= iolat->min_lat_nsec)
+		goto out;
+
+	if (stat.mean <= iolat->min_lat_nsec &&
+	    stat.nr_samples >= BLKIOLATENCY_MIN_GOOD_SAMPLES) {
+		if (lat_info->scale_grp == iolat) {
+			lat_info->last_scale_event = now;
+			scale_cookie_change(iolat->blkiolat, lat_info, true);
+		}
+	} else if (stat.mean > iolat->min_lat_nsec) {
+		lat_info->last_scale_event = now;
+		if (!lat_info->scale_grp ||
+		    lat_info->scale_lat > iolat->min_lat_nsec) {
+			WRITE_ONCE(lat_info->scale_lat, iolat->min_lat_nsec);
+			lat_info->scale_grp = iolat;
+		}
+		scale_cookie_change(iolat->blkiolat, lat_info, false);
+	}
+out:
+	spin_unlock_irqrestore(&lat_info->lock, flags);
+}
+
+static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
+{
+	struct blkcg_gq *blkg;
+	struct rq_wait *rqw;
+	struct iolatency_grp *iolat;
+	u64 window_start;
+	u64 now = ktime_to_ns(ktime_get());
+	bool issue_as_root = bio_issue_as_root_blkg(bio);
+	bool enabled = false;
+
+	blkg = bio->bi_blkg;
+	if (!blkg)
+		return;
+
+	iolat = blkg_to_lat(bio->bi_blkg);
+	if (!iolat)
+		return;
+
+	enabled = blk_iolatency_enabled(iolat->blkiolat);
+	while (blkg && blkg->parent) {
+		iolat = blkg_to_lat(blkg);
+		if (!iolat) {
+			blkg = blkg->parent;
+			continue;
+		}
+		rqw = &iolat->rq_wait;
+
+		atomic_dec(&rqw->inflight);
+		if (!enabled || iolat->min_lat_nsec == 0)
+			goto next;
+		iolatency_record_time(iolat, &bio->bi_issue, now,
+				      issue_as_root);
+		window_start = atomic64_read(&iolat->window_start);
+		if (now > window_start &&
+		    (now - window_start) >= iolat->cur_win_nsec) {
+			if (atomic64_cmpxchg(&iolat->window_start,
+					window_start, now) == window_start)
+				iolatency_check_latencies(iolat, now);
+		}
+next:
+		wake_up(&rqw->wait);
+		blkg = blkg->parent;
+	}
+}
+
+static void blkcg_iolatency_cleanup(struct rq_qos *rqos, struct bio *bio)
+{
+	struct blkcg_gq *blkg;
+
+	blkg = bio->bi_blkg;
+	while (blkg && blkg->parent) {
+		struct rq_wait *rqw;
+		struct iolatency_grp *iolat;
+
+		iolat = blkg_to_lat(blkg);
+		if (!iolat)
+			goto next;
+
+		rqw = &iolat->rq_wait;
+		atomic_dec(&rqw->inflight);
+		wake_up(&rqw->wait);
+next:
+		blkg = blkg->parent;
+	}
+}
+
+static void blkcg_iolatency_exit(struct rq_qos *rqos)
+{
+	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+
+	del_timer_sync(&blkiolat->timer);
+	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency);
+	kfree(blkiolat);
+}
+
+static struct rq_qos_ops blkcg_iolatency_ops = {
+	.throttle = blkcg_iolatency_throttle,
+	.cleanup = blkcg_iolatency_cleanup,
+	.done_bio = blkcg_iolatency_done_bio,
+	.exit = blkcg_iolatency_exit,
+};
+
+static void blkiolatency_timer_fn(struct timer_list *t)
+{
+	struct blk_iolatency *blkiolat = from_timer(blkiolat, t, timer);
+	struct blkcg_gq *blkg;
+	struct cgroup_subsys_state *pos_css;
+	u64 now = ktime_to_ns(ktime_get());
+
+	rcu_read_lock();
+	blkg_for_each_descendant_pre(blkg, pos_css,
+				     blkiolat->rqos.q->root_blkg) {
+		struct iolatency_grp *iolat;
+		struct child_latency_info *lat_info;
+		unsigned long flags;
+		u64 cookie;
+
+		/*
+		 * We could be exiting, don't access the pd unless we have a
+		 * ref on the blkg.
+		 */
+		if (!blkg_try_get(blkg))
+			continue;
+
+		iolat = blkg_to_lat(blkg);
+		if (!iolat)
+			goto next;
+
+		lat_info = &iolat->child_lat;
+		cookie = atomic_read(&lat_info->scale_cookie);
+
+		if (cookie >= DEFAULT_SCALE_COOKIE)
+			goto next;
+
+		spin_lock_irqsave(&lat_info->lock, flags);
+		if (lat_info->last_scale_event >= now)
+			goto next_lock;
+
+		/*
+		 * We scaled down but don't have a scale_grp, scale up and carry
+		 * on.
+		 */
+		if (lat_info->scale_grp == NULL) {
+			scale_cookie_change(iolat->blkiolat, lat_info, true);
+			goto next_lock;
+		}
+
+		/*
+		 * It's been 5 seconds since our last scale event, clear the
+		 * scale grp in case the group that needed the scale down isn't
+		 * doing any IO currently.
+		 */
+		if (now - lat_info->last_scale_event >=
+		    ((u64)NSEC_PER_SEC * 5))
+			lat_info->scale_grp = NULL;
+next_lock:
+		spin_unlock_irqrestore(&lat_info->lock, flags);
+next:
+		blkg_put(blkg);
+	}
+	rcu_read_unlock();
+}
+
+int blk_iolatency_init(struct request_queue *q)
+{
+	struct blk_iolatency *blkiolat;
+	struct rq_qos *rqos;
+	int ret;
+
+	blkiolat = kzalloc(sizeof(*blkiolat), GFP_KERNEL);
+	if (!blkiolat)
+		return -ENOMEM;
+
+	rqos = &blkiolat->rqos;
+	rqos->id = RQ_QOS_CGROUP;
+	rqos->ops = &blkcg_iolatency_ops;
+	rqos->q = q;
+
+	rq_qos_add(q, rqos);
+
+	ret = blkcg_activate_policy(q, &blkcg_policy_iolatency);
+	if (ret) {
+		rq_qos_del(q, rqos);
+		kfree(blkiolat);
+		return ret;
+	}
+
+	timer_setup(&blkiolat->timer, blkiolatency_timer_fn, 0);
+
+	return 0;
+}
+
+static void iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
+{
+	struct iolatency_grp *iolat = blkg_to_lat(blkg);
+	struct blk_iolatency *blkiolat = iolat->blkiolat;
+	u64 oldval = iolat->min_lat_nsec;
+
+	iolat->min_lat_nsec = val;
+	iolat->cur_win_nsec = max_t(u64, val << 4, BLKIOLATENCY_MIN_WIN_SIZE);
+	iolat->cur_win_nsec = min_t(u64, iolat->cur_win_nsec,
+				    BLKIOLATENCY_MAX_WIN_SIZE);
+
+	if (!oldval && val)
+		atomic_inc(&blkiolat->enabled);
+	if (oldval && !val)
+		atomic_dec(&blkiolat->enabled);
+}
+
+static void iolatency_clear_scaling(struct blkcg_gq *blkg)
+{
+	if (blkg->parent) {
+		struct iolatency_grp *iolat = blkg_to_lat(blkg->parent);
+		struct child_latency_info *lat_info;
+		if (!iolat)
+			return;
+
+		lat_info = &iolat->child_lat;
+		spin_lock(&lat_info->lock);
+		atomic_set(&lat_info->scale_cookie, DEFAULT_SCALE_COOKIE);
+		lat_info->last_scale_event = 0;
+		lat_info->scale_grp = NULL;
+		lat_info->scale_lat = 0;
+		spin_unlock(&lat_info->lock);
+	}
+}
+
+static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
+			     size_t nbytes, loff_t off)
+{
+	struct blkcg *blkcg = css_to_blkcg(of_css(of));
+	struct blkcg_gq *blkg;
+	struct blk_iolatency *blkiolat;
+	struct blkg_conf_ctx ctx;
+	struct iolatency_grp *iolat;
+	char *p, *tok;
+	u64 lat_val = 0;
+	u64 oldval;
+	int ret;
+
+	ret = blkg_conf_prep(blkcg, &blkcg_policy_iolatency, buf, &ctx);
+	if (ret)
+		return ret;
+
+	iolat = blkg_to_lat(ctx.blkg);
+	blkiolat = iolat->blkiolat;
+	p = ctx.body;
+
+	ret = -EINVAL;
+	while ((tok = strsep(&p, " "))) {
+		char key[16];
+		char val[21];	/* 18446744073709551616 */
+
+		if (sscanf(tok, "%15[^=]=%20s", key, val) != 2)
+			goto out;
+
+		if (!strcmp(key, "target")) {
+			u64 v;
+
+			if (!strcmp(val, "max"))
+				lat_val = 0;
+			else if (sscanf(val, "%llu", &v) == 1)
+				lat_val = v * NSEC_PER_USEC;
+			else
+				goto out;
+		} else {
+			goto out;
+		}
+	}
+
+	/* Walk up the tree to see if our new val is lower than it should be. */
+	blkg = ctx.blkg;
+	oldval = iolat->min_lat_nsec;
+
+	iolatency_set_min_lat_nsec(blkg, lat_val);
+	if (oldval != iolat->min_lat_nsec) {
+		iolatency_clear_scaling(blkg);
+	}
+
+	ret = 0;
+out:
+	blkg_conf_finish(&ctx);
+	return ret ?: nbytes;
+}
+
+static u64 iolatency_prfill_limit(struct seq_file *sf,
+				  struct blkg_policy_data *pd, int off)
+{
+	struct iolatency_grp *iolat = pd_to_lat(pd);
+	const char *dname = blkg_dev_name(pd->blkg);
+
+	if (!dname || !iolat->min_lat_nsec)
+		return 0;
+	seq_printf(sf, "%s target=%llu\n",
+		   dname, div_u64(iolat->min_lat_nsec, NSEC_PER_USEC));
+	return 0;
+}
+
+static int iolatency_print_limit(struct seq_file *sf, void *v)
+{
+	blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+			  iolatency_prfill_limit,
+			  &blkcg_policy_iolatency, seq_cft(sf)->private, false);
+	return 0;
+}
+
+static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf,
+				size_t size)
+{
+	struct iolatency_grp *iolat = pd_to_lat(pd);
+	unsigned long long avg_lat = div64_u64(iolat->lat_avg, NSEC_PER_USEC);
+	unsigned long long cur_win = div64_u64(iolat->cur_win_nsec, NSEC_PER_MSEC);
+
+	if (iolat->rq_depth.max_depth == UINT_MAX)
+		return scnprintf(buf, size, " depth=max avg_lat=%llu win=%llu",
+				 avg_lat, cur_win);
+
+	return scnprintf(buf, size, " depth=%u avg_lat=%llu win=%llu",
+			 iolat->rq_depth.max_depth, avg_lat, cur_win);
+}
+
+
+static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, int node)
+{
+	struct iolatency_grp *iolat;
+
+	iolat = kzalloc_node(sizeof(*iolat), gfp, node);
+	if (!iolat)
+		return NULL;
+	iolat->stats = __alloc_percpu_gfp(sizeof(struct blk_rq_stat),
+				       __alignof__(struct blk_rq_stat), gfp);
+	if (!iolat->stats) {
+		kfree(iolat);
+		return NULL;
+	}
+	return &iolat->pd;
+}
+
+static void iolatency_pd_init(struct blkg_policy_data *pd)
+{
+	struct iolatency_grp *iolat = pd_to_lat(pd);
+	struct blkcg_gq *blkg = lat_to_blkg(iolat);
+	struct rq_qos *rqos = blkcg_rq_qos(blkg->q);
+	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+	u64 now = ktime_to_ns(ktime_get());
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct blk_rq_stat *stat;
+		stat = per_cpu_ptr(iolat->stats, cpu);
+		blk_rq_stat_init(stat);
+	}
+
+	rq_wait_init(&iolat->rq_wait);
+	spin_lock_init(&iolat->child_lat.lock);
+	iolat->rq_depth.queue_depth = blk_queue_depth(blkg->q);
+	iolat->rq_depth.max_depth = UINT_MAX;
+	iolat->rq_depth.default_depth = iolat->rq_depth.queue_depth;
+	iolat->blkiolat = blkiolat;
+	iolat->cur_win_nsec = 100 * NSEC_PER_MSEC;
+	atomic64_set(&iolat->window_start, now);
+
+	/*
+	 * We init things in list order, so the pd for the parent may not be
+	 * init'ed yet for whatever reason.
+	 */
+	if (blkg->parent && blkg_to_pd(blkg->parent, &blkcg_policy_iolatency)) {
+		struct iolatency_grp *parent = blkg_to_lat(blkg->parent);
+		atomic_set(&iolat->scale_cookie,
+			   atomic_read(&parent->child_lat.scale_cookie));
+	} else {
+		atomic_set(&iolat->scale_cookie, DEFAULT_SCALE_COOKIE);
+	}
+
+	atomic_set(&iolat->child_lat.scale_cookie, DEFAULT_SCALE_COOKIE);
+}
+
+static void iolatency_pd_offline(struct blkg_policy_data *pd)
+{
+	struct iolatency_grp *iolat = pd_to_lat(pd);
+	struct blkcg_gq *blkg = lat_to_blkg(iolat);
+
+	iolatency_set_min_lat_nsec(blkg, 0);
+	iolatency_clear_scaling(blkg);
+}
+
+static void iolatency_pd_free(struct blkg_policy_data *pd)
+{
+	struct iolatency_grp *iolat = pd_to_lat(pd);
+	free_percpu(iolat->stats);
+	kfree(iolat);
+}
+
+static struct cftype iolatency_files[] = {
+	{
+		.name = "latency",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = iolatency_print_limit,
+		.write = iolatency_set_limit,
+	},
+	{}
+};
+
+static struct blkcg_policy blkcg_policy_iolatency = {
+	.dfl_cftypes	= iolatency_files,
+	.pd_alloc_fn	= iolatency_pd_alloc,
+	.pd_init_fn	= iolatency_pd_init,
+	.pd_offline_fn	= iolatency_pd_offline,
+	.pd_free_fn	= iolatency_pd_free,
+	.pd_stat_fn	= iolatency_pd_stat,
+};
+
+static int __init iolatency_init(void)
+{
+	return blkcg_policy_register(&blkcg_policy_iolatency);
+}
+
+static void __exit iolatency_exit(void)
+{
+	return blkcg_policy_unregister(&blkcg_policy_iolatency);
+}
+
+module_init(iolatency_init);
+module_exit(iolatency_exit);

block/blk-lib.c

@@ -68,6 +68,8 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		 */
 		req_sects = min_t(sector_t, nr_sects,
 					q->limits.max_discard_sectors);
+		if (!req_sects)
+			goto fail;
 		if (req_sects > UINT_MAX >> 9)
 			req_sects = UINT_MAX >> 9;
 
@@ -105,6 +107,14 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
 	*biop = bio;
 	return 0;
+
+fail:
+	if (bio) {
+		submit_bio_wait(bio);
+		bio_put(bio);
+	}
+	*biop = NULL;
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL(__blkdev_issue_discard);
 

block/blk-mq-debugfs-zoned.c

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Western Digital Corporation or its affiliates.
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/blkdev.h>
+#include "blk-mq-debugfs.h"
+
+int queue_zone_wlock_show(void *data, struct seq_file *m)
+{
+	struct request_queue *q = data;
+	unsigned int i;
+
+	if (!q->seq_zones_wlock)
+		return 0;
+
+	for (i = 0; i < q->nr_zones; i++)
+		if (test_bit(i, q->seq_zones_wlock))
+			seq_printf(m, "%u\n", i);
+
+	return 0;
+}

block/blk-mq-debugfs.c

@@ -206,21 +206,6 @@ static ssize_t queue_write_hint_store(void *data, const char __user *buf,
 	return count;
 }
 
-static int queue_zone_wlock_show(void *data, struct seq_file *m)
-{
-	struct request_queue *q = data;
-	unsigned int i;
-
-	if (!q->seq_zones_wlock)
-		return 0;
-
-	for (i = 0; i < blk_queue_nr_zones(q); i++)
-		if (test_bit(i, q->seq_zones_wlock))
-			seq_printf(m, "%u\n", i);
-
-	return 0;
-}
-
 static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 	{ "poll_stat", 0400, queue_poll_stat_show },
 	{ "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops },
@@ -637,6 +622,14 @@ static int hctx_active_show(void *data, struct seq_file *m)
 	return 0;
 }
 
+static int hctx_dispatch_busy_show(void *data, struct seq_file *m)
+{
+	struct blk_mq_hw_ctx *hctx = data;
+
+	seq_printf(m, "%u\n", hctx->dispatch_busy);
+	return 0;
+}
+
 static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)
 	__acquires(&ctx->lock)
 {
@@ -798,6 +791,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = {
 	{"queued", 0600, hctx_queued_show, hctx_queued_write},
 	{"run", 0600, hctx_run_show, hctx_run_write},
 	{"active", 0400, hctx_active_show},
+	{"dispatch_busy", 0400, hctx_dispatch_busy_show},
 	{},
 };
 

block/blk-mq-debugfs.h

@@ -80,4 +80,13 @@ static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hc
 }
 #endif
 
+#ifdef CONFIG_BLK_DEBUG_FS_ZONED
+int queue_zone_wlock_show(void *data, struct seq_file *m);
+#else
+static inline int queue_zone_wlock_show(void *data, struct seq_file *m)
+{
+	return 0;
+}
+#endif
+
 #endif

block/blk-mq-pci.c

@@ -17,6 +17,8 @@
 #include <linux/pci.h>
 #include <linux/module.h>
 
+#include "blk-mq.h"
+
 /**
  * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
  * @set:	tagset to provide the mapping for
@@ -48,8 +50,7 @@ int blk_mq_pci_map_queues(struct blk_mq_tag_set *set, struct pci_dev *pdev,
 
 fallback:
 	WARN_ON_ONCE(set->nr_hw_queues > 1);
-	for_each_possible_cpu(cpu)
-		set->mq_map[cpu] = 0;
+	blk_mq_clear_mq_map(set);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);

block/blk-mq-sched.c

@@ -59,29 +59,16 @@ static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
 	if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
 		return;
 
-	if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
-		struct request_queue *q = hctx->queue;
-
-		if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
-			atomic_inc(&q->shared_hctx_restart);
-	} else
-		set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+	set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
 }
 
-static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
+void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx)
 {
 	if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
-		return false;
-
-	if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
-		struct request_queue *q = hctx->queue;
-
-		if (test_and_clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
-			atomic_dec(&q->shared_hctx_restart);
-	} else
-		clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+		return;
+	clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
 
-	return blk_mq_run_hw_queue(hctx, true);
+	blk_mq_run_hw_queue(hctx, true);
 }
 
 /*
@@ -219,15 +206,8 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
 		}
 	} else if (has_sched_dispatch) {
 		blk_mq_do_dispatch_sched(hctx);
-	} else if (q->mq_ops->get_budget) {
-		/*
-		 * If we need to get budget before queuing request, we
-		 * dequeue request one by one from sw queue for avoiding
-		 * to mess up I/O merge when dispatch runs out of resource.
-		 *
-		 * TODO: get more budgets, and dequeue more requests in
-		 * one time.
-		 */
+	} else if (hctx->dispatch_busy) {
+		/* dequeue request one by one from sw queue if queue is busy */
 		blk_mq_do_dispatch_ctx(hctx);
 	} else {
 		blk_mq_flush_busy_ctxs(hctx, &rq_list);
@@ -339,7 +319,8 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
 		return e->type->ops.mq.bio_merge(hctx, bio);
 	}
 
-	if (hctx->flags & BLK_MQ_F_SHOULD_MERGE) {
+	if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
+			!list_empty_careful(&ctx->rq_list)) {
 		/* default per sw-queue merge */
 		spin_lock(&ctx->lock);
 		ret = blk_mq_attempt_merge(q, ctx, bio);
@@ -380,68 +361,6 @@ static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
 	return false;
 }
 
-/**
- * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list
- * @pos:    loop cursor.
- * @skip:   the list element that will not be examined. Iteration starts at
- *          @skip->next.
- * @head:   head of the list to examine. This list must have at least one
- *          element, namely @skip.
- * @member: name of the list_head structure within typeof(*pos).
- */
-#define list_for_each_entry_rcu_rr(pos, skip, head, member)		\
-	for ((pos) = (skip);						\
-	     (pos = (pos)->member.next != (head) ? list_entry_rcu(	\
-			(pos)->member.next, typeof(*pos), member) :	\
-	      list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \
-	     (pos) != (skip); )
-
-/*
- * Called after a driver tag has been freed to check whether a hctx needs to
- * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware
- * queues in a round-robin fashion if the tag set of @hctx is shared with other
- * hardware queues.
- */
-void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx)
-{
-	struct blk_mq_tags *const tags = hctx->tags;
-	struct blk_mq_tag_set *const set = hctx->queue->tag_set;
-	struct request_queue *const queue = hctx->queue, *q;
-	struct blk_mq_hw_ctx *hctx2;
-	unsigned int i, j;
-
-	if (set->flags & BLK_MQ_F_TAG_SHARED) {
-		/*
-		 * If this is 0, then we know that no hardware queues
-		 * have RESTART marked. We're done.
-		 */
-		if (!atomic_read(&queue->shared_hctx_restart))
-			return;
-
-		rcu_read_lock();
-		list_for_each_entry_rcu_rr(q, queue, &set->tag_list,
-					   tag_set_list) {
-			queue_for_each_hw_ctx(q, hctx2, i)
-				if (hctx2->tags == tags &&
-				    blk_mq_sched_restart_hctx(hctx2))
-					goto done;
-		}
-		j = hctx->queue_num + 1;
-		for (i = 0; i < queue->nr_hw_queues; i++, j++) {
-			if (j == queue->nr_hw_queues)
-				j = 0;
-			hctx2 = queue->queue_hw_ctx[j];
-			if (hctx2->tags == tags &&
-			    blk_mq_sched_restart_hctx(hctx2))
-				break;
-		}
-done:
-		rcu_read_unlock();
-	} else {
-		blk_mq_sched_restart_hctx(hctx);
-	}
-}
-
 void blk_mq_sched_insert_request(struct request *rq, bool at_head,
 				 bool run_queue, bool async)
 {
@@ -486,8 +405,19 @@ void blk_mq_sched_insert_requests(struct request_queue *q,
 
 	if (e && e->type->ops.mq.insert_requests)
 		e->type->ops.mq.insert_requests(hctx, list, false);
-	else
+	else {
+		/*
+		 * try to issue requests directly if the hw queue isn't
+		 * busy in case of 'none' scheduler, and this way may save
+		 * us one extra enqueue & dequeue to sw queue.
+		 */
+		if (!hctx->dispatch_busy && !e && !run_queue_async) {
+			blk_mq_try_issue_list_directly(hctx, list);
+			if (list_empty(list))
+				return;
+		}
 		blk_mq_insert_requests(hctx, ctx, list);
+	}
 
 	blk_mq_run_hw_queue(hctx, run_queue_async);
 }

block/blk-mq-tag.c

@@ -23,6 +23,9 @@ bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
 
 /*
  * If a previously inactive queue goes active, bump the active user count.
+ * We need to do this before try to allocate driver tag, then even if fail
+ * to get tag when first time, the other shared-tag users could reserve
+ * budget for it.
  */
 bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
 {
@@ -399,8 +402,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 	if (tdepth <= tags->nr_reserved_tags)
 		return -EINVAL;
 
-	tdepth -= tags->nr_reserved_tags;
-
 	/*
 	 * If we are allowed to grow beyond the original size, allocate
 	 * a new set of tags before freeing the old one.
@@ -420,7 +421,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 		if (tdepth > 16 * BLKDEV_MAX_RQ)
 			return -EINVAL;
 
-		new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, 0);
+		new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth,
+				tags->nr_reserved_tags);
 		if (!new)
 			return -ENOMEM;
 		ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth);
@@ -437,7 +439,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 		 * Don't need (or can't) update reserved tags here, they
 		 * remain static and should never need resizing.
 		 */
-		sbitmap_queue_resize(&tags->bitmap_tags, tdepth);
+		sbitmap_queue_resize(&tags->bitmap_tags,
+				tdepth - tags->nr_reserved_tags);
 	}
 
 	return 0;

block/blk-mq.c

@@ -34,8 +34,8 @@
 #include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
 #include "blk-stat.h"
-#include "blk-wbt.h"
 #include "blk-mq-sched.h"
+#include "blk-rq-qos.h"
 
 static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);
 static void blk_mq_poll_stats_start(struct request_queue *q);
@@ -285,7 +285,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 		rq->tag = -1;
 		rq->internal_tag = tag;
 	} else {
-		if (blk_mq_tag_busy(data->hctx)) {
+		if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) {
 			rq_flags = RQF_MQ_INFLIGHT;
 			atomic_inc(&data->hctx->nr_active);
 		}
@@ -367,6 +367,8 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 		if (!op_is_flush(op) && e->type->ops.mq.limit_depth &&
 		    !(data->flags & BLK_MQ_REQ_RESERVED))
 			e->type->ops.mq.limit_depth(op, data);
+	} else {
+		blk_mq_tag_busy(data->hctx);
 	}
 
 	tag = blk_mq_get_tag(data);
@@ -504,7 +506,7 @@ void blk_mq_free_request(struct request *rq)
 	if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
 		laptop_io_completion(q->backing_dev_info);
 
-	wbt_done(q->rq_wb, rq);
+	rq_qos_done(q, rq);
 
 	if (blk_rq_rl(rq))
 		blk_put_rl(blk_rq_rl(rq));
@@ -527,7 +529,7 @@ inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
 	blk_account_io_done(rq, now);
 
 	if (rq->end_io) {
-		wbt_done(rq->q->rq_wb, rq);
+		rq_qos_done(rq->q, rq);
 		rq->end_io(rq, error);
 	} else {
 		if (unlikely(blk_bidi_rq(rq)))
@@ -639,7 +641,7 @@ void blk_mq_start_request(struct request *rq)
 		rq->throtl_size = blk_rq_sectors(rq);
 #endif
 		rq->rq_flags |= RQF_STATS;
-		wbt_issue(q->rq_wb, rq);
+		rq_qos_issue(q, rq);
 	}
 
 	WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
@@ -665,7 +667,7 @@ static void __blk_mq_requeue_request(struct request *rq)
 	blk_mq_put_driver_tag(rq);
 
 	trace_block_rq_requeue(q, rq);
-	wbt_requeue(q->rq_wb, rq);
+	rq_qos_requeue(q, rq);
 
 	if (blk_mq_request_started(rq)) {
 		WRITE_ONCE(rq->state, MQ_RQ_IDLE);
@@ -962,16 +964,14 @@ static inline unsigned int queued_to_index(unsigned int queued)
 	return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
 }
 
-bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
-			   bool wait)
+bool blk_mq_get_driver_tag(struct request *rq)
 {
 	struct blk_mq_alloc_data data = {
 		.q = rq->q,
 		.hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu),
-		.flags = wait ? 0 : BLK_MQ_REQ_NOWAIT,
+		.flags = BLK_MQ_REQ_NOWAIT,
 	};
-
-	might_sleep_if(wait);
+	bool shared;
 
 	if (rq->tag != -1)
 		goto done;
@@ -979,9 +979,10 @@ bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
 	if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag))
 		data.flags |= BLK_MQ_REQ_RESERVED;
 
+	shared = blk_mq_tag_busy(data.hctx);
 	rq->tag = blk_mq_get_tag(&data);
 	if (rq->tag >= 0) {
-		if (blk_mq_tag_busy(data.hctx)) {
+		if (shared) {
 			rq->rq_flags |= RQF_MQ_INFLIGHT;
 			atomic_inc(&data.hctx->nr_active);
 		}
@@ -989,8 +990,6 @@ bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
 	}
 
 done:
-	if (hctx)
-		*hctx = data.hctx;
 	return rq->tag != -1;
 }
 
@@ -1001,7 +1000,10 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
 
 	hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait);
 
+	spin_lock(&hctx->dispatch_wait_lock);
 	list_del_init(&wait->entry);
+	spin_unlock(&hctx->dispatch_wait_lock);
+
 	blk_mq_run_hw_queue(hctx, true);
 	return 1;
 }
@@ -1012,17 +1014,16 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
  * restart. For both cases, take care to check the condition again after
  * marking us as waiting.
  */
-static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx **hctx,
+static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx,
 				 struct request *rq)
 {
-	struct blk_mq_hw_ctx *this_hctx = *hctx;
-	struct sbq_wait_state *ws;
+	struct wait_queue_head *wq;
 	wait_queue_entry_t *wait;
 	bool ret;
 
-	if (!(this_hctx->flags & BLK_MQ_F_TAG_SHARED)) {
-		if (!test_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state))
-			set_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state);
+	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) {
+		if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+			set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
 
 		/*
 		 * It's possible that a tag was freed in the window between the
@@ -1032,30 +1033,35 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx **hctx,
 		 * Don't clear RESTART here, someone else could have set it.
 		 * At most this will cost an extra queue run.
 		 */
-		return blk_mq_get_driver_tag(rq, hctx, false);
+		return blk_mq_get_driver_tag(rq);
 	}
 
-	wait = &this_hctx->dispatch_wait;
+	wait = &hctx->dispatch_wait;
 	if (!list_empty_careful(&wait->entry))
 		return false;
 
-	spin_lock(&this_hctx->lock);
+	wq = &bt_wait_ptr(&hctx->tags->bitmap_tags, hctx)->wait;
+
+	spin_lock_irq(&wq->lock);
+	spin_lock(&hctx->dispatch_wait_lock);
 	if (!list_empty(&wait->entry)) {
-		spin_unlock(&this_hctx->lock);
+		spin_unlock(&hctx->dispatch_wait_lock);
+		spin_unlock_irq(&wq->lock);
 		return false;
 	}
 
-	ws = bt_wait_ptr(&this_hctx->tags->bitmap_tags, this_hctx);
-	add_wait_queue(&ws->wait, wait);
+	wait->flags &= ~WQ_FLAG_EXCLUSIVE;
+	__add_wait_queue(wq, wait);
 
 	/*
 	 * It's possible that a tag was freed in the window between the
 	 * allocation failure and adding the hardware queue to the wait
 	 * queue.
 	 */
-	ret = blk_mq_get_driver_tag(rq, hctx, false);
+	ret = blk_mq_get_driver_tag(rq);
 	if (!ret) {
-		spin_unlock(&this_hctx->lock);
+		spin_unlock(&hctx->dispatch_wait_lock);
+		spin_unlock_irq(&wq->lock);
 		return false;
 	}
 
@@ -1063,14 +1069,42 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx **hctx,
 	 * We got a tag, remove ourselves from the wait queue to ensure
 	 * someone else gets the wakeup.
 	 */
-	spin_lock_irq(&ws->wait.lock);
 	list_del_init(&wait->entry);
-	spin_unlock_irq(&ws->wait.lock);
-	spin_unlock(&this_hctx->lock);
+	spin_unlock(&hctx->dispatch_wait_lock);
+	spin_unlock_irq(&wq->lock);
 
 	return true;
 }
 
+#define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT  8
+#define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR  4
+/*
+ * Update dispatch busy with the Exponential Weighted Moving Average(EWMA):
+ * - EWMA is one simple way to compute running average value
+ * - weight(7/8 and 1/8) is applied so that it can decrease exponentially
+ * - take 4 as factor for avoiding to get too small(0) result, and this
+ *   factor doesn't matter because EWMA decreases exponentially
+ */
+static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
+{
+	unsigned int ewma;
+
+	if (hctx->queue->elevator)
+		return;
+
+	ewma = hctx->dispatch_busy;
+
+	if (!ewma && !busy)
+		return;
+
+	ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1;
+	if (busy)
+		ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR;
+	ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT;
+
+	hctx->dispatch_busy = ewma;
+}
+
 #define BLK_MQ_RESOURCE_DELAY	3		/* ms units */
 
 /*
@@ -1103,7 +1137,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
 		if (!got_budget && !blk_mq_get_dispatch_budget(hctx))
 			break;
 
-		if (!blk_mq_get_driver_tag(rq, NULL, false)) {
+		if (!blk_mq_get_driver_tag(rq)) {
 			/*
 			 * The initial allocation attempt failed, so we need to
 			 * rerun the hardware queue when a tag is freed. The
@@ -1111,7 +1145,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
 			 * before we add this entry back on the dispatch list,
 			 * we'll re-run it below.
 			 */
-			if (!blk_mq_mark_tag_wait(&hctx, rq)) {
+			if (!blk_mq_mark_tag_wait(hctx, rq)) {
 				blk_mq_put_dispatch_budget(hctx);
 				/*
 				 * For non-shared tags, the RESTART check
@@ -1135,7 +1169,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
 			bd.last = true;
 		else {
 			nxt = list_first_entry(list, struct request, queuelist);
-			bd.last = !blk_mq_get_driver_tag(nxt, NULL, false);
+			bd.last = !blk_mq_get_driver_tag(nxt);
 		}
 
 		ret = q->mq_ops->queue_rq(hctx, &bd);
@@ -1207,8 +1241,10 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
 		else if (needs_restart && (ret == BLK_STS_RESOURCE))
 			blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
 
+		blk_mq_update_dispatch_busy(hctx, true);
 		return false;
-	}
+	} else
+		blk_mq_update_dispatch_busy(hctx, false);
 
 	/*
 	 * If the host/device is unable to accept more work, inform the
@@ -1542,19 +1578,19 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 			    struct list_head *list)
 
 {
+	struct request *rq;
+
 	/*
 	 * preemption doesn't flush plug list, so it's possible ctx->cpu is
 	 * offline now
 	 */
-	spin_lock(&ctx->lock);
-	while (!list_empty(list)) {
-		struct request *rq;
-
-		rq = list_first_entry(list, struct request, queuelist);
+	list_for_each_entry(rq, list, queuelist) {
 		BUG_ON(rq->mq_ctx != ctx);
-		list_del_init(&rq->queuelist);
-		__blk_mq_insert_req_list(hctx, rq, false);
+		trace_block_rq_insert(hctx->queue, rq);
 	}
+
+	spin_lock(&ctx->lock);
+	list_splice_tail_init(list, &ctx->rq_list);
 	blk_mq_hctx_mark_pending(hctx, ctx);
 	spin_unlock(&ctx->lock);
 }
@@ -1657,13 +1693,16 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
 	ret = q->mq_ops->queue_rq(hctx, &bd);
 	switch (ret) {
 	case BLK_STS_OK:
+		blk_mq_update_dispatch_busy(hctx, false);
 		*cookie = new_cookie;
 		break;
 	case BLK_STS_RESOURCE:
 	case BLK_STS_DEV_RESOURCE:
+		blk_mq_update_dispatch_busy(hctx, true);
 		__blk_mq_requeue_request(rq);
 		break;
 	default:
+		blk_mq_update_dispatch_busy(hctx, false);
 		*cookie = BLK_QC_T_NONE;
 		break;
 	}
@@ -1698,7 +1737,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 	if (!blk_mq_get_dispatch_budget(hctx))
 		goto insert;
 
-	if (!blk_mq_get_driver_tag(rq, NULL, false)) {
+	if (!blk_mq_get_driver_tag(rq)) {
 		blk_mq_put_dispatch_budget(hctx);
 		goto insert;
 	}
@@ -1746,6 +1785,27 @@ blk_status_t blk_mq_request_issue_directly(struct request *rq)
 	return ret;
 }
 
+void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
+		struct list_head *list)
+{
+	while (!list_empty(list)) {
+		blk_status_t ret;
+		struct request *rq = list_first_entry(list, struct request,
+				queuelist);
+
+		list_del_init(&rq->queuelist);
+		ret = blk_mq_request_issue_directly(rq);
+		if (ret != BLK_STS_OK) {
+			if (ret == BLK_STS_RESOURCE ||
+					ret == BLK_STS_DEV_RESOURCE) {
+				list_add(&rq->queuelist, list);
+				break;
+			}
+			blk_mq_end_request(rq, ret);
+		}
+	}
+}
+
 static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 {
 	const int is_sync = op_is_sync(bio->bi_opf);
@@ -1756,7 +1816,6 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	struct blk_plug *plug;
 	struct request *same_queue_rq = NULL;
 	blk_qc_t cookie;
-	unsigned int wb_acct;
 
 	blk_queue_bounce(q, &bio);
 
@@ -1772,19 +1831,19 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	if (blk_mq_sched_bio_merge(q, bio))
 		return BLK_QC_T_NONE;
 
-	wb_acct = wbt_wait(q->rq_wb, bio, NULL);
+	rq_qos_throttle(q, bio, NULL);
 
 	trace_block_getrq(q, bio, bio->bi_opf);
 
 	rq = blk_mq_get_request(q, bio, bio->bi_opf, &data);
 	if (unlikely(!rq)) {
-		__wbt_done(q->rq_wb, wb_acct);
+		rq_qos_cleanup(q, bio);
 		if (bio->bi_opf & REQ_NOWAIT)
 			bio_wouldblock_error(bio);
 		return BLK_QC_T_NONE;
 	}
 
-	wbt_track(rq, wb_acct);
+	rq_qos_track(q, rq, bio);
 
 	cookie = request_to_qc_t(data.hctx, rq);
 
@@ -1847,7 +1906,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 			blk_mq_try_issue_directly(data.hctx, same_queue_rq,
 					&cookie);
 		}
-	} else if (q->nr_hw_queues > 1 && is_sync) {
+	} else if ((q->nr_hw_queues > 1 && is_sync) || (!q->elevator &&
+			!data.hctx->dispatch_busy)) {
 		blk_mq_put_ctx(data.ctx);
 		blk_mq_bio_to_request(rq, bio);
 		blk_mq_try_issue_directly(data.hctx, rq, &cookie);
@@ -2146,6 +2206,7 @@ static int blk_mq_init_hctx(struct request_queue *q,
 
 	hctx->nr_ctx = 0;
 
+	spin_lock_init(&hctx->dispatch_wait_lock);
 	init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
 	INIT_LIST_HEAD(&hctx->dispatch_wait.entry);
 
@@ -2331,15 +2392,10 @@ static void queue_set_hctx_shared(struct request_queue *q, bool shared)
 	int i;
 
 	queue_for_each_hw_ctx(q, hctx, i) {
-		if (shared) {
-			if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
-				atomic_inc(&q->shared_hctx_restart);
+		if (shared)
 			hctx->flags |= BLK_MQ_F_TAG_SHARED;
-		} else {
-			if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
-				atomic_dec(&q->shared_hctx_restart);
+		else
 			hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
-		}
 	}
 }
 
@@ -2370,7 +2426,6 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q)
 		blk_mq_update_tag_set_depth(set, false);
 	}
 	mutex_unlock(&set->tag_list_lock);
-	synchronize_rcu();
 	INIT_LIST_HEAD(&q->tag_set_list);
 }
 
@@ -2685,7 +2740,6 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
 static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
 {
 	if (set->ops->map_queues) {
-		int cpu;
 		/*
 		 * transport .map_queues is usually done in the following
 		 * way:
@@ -2700,8 +2754,7 @@ static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
 		 * killing stale mapping since one CPU may not be mapped
 		 * to any hw queue.
 		 */
-		for_each_possible_cpu(cpu)
-			set->mq_map[cpu] = 0;
+		blk_mq_clear_mq_map(set);
 
 		return set->ops->map_queues(set);
 	} else
@@ -2711,7 +2764,7 @@ static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
 /*
  * Alloc a tag set to be associated with one or more request queues.
  * May fail with EINVAL for various error conditions. May adjust the
- * requested depth down, if if it too large. In that case, the set
+ * requested depth down, if it's too large. In that case, the set
  * value will be stored in set->queue_depth.
  */
 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)

block/blk-mq.h

@@ -36,8 +36,7 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
 void blk_mq_wake_waiters(struct request_queue *q);
 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
-bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
-				bool wait);
+bool blk_mq_get_driver_tag(struct request *rq);
 struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
 					struct blk_mq_ctx *start);
 
@@ -65,6 +64,8 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 
 /* Used by blk_insert_cloned_request() to issue request directly */
 blk_status_t blk_mq_request_issue_directly(struct request *rq);
+void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
+				    struct list_head *list);
 
 /*
  * CPU -> queue mappings
@@ -203,4 +204,12 @@ static inline void blk_mq_put_driver_tag(struct request *rq)
 	__blk_mq_put_driver_tag(hctx, rq);
 }
 
+static inline void blk_mq_clear_mq_map(struct blk_mq_tag_set *set)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		set->mq_map[cpu] = 0;
+}
+
 #endif

block/blk-rq-qos.c

@@ -0,0 +1,194 @@
+#include "blk-rq-qos.h"
+
+/*
+ * Increment 'v', if 'v' is below 'below'. Returns true if we succeeded,
+ * false if 'v' + 1 would be bigger than 'below'.
+ */
+static bool atomic_inc_below(atomic_t *v, unsigned int below)
+{
+	unsigned int cur = atomic_read(v);
+
+	for (;;) {
+		unsigned int old;
+
+		if (cur >= below)
+			return false;
+		old = atomic_cmpxchg(v, cur, cur + 1);
+		if (old == cur)
+			break;
+		cur = old;
+	}
+
+	return true;
+}
+
+bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit)
+{
+	return atomic_inc_below(&rq_wait->inflight, limit);
+}
+
+void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
+{
+	struct rq_qos *rqos;
+
+	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->cleanup)
+			rqos->ops->cleanup(rqos, bio);
+	}
+}
+
+void rq_qos_done(struct request_queue *q, struct request *rq)
+{
+	struct rq_qos *rqos;
+
+	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->done)
+			rqos->ops->done(rqos, rq);
+	}
+}
+
+void rq_qos_issue(struct request_queue *q, struct request *rq)
+{
+	struct rq_qos *rqos;
+
+	for(rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->issue)
+			rqos->ops->issue(rqos, rq);
+	}
+}
+
+void rq_qos_requeue(struct request_queue *q, struct request *rq)
+{
+	struct rq_qos *rqos;
+
+	for(rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->requeue)
+			rqos->ops->requeue(rqos, rq);
+	}
+}
+
+void rq_qos_throttle(struct request_queue *q, struct bio *bio,
+		     spinlock_t *lock)
+{
+	struct rq_qos *rqos;
+
+	for(rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->throttle)
+			rqos->ops->throttle(rqos, bio, lock);
+	}
+}
+
+void rq_qos_track(struct request_queue *q, struct request *rq, struct bio *bio)
+{
+	struct rq_qos *rqos;
+
+	for(rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->track)
+			rqos->ops->track(rqos, rq, bio);
+	}
+}
+
+void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
+{
+	struct rq_qos *rqos;
+
+	for(rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->ops->done_bio)
+			rqos->ops->done_bio(rqos, bio);
+	}
+}
+
+/*
+ * Return true, if we can't increase the depth further by scaling
+ */
+bool rq_depth_calc_max_depth(struct rq_depth *rqd)
+{
+	unsigned int depth;
+	bool ret = false;
+
+	/*
+	 * For QD=1 devices, this is a special case. It's important for those
+	 * to have one request ready when one completes, so force a depth of
+	 * 2 for those devices. On the backend, it'll be a depth of 1 anyway,
+	 * since the device can't have more than that in flight. If we're
+	 * scaling down, then keep a setting of 1/1/1.
+	 */
+	if (rqd->queue_depth == 1) {
+		if (rqd->scale_step > 0)
+			rqd->max_depth = 1;
+		else {
+			rqd->max_depth = 2;
+			ret = true;
+		}
+	} else {
+		/*
+		 * scale_step == 0 is our default state. If we have suffered
+		 * latency spikes, step will be > 0, and we shrink the
+		 * allowed write depths. If step is < 0, we're only doing
+		 * writes, and we allow a temporarily higher depth to
+		 * increase performance.
+		 */
+		depth = min_t(unsigned int, rqd->default_depth,
+			      rqd->queue_depth);
+		if (rqd->scale_step > 0)
+			depth = 1 + ((depth - 1) >> min(31, rqd->scale_step));
+		else if (rqd->scale_step < 0) {
+			unsigned int maxd = 3 * rqd->queue_depth / 4;
+
+			depth = 1 + ((depth - 1) << -rqd->scale_step);
+			if (depth > maxd) {
+				depth = maxd;
+				ret = true;
+			}
+		}
+
+		rqd->max_depth = depth;
+	}
+
+	return ret;
+}
+
+void rq_depth_scale_up(struct rq_depth *rqd)
+{
+	/*
+	 * Hit max in previous round, stop here
+	 */
+	if (rqd->scaled_max)
+		return;
+
+	rqd->scale_step--;
+
+	rqd->scaled_max = rq_depth_calc_max_depth(rqd);
+}
+
+/*
+ * Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
+ * had a latency violation.
+ */
+void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
+{
+	/*
+	 * Stop scaling down when we've hit the limit. This also prevents
+	 * ->scale_step from going to crazy values, if the device can't
+	 * keep up.
+	 */
+	if (rqd->max_depth == 1)
+		return;
+
+	if (rqd->scale_step < 0 && hard_throttle)
+		rqd->scale_step = 0;
+	else
+		rqd->scale_step++;
+
+	rqd->scaled_max = false;
+	rq_depth_calc_max_depth(rqd);
+}
+
+void rq_qos_exit(struct request_queue *q)
+{
+	while (q->rq_qos) {
+		struct rq_qos *rqos = q->rq_qos;
+		q->rq_qos = rqos->next;
+		rqos->ops->exit(rqos);
+	}
+}

block/blk-rq-qos.h

@@ -0,0 +1,109 @@
+#ifndef RQ_QOS_H
+#define RQ_QOS_H
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/blk_types.h>
+#include <linux/atomic.h>
+#include <linux/wait.h>
+
+enum rq_qos_id {
+	RQ_QOS_WBT,
+	RQ_QOS_CGROUP,
+};
+
+struct rq_wait {
+	wait_queue_head_t wait;
+	atomic_t inflight;
+};
+
+struct rq_qos {
+	struct rq_qos_ops *ops;
+	struct request_queue *q;
+	enum rq_qos_id id;
+	struct rq_qos *next;
+};
+
+struct rq_qos_ops {
+	void (*throttle)(struct rq_qos *, struct bio *, spinlock_t *);
+	void (*track)(struct rq_qos *, struct request *, struct bio *);
+	void (*issue)(struct rq_qos *, struct request *);
+	void (*requeue)(struct rq_qos *, struct request *);
+	void (*done)(struct rq_qos *, struct request *);
+	void (*done_bio)(struct rq_qos *, struct bio *);
+	void (*cleanup)(struct rq_qos *, struct bio *);
+	void (*exit)(struct rq_qos *);
+};
+
+struct rq_depth {
+	unsigned int max_depth;
+
+	int scale_step;
+	bool scaled_max;
+
+	unsigned int queue_depth;
+	unsigned int default_depth;
+};
+
+static inline struct rq_qos *rq_qos_id(struct request_queue *q,
+				       enum rq_qos_id id)
+{
+	struct rq_qos *rqos;
+	for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
+		if (rqos->id == id)
+			break;
+	}
+	return rqos;
+}
+
+static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
+{
+	return rq_qos_id(q, RQ_QOS_WBT);
+}
+
+static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
+{
+	return rq_qos_id(q, RQ_QOS_CGROUP);
+}
+
+static inline void rq_wait_init(struct rq_wait *rq_wait)
+{
+	atomic_set(&rq_wait->inflight, 0);
+	init_waitqueue_head(&rq_wait->wait);
+}
+
+static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
+{
+	rqos->next = q->rq_qos;
+	q->rq_qos = rqos;
+}
+
+static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
+{
+	struct rq_qos *cur, *prev = NULL;
+	for (cur = q->rq_qos; cur; cur = cur->next) {
+		if (cur == rqos) {
+			if (prev)
+				prev->next = rqos->next;
+			else
+				q->rq_qos = cur;
+			break;
+		}
+		prev = cur;
+	}
+}
+
+bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
+void rq_depth_scale_up(struct rq_depth *rqd);
+void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
+bool rq_depth_calc_max_depth(struct rq_depth *rqd);
+
+void rq_qos_cleanup(struct request_queue *, struct bio *);
+void rq_qos_done(struct request_queue *, struct request *);
+void rq_qos_issue(struct request_queue *, struct request *);
+void rq_qos_requeue(struct request_queue *, struct request *);
+void rq_qos_done_bio(struct request_queue *q, struct bio *bio);
+void rq_qos_throttle(struct request_queue *, struct bio *, spinlock_t *);
+void rq_qos_track(struct request_queue *q, struct request *, struct bio *);
+void rq_qos_exit(struct request_queue *);
+#endif

block/blk-settings.c

@@ -128,7 +128,7 @@ void blk_set_stacking_limits(struct queue_limits *lim)
 
 	/* Inherit limits from component devices */
 	lim->max_segments = USHRT_MAX;
-	lim->max_discard_segments = 1;
+	lim->max_discard_segments = USHRT_MAX;
 	lim->max_hw_sectors = UINT_MAX;
 	lim->max_segment_size = UINT_MAX;
 	lim->max_sectors = UINT_MAX;
@@ -875,7 +875,7 @@ EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);
 void blk_set_queue_depth(struct request_queue *q, unsigned int depth)
 {
 	q->queue_depth = depth;
-	wbt_set_queue_depth(q->rq_wb, depth);
+	wbt_set_queue_depth(q, depth);
 }
 EXPORT_SYMBOL(blk_set_queue_depth);
 
@@ -900,7 +900,7 @@ void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
 		queue_flag_clear(QUEUE_FLAG_FUA, q);
 	spin_unlock_irq(q->queue_lock);
 
-	wbt_set_write_cache(q->rq_wb, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
+	wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
 }
 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
 

block/blk-stat.c

@@ -17,7 +17,7 @@ struct blk_queue_stats {
 	bool enable_accounting;
 };
 
-static void blk_stat_init(struct blk_rq_stat *stat)
+void blk_rq_stat_init(struct blk_rq_stat *stat)
 {
 	stat->min = -1ULL;
 	stat->max = stat->nr_samples = stat->mean = 0;
@@ -25,7 +25,7 @@ static void blk_stat_init(struct blk_rq_stat *stat)
 }
 
 /* src is a per-cpu stat, mean isn't initialized */
-static void blk_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
+void blk_rq_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
 {
 	if (!src->nr_samples)
 		return;
@@ -39,7 +39,7 @@ static void blk_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
 	dst->nr_samples += src->nr_samples;
 }
 
-static void __blk_stat_add(struct blk_rq_stat *stat, u64 value)
+void blk_rq_stat_add(struct blk_rq_stat *stat, u64 value)
 {
 	stat->min = min(stat->min, value);
 	stat->max = max(stat->max, value);
@@ -69,7 +69,7 @@ void blk_stat_add(struct request *rq, u64 now)
 			continue;
 
 		stat = &get_cpu_ptr(cb->cpu_stat)[bucket];
-		__blk_stat_add(stat, value);
+		blk_rq_stat_add(stat, value);
 		put_cpu_ptr(cb->cpu_stat);
 	}
 	rcu_read_unlock();
@@ -82,15 +82,15 @@ static void blk_stat_timer_fn(struct timer_list *t)
 	int cpu;
 
 	for (bucket = 0; bucket < cb->buckets; bucket++)
-		blk_stat_init(&cb->stat[bucket]);
+		blk_rq_stat_init(&cb->stat[bucket]);
 
 	for_each_online_cpu(cpu) {
 		struct blk_rq_stat *cpu_stat;
 
 		cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
 		for (bucket = 0; bucket < cb->buckets; bucket++) {
-			blk_stat_sum(&cb->stat[bucket], &cpu_stat[bucket]);
-			blk_stat_init(&cpu_stat[bucket]);
+			blk_rq_stat_sum(&cb->stat[bucket], &cpu_stat[bucket]);
+			blk_rq_stat_init(&cpu_stat[bucket]);
 		}
 	}
 
@@ -143,7 +143,7 @@ void blk_stat_add_callback(struct request_queue *q,
 
 		cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
 		for (bucket = 0; bucket < cb->buckets; bucket++)
-			blk_stat_init(&cpu_stat[bucket]);
+			blk_rq_stat_init(&cpu_stat[bucket]);
 	}
 
 	spin_lock(&q->stats->lock);

block/blk-stat.h

@@ -159,4 +159,8 @@ static inline void blk_stat_activate_msecs(struct blk_stat_callback *cb,
 	mod_timer(&cb->timer, jiffies + msecs_to_jiffies(msecs));
 }
 
+void blk_rq_stat_add(struct blk_rq_stat *, u64);
+void blk_rq_stat_sum(struct blk_rq_stat *, struct blk_rq_stat *);
+void blk_rq_stat_init(struct blk_rq_stat *);
+
 #endif

block/blk-sysfs.c

@@ -422,16 +422,16 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page,
 
 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
 {
-	if (!q->rq_wb)
+	if (!wbt_rq_qos(q))
 		return -EINVAL;
 
-	return sprintf(page, "%llu\n", div_u64(q->rq_wb->min_lat_nsec, 1000));
+	return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
 }
 
 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 				  size_t count)
 {
-	struct rq_wb *rwb;
+	struct rq_qos *rqos;
 	ssize_t ret;
 	s64 val;
 
@@ -441,23 +441,21 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 	if (val < -1)
 		return -EINVAL;
 
-	rwb = q->rq_wb;
-	if (!rwb) {
+	rqos = wbt_rq_qos(q);
+	if (!rqos) {
 		ret = wbt_init(q);
 		if (ret)
 			return ret;
 	}
 
-	rwb = q->rq_wb;
 	if (val == -1)
-		rwb->min_lat_nsec = wbt_default_latency_nsec(q);
+		val = wbt_default_latency_nsec(q);
 	else if (val >= 0)
-		rwb->min_lat_nsec = val * 1000ULL;
+		val *= 1000ULL;
 
-	if (rwb->enable_state == WBT_STATE_ON_DEFAULT)
-		rwb->enable_state = WBT_STATE_ON_MANUAL;
+	wbt_set_min_lat(q, val);
 
-	wbt_update_limits(rwb);
+	wbt_update_limits(q);
 	return count;
 }
 
@@ -804,6 +802,21 @@ static void __blk_release_queue(struct work_struct *work)
 		blk_stat_remove_callback(q, q->poll_cb);
 	blk_stat_free_callback(q->poll_cb);
 
+	if (!blk_queue_dead(q)) {
+		/*
+		 * Last reference was dropped without having called
+		 * blk_cleanup_queue().
+		 */
+		WARN_ONCE(blk_queue_init_done(q),
+			  "request queue %p has been registered but blk_cleanup_queue() has not been called for that queue\n",
+			  q);
+		blk_exit_queue(q);
+	}
+
+	WARN(blk_queue_root_blkg(q),
+	     "request queue %p is being released but it has not yet been removed from the blkcg controller\n",
+	     q);
+
 	blk_free_queue_stats(q->stats);
 
 	blk_exit_rl(q, &q->root_rl);
@@ -964,7 +977,7 @@ void blk_unregister_queue(struct gendisk *disk)
 	kobject_del(&q->kobj);
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
-	wbt_exit(q);
+	rq_qos_exit(q);
 
 	mutex_lock(&q->sysfs_lock);
 	if (q->request_fn || (q->mq_ops && q->elevator))

block/blk-throttle.c

@@ -579,8 +579,10 @@ static void blk_throtl_update_limit_valid(struct throtl_data *td)
 		struct throtl_grp *tg = blkg_to_tg(blkg);
 
 		if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] ||
-		    tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW])
+		    tg->iops[READ][LIMIT_LOW] || tg->iops[WRITE][LIMIT_LOW]) {
 			low_valid = true;
+			break;
+		}
 	}
 	rcu_read_unlock();
 
@@ -920,12 +922,7 @@ static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio,
 	}
 
 	/* Calc approx time to dispatch */
-	jiffy_wait = ((tg->io_disp[rw] + 1) * HZ) / tg_iops_limit(tg, rw) + 1;
-
-	if (jiffy_wait > jiffy_elapsed)
-		jiffy_wait = jiffy_wait - jiffy_elapsed;
-	else
-		jiffy_wait = 1;
+	jiffy_wait = jiffy_elapsed_rnd - jiffy_elapsed;
 
 	if (wait)
 		*wait = jiffy_wait;
@@ -2132,12 +2129,8 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td)
 static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio)
 {
 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
-	if (bio->bi_css) {
-		if (bio->bi_cg_private)
-			blkg_put(tg_to_blkg(bio->bi_cg_private));
-		bio->bi_cg_private = tg;
-		blkg_get(tg_to_blkg(tg));
-	}
+	if (bio->bi_css)
+		bio_associate_blkg(bio, tg_to_blkg(tg));
 	bio_issue_init(&bio->bi_issue, bio_sectors(bio));
 #endif
 }
@@ -2285,6 +2278,7 @@ void blk_throtl_stat_add(struct request *rq, u64 time_ns)
 
 void blk_throtl_bio_endio(struct bio *bio)
 {
+	struct blkcg_gq *blkg;
 	struct throtl_grp *tg;
 	u64 finish_time_ns;
 	unsigned long finish_time;
@@ -2292,20 +2286,18 @@ void blk_throtl_bio_endio(struct bio *bio)
 	unsigned long lat;
 	int rw = bio_data_dir(bio);
 
-	tg = bio->bi_cg_private;
-	if (!tg)
+	blkg = bio->bi_blkg;
+	if (!blkg)
 		return;
-	bio->bi_cg_private = NULL;
+	tg = blkg_to_tg(blkg);
 
 	finish_time_ns = ktime_get_ns();
 	tg->last_finish_time = finish_time_ns >> 10;
 
 	start_time = bio_issue_time(&bio->bi_issue) >> 10;
 	finish_time = __bio_issue_time(finish_time_ns) >> 10;
-	if (!start_time || finish_time <= start_time) {
-		blkg_put(tg_to_blkg(tg));
+	if (!start_time || finish_time <= start_time)
 		return;
-	}
 
 	lat = finish_time - start_time;
 	/* this is only for bio based driver */
@@ -2334,8 +2326,6 @@ void blk_throtl_bio_endio(struct bio *bio)
 		tg->bio_cnt /= 2;
 		tg->bad_bio_cnt /= 2;
 	}
-
-	blkg_put(tg_to_blkg(tg));
 }
 #endif
 

block/blk-wbt.c

@@ -25,6 +25,7 @@
 #include <linux/swap.h>
 
 #include "blk-wbt.h"
+#include "blk-rq-qos.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/wbt.h>
@@ -78,28 +79,6 @@ static inline bool rwb_enabled(struct rq_wb *rwb)
 	return rwb && rwb->wb_normal != 0;
 }
 
-/*
- * Increment 'v', if 'v' is below 'below'. Returns true if we succeeded,
- * false if 'v' + 1 would be bigger than 'below'.
- */
-static bool atomic_inc_below(atomic_t *v, int below)
-{
-	int cur = atomic_read(v);
-
-	for (;;) {
-		int old;
-
-		if (cur >= below)
-			return false;
-		old = atomic_cmpxchg(v, cur, cur + 1);
-		if (old == cur)
-			break;
-		cur = old;
-	}
-
-	return true;
-}
-
 static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
 {
 	if (rwb_enabled(rwb)) {
@@ -116,7 +95,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
  */
 static bool wb_recent_wait(struct rq_wb *rwb)
 {
-	struct bdi_writeback *wb = &rwb->queue->backing_dev_info->wb;
+	struct bdi_writeback *wb = &rwb->rqos.q->backing_dev_info->wb;
 
 	return time_before(jiffies, wb->dirty_sleep + HZ);
 }
@@ -144,8 +123,9 @@ static void rwb_wake_all(struct rq_wb *rwb)
 	}
 }
 
-void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
+static void __wbt_done(struct rq_qos *rqos, enum wbt_flags wb_acct)
 {
+	struct rq_wb *rwb = RQWB(rqos);
 	struct rq_wait *rqw;
 	int inflight, limit;
 
@@ -186,7 +166,7 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
 		int diff = limit - inflight;
 
 		if (!inflight || diff >= rwb->wb_background / 2)
-			wake_up_all(&rqw->wait);
+			wake_up(&rqw->wait);
 	}
 }
 
@@ -194,10 +174,9 @@ void __wbt_done(struct rq_wb *rwb, enum wbt_flags wb_acct)
  * Called on completion of a request. Note that it's also called when
  * a request is merged, when the request gets freed.
  */
-void wbt_done(struct rq_wb *rwb, struct request *rq)
+static void wbt_done(struct rq_qos *rqos, struct request *rq)
 {
-	if (!rwb)
-		return;
+	struct rq_wb *rwb = RQWB(rqos);
 
 	if (!wbt_is_tracked(rq)) {
 		if (rwb->sync_cookie == rq) {
@@ -209,72 +188,11 @@ void wbt_done(struct rq_wb *rwb, struct request *rq)
 			wb_timestamp(rwb, &rwb->last_comp);
 	} else {
 		WARN_ON_ONCE(rq == rwb->sync_cookie);
-		__wbt_done(rwb, wbt_flags(rq));
+		__wbt_done(rqos, wbt_flags(rq));
 	}
 	wbt_clear_state(rq);
 }
 
-/*
- * Return true, if we can't increase the depth further by scaling
- */
-static bool calc_wb_limits(struct rq_wb *rwb)
-{
-	unsigned int depth;
-	bool ret = false;
-
-	if (!rwb->min_lat_nsec) {
-		rwb->wb_max = rwb->wb_normal = rwb->wb_background = 0;
-		return false;
-	}
-
-	/*
-	 * For QD=1 devices, this is a special case. It's important for those
-	 * to have one request ready when one completes, so force a depth of
-	 * 2 for those devices. On the backend, it'll be a depth of 1 anyway,
-	 * since the device can't have more than that in flight. If we're
-	 * scaling down, then keep a setting of 1/1/1.
-	 */
-	if (rwb->queue_depth == 1) {
-		if (rwb->scale_step > 0)
-			rwb->wb_max = rwb->wb_normal = 1;
-		else {
-			rwb->wb_max = rwb->wb_normal = 2;
-			ret = true;
-		}
-		rwb->wb_background = 1;
-	} else {
-		/*
-		 * scale_step == 0 is our default state. If we have suffered
-		 * latency spikes, step will be > 0, and we shrink the
-		 * allowed write depths. If step is < 0, we're only doing
-		 * writes, and we allow a temporarily higher depth to
-		 * increase performance.
-		 */
-		depth = min_t(unsigned int, RWB_DEF_DEPTH, rwb->queue_depth);
-		if (rwb->scale_step > 0)
-			depth = 1 + ((depth - 1) >> min(31, rwb->scale_step));
-		else if (rwb->scale_step < 0) {
-			unsigned int maxd = 3 * rwb->queue_depth / 4;
-
-			depth = 1 + ((depth - 1) << -rwb->scale_step);
-			if (depth > maxd) {
-				depth = maxd;
-				ret = true;
-			}
-		}
-
-		/*
-		 * Set our max/normal/bg queue depths based on how far
-		 * we have scaled down (->scale_step).
-		 */
-		rwb->wb_max = depth;
-		rwb->wb_normal = (rwb->wb_max + 1) / 2;
-		rwb->wb_background = (rwb->wb_max + 3) / 4;
-	}
-
-	return ret;
-}
-
 static inline bool stat_sample_valid(struct blk_rq_stat *stat)
 {
 	/*
@@ -307,7 +225,8 @@ enum {
 
 static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 {
-	struct backing_dev_info *bdi = rwb->queue->backing_dev_info;
+	struct backing_dev_info *bdi = rwb->rqos.q->backing_dev_info;
+	struct rq_depth *rqd = &rwb->rq_depth;
 	u64 thislat;
 
 	/*
@@ -351,7 +270,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 		return LAT_EXCEEDED;
 	}
 
-	if (rwb->scale_step)
+	if (rqd->scale_step)
 		trace_wbt_stat(bdi, stat);
 
 	return LAT_OK;
@@ -359,58 +278,48 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 
 static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
 {
-	struct backing_dev_info *bdi = rwb->queue->backing_dev_info;
+	struct backing_dev_info *bdi = rwb->rqos.q->backing_dev_info;
+	struct rq_depth *rqd = &rwb->rq_depth;
 
-	trace_wbt_step(bdi, msg, rwb->scale_step, rwb->cur_win_nsec,
-			rwb->wb_background, rwb->wb_normal, rwb->wb_max);
+	trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,
+			rwb->wb_background, rwb->wb_normal, rqd->max_depth);
 }
 
-static void scale_up(struct rq_wb *rwb)
+static void calc_wb_limits(struct rq_wb *rwb)
 {
-	/*
-	 * Hit max in previous round, stop here
-	 */
-	if (rwb->scaled_max)
-		return;
+	if (rwb->min_lat_nsec == 0) {
+		rwb->wb_normal = rwb->wb_background = 0;
+	} else if (rwb->rq_depth.max_depth <= 2) {
+		rwb->wb_normal = rwb->rq_depth.max_depth;
+		rwb->wb_background = 1;
+	} else {
+		rwb->wb_normal = (rwb->rq_depth.max_depth + 1) / 2;
+		rwb->wb_background = (rwb->rq_depth.max_depth + 3) / 4;
+	}
+}
 
-	rwb->scale_step--;
+static void scale_up(struct rq_wb *rwb)
+{
+	rq_depth_scale_up(&rwb->rq_depth);
+	calc_wb_limits(rwb);
 	rwb->unknown_cnt = 0;
-
-	rwb->scaled_max = calc_wb_limits(rwb);
-
-	rwb_wake_all(rwb);
-
-	rwb_trace_step(rwb, "step up");
+	rwb_trace_step(rwb, "scale up");
 }
 
-/*
- * Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
- * had a latency violation.
- */
 static void scale_down(struct rq_wb *rwb, bool hard_throttle)
 {
-	/*
-	 * Stop scaling down when we've hit the limit. This also prevents
-	 * ->scale_step from going to crazy values, if the device can't
-	 * keep up.
-	 */
-	if (rwb->wb_max == 1)
-		return;
-
-	if (rwb->scale_step < 0 && hard_throttle)
-		rwb->scale_step = 0;
-	else
-		rwb->scale_step++;
-
-	rwb->scaled_max = false;
-	rwb->unknown_cnt = 0;
+	rq_depth_scale_down(&rwb->rq_depth, hard_throttle);
 	calc_wb_limits(rwb);
-	rwb_trace_step(rwb, "step down");
+	rwb->unknown_cnt = 0;
+	rwb_wake_all(rwb);
+	rwb_trace_step(rwb, "scale down");
 }
 
 static void rwb_arm_timer(struct rq_wb *rwb)
 {
-	if (rwb->scale_step > 0) {
+	struct rq_depth *rqd = &rwb->rq_depth;
+
+	if (rqd->scale_step > 0) {
 		/*
 		 * We should speed this up, using some variant of a fast
 		 * integer inverse square root calculation. Since we only do
@@ -418,7 +327,7 @@ static void rwb_arm_timer(struct rq_wb *rwb)
 		 * though.
 		 */
 		rwb->cur_win_nsec = div_u64(rwb->win_nsec << 4,
-					int_sqrt((rwb->scale_step + 1) << 8));
+					int_sqrt((rqd->scale_step + 1) << 8));
 	} else {
 		/*
 		 * For step < 0, we don't want to increase/decrease the
@@ -433,12 +342,13 @@ static void rwb_arm_timer(struct rq_wb *rwb)
 static void wb_timer_fn(struct blk_stat_callback *cb)
 {
 	struct rq_wb *rwb = cb->data;
+	struct rq_depth *rqd = &rwb->rq_depth;
 	unsigned int inflight = wbt_inflight(rwb);
 	int status;
 
 	status = latency_exceeded(rwb, cb->stat);
 
-	trace_wbt_timer(rwb->queue->backing_dev_info, status, rwb->scale_step,
+	trace_wbt_timer(rwb->rqos.q->backing_dev_info, status, rqd->scale_step,
 			inflight);
 
 	/*
@@ -469,9 +379,9 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
 		 * currently don't have a valid read/write sample. For that
 		 * case, slowly return to center state (step == 0).
 		 */
-		if (rwb->scale_step > 0)
+		if (rqd->scale_step > 0)
 			scale_up(rwb);
-		else if (rwb->scale_step < 0)
+		else if (rqd->scale_step < 0)
 			scale_down(rwb, false);
 		break;
 	default:
@@ -481,19 +391,50 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
 	/*
 	 * Re-arm timer, if we have IO in flight
 	 */
-	if (rwb->scale_step || inflight)
+	if (rqd->scale_step || inflight)
 		rwb_arm_timer(rwb);
 }
 
-void wbt_update_limits(struct rq_wb *rwb)
+static void __wbt_update_limits(struct rq_wb *rwb)
 {
-	rwb->scale_step = 0;
-	rwb->scaled_max = false;
+	struct rq_depth *rqd = &rwb->rq_depth;
+
+	rqd->scale_step = 0;
+	rqd->scaled_max = false;
+
+	rq_depth_calc_max_depth(rqd);
 	calc_wb_limits(rwb);
 
 	rwb_wake_all(rwb);
 }
 
+void wbt_update_limits(struct request_queue *q)
+{
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	if (!rqos)
+		return;
+	__wbt_update_limits(RQWB(rqos));
+}
+
+u64 wbt_get_min_lat(struct request_queue *q)
+{
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	if (!rqos)
+		return 0;
+	return RQWB(rqos)->min_lat_nsec;
+}
+
+void wbt_set_min_lat(struct request_queue *q, u64 val)
+{
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	if (!rqos)
+		return;
+	RQWB(rqos)->min_lat_nsec = val;
+	RQWB(rqos)->enable_state = WBT_STATE_ON_MANUAL;
+	__wbt_update_limits(RQWB(rqos));
+}
+
+
 static bool close_io(struct rq_wb *rwb)
 {
 	const unsigned long now = jiffies;
@@ -520,7 +461,7 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
 	 * IO for a bit.
 	 */
 	if ((rw & REQ_HIPRIO) || wb_recent_wait(rwb) || current_is_kswapd())
-		limit = rwb->wb_max;
+		limit = rwb->rq_depth.max_depth;
 	else if ((rw & REQ_BACKGROUND) || close_io(rwb)) {
 		/*
 		 * If less than 100ms since we completed unrelated IO,
@@ -533,30 +474,6 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
 	return limit;
 }
 
-static inline bool may_queue(struct rq_wb *rwb, struct rq_wait *rqw,
-			     wait_queue_entry_t *wait, unsigned long rw)
-{
-	/*
-	 * inc it here even if disabled, since we'll dec it at completion.
-	 * this only happens if the task was sleeping in __wbt_wait(),
-	 * and someone turned it off at the same time.
-	 */
-	if (!rwb_enabled(rwb)) {
-		atomic_inc(&rqw->inflight);
-		return true;
-	}
-
-	/*
-	 * If the waitqueue is already active and we are not the next
-	 * in line to be woken up, wait for our turn.
-	 */
-	if (waitqueue_active(&rqw->wait) &&
-	    rqw->wait.head.next != &wait->entry)
-		return false;
-
-	return atomic_inc_below(&rqw->inflight, get_limit(rwb, rw));
-}
-
 /*
  * Block if we will exceed our limit, or if we are currently waiting for
  * the timer to kick off queuing again.
@@ -567,16 +484,32 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
 	__acquires(lock)
 {
 	struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);
-	DEFINE_WAIT(wait);
+	DECLARE_WAITQUEUE(wait, current);
 
-	if (may_queue(rwb, rqw, &wait, rw))
+	/*
+	* inc it here even if disabled, since we'll dec it at completion.
+	* this only happens if the task was sleeping in __wbt_wait(),
+	* and someone turned it off at the same time.
+	*/
+	if (!rwb_enabled(rwb)) {
+		atomic_inc(&rqw->inflight);
 		return;
+	}
 
+	if (!waitqueue_active(&rqw->wait)
+		&& rq_wait_inc_below(rqw, get_limit(rwb, rw)))
+		return;
+
+	add_wait_queue_exclusive(&rqw->wait, &wait);
 	do {
-		prepare_to_wait_exclusive(&rqw->wait, &wait,
-						TASK_UNINTERRUPTIBLE);
+		set_current_state(TASK_UNINTERRUPTIBLE);
 
-		if (may_queue(rwb, rqw, &wait, rw))
+		if (!rwb_enabled(rwb)) {
+			atomic_inc(&rqw->inflight);
+			break;
+		}
+
+		if (rq_wait_inc_below(rqw, get_limit(rwb, rw)))
 			break;
 
 		if (lock) {
@@ -587,7 +520,8 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
 			io_schedule();
 	} while (1);
 
-	finish_wait(&rqw->wait, &wait);
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&rqw->wait, &wait);
 }
 
 static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
@@ -608,43 +542,72 @@ static inline bool wbt_should_throttle(struct rq_wb *rwb, struct bio *bio)
 	}
 }
 
+static enum wbt_flags bio_to_wbt_flags(struct rq_wb *rwb, struct bio *bio)
+{
+	enum wbt_flags flags = 0;
+
+	if (bio_op(bio) == REQ_OP_READ) {
+		flags = WBT_READ;
+	} else if (wbt_should_throttle(rwb, bio)) {
+		if (current_is_kswapd())
+			flags |= WBT_KSWAPD;
+		if (bio_op(bio) == REQ_OP_DISCARD)
+			flags |= WBT_DISCARD;
+		flags |= WBT_TRACKED;
+	}
+	return flags;
+}
+
+static void wbt_cleanup(struct rq_qos *rqos, struct bio *bio)
+{
+	struct rq_wb *rwb = RQWB(rqos);
+	enum wbt_flags flags = bio_to_wbt_flags(rwb, bio);
+	__wbt_done(rqos, flags);
+}
+
 /*
  * Returns true if the IO request should be accounted, false if not.
  * May sleep, if we have exceeded the writeback limits. Caller can pass
  * in an irq held spinlock, if it holds one when calling this function.
  * If we do sleep, we'll release and re-grab it.
  */
-enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio, spinlock_t *lock)
+static void wbt_wait(struct rq_qos *rqos, struct bio *bio, spinlock_t *lock)
 {
-	enum wbt_flags ret = 0;
+	struct rq_wb *rwb = RQWB(rqos);
+	enum wbt_flags flags;
 
 	if (!rwb_enabled(rwb))
-		return 0;
+		return;
 
-	if (bio_op(bio) == REQ_OP_READ)
-		ret = WBT_READ;
+	flags = bio_to_wbt_flags(rwb, bio);
 
 	if (!wbt_should_throttle(rwb, bio)) {
-		if (ret & WBT_READ)
+		if (flags & WBT_READ)
 			wb_timestamp(rwb, &rwb->last_issue);
-		return ret;
+		return;
 	}
 
 	if (current_is_kswapd())
-		ret |= WBT_KSWAPD;
+		flags |= WBT_KSWAPD;
 	if (bio_op(bio) == REQ_OP_DISCARD)
-		ret |= WBT_DISCARD;
+		flags |= WBT_DISCARD;
 
-	__wbt_wait(rwb, ret, bio->bi_opf, lock);
+	__wbt_wait(rwb, flags, bio->bi_opf, lock);
 
 	if (!blk_stat_is_active(rwb->cb))
 		rwb_arm_timer(rwb);
+}
 
-	return ret | WBT_TRACKED;
+static void wbt_track(struct rq_qos *rqos, struct request *rq, struct bio *bio)
+{
+	struct rq_wb *rwb = RQWB(rqos);
+	rq->wbt_flags |= bio_to_wbt_flags(rwb, bio);
 }
 
-void wbt_issue(struct rq_wb *rwb, struct request *rq)
+void wbt_issue(struct rq_qos *rqos, struct request *rq)
 {
+	struct rq_wb *rwb = RQWB(rqos);
+
 	if (!rwb_enabled(rwb))
 		return;
 
@@ -661,8 +624,9 @@ void wbt_issue(struct rq_wb *rwb, struct request *rq)
 	}
 }
 
-void wbt_requeue(struct rq_wb *rwb, struct request *rq)
+void wbt_requeue(struct rq_qos *rqos, struct request *rq)
 {
+	struct rq_wb *rwb = RQWB(rqos);
 	if (!rwb_enabled(rwb))
 		return;
 	if (rq == rwb->sync_cookie) {
@@ -671,39 +635,30 @@ void wbt_requeue(struct rq_wb *rwb, struct request *rq)
 	}
 }
 
-void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
+void wbt_set_queue_depth(struct request_queue *q, unsigned int depth)
 {
-	if (rwb) {
-		rwb->queue_depth = depth;
-		wbt_update_limits(rwb);
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	if (rqos) {
+		RQWB(rqos)->rq_depth.queue_depth = depth;
+		__wbt_update_limits(RQWB(rqos));
 	}
 }
 
-void wbt_set_write_cache(struct rq_wb *rwb, bool write_cache_on)
+void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
 {
-	if (rwb)
-		rwb->wc = write_cache_on;
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	if (rqos)
+		RQWB(rqos)->wc = write_cache_on;
 }
 
-/*
- * Disable wbt, if enabled by default.
- */
-void wbt_disable_default(struct request_queue *q)
-{
-	struct rq_wb *rwb = q->rq_wb;
-
-	if (rwb && rwb->enable_state == WBT_STATE_ON_DEFAULT)
-		wbt_exit(q);
-}
-EXPORT_SYMBOL_GPL(wbt_disable_default);
-
 /*
  * Enable wbt if defaults are configured that way
  */
 void wbt_enable_default(struct request_queue *q)
 {
+	struct rq_qos *rqos = wbt_rq_qos(q);
 	/* Throttling already enabled? */
-	if (q->rq_wb)
+	if (rqos)
 		return;
 
 	/* Queue not registered? Maybe shutting down... */
@@ -741,6 +696,42 @@ static int wbt_data_dir(const struct request *rq)
 	return -1;
 }
 
+static void wbt_exit(struct rq_qos *rqos)
+{
+	struct rq_wb *rwb = RQWB(rqos);
+	struct request_queue *q = rqos->q;
+
+	blk_stat_remove_callback(q, rwb->cb);
+	blk_stat_free_callback(rwb->cb);
+	kfree(rwb);
+}
+
+/*
+ * Disable wbt, if enabled by default.
+ */
+void wbt_disable_default(struct request_queue *q)
+{
+	struct rq_qos *rqos = wbt_rq_qos(q);
+	struct rq_wb *rwb;
+	if (!rqos)
+		return;
+	rwb = RQWB(rqos);
+	if (rwb->enable_state == WBT_STATE_ON_DEFAULT)
+		rwb->wb_normal = 0;
+}
+EXPORT_SYMBOL_GPL(wbt_disable_default);
+
+
+static struct rq_qos_ops wbt_rqos_ops = {
+	.throttle = wbt_wait,
+	.issue = wbt_issue,
+	.track = wbt_track,
+	.requeue = wbt_requeue,
+	.done = wbt_done,
+	.cleanup = wbt_cleanup,
+	.exit = wbt_exit,
+};
+
 int wbt_init(struct request_queue *q)
 {
 	struct rq_wb *rwb;
@@ -756,39 +747,29 @@ int wbt_init(struct request_queue *q)
 		return -ENOMEM;
 	}
 
-	for (i = 0; i < WBT_NUM_RWQ; i++) {
-		atomic_set(&rwb->rq_wait[i].inflight, 0);
-		init_waitqueue_head(&rwb->rq_wait[i].wait);
-	}
+	for (i = 0; i < WBT_NUM_RWQ; i++)
+		rq_wait_init(&rwb->rq_wait[i]);
 
+	rwb->rqos.id = RQ_QOS_WBT;
+	rwb->rqos.ops = &wbt_rqos_ops;
+	rwb->rqos.q = q;
 	rwb->last_comp = rwb->last_issue = jiffies;
-	rwb->queue = q;
 	rwb->win_nsec = RWB_WINDOW_NSEC;
 	rwb->enable_state = WBT_STATE_ON_DEFAULT;
-	wbt_update_limits(rwb);
+	rwb->wc = 1;
+	rwb->rq_depth.default_depth = RWB_DEF_DEPTH;
+	__wbt_update_limits(rwb);
 
 	/*
 	 * Assign rwb and add the stats callback.
 	 */
-	q->rq_wb = rwb;
+	rq_qos_add(q, &rwb->rqos);
 	blk_stat_add_callback(q, rwb->cb);
 
 	rwb->min_lat_nsec = wbt_default_latency_nsec(q);
 
-	wbt_set_queue_depth(rwb, blk_queue_depth(q));
-	wbt_set_write_cache(rwb, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
+	wbt_set_queue_depth(q, blk_queue_depth(q));
+	wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
 
 	return 0;
 }
-
-void wbt_exit(struct request_queue *q)
-{
-	struct rq_wb *rwb = q->rq_wb;
-
-	if (rwb) {
-		blk_stat_remove_callback(q, rwb->cb);
-		blk_stat_free_callback(rwb->cb);
-		q->rq_wb = NULL;
-		kfree(rwb);
-	}
-}

block/blk-wbt.h

@@ -9,6 +9,7 @@
 #include <linux/ktime.h>
 
 #include "blk-stat.h"
+#include "blk-rq-qos.h"
 
 enum wbt_flags {
 	WBT_TRACKED		= 1,	/* write, tracked for throttling */
@@ -35,20 +36,12 @@ enum {
 	WBT_STATE_ON_MANUAL	= 2,
 };
 
-struct rq_wait {
-	wait_queue_head_t wait;
-	atomic_t inflight;
-};
-
 struct rq_wb {
 	/*
 	 * Settings that govern how we throttle
 	 */
 	unsigned int wb_background;		/* background writeback */
 	unsigned int wb_normal;			/* normal writeback */
-	unsigned int wb_max;			/* max throughput writeback */
-	int scale_step;
-	bool scaled_max;
 
 	short enable_state;			/* WBT_STATE_* */
 
@@ -67,15 +60,20 @@ struct rq_wb {
 	void *sync_cookie;
 
 	unsigned int wc;
-	unsigned int queue_depth;
 
 	unsigned long last_issue;		/* last non-throttled issue */
 	unsigned long last_comp;		/* last non-throttled comp */
 	unsigned long min_lat_nsec;
-	struct request_queue *queue;
+	struct rq_qos rqos;
 	struct rq_wait rq_wait[WBT_NUM_RWQ];
+	struct rq_depth rq_depth;
 };
 
+static inline struct rq_wb *RQWB(struct rq_qos *rqos)
+{
+	return container_of(rqos, struct rq_wb, rqos);
+}
+
 static inline unsigned int wbt_inflight(struct rq_wb *rwb)
 {
 	unsigned int i, ret = 0;
@@ -86,26 +84,19 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
 	return ret;
 }
 
-#ifdef CONFIG_BLK_WBT
 
-static inline void wbt_track(struct request *rq, enum wbt_flags flags)
-{
-	rq->wbt_flags |= flags;
-}
+#ifdef CONFIG_BLK_WBT
 
-void __wbt_done(struct rq_wb *, enum wbt_flags);
-void wbt_done(struct rq_wb *, struct request *);
-enum wbt_flags wbt_wait(struct rq_wb *, struct bio *, spinlock_t *);
 int wbt_init(struct request_queue *);
-void wbt_exit(struct request_queue *);
-void wbt_update_limits(struct rq_wb *);
-void wbt_requeue(struct rq_wb *, struct request *);
-void wbt_issue(struct rq_wb *, struct request *);
+void wbt_update_limits(struct request_queue *);
 void wbt_disable_default(struct request_queue *);
 void wbt_enable_default(struct request_queue *);
 
-void wbt_set_queue_depth(struct rq_wb *, unsigned int);
-void wbt_set_write_cache(struct rq_wb *, bool);
+u64 wbt_get_min_lat(struct request_queue *q);
+void wbt_set_min_lat(struct request_queue *q, u64 val);
+
+void wbt_set_queue_depth(struct request_queue *, unsigned int);
+void wbt_set_write_cache(struct request_queue *, bool);
 
 u64 wbt_default_latency_nsec(struct request_queue *);
 
@@ -114,43 +105,30 @@ u64 wbt_default_latency_nsec(struct request_queue *);
 static inline void wbt_track(struct request *rq, enum wbt_flags flags)
 {
 }
-static inline void __wbt_done(struct rq_wb *rwb, enum wbt_flags flags)
-{
-}
-static inline void wbt_done(struct rq_wb *rwb, struct request *rq)
-{
-}
-static inline enum wbt_flags wbt_wait(struct rq_wb *rwb, struct bio *bio,
-				      spinlock_t *lock)
-{
-	return 0;
-}
 static inline int wbt_init(struct request_queue *q)
 {
 	return -EINVAL;
 }
-static inline void wbt_exit(struct request_queue *q)
-{
-}
-static inline void wbt_update_limits(struct rq_wb *rwb)
+static inline void wbt_update_limits(struct request_queue *q)
 {
 }
-static inline void wbt_requeue(struct rq_wb *rwb, struct request *rq)
+static inline void wbt_disable_default(struct request_queue *q)
 {
 }
-static inline void wbt_issue(struct rq_wb *rwb, struct request *rq)
+static inline void wbt_enable_default(struct request_queue *q)
 {
 }
-static inline void wbt_disable_default(struct request_queue *q)
+static inline void wbt_set_queue_depth(struct request_queue *q, unsigned int depth)
 {
 }
-static inline void wbt_enable_default(struct request_queue *q)
+static inline void wbt_set_write_cache(struct request_queue *q, bool wc)
 {
 }
-static inline void wbt_set_queue_depth(struct rq_wb *rwb, unsigned int depth)
+static inline u64 wbt_get_min_lat(struct request_queue *q)
 {
+	return 0;
 }
-static inline void wbt_set_write_cache(struct rq_wb *rwb, bool wc)
+static inline void wbt_set_min_lat(struct request_queue *q, u64 val)
 {
 }
 static inline u64 wbt_default_latency_nsec(struct request_queue *q)

block/blk-zoned.c

@@ -200,7 +200,7 @@ int blkdev_report_zones(struct block_device *bdev,
 		/* Get header in the first page */
 		ofst = 0;
 		if (!nr_rep) {
-			hdr = (struct blk_zone_report_hdr *) addr;
+			hdr = addr;
 			nr_rep = hdr->nr_zones;
 			ofst = sizeof(struct blk_zone_report_hdr);
 		}

block/blk.h

@@ -130,6 +130,7 @@ void blk_free_flush_queue(struct blk_flush_queue *q);
 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 		gfp_t gfp_mask);
 void blk_exit_rl(struct request_queue *q, struct request_list *rl);
+void blk_exit_queue(struct request_queue *q);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);
 void blk_queue_bypass_start(struct request_queue *q);
@@ -412,4 +413,10 @@ static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 
 extern void blk_drain_queue(struct request_queue *q);
 
+#ifdef CONFIG_BLK_CGROUP_IOLATENCY
+extern int blk_iolatency_init(struct request_queue *q);
+#else
+static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
+#endif
+
 #endif /* BLK_INTERNAL_H */

block/bounce.c

@@ -195,6 +195,73 @@ static void bounce_end_io_read_isa(struct bio *bio)
 	__bounce_end_io_read(bio, &isa_page_pool);
 }
 
+static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask,
+		struct bio_set *bs)
+{
+	struct bvec_iter iter;
+	struct bio_vec bv;
+	struct bio *bio;
+
+	/*
+	 * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
+	 * bio_src->bi_io_vec to bio->bi_io_vec.
+	 *
+	 * We can't do that anymore, because:
+	 *
+	 *  - The point of cloning the biovec is to produce a bio with a biovec
+	 *    the caller can modify: bi_idx and bi_bvec_done should be 0.
+	 *
+	 *  - The original bio could've had more than BIO_MAX_PAGES biovecs; if
+	 *    we tried to clone the whole thing bio_alloc_bioset() would fail.
+	 *    But the clone should succeed as long as the number of biovecs we
+	 *    actually need to allocate is fewer than BIO_MAX_PAGES.
+	 *
+	 *  - Lastly, bi_vcnt should not be looked at or relied upon by code
+	 *    that does not own the bio - reason being drivers don't use it for
+	 *    iterating over the biovec anymore, so expecting it to be kept up
+	 *    to date (i.e. for clones that share the parent biovec) is just
+	 *    asking for trouble and would force extra work on
+	 *    __bio_clone_fast() anyways.
+	 */
+
+	bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
+	if (!bio)
+		return NULL;
+	bio->bi_disk		= bio_src->bi_disk;
+	bio->bi_opf		= bio_src->bi_opf;
+	bio->bi_write_hint	= bio_src->bi_write_hint;
+	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
+	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
+
+	switch (bio_op(bio)) {
+	case REQ_OP_DISCARD:
+	case REQ_OP_SECURE_ERASE:
+	case REQ_OP_WRITE_ZEROES:
+		break;
+	case REQ_OP_WRITE_SAME:
+		bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
+		break;
+	default:
+		bio_for_each_segment(bv, bio_src, iter)
+			bio->bi_io_vec[bio->bi_vcnt++] = bv;
+		break;
+	}
+
+	if (bio_integrity(bio_src)) {
+		int ret;
+
+		ret = bio_integrity_clone(bio, bio_src, gfp_mask);
+		if (ret < 0) {
+			bio_put(bio);
+			return NULL;
+		}
+	}
+
+	bio_clone_blkcg_association(bio, bio_src);
+
+	return bio;
+}
+
 static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
 			       mempool_t *pool)
 {
@@ -222,7 +289,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
 		generic_make_request(*bio_orig);
 		*bio_orig = bio;
 	}
-	bio = bio_clone_bioset(*bio_orig, GFP_NOIO, passthrough ? NULL :
+	bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL :
 			&bounce_bio_set);
 
 	bio_for_each_segment_all(to, bio, i) {

block/bsg-lib.c

@@ -48,9 +48,8 @@ static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
 
 	job->request_len = hdr->request_len;
 	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
-	if (IS_ERR(job->request))
-		return PTR_ERR(job->request);
-	return 0;
+
+	return PTR_ERR_OR_ZERO(job->request);
 }
 
 static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)

block/bsg.c

@@ -13,11 +13,9 @@
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/blkdev.h>
-#include <linux/poll.h>
 #include <linux/cdev.h>
 #include <linux/jiffies.h>
 #include <linux/percpu.h>
-#include <linux/uio.h>
 #include <linux/idr.h>
 #include <linux/bsg.h>
 #include <linux/slab.h>
@@ -38,21 +36,10 @@
 struct bsg_device {
 	struct request_queue *queue;
 	spinlock_t lock;
-	struct list_head busy_list;
-	struct list_head done_list;
 	struct hlist_node dev_list;
 	atomic_t ref_count;
-	int queued_cmds;
-	int done_cmds;
-	wait_queue_head_t wq_done;
-	wait_queue_head_t wq_free;
 	char name[20];
 	int max_queue;
-	unsigned long flags;
-};
-
-enum {
-	BSG_F_BLOCK		= 1,
 };
 
 #define BSG_DEFAULT_CMDS	64
@@ -67,64 +54,6 @@ static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
 static struct class *bsg_class;
 static int bsg_major;
 
-static struct kmem_cache *bsg_cmd_cachep;
-
-/*
- * our internal command type
- */
-struct bsg_command {
-	struct bsg_device *bd;
-	struct list_head list;
-	struct request *rq;
-	struct bio *bio;
-	struct bio *bidi_bio;
-	int err;
-	struct sg_io_v4 hdr;
-};
-
-static void bsg_free_command(struct bsg_command *bc)
-{
-	struct bsg_device *bd = bc->bd;
-	unsigned long flags;
-
-	kmem_cache_free(bsg_cmd_cachep, bc);
-
-	spin_lock_irqsave(&bd->lock, flags);
-	bd->queued_cmds--;
-	spin_unlock_irqrestore(&bd->lock, flags);
-
-	wake_up(&bd->wq_free);
-}
-
-static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
-{
-	struct bsg_command *bc = ERR_PTR(-EINVAL);
-
-	spin_lock_irq(&bd->lock);
-
-	if (bd->queued_cmds >= bd->max_queue)
-		goto out;
-
-	bd->queued_cmds++;
-	spin_unlock_irq(&bd->lock);
-
-	bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
-	if (unlikely(!bc)) {
-		spin_lock_irq(&bd->lock);
-		bd->queued_cmds--;
-		bc = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
-	bc->bd = bd;
-	INIT_LIST_HEAD(&bc->list);
-	bsg_dbg(bd, "returning free cmd %p\n", bc);
-	return bc;
-out:
-	spin_unlock_irq(&bd->lock);
-	return bc;
-}
-
 static inline struct hlist_head *bsg_dev_idx_hash(int index)
 {
 	return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
@@ -285,101 +214,6 @@ out:
 	return ERR_PTR(ret);
 }
 
-/*
- * async completion call-back from the block layer, when scsi/ide/whatever
- * calls end_that_request_last() on a request
- */
-static void bsg_rq_end_io(struct request *rq, blk_status_t status)
-{
-	struct bsg_command *bc = rq->end_io_data;
-	struct bsg_device *bd = bc->bd;
-	unsigned long flags;
-
-	bsg_dbg(bd, "finished rq %p bc %p, bio %p\n",
-		rq, bc, bc->bio);
-
-	bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
-
-	spin_lock_irqsave(&bd->lock, flags);
-	list_move_tail(&bc->list, &bd->done_list);
-	bd->done_cmds++;
-	spin_unlock_irqrestore(&bd->lock, flags);
-
-	wake_up(&bd->wq_done);
-}
-
-/*
- * do final setup of a 'bc' and submit the matching 'rq' to the block
- * layer for io
- */
-static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
-			    struct bsg_command *bc, struct request *rq)
-{
-	int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
-
-	/*
-	 * add bc command to busy queue and submit rq for io
-	 */
-	bc->rq = rq;
-	bc->bio = rq->bio;
-	if (rq->next_rq)
-		bc->bidi_bio = rq->next_rq->bio;
-	bc->hdr.duration = jiffies;
-	spin_lock_irq(&bd->lock);
-	list_add_tail(&bc->list, &bd->busy_list);
-	spin_unlock_irq(&bd->lock);
-
-	bsg_dbg(bd, "queueing rq %p, bc %p\n", rq, bc);
-
-	rq->end_io_data = bc;
-	blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
-}
-
-static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
-{
-	struct bsg_command *bc = NULL;
-
-	spin_lock_irq(&bd->lock);
-	if (bd->done_cmds) {
-		bc = list_first_entry(&bd->done_list, struct bsg_command, list);
-		list_del(&bc->list);
-		bd->done_cmds--;
-	}
-	spin_unlock_irq(&bd->lock);
-
-	return bc;
-}
-
-/*
- * Get a finished command from the done list
- */
-static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
-{
-	struct bsg_command *bc;
-	int ret;
-
-	do {
-		bc = bsg_next_done_cmd(bd);
-		if (bc)
-			break;
-
-		if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
-			bc = ERR_PTR(-EAGAIN);
-			break;
-		}
-
-		ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
-		if (ret) {
-			bc = ERR_PTR(-ERESTARTSYS);
-			break;
-		}
-	} while (1);
-
-	bsg_dbg(bd, "returning done %p\n", bc);
-
-	return bc;
-}
-
 static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 				    struct bio *bio, struct bio *bidi_bio)
 {
@@ -398,234 +232,6 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	return ret;
 }
 
-static bool bsg_complete(struct bsg_device *bd)
-{
-	bool ret = false;
-	bool spin;
-
-	do {
-		spin_lock_irq(&bd->lock);
-
-		BUG_ON(bd->done_cmds > bd->queued_cmds);
-
-		/*
-		 * All commands consumed.
-		 */
-		if (bd->done_cmds == bd->queued_cmds)
-			ret = true;
-
-		spin = !test_bit(BSG_F_BLOCK, &bd->flags);
-
-		spin_unlock_irq(&bd->lock);
-	} while (!ret && spin);
-
-	return ret;
-}
-
-static int bsg_complete_all_commands(struct bsg_device *bd)
-{
-	struct bsg_command *bc;
-	int ret, tret;
-
-	bsg_dbg(bd, "entered\n");
-
-	/*
-	 * wait for all commands to complete
-	 */
-	io_wait_event(bd->wq_done, bsg_complete(bd));
-
-	/*
-	 * discard done commands
-	 */
-	ret = 0;
-	do {
-		spin_lock_irq(&bd->lock);
-		if (!bd->queued_cmds) {
-			spin_unlock_irq(&bd->lock);
-			break;
-		}
-		spin_unlock_irq(&bd->lock);
-
-		bc = bsg_get_done_cmd(bd);
-		if (IS_ERR(bc))
-			break;
-
-		tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
-						bc->bidi_bio);
-		if (!ret)
-			ret = tret;
-
-		bsg_free_command(bc);
-	} while (1);
-
-	return ret;
-}
-
-static int
-__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
-	   const struct iovec *iov, ssize_t *bytes_read)
-{
-	struct bsg_command *bc;
-	int nr_commands, ret;
-
-	if (count % sizeof(struct sg_io_v4))
-		return -EINVAL;
-
-	ret = 0;
-	nr_commands = count / sizeof(struct sg_io_v4);
-	while (nr_commands) {
-		bc = bsg_get_done_cmd(bd);
-		if (IS_ERR(bc)) {
-			ret = PTR_ERR(bc);
-			break;
-		}
-
-		/*
-		 * this is the only case where we need to copy data back
-		 * after completing the request. so do that here,
-		 * bsg_complete_work() cannot do that for us
-		 */
-		ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
-					       bc->bidi_bio);
-
-		if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
-			ret = -EFAULT;
-
-		bsg_free_command(bc);
-
-		if (ret)
-			break;
-
-		buf += sizeof(struct sg_io_v4);
-		*bytes_read += sizeof(struct sg_io_v4);
-		nr_commands--;
-	}
-
-	return ret;
-}
-
-static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
-{
-	if (file->f_flags & O_NONBLOCK)
-		clear_bit(BSG_F_BLOCK, &bd->flags);
-	else
-		set_bit(BSG_F_BLOCK, &bd->flags);
-}
-
-/*
- * Check if the error is a "real" error that we should return.
- */
-static inline int err_block_err(int ret)
-{
-	if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
-		return 1;
-
-	return 0;
-}
-
-static ssize_t
-bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
-	struct bsg_device *bd = file->private_data;
-	int ret;
-	ssize_t bytes_read;
-
-	bsg_dbg(bd, "read %zd bytes\n", count);
-
-	bsg_set_block(bd, file);
-
-	bytes_read = 0;
-	ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
-	*ppos = bytes_read;
-
-	if (!bytes_read || err_block_err(ret))
-		bytes_read = ret;
-
-	return bytes_read;
-}
-
-static int __bsg_write(struct bsg_device *bd, const char __user *buf,
-		       size_t count, ssize_t *bytes_written, fmode_t mode)
-{
-	struct bsg_command *bc;
-	struct request *rq;
-	int ret, nr_commands;
-
-	if (count % sizeof(struct sg_io_v4))
-		return -EINVAL;
-
-	nr_commands = count / sizeof(struct sg_io_v4);
-	rq = NULL;
-	bc = NULL;
-	ret = 0;
-	while (nr_commands) {
-		struct request_queue *q = bd->queue;
-
-		bc = bsg_alloc_command(bd);
-		if (IS_ERR(bc)) {
-			ret = PTR_ERR(bc);
-			bc = NULL;
-			break;
-		}
-
-		if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
-			ret = -EFAULT;
-			break;
-		}
-
-		/*
-		 * get a request, fill in the blanks, and add to request queue
-		 */
-		rq = bsg_map_hdr(bd->queue, &bc->hdr, mode);
-		if (IS_ERR(rq)) {
-			ret = PTR_ERR(rq);
-			rq = NULL;
-			break;
-		}
-
-		bsg_add_command(bd, q, bc, rq);
-		bc = NULL;
-		rq = NULL;
-		nr_commands--;
-		buf += sizeof(struct sg_io_v4);
-		*bytes_written += sizeof(struct sg_io_v4);
-	}
-
-	if (bc)
-		bsg_free_command(bc);
-
-	return ret;
-}
-
-static ssize_t
-bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
-{
-	struct bsg_device *bd = file->private_data;
-	ssize_t bytes_written;
-	int ret;
-
-	bsg_dbg(bd, "write %zd bytes\n", count);
-
-	if (unlikely(uaccess_kernel()))
-		return -EINVAL;
-
-	bsg_set_block(bd, file);
-
-	bytes_written = 0;
-	ret = __bsg_write(bd, buf, count, &bytes_written, file->f_mode);
-
-	*ppos = bytes_written;
-
-	/*
-	 * return bytes written on non-fatal errors
-	 */
-	if (!bytes_written || err_block_err(ret))
-		bytes_written = ret;
-
-	bsg_dbg(bd, "returning %zd\n", bytes_written);
-	return bytes_written;
-}
-
 static struct bsg_device *bsg_alloc_device(void)
 {
 	struct bsg_device *bd;
@@ -635,29 +241,20 @@ static struct bsg_device *bsg_alloc_device(void)
 		return NULL;
 
 	spin_lock_init(&bd->lock);
-
 	bd->max_queue = BSG_DEFAULT_CMDS;
-
-	INIT_LIST_HEAD(&bd->busy_list);
-	INIT_LIST_HEAD(&bd->done_list);
 	INIT_HLIST_NODE(&bd->dev_list);
-
-	init_waitqueue_head(&bd->wq_free);
-	init_waitqueue_head(&bd->wq_done);
 	return bd;
 }
 
 static int bsg_put_device(struct bsg_device *bd)
 {
-	int ret = 0, do_free;
 	struct request_queue *q = bd->queue;
 
 	mutex_lock(&bsg_mutex);
 
-	do_free = atomic_dec_and_test(&bd->ref_count);
-	if (!do_free) {
+	if (!atomic_dec_and_test(&bd->ref_count)) {
 		mutex_unlock(&bsg_mutex);
-		goto out;
+		return 0;
 	}
 
 	hlist_del(&bd->dev_list);
@@ -668,20 +265,9 @@ static int bsg_put_device(struct bsg_device *bd)
 	/*
 	 * close can always block
 	 */
-	set_bit(BSG_F_BLOCK, &bd->flags);
-
-	/*
-	 * correct error detection baddies here again. it's the responsibility
-	 * of the app to properly reap commands before close() if it wants
-	 * fool-proof error detection
-	 */
-	ret = bsg_complete_all_commands(bd);
-
 	kfree(bd);
-out:
-	if (do_free)
-		blk_put_queue(q);
-	return ret;
+	blk_put_queue(q);
+	return 0;
 }
 
 static struct bsg_device *bsg_add_device(struct inode *inode,
@@ -704,8 +290,6 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
 
 	bd->queue = rq;
 
-	bsg_set_block(bd, file);
-
 	atomic_set(&bd->ref_count, 1);
 	hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
 
@@ -779,24 +363,6 @@ static int bsg_release(struct inode *inode, struct file *file)
 	return bsg_put_device(bd);
 }
 
-static __poll_t bsg_poll(struct file *file, poll_table *wait)
-{
-	struct bsg_device *bd = file->private_data;
-	__poll_t mask = 0;
-
-	poll_wait(file, &bd->wq_done, wait);
-	poll_wait(file, &bd->wq_free, wait);
-
-	spin_lock_irq(&bd->lock);
-	if (!list_empty(&bd->done_list))
-		mask |= EPOLLIN | EPOLLRDNORM;
-	if (bd->queued_cmds < bd->max_queue)
-		mask |= EPOLLOUT;
-	spin_unlock_irq(&bd->lock);
-
-	return mask;
-}
-
 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct bsg_device *bd = file->private_data;
@@ -870,9 +436,6 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 }
 
 static const struct file_operations bsg_fops = {
-	.read		=	bsg_read,
-	.write		=	bsg_write,
-	.poll		=	bsg_poll,
 	.open		=	bsg_open,
 	.release	=	bsg_release,
 	.unlocked_ioctl	=	bsg_ioctl,
@@ -977,21 +540,12 @@ static int __init bsg_init(void)
 	int ret, i;
 	dev_t devid;
 
-	bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
-				sizeof(struct bsg_command), 0, 0, NULL);
-	if (!bsg_cmd_cachep) {
-		printk(KERN_ERR "bsg: failed creating slab cache\n");
-		return -ENOMEM;
-	}
-
 	for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
 		INIT_HLIST_HEAD(&bsg_device_list[i]);
 
 	bsg_class = class_create(THIS_MODULE, "bsg");
-	if (IS_ERR(bsg_class)) {
-		ret = PTR_ERR(bsg_class);
-		goto destroy_kmemcache;
-	}
+	if (IS_ERR(bsg_class))
+		return PTR_ERR(bsg_class);
 	bsg_class->devnode = bsg_devnode;
 
 	ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
@@ -1012,8 +566,6 @@ unregister_chrdev:
 	unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
 destroy_bsg_class:
 	class_destroy(bsg_class);
-destroy_kmemcache:
-	kmem_cache_destroy(bsg_cmd_cachep);
 	return ret;
 }
 

block/cfq-iosched.c

@@ -3666,6 +3666,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic)
 	switch (ioprio_class) {
 	default:
 		printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
+		/* fall through */
 	case IOPRIO_CLASS_NONE:
 		/*
 		 * no prio set, inherit CPU scheduling settings
@@ -4735,12 +4736,13 @@ USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency);
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct cfq_data *cfqd = e->elevator_data;			\
-	unsigned int __data;						\
+	unsigned int __data, __min = (MIN), __max = (MAX);		\
+									\
 	cfq_var_store(&__data, (page));					\
-	if (__data < (MIN))						\
-		__data = (MIN);						\
-	else if (__data > (MAX))					\
-		__data = (MAX);						\
+	if (__data < __min)						\
+		__data = __min;						\
+	else if (__data > __max)					\
+		__data = __max;						\
 	if (__CONV)							\
 		*(__PTR) = (u64)__data * NSEC_PER_MSEC;			\
 	else								\
@@ -4769,12 +4771,13 @@ STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX,
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct cfq_data *cfqd = e->elevator_data;			\
-	unsigned int __data;						\
+	unsigned int __data, __min = (MIN), __max = (MAX);		\
+									\
 	cfq_var_store(&__data, (page));					\
-	if (__data < (MIN))						\
-		__data = (MIN);						\
-	else if (__data > (MAX))					\
-		__data = (MAX);						\
+	if (__data < __min)						\
+		__data = __min;						\
+	else if (__data > __max)					\
+		__data = __max;						\
 	*(__PTR) = (u64)__data * NSEC_PER_USEC;				\
 	return count;							\
 }

block/genhd.c

@@ -1333,21 +1333,28 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 		part_round_stats(gp->queue, cpu, hd);
 		part_stat_unlock();
 		part_in_flight(gp->queue, hd, inflight);
-		seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
-			   "%u %lu %lu %lu %u %u %u %u\n",
+		seq_printf(seqf, "%4d %7d %s "
+			   "%lu %lu %lu %u "
+			   "%lu %lu %lu %u "
+			   "%u %u %u "
+			   "%lu %lu %lu %u\n",
 			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
 			   disk_name(gp, hd->partno, buf),
-			   part_stat_read(hd, ios[READ]),
-			   part_stat_read(hd, merges[READ]),
-			   part_stat_read(hd, sectors[READ]),
-			   jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
-			   part_stat_read(hd, ios[WRITE]),
-			   part_stat_read(hd, merges[WRITE]),
-			   part_stat_read(hd, sectors[WRITE]),
-			   jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
+			   part_stat_read(hd, ios[STAT_READ]),
+			   part_stat_read(hd, merges[STAT_READ]),
+			   part_stat_read(hd, sectors[STAT_READ]),
+			   jiffies_to_msecs(part_stat_read(hd, ticks[STAT_READ])),
+			   part_stat_read(hd, ios[STAT_WRITE]),
+			   part_stat_read(hd, merges[STAT_WRITE]),
+			   part_stat_read(hd, sectors[STAT_WRITE]),
+			   jiffies_to_msecs(part_stat_read(hd, ticks[STAT_WRITE])),
 			   inflight[0],
 			   jiffies_to_msecs(part_stat_read(hd, io_ticks)),
-			   jiffies_to_msecs(part_stat_read(hd, time_in_queue))
+			   jiffies_to_msecs(part_stat_read(hd, time_in_queue)),
+			   part_stat_read(hd, ios[STAT_DISCARD]),
+			   part_stat_read(hd, merges[STAT_DISCARD]),
+			   part_stat_read(hd, sectors[STAT_DISCARD]),
+			   jiffies_to_msecs(part_stat_read(hd, ticks[STAT_DISCARD]))
 			);
 	}
 	disk_part_iter_exit(&piter);

block/partition-generic.c

@@ -130,19 +130,24 @@ ssize_t part_stat_show(struct device *dev,
 	return sprintf(buf,
 		"%8lu %8lu %8llu %8u "
 		"%8lu %8lu %8llu %8u "
-		"%8u %8u %8u"
+		"%8u %8u %8u "
+		"%8lu %8lu %8llu %8u"
 		"\n",
-		part_stat_read(p, ios[READ]),
-		part_stat_read(p, merges[READ]),
-		(unsigned long long)part_stat_read(p, sectors[READ]),
-		jiffies_to_msecs(part_stat_read(p, ticks[READ])),
-		part_stat_read(p, ios[WRITE]),
-		part_stat_read(p, merges[WRITE]),
-		(unsigned long long)part_stat_read(p, sectors[WRITE]),
-		jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
+		part_stat_read(p, ios[STAT_READ]),
+		part_stat_read(p, merges[STAT_READ]),
+		(unsigned long long)part_stat_read(p, sectors[STAT_READ]),
+		jiffies_to_msecs(part_stat_read(p, ticks[STAT_READ])),
+		part_stat_read(p, ios[STAT_WRITE]),
+		part_stat_read(p, merges[STAT_WRITE]),
+		(unsigned long long)part_stat_read(p, sectors[STAT_WRITE]),
+		jiffies_to_msecs(part_stat_read(p, ticks[STAT_WRITE])),
 		inflight[0],
 		jiffies_to_msecs(part_stat_read(p, io_ticks)),
-		jiffies_to_msecs(part_stat_read(p, time_in_queue)));
+		jiffies_to_msecs(part_stat_read(p, time_in_queue)),
+		part_stat_read(p, ios[STAT_DISCARD]),
+		part_stat_read(p, merges[STAT_DISCARD]),
+		(unsigned long long)part_stat_read(p, sectors[STAT_DISCARD]),
+		jiffies_to_msecs(part_stat_read(p, ticks[STAT_DISCARD])));
 }
 
 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,

block/partitions/aix.c

@@ -178,7 +178,7 @@ int aix_partition(struct parsed_partitions *state)
 	u32 vgda_sector = 0;
 	u32 vgda_len = 0;
 	int numlvs = 0;
-	struct pvd *pvd;
+	struct pvd *pvd = NULL;
 	struct lv_info {
 		unsigned short pps_per_lv;
 		unsigned short pps_found;
@@ -232,10 +232,11 @@ int aix_partition(struct parsed_partitions *state)
 				if (lvip[i].pps_per_lv)
 					foundlvs += 1;
 			}
+			/* pvd loops depend on n[].name and lvip[].pps_per_lv */
+			pvd = alloc_pvd(state, vgda_sector + 17);
 		}
 		put_dev_sector(sect);
 	}
-	pvd = alloc_pvd(state, vgda_sector + 17);
 	if (pvd) {
 		int numpps = be16_to_cpu(pvd->pp_count);
 		int psn_part1 = be32_to_cpu(pvd->psn_part1);
@@ -282,10 +283,14 @@ int aix_partition(struct parsed_partitions *state)
 				next_lp_ix += 1;
 		}
 		for (i = 0; i < state->limit; i += 1)
-			if (lvip[i].pps_found && !lvip[i].lv_is_contiguous)
+			if (lvip[i].pps_found && !lvip[i].lv_is_contiguous) {
+				char tmp[sizeof(n[i].name) + 1]; // null char
+
+				snprintf(tmp, sizeof(tmp), "%s", n[i].name);
 				pr_warn("partition %s (%u pp's found) is "
 					"not contiguous\n",
-					n[i].name, lvip[i].pps_found);
+					tmp, lvip[i].pps_found);
+			}
 		kfree(pvd);
 	}
 	kfree(n);

block/partitions/ldm.c

@@ -830,7 +830,6 @@ static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
 {
 	char buf[64];
 	int r_objid, r_name, r_id1, r_id2, len;
-	struct vblk_dgrp *dgrp;
 
 	BUG_ON (!buffer || !vb);
 
@@ -853,8 +852,6 @@ static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
 	if (len != get_unaligned_be32(buffer + 0x14))
 		return false;
 
-	dgrp = &vb->vblk.dgrp;
-
 	ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
 	return true;
 }

block/t10-pi.c

@@ -184,3 +184,113 @@ const struct blk_integrity_profile t10_pi_type3_ip = {
 	.verify_fn		= t10_pi_type3_verify_ip,
 };
 EXPORT_SYMBOL(t10_pi_type3_ip);
+
+/**
+ * t10_pi_prepare - prepare PI prior submitting request to device
+ * @rq:              request with PI that should be prepared
+ * @protection_type: PI type (Type 1/Type 2/Type 3)
+ *
+ * For Type 1/Type 2, the virtual start sector is the one that was
+ * originally submitted by the block layer for the ref_tag usage. Due to
+ * partitioning, MD/DM cloning, etc. the actual physical start sector is
+ * likely to be different. Remap protection information to match the
+ * physical LBA.
+ *
+ * Type 3 does not have a reference tag so no remapping is required.
+ */
+void t10_pi_prepare(struct request *rq, u8 protection_type)
+{
+	const int tuple_sz = rq->q->integrity.tuple_size;
+	u32 ref_tag = t10_pi_ref_tag(rq);
+	struct bio *bio;
+
+	if (protection_type == T10_PI_TYPE3_PROTECTION)
+		return;
+
+	__rq_for_each_bio(bio, rq) {
+		struct bio_integrity_payload *bip = bio_integrity(bio);
+		u32 virt = bip_get_seed(bip) & 0xffffffff;
+		struct bio_vec iv;
+		struct bvec_iter iter;
+
+		/* Already remapped? */
+		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
+			break;
+
+		bip_for_each_vec(iv, bip, iter) {
+			void *p, *pmap;
+			unsigned int j;
+
+			pmap = kmap_atomic(iv.bv_page);
+			p = pmap + iv.bv_offset;
+			for (j = 0; j < iv.bv_len; j += tuple_sz) {
+				struct t10_pi_tuple *pi = p;
+
+				if (be32_to_cpu(pi->ref_tag) == virt)
+					pi->ref_tag = cpu_to_be32(ref_tag);
+				virt++;
+				ref_tag++;
+				p += tuple_sz;
+			}
+
+			kunmap_atomic(pmap);
+		}
+
+		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
+	}
+}
+EXPORT_SYMBOL(t10_pi_prepare);
+
+/**
+ * t10_pi_complete - prepare PI prior returning request to the block layer
+ * @rq:              request with PI that should be prepared
+ * @protection_type: PI type (Type 1/Type 2/Type 3)
+ * @intervals:       total elements to prepare
+ *
+ * For Type 1/Type 2, the virtual start sector is the one that was
+ * originally submitted by the block layer for the ref_tag usage. Due to
+ * partitioning, MD/DM cloning, etc. the actual physical start sector is
+ * likely to be different. Since the physical start sector was submitted
+ * to the device, we should remap it back to virtual values expected by the
+ * block layer.
+ *
+ * Type 3 does not have a reference tag so no remapping is required.
+ */
+void t10_pi_complete(struct request *rq, u8 protection_type,
+		     unsigned int intervals)
+{
+	const int tuple_sz = rq->q->integrity.tuple_size;
+	u32 ref_tag = t10_pi_ref_tag(rq);
+	struct bio *bio;
+
+	if (protection_type == T10_PI_TYPE3_PROTECTION)
+		return;
+
+	__rq_for_each_bio(bio, rq) {
+		struct bio_integrity_payload *bip = bio_integrity(bio);
+		u32 virt = bip_get_seed(bip) & 0xffffffff;
+		struct bio_vec iv;
+		struct bvec_iter iter;
+
+		bip_for_each_vec(iv, bip, iter) {
+			void *p, *pmap;
+			unsigned int j;
+
+			pmap = kmap_atomic(iv.bv_page);
+			p = pmap + iv.bv_offset;
+			for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
+				struct t10_pi_tuple *pi = p;
+
+				if (be32_to_cpu(pi->ref_tag) == ref_tag)
+					pi->ref_tag = cpu_to_be32(virt);
+				virt++;
+				ref_tag++;
+				intervals--;
+				p += tuple_sz;
+			}
+
+			kunmap_atomic(pmap);
+		}
+	}
+}
+EXPORT_SYMBOL(t10_pi_complete);

drivers/Makefile

@@ -76,7 +76,7 @@ obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
 obj-$(CONFIG_NUBUS)		+= nubus/
 obj-y				+= macintosh/
 obj-$(CONFIG_IDE)		+= ide/
-obj-$(CONFIG_SCSI)		+= scsi/
+obj-y				+= scsi/
 obj-y				+= nvme/
 obj-$(CONFIG_ATA)		+= ata/
 obj-$(CONFIG_TARGET_CORE)	+= target/

drivers/ata/libata-scsi.c

@@ -597,8 +597,9 @@ static int ata_get_identity(struct ata_port *ap, struct scsi_device *sdev,
 int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 {
 	int rc = 0;
+	u8 sensebuf[SCSI_SENSE_BUFFERSIZE];
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
-	u8 args[4], *argbuf = NULL, *sensebuf = NULL;
+	u8 args[4], *argbuf = NULL;
 	int argsize = 0;
 	enum dma_data_direction data_dir;
 	struct scsi_sense_hdr sshdr;
@@ -610,10 +611,7 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 	if (copy_from_user(args, arg, sizeof(args)))
 		return -EFAULT;
 
-	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
-	if (!sensebuf)
-		return -ENOMEM;
-
+	memset(sensebuf, 0, sizeof(sensebuf));
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 
 	if (args[3]) {
@@ -685,7 +683,6 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 	 && copy_to_user(arg + sizeof(args), argbuf, argsize))
 		rc = -EFAULT;
 error:
-	kfree(sensebuf);
 	kfree(argbuf);
 	return rc;
 }
@@ -704,8 +701,9 @@ error:
 int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 {
 	int rc = 0;
+	u8 sensebuf[SCSI_SENSE_BUFFERSIZE];
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
-	u8 args[7], *sensebuf = NULL;
+	u8 args[7];
 	struct scsi_sense_hdr sshdr;
 	int cmd_result;
 
@@ -715,10 +713,7 @@ int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 	if (copy_from_user(args, arg, sizeof(args)))
 		return -EFAULT;
 
-	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
-	if (!sensebuf)
-		return -ENOMEM;
-
+	memset(sensebuf, 0, sizeof(sensebuf));
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 	scsi_cmd[0]  = ATA_16;
 	scsi_cmd[1]  = (3 << 1); /* Non-data */
@@ -769,7 +764,6 @@ int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 	}
 
  error:
-	kfree(sensebuf);
 	return rc;
 }
 

drivers/block/DAC960.c

@@ -21,6 +21,7 @@
 #define DAC960_DriverDate			"21 Aug 2007"
 
 
+#include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/miscdevice.h>
@@ -6426,7 +6427,7 @@ static bool DAC960_V2_ExecuteUserCommand(DAC960_Controller_T *Controller,
   return true;
 }
 
-static int dac960_proc_show(struct seq_file *m, void *v)
+static int __maybe_unused dac960_proc_show(struct seq_file *m, void *v)
 {
   unsigned char *StatusMessage = "OK\n";
   int ControllerNumber;
@@ -6446,14 +6447,16 @@ static int dac960_proc_show(struct seq_file *m, void *v)
   return 0;
 }
 
-static int dac960_initial_status_proc_show(struct seq_file *m, void *v)
+static int __maybe_unused dac960_initial_status_proc_show(struct seq_file *m,
+							  void *v)
 {
 	DAC960_Controller_T *Controller = (DAC960_Controller_T *)m->private;
 	seq_printf(m, "%.*s", Controller->InitialStatusLength, Controller->CombinedStatusBuffer);
 	return 0;
 }
 
-static int dac960_current_status_proc_show(struct seq_file *m, void *v)
+static int __maybe_unused dac960_current_status_proc_show(struct seq_file *m,
+							  void *v)
 {
   DAC960_Controller_T *Controller = (DAC960_Controller_T *) m->private;
   unsigned char *StatusMessage =

drivers/block/Kconfig

@@ -74,12 +74,12 @@ config AMIGA_Z2RAM
 
 config CDROM
 	tristate
+	select BLK_SCSI_REQUEST
 
 config GDROM
 	tristate "SEGA Dreamcast GD-ROM drive"
 	depends on SH_DREAMCAST
 	select CDROM
-	select BLK_SCSI_REQUEST # only for the generic cdrom code
 	help
 	  A standard SEGA Dreamcast comes with a modified CD ROM drive called a
 	  "GD-ROM" by SEGA to signify it is capable of reading special disks

drivers/block/Makefile

@@ -36,8 +36,11 @@ obj-$(CONFIG_BLK_DEV_RBD)     += rbd.o
 obj-$(CONFIG_BLK_DEV_PCIESSD_MTIP32XX)	+= mtip32xx/
 
 obj-$(CONFIG_BLK_DEV_RSXX) += rsxx/
-obj-$(CONFIG_BLK_DEV_NULL_BLK)	+= null_blk.o
 obj-$(CONFIG_ZRAM) += zram/
 
+obj-$(CONFIG_BLK_DEV_NULL_BLK)	+= null_blk.o
+null_blk-objs	:= null_blk_main.o
+null_blk-$(CONFIG_BLK_DEV_ZONED) += null_blk_zoned.o
+
 skd-y		:= skd_main.o
 swim_mod-y	:= swim.o swim_asm.o

drivers/block/aoe/aoecmd.c

@@ -1137,6 +1137,7 @@ noskb:		if (buf)
 			break;
 		}
 		bvcpy(skb, f->buf->bio, f->iter, n);
+		/* fall through */
 	case ATA_CMD_PIO_WRITE:
 	case ATA_CMD_PIO_WRITE_EXT:
 		spin_lock_irq(&d->lock);

drivers/block/aoe/aoedev.c

@@ -284,8 +284,8 @@ freedev(struct aoedev *d)
 	e = t + d->ntargets;
 	for (; t < e && *t; t++)
 		freetgt(d, *t);
-	if (d->bufpool)
-		mempool_destroy(d->bufpool);
+
+	mempool_destroy(d->bufpool);
 	skbpoolfree(d);
 	minor_free(d->sysminor);
 

drivers/block/brd.c

@@ -254,20 +254,20 @@ static void copy_from_brd(void *dst, struct brd_device *brd,
  * Process a single bvec of a bio.
  */
 static int brd_do_bvec(struct brd_device *brd, struct page *page,
-			unsigned int len, unsigned int off, bool is_write,
+			unsigned int len, unsigned int off, unsigned int op,
 			sector_t sector)
 {
 	void *mem;
 	int err = 0;
 
-	if (is_write) {
+	if (op_is_write(op)) {
 		err = copy_to_brd_setup(brd, sector, len);
 		if (err)
 			goto out;
 	}
 
 	mem = kmap_atomic(page);
-	if (!is_write) {
+	if (!op_is_write(op)) {
 		copy_from_brd(mem + off, brd, sector, len);
 		flush_dcache_page(page);
 	} else {
@@ -296,7 +296,7 @@ static blk_qc_t brd_make_request(struct request_queue *q, struct bio *bio)
 		int err;
 
 		err = brd_do_bvec(brd, bvec.bv_page, len, bvec.bv_offset,
-					op_is_write(bio_op(bio)), sector);
+				  bio_op(bio), sector);
 		if (err)
 			goto io_error;
 		sector += len >> SECTOR_SHIFT;
@@ -310,15 +310,15 @@ io_error:
 }
 
 static int brd_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, bool is_write)
+		       struct page *page, unsigned int op)
 {
 	struct brd_device *brd = bdev->bd_disk->private_data;
 	int err;
 
 	if (PageTransHuge(page))
 		return -ENOTSUPP;
-	err = brd_do_bvec(brd, page, PAGE_SIZE, 0, is_write, sector);
-	page_endio(page, is_write, err);
+	err = brd_do_bvec(brd, page, PAGE_SIZE, 0, op, sector);
+	page_endio(page, op_is_write(op), err);
 	return err;
 }
 

drivers/block/drbd/drbd_int.h

@@ -55,12 +55,10 @@
 # define __protected_by(x)       __attribute__((require_context(x,1,999,"rdwr")))
 # define __protected_read_by(x)  __attribute__((require_context(x,1,999,"read")))
 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write")))
-# define __must_hold(x)       __attribute__((context(x,1,1), require_context(x,1,999,"call")))
 #else
 # define __protected_by(x)
 # define __protected_read_by(x)
 # define __protected_write_by(x)
-# define __must_hold(x)
 #endif
 
 /* shared module parameters, defined in drbd_main.c */

drivers/block/drbd/drbd_main.c

@@ -2103,14 +2103,10 @@ static void drbd_destroy_mempools(void)
 	mempool_exit(&drbd_md_io_page_pool);
 	mempool_exit(&drbd_ee_mempool);
 	mempool_exit(&drbd_request_mempool);
-	if (drbd_ee_cache)
-		kmem_cache_destroy(drbd_ee_cache);
-	if (drbd_request_cache)
-		kmem_cache_destroy(drbd_request_cache);
-	if (drbd_bm_ext_cache)
-		kmem_cache_destroy(drbd_bm_ext_cache);
-	if (drbd_al_ext_cache)
-		kmem_cache_destroy(drbd_al_ext_cache);
+	kmem_cache_destroy(drbd_ee_cache);
+	kmem_cache_destroy(drbd_request_cache);
+	kmem_cache_destroy(drbd_bm_ext_cache);
+	kmem_cache_destroy(drbd_al_ext_cache);
 
 	drbd_ee_cache        = NULL;
 	drbd_request_cache   = NULL;

drivers/block/drbd/drbd_receiver.c

@@ -2674,8 +2674,7 @@ bool drbd_rs_c_min_rate_throttle(struct drbd_device *device)
 	if (c_min_rate == 0)
 		return false;
 
-	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
-		      (int)part_stat_read(&disk->part0, sectors[1]) -
+	curr_events = (int)part_stat_read_accum(&disk->part0, sectors) -
 			atomic_read(&device->rs_sect_ev);
 
 	if (atomic_read(&device->ap_actlog_cnt)
@@ -2790,6 +2789,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
 		   then we would do something smarter here than reading
 		   the block... */
 		peer_req->flags |= EE_RS_THIN_REQ;
+		/* fall through */
 	case P_RS_DATA_REQUEST:
 		peer_req->w.cb = w_e_end_rsdata_req;
 		fault_type = DRBD_FAULT_RS_RD;
@@ -2968,6 +2968,7 @@ static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold
 		/* Else fall through to one of the other strategies... */
 		drbd_warn(device, "Discard younger/older primary did not find a decision\n"
 		     "Using discard-least-changes instead\n");
+		/* fall through */
 	case ASB_DISCARD_ZERO_CHG:
 		if (ch_peer == 0 && ch_self == 0) {
 			rv = test_bit(RESOLVE_CONFLICTS, &peer_device->connection->flags)
@@ -2979,6 +2980,7 @@ static int drbd_asb_recover_0p(struct drbd_peer_device *peer_device) __must_hold
 		}
 		if (after_sb_0p == ASB_DISCARD_ZERO_CHG)
 			break;
+		/* else: fall through */
 	case ASB_DISCARD_LEAST_CHG:
 		if	(ch_self < ch_peer)
 			rv = -1;

drivers/block/drbd/drbd_req.c

@@ -38,7 +38,7 @@ static void _drbd_start_io_acct(struct drbd_device *device, struct drbd_request
 {
 	struct request_queue *q = device->rq_queue;
 
-	generic_start_io_acct(q, bio_data_dir(req->master_bio),
+	generic_start_io_acct(q, bio_op(req->master_bio),
 				req->i.size >> 9, &device->vdisk->part0);
 }
 
@@ -47,7 +47,7 @@ static void _drbd_end_io_acct(struct drbd_device *device, struct drbd_request *r
 {
 	struct request_queue *q = device->rq_queue;
 
-	generic_end_io_acct(q, bio_data_dir(req->master_bio),
+	generic_end_io_acct(q, bio_op(req->master_bio),
 			    &device->vdisk->part0, req->start_jif);
 }
 

drivers/block/drbd/drbd_worker.c

@@ -1690,9 +1690,7 @@ void drbd_rs_controller_reset(struct drbd_device *device)
 	atomic_set(&device->rs_sect_in, 0);
 	atomic_set(&device->rs_sect_ev, 0);
 	device->rs_in_flight = 0;
-	device->rs_last_events =
-		(int)part_stat_read(&disk->part0, sectors[0]) +
-		(int)part_stat_read(&disk->part0, sectors[1]);
+	device->rs_last_events = (int)part_stat_read_accum(&disk->part0, sectors);
 
 	/* Updating the RCU protected object in place is necessary since
 	   this function gets called from atomic context.

drivers/block/floppy.c

@@ -1461,7 +1461,6 @@ static void setup_rw_floppy(void)
 	int i;
 	int r;
 	int flags;
-	int dflags;
 	unsigned long ready_date;
 	void (*function)(void);
 
@@ -1485,8 +1484,6 @@ static void setup_rw_floppy(void)
 		if (fd_wait_for_completion(ready_date, function))
 			return;
 	}
-	dflags = DRS->flags;
-
 	if ((flags & FD_RAW_READ) || (flags & FD_RAW_WRITE))
 		setup_DMA();
 

drivers/block/loop.c

@@ -690,7 +690,6 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
 			  unsigned int arg)
 {
 	struct file	*file, *old_file;
-	struct inode	*inode;
 	int		error;
 
 	error = -ENXIO;
@@ -711,7 +710,6 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
 	if (error)
 		goto out_putf;
 
-	inode = file->f_mapping->host;
 	old_file = lo->lo_backing_file;
 
 	error = -EINVAL;
@@ -1611,6 +1609,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
 	case LOOP_GET_STATUS64:
 	case LOOP_SET_STATUS64:
 		arg = (unsigned long) compat_ptr(arg);
+		/* fall through */
 	case LOOP_SET_FD:
 	case LOOP_CHANGE_FD:
 	case LOOP_SET_BLOCK_SIZE:

drivers/block/mtip32xx/mtip32xx.c

@@ -2575,8 +2575,7 @@ static int mtip_hw_debugfs_init(struct driver_data *dd)
 
 static void mtip_hw_debugfs_exit(struct driver_data *dd)
 {
-	if (dd->dfs_node)
-		debugfs_remove_recursive(dd->dfs_node);
+	debugfs_remove_recursive(dd->dfs_node);
 }
 
 /*

drivers/block/null_blk.h

@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BLK_NULL_BLK_H
+#define __BLK_NULL_BLK_H
+
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/blk-mq.h>
+#include <linux/hrtimer.h>
+#include <linux/configfs.h>
+#include <linux/badblocks.h>
+#include <linux/fault-inject.h>
+
+struct nullb_cmd {
+	struct list_head list;
+	struct llist_node ll_list;
+	struct __call_single_data csd;
+	struct request *rq;
+	struct bio *bio;
+	unsigned int tag;
+	blk_status_t error;
+	struct nullb_queue *nq;
+	struct hrtimer timer;
+};
+
+struct nullb_queue {
+	unsigned long *tag_map;
+	wait_queue_head_t wait;
+	unsigned int queue_depth;
+	struct nullb_device *dev;
+	unsigned int requeue_selection;
+
+	struct nullb_cmd *cmds;
+};
+
+struct nullb_device {
+	struct nullb *nullb;
+	struct config_item item;
+	struct radix_tree_root data; /* data stored in the disk */
+	struct radix_tree_root cache; /* disk cache data */
+	unsigned long flags; /* device flags */
+	unsigned int curr_cache;
+	struct badblocks badblocks;
+
+	unsigned int nr_zones;
+	struct blk_zone *zones;
+	sector_t zone_size_sects;
+
+	unsigned long size; /* device size in MB */
+	unsigned long completion_nsec; /* time in ns to complete a request */
+	unsigned long cache_size; /* disk cache size in MB */
+	unsigned long zone_size; /* zone size in MB if device is zoned */
+	unsigned int submit_queues; /* number of submission queues */
+	unsigned int home_node; /* home node for the device */
+	unsigned int queue_mode; /* block interface */
+	unsigned int blocksize; /* block size */
+	unsigned int irqmode; /* IRQ completion handler */
+	unsigned int hw_queue_depth; /* queue depth */
+	unsigned int index; /* index of the disk, only valid with a disk */
+	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
+	bool blocking; /* blocking blk-mq device */
+	bool use_per_node_hctx; /* use per-node allocation for hardware context */
+	bool power; /* power on/off the device */
+	bool memory_backed; /* if data is stored in memory */
+	bool discard; /* if support discard */
+	bool zoned; /* if device is zoned */
+};
+
+struct nullb {
+	struct nullb_device *dev;
+	struct list_head list;
+	unsigned int index;
+	struct request_queue *q;
+	struct gendisk *disk;
+	struct blk_mq_tag_set *tag_set;
+	struct blk_mq_tag_set __tag_set;
+	unsigned int queue_depth;
+	atomic_long_t cur_bytes;
+	struct hrtimer bw_timer;
+	unsigned long cache_flush_pos;
+	spinlock_t lock;
+
+	struct nullb_queue *queues;
+	unsigned int nr_queues;
+	char disk_name[DISK_NAME_LEN];
+};
+
+#ifdef CONFIG_BLK_DEV_ZONED
+int null_zone_init(struct nullb_device *dev);
+void null_zone_exit(struct nullb_device *dev);
+blk_status_t null_zone_report(struct nullb *nullb,
+					    struct nullb_cmd *cmd);
+void null_zone_write(struct nullb_cmd *cmd);
+void null_zone_reset(struct nullb_cmd *cmd);
+#else
+static inline int null_zone_init(struct nullb_device *dev)
+{
+	return -EINVAL;
+}
+static inline void null_zone_exit(struct nullb_device *dev) {}
+static inline blk_status_t null_zone_report(struct nullb *nullb,
+					    struct nullb_cmd *cmd)
+{
+	return BLK_STS_NOTSUPP;
+}
+static inline void null_zone_write(struct nullb_cmd *cmd) {}
+static inline void null_zone_reset(struct nullb_cmd *cmd) {}
+#endif /* CONFIG_BLK_DEV_ZONED */
+#endif /* __NULL_BLK_H */

drivers/block/null_blk.c → drivers/block/null_blk_main.c

@@ -7,14 +7,8 @@
 #include <linux/moduleparam.h>
 #include <linux/sched.h>
 #include <linux/fs.h>
-#include <linux/blkdev.h>
 #include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/blk-mq.h>
-#include <linux/hrtimer.h>
-#include <linux/configfs.h>
-#include <linux/badblocks.h>
-#include <linux/fault-inject.h>
+#include "null_blk.h"
 
 #define PAGE_SECTORS_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define PAGE_SECTORS		(1 << PAGE_SECTORS_SHIFT)
@@ -35,28 +29,6 @@ static inline u64 mb_per_tick(int mbps)
 	return (1 << 20) / TICKS_PER_SEC * ((u64) mbps);
 }
 
-struct nullb_cmd {
-	struct list_head list;
-	struct llist_node ll_list;
-	struct __call_single_data csd;
-	struct request *rq;
-	struct bio *bio;
-	unsigned int tag;
-	blk_status_t error;
-	struct nullb_queue *nq;
-	struct hrtimer timer;
-};
-
-struct nullb_queue {
-	unsigned long *tag_map;
-	wait_queue_head_t wait;
-	unsigned int queue_depth;
-	struct nullb_device *dev;
-	unsigned int requeue_selection;
-
-	struct nullb_cmd *cmds;
-};
-
 /*
  * Status flags for nullb_device.
  *
@@ -92,52 +64,6 @@ struct nullb_page {
 #define NULLB_PAGE_LOCK (MAP_SZ - 1)
 #define NULLB_PAGE_FREE (MAP_SZ - 2)
 
-struct nullb_device {
-	struct nullb *nullb;
-	struct config_item item;
-	struct radix_tree_root data; /* data stored in the disk */
-	struct radix_tree_root cache; /* disk cache data */
-	unsigned long flags; /* device flags */
-	unsigned int curr_cache;
-	struct badblocks badblocks;
-
-	unsigned long size; /* device size in MB */
-	unsigned long completion_nsec; /* time in ns to complete a request */
-	unsigned long cache_size; /* disk cache size in MB */
-	unsigned int submit_queues; /* number of submission queues */
-	unsigned int home_node; /* home node for the device */
-	unsigned int queue_mode; /* block interface */
-	unsigned int blocksize; /* block size */
-	unsigned int irqmode; /* IRQ completion handler */
-	unsigned int hw_queue_depth; /* queue depth */
-	unsigned int index; /* index of the disk, only valid with a disk */
-	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
-	bool blocking; /* blocking blk-mq device */
-	bool use_per_node_hctx; /* use per-node allocation for hardware context */
-	bool power; /* power on/off the device */
-	bool memory_backed; /* if data is stored in memory */
-	bool discard; /* if support discard */
-};
-
-struct nullb {
-	struct nullb_device *dev;
-	struct list_head list;
-	unsigned int index;
-	struct request_queue *q;
-	struct gendisk *disk;
-	struct blk_mq_tag_set *tag_set;
-	struct blk_mq_tag_set __tag_set;
-	unsigned int queue_depth;
-	atomic_long_t cur_bytes;
-	struct hrtimer bw_timer;
-	unsigned long cache_flush_pos;
-	spinlock_t lock;
-
-	struct nullb_queue *queues;
-	unsigned int nr_queues;
-	char disk_name[DISK_NAME_LEN];
-};
-
 static LIST_HEAD(nullb_list);
 static struct mutex lock;
 static int null_major;
@@ -254,6 +180,14 @@ static bool g_use_per_node_hctx;
 module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444);
 MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
 
+static bool g_zoned;
+module_param_named(zoned, g_zoned, bool, S_IRUGO);
+MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false");
+
+static unsigned long g_zone_size = 256;
+module_param_named(zone_size, g_zone_size, ulong, S_IRUGO);
+MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256");
+
 static struct nullb_device *null_alloc_dev(void);
 static void null_free_dev(struct nullb_device *dev);
 static void null_del_dev(struct nullb *nullb);
@@ -357,6 +291,8 @@ NULLB_DEVICE_ATTR(memory_backed, bool);
 NULLB_DEVICE_ATTR(discard, bool);
 NULLB_DEVICE_ATTR(mbps, uint);
 NULLB_DEVICE_ATTR(cache_size, ulong);
+NULLB_DEVICE_ATTR(zoned, bool);
+NULLB_DEVICE_ATTR(zone_size, ulong);
 
 static ssize_t nullb_device_power_show(struct config_item *item, char *page)
 {
@@ -390,6 +326,7 @@ static ssize_t nullb_device_power_store(struct config_item *item,
 		null_del_dev(dev->nullb);
 		mutex_unlock(&lock);
 		clear_bit(NULLB_DEV_FL_UP, &dev->flags);
+		clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
 	}
 
 	return count;
@@ -468,6 +405,8 @@ static struct configfs_attribute *nullb_device_attrs[] = {
 	&nullb_device_attr_mbps,
 	&nullb_device_attr_cache_size,
 	&nullb_device_attr_badblocks,
+	&nullb_device_attr_zoned,
+	&nullb_device_attr_zone_size,
 	NULL,
 };
 
@@ -520,7 +459,7 @@ nullb_group_drop_item(struct config_group *group, struct config_item *item)
 
 static ssize_t memb_group_features_show(struct config_item *item, char *page)
 {
-	return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks\n");
+	return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size\n");
 }
 
 CONFIGFS_ATTR_RO(memb_group_, features);
@@ -579,6 +518,8 @@ static struct nullb_device *null_alloc_dev(void)
 	dev->hw_queue_depth = g_hw_queue_depth;
 	dev->blocking = g_blocking;
 	dev->use_per_node_hctx = g_use_per_node_hctx;
+	dev->zoned = g_zoned;
+	dev->zone_size = g_zone_size;
 	return dev;
 }
 
@@ -587,6 +528,7 @@ static void null_free_dev(struct nullb_device *dev)
 	if (!dev)
 		return;
 
+	null_zone_exit(dev);
 	badblocks_exit(&dev->badblocks);
 	kfree(dev);
 }
@@ -862,7 +804,9 @@ static struct nullb_page *null_lookup_page(struct nullb *nullb,
 }
 
 static struct nullb_page *null_insert_page(struct nullb *nullb,
-	sector_t sector, bool ignore_cache)
+					   sector_t sector, bool ignore_cache)
+	__releases(&nullb->lock)
+	__acquires(&nullb->lock)
 {
 	u64 idx;
 	struct nullb_page *t_page;
@@ -1219,6 +1163,11 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
 	struct nullb *nullb = dev->nullb;
 	int err = 0;
 
+	if (req_op(cmd->rq) == REQ_OP_ZONE_REPORT) {
+		cmd->error = null_zone_report(nullb, cmd);
+		goto out;
+	}
+
 	if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) {
 		struct request *rq = cmd->rq;
 
@@ -1283,6 +1232,13 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd)
 		}
 	}
 	cmd->error = errno_to_blk_status(err);
+
+	if (!cmd->error && dev->zoned) {
+		if (req_op(cmd->rq) == REQ_OP_WRITE)
+			null_zone_write(cmd);
+		else if (req_op(cmd->rq) == REQ_OP_ZONE_RESET)
+			null_zone_reset(cmd);
+	}
 out:
 	/* Complete IO by inline, softirq or timer */
 	switch (dev->irqmode) {
@@ -1810,6 +1766,15 @@ static int null_add_dev(struct nullb_device *dev)
 		blk_queue_flush_queueable(nullb->q, true);
 	}
 
+	if (dev->zoned) {
+		rv = null_zone_init(dev);
+		if (rv)
+			goto out_cleanup_blk_queue;
+
+		blk_queue_chunk_sectors(nullb->q, dev->zone_size_sects);
+		nullb->q->limits.zoned = BLK_ZONED_HM;
+	}
+
 	nullb->q->queuedata = nullb;
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q);
@@ -1828,13 +1793,16 @@ static int null_add_dev(struct nullb_device *dev)
 
 	rv = null_gendisk_register(nullb);
 	if (rv)
-		goto out_cleanup_blk_queue;
+		goto out_cleanup_zone;
 
 	mutex_lock(&lock);
 	list_add_tail(&nullb->list, &nullb_list);
 	mutex_unlock(&lock);
 
 	return 0;
+out_cleanup_zone:
+	if (dev->zoned)
+		null_zone_exit(dev);
 out_cleanup_blk_queue:
 	blk_cleanup_queue(nullb->q);
 out_cleanup_tags:
@@ -1861,6 +1829,11 @@ static int __init null_init(void)
 		g_bs = PAGE_SIZE;
 	}
 
+	if (!is_power_of_2(g_zone_size)) {
+		pr_err("null_blk: zone_size must be power-of-two\n");
+		return -EINVAL;
+	}
+
 	if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) {
 		if (g_submit_queues != nr_online_nodes) {
 			pr_warn("null_blk: submit_queues param is set to %u.\n",

drivers/block/null_blk_zoned.c

@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/vmalloc.h>
+#include "null_blk.h"
+
+/* zone_size in MBs to sectors. */
+#define ZONE_SIZE_SHIFT		11
+
+static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
+{
+	return sect >> ilog2(dev->zone_size_sects);
+}
+
+int null_zone_init(struct nullb_device *dev)
+{
+	sector_t dev_size = (sector_t)dev->size * 1024 * 1024;
+	sector_t sector = 0;
+	unsigned int i;
+
+	if (!is_power_of_2(dev->zone_size)) {
+		pr_err("null_blk: zone_size must be power-of-two\n");
+		return -EINVAL;
+	}
+
+	dev->zone_size_sects = dev->zone_size << ZONE_SIZE_SHIFT;
+	dev->nr_zones = dev_size >>
+				(SECTOR_SHIFT + ilog2(dev->zone_size_sects));
+	dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct blk_zone),
+			GFP_KERNEL | __GFP_ZERO);
+	if (!dev->zones)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->nr_zones; i++) {
+		struct blk_zone *zone = &dev->zones[i];
+
+		zone->start = zone->wp = sector;
+		zone->len = dev->zone_size_sects;
+		zone->type = BLK_ZONE_TYPE_SEQWRITE_REQ;
+		zone->cond = BLK_ZONE_COND_EMPTY;
+
+		sector += dev->zone_size_sects;
+	}
+
+	return 0;
+}
+
+void null_zone_exit(struct nullb_device *dev)
+{
+	kvfree(dev->zones);
+}
+
+static void null_zone_fill_rq(struct nullb_device *dev, struct request *rq,
+			      unsigned int zno, unsigned int nr_zones)
+{
+	struct blk_zone_report_hdr *hdr = NULL;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	void *addr;
+	unsigned int zones_to_cpy;
+
+	bio_for_each_segment(bvec, rq->bio, iter) {
+		addr = kmap_atomic(bvec.bv_page);
+
+		zones_to_cpy = bvec.bv_len / sizeof(struct blk_zone);
+
+		if (!hdr) {
+			hdr = (struct blk_zone_report_hdr *)addr;
+			hdr->nr_zones = nr_zones;
+			zones_to_cpy--;
+			addr += sizeof(struct blk_zone_report_hdr);
+		}
+
+		zones_to_cpy = min_t(unsigned int, zones_to_cpy, nr_zones);
+
+		memcpy(addr, &dev->zones[zno],
+				zones_to_cpy * sizeof(struct blk_zone));
+
+		kunmap_atomic(addr);
+
+		nr_zones -= zones_to_cpy;
+		zno += zones_to_cpy;
+
+		if (!nr_zones)
+			break;
+	}
+}
+
+blk_status_t null_zone_report(struct nullb *nullb,
+				     struct nullb_cmd *cmd)
+{
+	struct nullb_device *dev = nullb->dev;
+	struct request *rq = cmd->rq;
+	unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
+	unsigned int nr_zones = dev->nr_zones - zno;
+	unsigned int max_zones = (blk_rq_bytes(rq) /
+					sizeof(struct blk_zone)) - 1;
+
+	nr_zones = min_t(unsigned int, nr_zones, max_zones);
+
+	null_zone_fill_rq(nullb->dev, rq, zno, nr_zones);
+
+	return BLK_STS_OK;
+}
+
+void null_zone_write(struct nullb_cmd *cmd)
+{
+	struct nullb_device *dev = cmd->nq->dev;
+	struct request *rq = cmd->rq;
+	sector_t sector = blk_rq_pos(rq);
+	unsigned int rq_sectors = blk_rq_sectors(rq);
+	unsigned int zno = null_zone_no(dev, sector);
+	struct blk_zone *zone = &dev->zones[zno];
+
+	switch (zone->cond) {
+	case BLK_ZONE_COND_FULL:
+		/* Cannot write to a full zone */
+		cmd->error = BLK_STS_IOERR;
+		break;
+	case BLK_ZONE_COND_EMPTY:
+	case BLK_ZONE_COND_IMP_OPEN:
+		/* Writes must be at the write pointer position */
+		if (blk_rq_pos(rq) != zone->wp) {
+			cmd->error = BLK_STS_IOERR;
+			break;
+		}
+
+		if (zone->cond == BLK_ZONE_COND_EMPTY)
+			zone->cond = BLK_ZONE_COND_IMP_OPEN;
+
+		zone->wp += rq_sectors;
+		if (zone->wp == zone->start + zone->len)
+			zone->cond = BLK_ZONE_COND_FULL;
+		break;
+	default:
+		/* Invalid zone condition */
+		cmd->error = BLK_STS_IOERR;
+		break;
+	}
+}
+
+void null_zone_reset(struct nullb_cmd *cmd)
+{
+	struct nullb_device *dev = cmd->nq->dev;
+	struct request *rq = cmd->rq;
+	unsigned int zno = null_zone_no(dev, blk_rq_pos(rq));
+	struct blk_zone *zone = &dev->zones[zno];
+
+	zone->cond = BLK_ZONE_COND_EMPTY;
+	zone->wp = zone->start;
+}

drivers/block/paride/bpck.c

@@ -347,7 +347,7 @@ static int bpck_test_proto( PIA *pi, char * scratch, int verbose )
 
 static void bpck_read_eeprom ( PIA *pi, char * buf )
 
-{       int i,j,k,n,p,v,f, om, od;
+{       int i, j, k, p, v, f, om, od;
 
 	bpck_force_spp(pi);
 
@@ -356,7 +356,6 @@ static void bpck_read_eeprom ( PIA *pi, char * buf )
 
 	bpck_connect(pi);
 	
-	n = 0;
 	WR(4,0);
 	for (i=0;i<64;i++) {
 	    WR(6,8);  

drivers/block/paride/pd.c

@@ -426,6 +426,7 @@ static void run_fsm(void)
 				pd_claimed = 1;
 				if (!pi_schedule_claimed(pi_current, run_fsm))
 					return;
+				/* fall through */
 			case 1:
 				pd_claimed = 2;
 				pi_current->proto->connect(pi_current);
@@ -445,6 +446,7 @@ static void run_fsm(void)
 				spin_unlock_irqrestore(&pd_lock, saved_flags);
 				if (stop)
 					return;
+				/* fall through */
 			case Hold:
 				schedule_fsm();
 				return;

drivers/block/pktcdvd.c

@@ -67,7 +67,7 @@
 #include <scsi/scsi.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
-
+#include <linux/nospec.h>
 #include <linux/uaccess.h>
 
 #define DRIVER_NAME	"pktcdvd"
@@ -748,13 +748,13 @@ static const char *sense_key_string(__u8 index)
 static void pkt_dump_sense(struct pktcdvd_device *pd,
 			   struct packet_command *cgc)
 {
-	struct request_sense *sense = cgc->sense;
+	struct scsi_sense_hdr *sshdr = cgc->sshdr;
 
-	if (sense)
+	if (sshdr)
 		pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
 			CDROM_PACKET_SIZE, cgc->cmd,
-			sense->sense_key, sense->asc, sense->ascq,
-			sense_key_string(sense->sense_key));
+			sshdr->sense_key, sshdr->asc, sshdr->ascq,
+			sense_key_string(sshdr->sense_key));
 	else
 		pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
 }
@@ -787,18 +787,19 @@ static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 				unsigned write_speed, unsigned read_speed)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	int ret;
 
 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 	cgc.cmd[0] = GPCMD_SET_SPEED;
 	cgc.cmd[2] = (read_speed >> 8) & 0xff;
 	cgc.cmd[3] = read_speed & 0xff;
 	cgc.cmd[4] = (write_speed >> 8) & 0xff;
 	cgc.cmd[5] = write_speed & 0xff;
 
-	if ((ret = pkt_generic_packet(pd, &cgc)))
+	ret = pkt_generic_packet(pd, &cgc);
+	if (ret)
 		pkt_dump_sense(pd, &cgc);
 
 	return ret;
@@ -1562,7 +1563,8 @@ static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
 	cgc.cmd[8] = cgc.buflen = 2;
 	cgc.quiet = 1;
 
-	if ((ret = pkt_generic_packet(pd, &cgc)))
+	ret = pkt_generic_packet(pd, &cgc);
+	if (ret)
 		return ret;
 
 	/* not all drives have the same disc_info length, so requeue
@@ -1591,7 +1593,8 @@ static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type,
 	cgc.cmd[8] = 8;
 	cgc.quiet = 1;
 
-	if ((ret = pkt_generic_packet(pd, &cgc)))
+	ret = pkt_generic_packet(pd, &cgc);
+	if (ret)
 		return ret;
 
 	cgc.buflen = be16_to_cpu(ti->track_information_length) +
@@ -1612,17 +1615,20 @@ static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
 	__u32 last_track;
 	int ret = -1;
 
-	if ((ret = pkt_get_disc_info(pd, &di)))
+	ret = pkt_get_disc_info(pd, &di);
+	if (ret)
 		return ret;
 
 	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
-	if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
+	ret = pkt_get_track_info(pd, last_track, 1, &ti);
+	if (ret)
 		return ret;
 
 	/* if this track is blank, try the previous. */
 	if (ti.blank) {
 		last_track--;
-		if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
+		ret = pkt_get_track_info(pd, last_track, 1, &ti);
+		if (ret)
 			return ret;
 	}
 
@@ -1645,7 +1651,7 @@ static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	write_param_page *wp;
 	char buffer[128];
 	int ret, size;
@@ -1656,8 +1662,9 @@ static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
 
 	memset(buffer, 0, sizeof(buffer));
 	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
-	cgc.sense = &sense;
-	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
+	cgc.sshdr = &sshdr;
+	ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
+	if (ret) {
 		pkt_dump_sense(pd, &cgc);
 		return ret;
 	}
@@ -1671,8 +1678,9 @@ static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
 	 * now get it all
 	 */
 	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
-	cgc.sense = &sense;
-	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
+	cgc.sshdr = &sshdr;
+	ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
+	if (ret) {
 		pkt_dump_sense(pd, &cgc);
 		return ret;
 	}
@@ -1714,7 +1722,8 @@ static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
 	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
 
 	cgc.buflen = cgc.cmd[8] = size;
-	if ((ret = pkt_mode_select(pd, &cgc))) {
+	ret = pkt_mode_select(pd, &cgc);
+	if (ret) {
 		pkt_dump_sense(pd, &cgc);
 		return ret;
 	}
@@ -1819,7 +1828,8 @@ static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
 	memset(&di, 0, sizeof(disc_information));
 	memset(&ti, 0, sizeof(track_information));
 
-	if ((ret = pkt_get_disc_info(pd, &di))) {
+	ret = pkt_get_disc_info(pd, &di);
+	if (ret) {
 		pkt_err(pd, "failed get_disc\n");
 		return ret;
 	}
@@ -1830,7 +1840,8 @@ static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
 	pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
 
 	track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
-	if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
+	ret = pkt_get_track_info(pd, track, 1, &ti);
+	if (ret) {
 		pkt_err(pd, "failed get_track\n");
 		return ret;
 	}
@@ -1905,12 +1916,12 @@ static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
 						int set)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	unsigned char buf[64];
 	int ret;
 
 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 	cgc.buflen = pd->mode_offset + 12;
 
 	/*
@@ -1918,7 +1929,8 @@ static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
 	 */
 	cgc.quiet = 1;
 
-	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
+	ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
+	if (ret)
 		return ret;
 
 	buf[pd->mode_offset + 10] |= (!!set << 2);
@@ -1950,14 +1962,14 @@ static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
 						unsigned *write_speed)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	unsigned char buf[256+18];
 	unsigned char *cap_buf;
 	int ret, offset;
 
 	cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 
 	ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
 	if (ret) {
@@ -2011,13 +2023,13 @@ static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
 						unsigned *speed)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	unsigned char buf[64];
 	unsigned int size, st, sp;
 	int ret;
 
 	init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
 	cgc.cmd[1] = 2;
 	cgc.cmd[2] = 4; /* READ ATIP */
@@ -2032,7 +2044,7 @@ static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
 		size = sizeof(buf);
 
 	init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
 	cgc.cmd[1] = 2;
 	cgc.cmd[2] = 4;
@@ -2083,17 +2095,18 @@ static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
 {
 	struct packet_command cgc;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	int ret;
 
 	pkt_dbg(2, pd, "Performing OPC\n");
 
 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
-	cgc.sense = &sense;
+	cgc.sshdr = &sshdr;
 	cgc.timeout = 60*HZ;
 	cgc.cmd[0] = GPCMD_SEND_OPC;
 	cgc.cmd[1] = 1;
-	if ((ret = pkt_generic_packet(pd, &cgc)))
+	ret = pkt_generic_packet(pd, &cgc);
+	if (ret)
 		pkt_dump_sense(pd, &cgc);
 	return ret;
 }
@@ -2103,19 +2116,22 @@ static int pkt_open_write(struct pktcdvd_device *pd)
 	int ret;
 	unsigned int write_speed, media_write_speed, read_speed;
 
-	if ((ret = pkt_probe_settings(pd))) {
+	ret = pkt_probe_settings(pd);
+	if (ret) {
 		pkt_dbg(2, pd, "failed probe\n");
 		return ret;
 	}
 
-	if ((ret = pkt_set_write_settings(pd))) {
+	ret = pkt_set_write_settings(pd);
+	if (ret) {
 		pkt_dbg(1, pd, "failed saving write settings\n");
 		return -EIO;
 	}
 
 	pkt_write_caching(pd, USE_WCACHING);
 
-	if ((ret = pkt_get_max_speed(pd, &write_speed)))
+	ret = pkt_get_max_speed(pd, &write_speed);
+	if (ret)
 		write_speed = 16 * 177;
 	switch (pd->mmc3_profile) {
 		case 0x13: /* DVD-RW */
@@ -2124,7 +2140,8 @@ static int pkt_open_write(struct pktcdvd_device *pd)
 			pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
 			break;
 		default:
-			if ((ret = pkt_media_speed(pd, &media_write_speed)))
+			ret = pkt_media_speed(pd, &media_write_speed);
+			if (ret)
 				media_write_speed = 16;
 			write_speed = min(write_speed, media_write_speed * 177);
 			pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
@@ -2132,14 +2149,16 @@ static int pkt_open_write(struct pktcdvd_device *pd)
 	}
 	read_speed = write_speed;
 
-	if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
+	ret = pkt_set_speed(pd, write_speed, read_speed);
+	if (ret) {
 		pkt_dbg(1, pd, "couldn't set write speed\n");
 		return -EIO;
 	}
 	pd->write_speed = write_speed;
 	pd->read_speed = read_speed;
 
-	if ((ret = pkt_perform_opc(pd))) {
+	ret = pkt_perform_opc(pd);
+	if (ret) {
 		pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
 	}
 
@@ -2161,10 +2180,12 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 	 * so bdget() can't fail.
 	 */
 	bdget(pd->bdev->bd_dev);
-	if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
+	ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd);
+	if (ret)
 		goto out;
 
-	if ((ret = pkt_get_last_written(pd, &lba))) {
+	ret = pkt_get_last_written(pd, &lba);
+	if (ret) {
 		pkt_err(pd, "pkt_get_last_written failed\n");
 		goto out_putdev;
 	}
@@ -2175,7 +2196,8 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 
 	q = bdev_get_queue(pd->bdev);
 	if (write) {
-		if ((ret = pkt_open_write(pd)))
+		ret = pkt_open_write(pd);
+		if (ret)
 			goto out_putdev;
 		/*
 		 * Some CDRW drives can not handle writes larger than one packet,
@@ -2190,7 +2212,8 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 		clear_bit(PACKET_WRITABLE, &pd->flags);
 	}
 
-	if ((ret = pkt_set_segment_merging(pd, q)))
+	ret = pkt_set_segment_merging(pd, q);
+	if (ret)
 		goto out_putdev;
 
 	if (write) {
@@ -2231,6 +2254,8 @@ static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
 {
 	if (dev_minor >= MAX_WRITERS)
 		return NULL;
+
+	dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
 	return pkt_devs[dev_minor];
 }
 

drivers/block/rsxx/dev.c

@@ -112,7 +112,7 @@ static const struct block_device_operations rsxx_fops = {
 
 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
 {
-	generic_start_io_acct(card->queue, bio_data_dir(bio), bio_sectors(bio),
+	generic_start_io_acct(card->queue, bio_op(bio), bio_sectors(bio),
 			     &card->gendisk->part0);
 }
 
@@ -120,8 +120,8 @@ static void disk_stats_complete(struct rsxx_cardinfo *card,
 				struct bio *bio,
 				unsigned long start_time)
 {
-	generic_end_io_acct(card->queue, bio_data_dir(bio),
-				&card->gendisk->part0, start_time);
+	generic_end_io_acct(card->queue, bio_op(bio),
+			    &card->gendisk->part0, start_time);
 }
 
 static void bio_dma_done_cb(struct rsxx_cardinfo *card,

drivers/block/skd_main.c

@@ -657,8 +657,8 @@ static bool skd_preop_sg_list(struct skd_device *skdev,
 
 	if (unlikely(skdev->dbg_level > 1)) {
 		dev_dbg(&skdev->pdev->dev,
-			"skreq=%x sksg_list=%p sksg_dma=%llx\n",
-			skreq->id, skreq->sksg_list, skreq->sksg_dma_address);
+			"skreq=%x sksg_list=%p sksg_dma=%pad\n",
+			skreq->id, skreq->sksg_list, &skreq->sksg_dma_address);
 		for (i = 0; i < n_sg; i++) {
 			struct fit_sg_descriptor *sgd = &skreq->sksg_list[i];
 
@@ -1190,8 +1190,8 @@ static void skd_send_fitmsg(struct skd_device *skdev,
 {
 	u64 qcmd;
 
-	dev_dbg(&skdev->pdev->dev, "dma address 0x%llx, busy=%d\n",
-		skmsg->mb_dma_address, skd_in_flight(skdev));
+	dev_dbg(&skdev->pdev->dev, "dma address %pad, busy=%d\n",
+		&skmsg->mb_dma_address, skd_in_flight(skdev));
 	dev_dbg(&skdev->pdev->dev, "msg_buf %p\n", skmsg->msg_buf);
 
 	qcmd = skmsg->mb_dma_address;
@@ -1250,9 +1250,9 @@ static void skd_send_special_fitmsg(struct skd_device *skdev,
 		}
 
 		dev_dbg(&skdev->pdev->dev,
-			"skspcl=%p id=%04x sksg_list=%p sksg_dma=%llx\n",
+			"skspcl=%p id=%04x sksg_list=%p sksg_dma=%pad\n",
 			skspcl, skspcl->req.id, skspcl->req.sksg_list,
-			skspcl->req.sksg_dma_address);
+			&skspcl->req.sksg_dma_address);
 		for (i = 0; i < skspcl->req.n_sg; i++) {
 			struct fit_sg_descriptor *sgd =
 				&skspcl->req.sksg_list[i];
@@ -2685,8 +2685,8 @@ static int skd_cons_skmsg(struct skd_device *skdev)
 
 		WARN(((uintptr_t)skmsg->msg_buf | skmsg->mb_dma_address) &
 		     (FIT_QCMD_ALIGN - 1),
-		     "not aligned: msg_buf %p mb_dma_address %#llx\n",
-		     skmsg->msg_buf, skmsg->mb_dma_address);
+		     "not aligned: msg_buf %p mb_dma_address %pad\n",
+		     skmsg->msg_buf, &skmsg->mb_dma_address);
 		memset(skmsg->msg_buf, 0, SKD_N_FITMSG_BYTES);
 	}
 

drivers/block/xen-blkfront.c

@@ -251,14 +251,9 @@ static DEFINE_SPINLOCK(minor_lock);
 #define GRANTS_PER_INDIRECT_FRAME \
 	(XEN_PAGE_SIZE / sizeof(struct blkif_request_segment))
 
-#define PSEGS_PER_INDIRECT_FRAME	\
-	(GRANTS_INDIRECT_FRAME / GRANTS_PSEGS)
-
 #define INDIRECT_GREFS(_grants)		\
 	DIV_ROUND_UP(_grants, GRANTS_PER_INDIRECT_FRAME)
 
-#define GREFS(_psegs)	((_psegs) * GRANTS_PER_PSEG)
-
 static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
 static void blkfront_gather_backend_features(struct blkfront_info *info);
 static int negotiate_mq(struct blkfront_info *info);
@@ -1441,7 +1436,7 @@ static bool blkif_completion(unsigned long *id,
 
 		/* Wait the second response if not yet here. */
 		if (s2->status == REQ_WAITING)
-			return 0;
+			return false;
 
 		bret->status = blkif_get_final_status(s->status,
 						      s2->status);
@@ -1542,7 +1537,7 @@ static bool blkif_completion(unsigned long *id,
 		}
 	}
 
-	return 1;
+	return true;
 }
 
 static irqreturn_t blkif_interrupt(int irq, void *dev_id)

drivers/block/zram/zram_drv.c

@@ -1287,17 +1287,16 @@ static void zram_bio_discard(struct zram *zram, u32 index,
  * Returns 1 if IO request was successfully submitted.
  */
 static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
-			int offset, bool is_write, struct bio *bio)
+			int offset, unsigned int op, struct bio *bio)
 {
 	unsigned long start_time = jiffies;
-	int rw_acct = is_write ? REQ_OP_WRITE : REQ_OP_READ;
 	struct request_queue *q = zram->disk->queue;
 	int ret;
 
-	generic_start_io_acct(q, rw_acct, bvec->bv_len >> SECTOR_SHIFT,
+	generic_start_io_acct(q, op, bvec->bv_len >> SECTOR_SHIFT,
 			&zram->disk->part0);
 
-	if (!is_write) {
+	if (!op_is_write(op)) {
 		atomic64_inc(&zram->stats.num_reads);
 		ret = zram_bvec_read(zram, bvec, index, offset, bio);
 		flush_dcache_page(bvec->bv_page);
@@ -1306,14 +1305,14 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
 		ret = zram_bvec_write(zram, bvec, index, offset, bio);
 	}
 
-	generic_end_io_acct(q, rw_acct, &zram->disk->part0, start_time);
+	generic_end_io_acct(q, op, &zram->disk->part0, start_time);
 
 	zram_slot_lock(zram, index);
 	zram_accessed(zram, index);
 	zram_slot_unlock(zram, index);
 
 	if (unlikely(ret < 0)) {
-		if (!is_write)
+		if (!op_is_write(op))
 			atomic64_inc(&zram->stats.failed_reads);
 		else
 			atomic64_inc(&zram->stats.failed_writes);
@@ -1351,7 +1350,7 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
 			bv.bv_len = min_t(unsigned int, PAGE_SIZE - offset,
 							unwritten);
 			if (zram_bvec_rw(zram, &bv, index, offset,
-					op_is_write(bio_op(bio)), bio) < 0)
+					 bio_op(bio), bio) < 0)
 				goto out;
 
 			bv.bv_offset += bv.bv_len;
@@ -1403,7 +1402,7 @@ static void zram_slot_free_notify(struct block_device *bdev,
 }
 
 static int zram_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, bool is_write)
+		       struct page *page, unsigned int op)
 {
 	int offset, ret;
 	u32 index;
@@ -1427,7 +1426,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
 	bv.bv_len = PAGE_SIZE;
 	bv.bv_offset = 0;
 
-	ret = zram_bvec_rw(zram, &bv, index, offset, is_write, NULL);
+	ret = zram_bvec_rw(zram, &bv, index, offset, op, NULL);
 out:
 	/*
 	 * If I/O fails, just return error(ie, non-zero) without
@@ -1442,7 +1441,7 @@ out:
 
 	switch (ret) {
 	case 0:
-		page_endio(page, is_write, 0);
+		page_endio(page, op_is_write(op), 0);
 		break;
 	case 1:
 		ret = 0;

drivers/cdrom/cdrom.c

@@ -282,6 +282,7 @@
 #include <linux/blkdev.h>
 #include <linux/times.h>
 #include <linux/uaccess.h>
+#include <scsi/scsi_common.h>
 #include <scsi/scsi_request.h>
 
 /* used to tell the module to turn on full debugging messages */
@@ -345,10 +346,10 @@ static LIST_HEAD(cdrom_list);
 int cdrom_dummy_generic_packet(struct cdrom_device_info *cdi,
 			       struct packet_command *cgc)
 {
-	if (cgc->sense) {
-		cgc->sense->sense_key = 0x05;
-		cgc->sense->asc = 0x20;
-		cgc->sense->ascq = 0x00;
+	if (cgc->sshdr) {
+		cgc->sshdr->sense_key = 0x05;
+		cgc->sshdr->asc = 0x20;
+		cgc->sshdr->ascq = 0x00;
 	}
 
 	cgc->stat = -EIO;
@@ -2222,9 +2223,12 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 
 		blk_execute_rq(q, cdi->disk, rq, 0);
 		if (scsi_req(rq)->result) {
-			struct request_sense *s = req->sense;
+			struct scsi_sense_hdr sshdr;
+
 			ret = -EIO;
-			cdi->last_sense = s->sense_key;
+			scsi_normalize_sense(req->sense, req->sense_len,
+					     &sshdr);
+			cdi->last_sense = sshdr.sense_key;
 		}
 
 		if (blk_rq_unmap_user(bio))
@@ -2943,7 +2947,7 @@ static noinline int mmc_ioctl_cdrom_read_data(struct cdrom_device_info *cdi,
 					      struct packet_command *cgc,
 					      int cmd)
 {
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	struct cdrom_msf msf;
 	int blocksize = 0, format = 0, lba;
 	int ret;
@@ -2971,13 +2975,13 @@ static noinline int mmc_ioctl_cdrom_read_data(struct cdrom_device_info *cdi,
 	if (cgc->buffer == NULL)
 		return -ENOMEM;
 
-	memset(&sense, 0, sizeof(sense));
-	cgc->sense = &sense;
+	memset(&sshdr, 0, sizeof(sshdr));
+	cgc->sshdr = &sshdr;
 	cgc->data_direction = CGC_DATA_READ;
 	ret = cdrom_read_block(cdi, cgc, lba, 1, format, blocksize);
-	if (ret && sense.sense_key == 0x05 &&
-	    sense.asc == 0x20 &&
-	    sense.ascq == 0x00) {
+	if (ret && sshdr.sense_key == 0x05 &&
+	    sshdr.asc == 0x20 &&
+	    sshdr.ascq == 0x00) {
 		/*
 		 * SCSI-II devices are not required to support
 		 * READ_CD, so let's try switching block size
@@ -2986,7 +2990,7 @@ static noinline int mmc_ioctl_cdrom_read_data(struct cdrom_device_info *cdi,
 		ret = cdrom_switch_blocksize(cdi, blocksize);
 		if (ret)
 			goto out;
-		cgc->sense = NULL;
+		cgc->sshdr = NULL;
 		ret = cdrom_read_cd(cdi, cgc, lba, blocksize, 1);
 		ret |= cdrom_switch_blocksize(cdi, blocksize);
 	}

drivers/ide/ide-cd.c

@@ -419,10 +419,11 @@ static void ide_cd_request_sense_fixup(ide_drive_t *drive, struct ide_cmd *cmd)
 
 int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 		    int write, void *buffer, unsigned *bufflen,
-		    struct request_sense *sense, int timeout,
+		    struct scsi_sense_hdr *sshdr, int timeout,
 		    req_flags_t rq_flags)
 {
 	struct cdrom_info *info = drive->driver_data;
+	struct scsi_sense_hdr local_sshdr;
 	int retries = 10;
 	bool failed;
 
@@ -430,6 +431,9 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 				  "rq_flags: 0x%x",
 				  cmd[0], write, timeout, rq_flags);
 
+	if (!sshdr)
+		sshdr = &local_sshdr;
+
 	/* start of retry loop */
 	do {
 		struct request *rq;
@@ -456,8 +460,8 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 
 		if (buffer)
 			*bufflen = scsi_req(rq)->resid_len;
-		if (sense)
-			memcpy(sense, scsi_req(rq)->sense, sizeof(*sense));
+		scsi_normalize_sense(scsi_req(rq)->sense,
+				     scsi_req(rq)->sense_len, sshdr);
 
 		/*
 		 * FIXME: we should probably abort/retry or something in case of
@@ -469,12 +473,10 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 			 * The request failed.  Retry if it was due to a unit
 			 * attention status (usually means media was changed).
 			 */
-			struct request_sense *reqbuf = scsi_req(rq)->sense;
-
-			if (reqbuf->sense_key == UNIT_ATTENTION)
+			if (sshdr->sense_key == UNIT_ATTENTION)
 				cdrom_saw_media_change(drive);
-			else if (reqbuf->sense_key == NOT_READY &&
-				 reqbuf->asc == 4 && reqbuf->ascq != 4) {
+			else if (sshdr->sense_key == NOT_READY &&
+				 sshdr->asc == 4 && sshdr->ascq != 4) {
 				/*
 				 * The drive is in the process of loading
 				 * a disk.  Retry, but wait a little to give
@@ -864,7 +866,7 @@ static void msf_from_bcd(struct atapi_msf *msf)
 	msf->frame  = bcd2bin(msf->frame);
 }
 
-int cdrom_check_status(ide_drive_t *drive, struct request_sense *sense)
+int cdrom_check_status(ide_drive_t *drive, struct scsi_sense_hdr *sshdr)
 {
 	struct cdrom_info *info = drive->driver_data;
 	struct cdrom_device_info *cdi;
@@ -886,12 +888,11 @@ int cdrom_check_status(ide_drive_t *drive, struct request_sense *sense)
 	 */
 	cmd[7] = cdi->sanyo_slot % 3;
 
-	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, sense, 0, RQF_QUIET);
+	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, sshdr, 0, RQF_QUIET);
 }
 
 static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
-			       unsigned long *sectors_per_frame,
-			       struct request_sense *sense)
+			       unsigned long *sectors_per_frame)
 {
 	struct {
 		__be32 lba;
@@ -908,7 +909,7 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
 	memset(cmd, 0, BLK_MAX_CDB);
 	cmd[0] = GPCMD_READ_CDVD_CAPACITY;
 
-	stat = ide_cd_queue_pc(drive, cmd, 0, &capbuf, &len, sense, 0,
+	stat = ide_cd_queue_pc(drive, cmd, 0, &capbuf, &len, NULL, 0,
 			       RQF_QUIET);
 	if (stat)
 		return stat;
@@ -944,8 +945,7 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
 }
 
 static int cdrom_read_tocentry(ide_drive_t *drive, int trackno, int msf_flag,
-				int format, char *buf, int buflen,
-				struct request_sense *sense)
+				int format, char *buf, int buflen)
 {
 	unsigned char cmd[BLK_MAX_CDB];
 
@@ -962,11 +962,11 @@ static int cdrom_read_tocentry(ide_drive_t *drive, int trackno, int msf_flag,
 	if (msf_flag)
 		cmd[1] = 2;
 
-	return ide_cd_queue_pc(drive, cmd, 0, buf, &buflen, sense, 0, RQF_QUIET);
+	return ide_cd_queue_pc(drive, cmd, 0, buf, &buflen, NULL, 0, RQF_QUIET);
 }
 
 /* Try to read the entire TOC for the disk into our internal buffer. */
-int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
+int ide_cd_read_toc(ide_drive_t *drive)
 {
 	int stat, ntracks, i;
 	struct cdrom_info *info = drive->driver_data;
@@ -996,14 +996,13 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 	 * Check to see if the existing data is still valid. If it is,
 	 * just return.
 	 */
-	(void) cdrom_check_status(drive, sense);
+	(void) cdrom_check_status(drive, NULL);
 
 	if (drive->atapi_flags & IDE_AFLAG_TOC_VALID)
 		return 0;
 
 	/* try to get the total cdrom capacity and sector size */
-	stat = cdrom_read_capacity(drive, &toc->capacity, &sectors_per_frame,
-				   sense);
+	stat = cdrom_read_capacity(drive, &toc->capacity, &sectors_per_frame);
 	if (stat)
 		toc->capacity = 0x1fffff;
 
@@ -1016,7 +1015,7 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 
 	/* first read just the header, so we know how long the TOC is */
 	stat = cdrom_read_tocentry(drive, 0, 1, 0, (char *) &toc->hdr,
-				    sizeof(struct atapi_toc_header), sense);
+				    sizeof(struct atapi_toc_header));
 	if (stat)
 		return stat;
 
@@ -1036,7 +1035,7 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 				  (char *)&toc->hdr,
 				   sizeof(struct atapi_toc_header) +
 				   (ntracks + 1) *
-				   sizeof(struct atapi_toc_entry), sense);
+				   sizeof(struct atapi_toc_entry));
 
 	if (stat && toc->hdr.first_track > 1) {
 		/*
@@ -1056,8 +1055,7 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 					   (char *)&toc->hdr,
 					   sizeof(struct atapi_toc_header) +
 					   (ntracks + 1) *
-					   sizeof(struct atapi_toc_entry),
-					   sense);
+					   sizeof(struct atapi_toc_entry));
 		if (stat)
 			return stat;
 
@@ -1094,7 +1092,7 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 	if (toc->hdr.first_track != CDROM_LEADOUT) {
 		/* read the multisession information */
 		stat = cdrom_read_tocentry(drive, 0, 0, 1, (char *)&ms_tmp,
-					   sizeof(ms_tmp), sense);
+					   sizeof(ms_tmp));
 		if (stat)
 			return stat;
 
@@ -1108,7 +1106,7 @@ int ide_cd_read_toc(ide_drive_t *drive, struct request_sense *sense)
 	if (drive->atapi_flags & IDE_AFLAG_TOCADDR_AS_BCD) {
 		/* re-read multisession information using MSF format */
 		stat = cdrom_read_tocentry(drive, 0, 1, 1, (char *)&ms_tmp,
-					   sizeof(ms_tmp), sense);
+					   sizeof(ms_tmp));
 		if (stat)
 			return stat;
 
@@ -1412,7 +1410,7 @@ static sector_t ide_cdrom_capacity(ide_drive_t *drive)
 {
 	unsigned long capacity, sectors_per_frame;
 
-	if (cdrom_read_capacity(drive, &capacity, &sectors_per_frame, NULL))
+	if (cdrom_read_capacity(drive, &capacity, &sectors_per_frame))
 		return 0;
 
 	return capacity * sectors_per_frame;
@@ -1710,9 +1708,8 @@ static unsigned int idecd_check_events(struct gendisk *disk,
 static int idecd_revalidate_disk(struct gendisk *disk)
 {
 	struct cdrom_info *info = ide_drv_g(disk, cdrom_info);
-	struct request_sense sense;
 
-	ide_cd_read_toc(info->drive, &sense);
+	ide_cd_read_toc(info->drive);
 
 	return  0;
 }
@@ -1736,7 +1733,6 @@ static int ide_cd_probe(ide_drive_t *drive)
 {
 	struct cdrom_info *info;
 	struct gendisk *g;
-	struct request_sense sense;
 
 	ide_debug_log(IDE_DBG_PROBE, "driver_req: %s, media: 0x%x",
 				     drive->driver_req, drive->media);
@@ -1785,7 +1781,7 @@ static int ide_cd_probe(ide_drive_t *drive)
 		goto failed;
 	}
 
-	ide_cd_read_toc(drive, &sense);
+	ide_cd_read_toc(drive);
 	g->fops = &idecd_ops;
 	g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 	device_add_disk(&drive->gendev, g);

drivers/ide/ide-cd.h

@@ -98,11 +98,11 @@ void ide_cd_log_error(const char *, struct request *, struct request_sense *);
 
 /* ide-cd.c functions used by ide-cd_ioctl.c */
 int ide_cd_queue_pc(ide_drive_t *, const unsigned char *, int, void *,
-		    unsigned *, struct request_sense *, int, req_flags_t);
-int ide_cd_read_toc(ide_drive_t *, struct request_sense *);
+		    unsigned *, struct scsi_sense_hdr *, int, req_flags_t);
+int ide_cd_read_toc(ide_drive_t *);
 int ide_cdrom_get_capabilities(ide_drive_t *, u8 *);
 void ide_cdrom_update_speed(ide_drive_t *, u8 *);
-int cdrom_check_status(ide_drive_t *, struct request_sense *);
+int cdrom_check_status(ide_drive_t *, struct scsi_sense_hdr *);
 
 /* ide-cd_ioctl.c */
 int ide_cdrom_open_real(struct cdrom_device_info *, int);

drivers/ide/ide-cd_ioctl.c

@@ -43,14 +43,14 @@ int ide_cdrom_drive_status(struct cdrom_device_info *cdi, int slot_nr)
 {
 	ide_drive_t *drive = cdi->handle;
 	struct media_event_desc med;
-	struct request_sense sense;
+	struct scsi_sense_hdr sshdr;
 	int stat;
 
 	if (slot_nr != CDSL_CURRENT)
 		return -EINVAL;
 
-	stat = cdrom_check_status(drive, &sense);
-	if (!stat || sense.sense_key == UNIT_ATTENTION)
+	stat = cdrom_check_status(drive, &sshdr);
+	if (!stat || sshdr.sense_key == UNIT_ATTENTION)
 		return CDS_DISC_OK;
 
 	if (!cdrom_get_media_event(cdi, &med)) {
@@ -62,8 +62,8 @@ int ide_cdrom_drive_status(struct cdrom_device_info *cdi, int slot_nr)
 			return CDS_NO_DISC;
 	}
 
-	if (sense.sense_key == NOT_READY && sense.asc == 0x04
-			&& sense.ascq == 0x04)
+	if (sshdr.sense_key == NOT_READY && sshdr.asc == 0x04
+			&& sshdr.ascq == 0x04)
 		return CDS_DISC_OK;
 
 	/*
@@ -71,8 +71,8 @@ int ide_cdrom_drive_status(struct cdrom_device_info *cdi, int slot_nr)
 	 * just return TRAY_OPEN since ATAPI doesn't provide
 	 * any other way to detect this...
 	 */
-	if (sense.sense_key == NOT_READY) {
-		if (sense.asc == 0x3a && sense.ascq == 1)
+	if (sshdr.sense_key == NOT_READY) {
+		if (sshdr.asc == 0x3a && sshdr.ascq == 1)
 			return CDS_NO_DISC;
 		else
 			return CDS_TRAY_OPEN;
@@ -105,8 +105,7 @@ unsigned int ide_cdrom_check_events_real(struct cdrom_device_info *cdi,
 /* Eject the disk if EJECTFLAG is 0.
    If EJECTFLAG is 1, try to reload the disk. */
 static
-int cdrom_eject(ide_drive_t *drive, int ejectflag,
-		struct request_sense *sense)
+int cdrom_eject(ide_drive_t *drive, int ejectflag)
 {
 	struct cdrom_info *cd = drive->driver_data;
 	struct cdrom_device_info *cdi = &cd->devinfo;
@@ -129,20 +128,16 @@ int cdrom_eject(ide_drive_t *drive, int ejectflag,
 	cmd[0] = GPCMD_START_STOP_UNIT;
 	cmd[4] = loej | (ejectflag != 0);
 
-	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, sense, 0, 0);
+	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, NULL, 0, 0);
 }
 
 /* Lock the door if LOCKFLAG is nonzero; unlock it otherwise. */
 static
-int ide_cd_lockdoor(ide_drive_t *drive, int lockflag,
-		    struct request_sense *sense)
+int ide_cd_lockdoor(ide_drive_t *drive, int lockflag)
 {
-	struct request_sense my_sense;
+	struct scsi_sense_hdr sshdr;
 	int stat;
 
-	if (sense == NULL)
-		sense = &my_sense;
-
 	/* If the drive cannot lock the door, just pretend. */
 	if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0) {
 		stat = 0;
@@ -155,14 +150,14 @@ int ide_cd_lockdoor(ide_drive_t *drive, int lockflag,
 		cmd[4] = lockflag ? 1 : 0;
 
 		stat = ide_cd_queue_pc(drive, cmd, 0, NULL, NULL,
-				       sense, 0, 0);
+				       &sshdr, 0, 0);
 	}
 
 	/* If we got an illegal field error, the drive
 	   probably cannot lock the door. */
 	if (stat != 0 &&
-	    sense->sense_key == ILLEGAL_REQUEST &&
-	    (sense->asc == 0x24 || sense->asc == 0x20)) {
+	    sshdr.sense_key == ILLEGAL_REQUEST &&
+	    (sshdr.asc == 0x24 || sshdr.asc == 0x20)) {
 		printk(KERN_ERR "%s: door locking not supported\n",
 			drive->name);
 		drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
@@ -170,7 +165,7 @@ int ide_cd_lockdoor(ide_drive_t *drive, int lockflag,
 	}
 
 	/* no medium, that's alright. */
-	if (stat != 0 && sense->sense_key == NOT_READY && sense->asc == 0x3a)
+	if (stat != 0 && sshdr.sense_key == NOT_READY && sshdr.asc == 0x3a)
 		stat = 0;
 
 	if (stat == 0) {
@@ -186,23 +181,22 @@ int ide_cd_lockdoor(ide_drive_t *drive, int lockflag,
 int ide_cdrom_tray_move(struct cdrom_device_info *cdi, int position)
 {
 	ide_drive_t *drive = cdi->handle;
-	struct request_sense sense;
 
 	if (position) {
-		int stat = ide_cd_lockdoor(drive, 0, &sense);
+		int stat = ide_cd_lockdoor(drive, 0);
 
 		if (stat)
 			return stat;
 	}
 
-	return cdrom_eject(drive, !position, &sense);
+	return cdrom_eject(drive, !position);
 }
 
 int ide_cdrom_lock_door(struct cdrom_device_info *cdi, int lock)
 {
 	ide_drive_t *drive = cdi->handle;
 
-	return ide_cd_lockdoor(drive, lock, NULL);
+	return ide_cd_lockdoor(drive, lock);
 }
 
 /*
@@ -213,7 +207,6 @@ int ide_cdrom_select_speed(struct cdrom_device_info *cdi, int speed)
 {
 	ide_drive_t *drive = cdi->handle;
 	struct cdrom_info *cd = drive->driver_data;
-	struct request_sense sense;
 	u8 buf[ATAPI_CAPABILITIES_PAGE_SIZE];
 	int stat;
 	unsigned char cmd[BLK_MAX_CDB];
@@ -236,7 +229,7 @@ int ide_cdrom_select_speed(struct cdrom_device_info *cdi, int speed)
 		cmd[5] = speed & 0xff;
 	}
 
-	stat = ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, &sense, 0, 0);
+	stat = ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, NULL, 0, 0);
 
 	if (!ide_cdrom_get_capabilities(drive, buf)) {
 		ide_cdrom_update_speed(drive, buf);
@@ -252,11 +245,10 @@ int ide_cdrom_get_last_session(struct cdrom_device_info *cdi,
 	struct atapi_toc *toc;
 	ide_drive_t *drive = cdi->handle;
 	struct cdrom_info *info = drive->driver_data;
-	struct request_sense sense;
 	int ret;
 
 	if ((drive->atapi_flags & IDE_AFLAG_TOC_VALID) == 0 || !info->toc) {
-		ret = ide_cd_read_toc(drive, &sense);
+		ret = ide_cd_read_toc(drive);
 		if (ret)
 			return ret;
 	}
@@ -300,7 +292,6 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 {
 	ide_drive_t *drive = cdi->handle;
 	struct cdrom_info *cd = drive->driver_data;
-	struct request_sense sense;
 	struct request *rq;
 	int ret;
 
@@ -315,7 +306,7 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	 * lock it again.
 	 */
 	if (drive->atapi_flags & IDE_AFLAG_DOOR_LOCKED)
-		(void)ide_cd_lockdoor(drive, 1, &sense);
+		(void)ide_cd_lockdoor(drive, 1);
 
 	return ret;
 }
@@ -355,7 +346,6 @@ static int ide_cd_fake_play_trkind(ide_drive_t *drive, void *arg)
 	struct atapi_toc_entry *first_toc, *last_toc;
 	unsigned long lba_start, lba_end;
 	int stat;
-	struct request_sense sense;
 	unsigned char cmd[BLK_MAX_CDB];
 
 	stat = ide_cd_get_toc_entry(drive, ti->cdti_trk0, &first_toc);
@@ -380,7 +370,7 @@ static int ide_cd_fake_play_trkind(ide_drive_t *drive, void *arg)
 	lba_to_msf(lba_start,   &cmd[3], &cmd[4], &cmd[5]);
 	lba_to_msf(lba_end - 1, &cmd[6], &cmd[7], &cmd[8]);
 
-	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, &sense, 0, 0);
+	return ide_cd_queue_pc(drive, cmd, 0, NULL, NULL, NULL, 0, 0);
 }
 
 static int ide_cd_read_tochdr(ide_drive_t *drive, void *arg)
@@ -391,7 +381,7 @@ static int ide_cd_read_tochdr(ide_drive_t *drive, void *arg)
 	int stat;
 
 	/* Make sure our saved TOC is valid. */
-	stat = ide_cd_read_toc(drive, NULL);
+	stat = ide_cd_read_toc(drive);
 	if (stat)
 		return stat;
 
@@ -461,8 +451,8 @@ int ide_cdrom_packet(struct cdrom_device_info *cdi,
 	   layer. the packet must be complete, as we do not
 	   touch it at all. */
 
-	if (cgc->sense)
-		memset(cgc->sense, 0, sizeof(struct request_sense));
+	if (cgc->sshdr)
+		memset(cgc->sshdr, 0, sizeof(*cgc->sshdr));
 
 	if (cgc->quiet)
 		flags |= RQF_QUIET;
@@ -470,7 +460,7 @@ int ide_cdrom_packet(struct cdrom_device_info *cdi,
 	cgc->stat = ide_cd_queue_pc(drive, cgc->cmd,
 				    cgc->data_direction == CGC_DATA_WRITE,
 				    cgc->buffer, &len,
-				    cgc->sense, cgc->timeout, flags);
+				    cgc->sshdr, cgc->timeout, flags);
 	if (!cgc->stat)
 		cgc->buflen -= len;
 	return cgc->stat;

drivers/infiniband/ulp/iser/iser_memory.c

@@ -311,7 +311,7 @@ iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs,
 {
 	domain->sig_type = IB_SIG_TYPE_T10_DIF;
 	domain->sig.dif.pi_interval = scsi_prot_interval(sc);
-	domain->sig.dif.ref_tag = scsi_prot_ref_tag(sc);
+	domain->sig.dif.ref_tag = t10_pi_ref_tag(sc->request);
 	/*
 	 * At the moment we hard code those, but in the future
 	 * we will take them from sc.

drivers/lightnvm/Kconfig

@@ -17,23 +17,25 @@ menuconfig NVM
 
 if NVM
 
-config NVM_DEBUG
-	bool "Open-Channel SSD debugging support"
-	default n
-	---help---
-	Exposes a debug management interface to create/remove targets at:
+config NVM_PBLK
+	tristate "Physical Block Device Open-Channel SSD target"
+	help
+	  Allows an open-channel SSD to be exposed as a block device to the
+	  host. The target assumes the device exposes raw flash and must be
+	  explicitly managed by the host.
 
-	  /sys/module/lnvm/parameters/configure_debug
+	  Please note the disk format is considered EXPERIMENTAL for now.
 
-	It is required to create/remove targets without IOCTLs.
+if NVM_PBLK
 
-config NVM_PBLK
-	tristate "Physical Block Device Open-Channel SSD target"
-	---help---
-	Allows an open-channel SSD to be exposed as a block device to the
-	host. The target assumes the device exposes raw flash and must be
-	explicitly managed by the host.
+config NVM_PBLK_DEBUG
+	bool "PBlk Debug Support"
+	default n
+	help
+	  Enables debug support for pblk. This includes extra checks, more
+	  vocal error messages, and extra tracking fields in the pblk sysfs
+	  entries.
 
-	Please note the disk format is considered EXPERIMENTAL for now.
+endif # NVM_PBLK_DEBUG
 
 endif # NVM

drivers/lightnvm/pblk-cache.c

@@ -27,7 +27,8 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
 	int nr_entries = pblk_get_secs(bio);
 	int i, ret;
 
-	generic_start_io_acct(q, WRITE, bio_sectors(bio), &pblk->disk->part0);
+	generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
+			      &pblk->disk->part0);
 
 	/* Update the write buffer head (mem) with the entries that we can
 	 * write. The write in itself cannot fail, so there is no need to
@@ -67,7 +68,7 @@ retry:
 
 	atomic64_add(nr_entries, &pblk->user_wa);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(nr_entries, &pblk->inflight_writes);
 	atomic_long_add(nr_entries, &pblk->req_writes);
 #endif
@@ -75,7 +76,7 @@ retry:
 	pblk_rl_inserted(&pblk->rl, nr_entries);
 
 out:
-	generic_end_io_acct(q, WRITE, &pblk->disk->part0, start_time);
+	generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
 	pblk_write_should_kick(pblk);
 	return ret;
 }
@@ -123,7 +124,7 @@ retry:
 
 	atomic64_add(valid_entries, &pblk->gc_wa);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(valid_entries, &pblk->inflight_writes);
 	atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 #endif

drivers/lightnvm/pblk-core.c

@@ -35,7 +35,7 @@ static void pblk_line_mark_bb(struct work_struct *work)
 		line = &pblk->lines[pblk_ppa_to_line(*ppa)];
 		pos = pblk_ppa_to_pos(&dev->geo, *ppa);
 
-		pr_err("pblk: failed to mark bb, line:%d, pos:%d\n",
+		pblk_err(pblk, "failed to mark bb, line:%d, pos:%d\n",
 				line->id, pos);
 	}
 
@@ -51,12 +51,12 @@ static void pblk_mark_bb(struct pblk *pblk, struct pblk_line *line,
 	struct ppa_addr *ppa;
 	int pos = pblk_ppa_to_pos(geo, ppa_addr);
 
-	pr_debug("pblk: erase failed: line:%d, pos:%d\n", line->id, pos);
+	pblk_debug(pblk, "erase failed: line:%d, pos:%d\n", line->id, pos);
 	atomic_long_inc(&pblk->erase_failed);
 
 	atomic_dec(&line->blk_in_line);
 	if (test_and_set_bit(pos, line->blk_bitmap))
-		pr_err("pblk: attempted to erase bb: line:%d, pos:%d\n",
+		pblk_err(pblk, "attempted to erase bb: line:%d, pos:%d\n",
 							line->id, pos);
 
 	/* Not necessary to mark bad blocks on 2.0 spec. */
@@ -194,7 +194,7 @@ void pblk_map_invalidate(struct pblk *pblk, struct ppa_addr ppa)
 	u64 paddr;
 	int line_id;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a device address */
 	BUG_ON(pblk_addr_in_cache(ppa));
 	BUG_ON(pblk_ppa_empty(ppa));
@@ -264,6 +264,7 @@ void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int type)
 	switch (type) {
 	case PBLK_WRITE:
 		kfree(((struct pblk_c_ctx *)nvm_rq_to_pdu(rqd))->lun_bitmap);
+		/* fall through */
 	case PBLK_WRITE_INT:
 		pool = &pblk->w_rq_pool;
 		break;
@@ -274,7 +275,7 @@ void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int type)
 		pool = &pblk->e_rq_pool;
 		break;
 	default:
-		pr_err("pblk: trying to free unknown rqd type\n");
+		pblk_err(pblk, "trying to free unknown rqd type\n");
 		return;
 	}
 
@@ -310,7 +311,7 @@ int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
 
 		ret = bio_add_pc_page(q, bio, page, PBLK_EXPOSED_PAGE_SIZE, 0);
 		if (ret != PBLK_EXPOSED_PAGE_SIZE) {
-			pr_err("pblk: could not add page to bio\n");
+			pblk_err(pblk, "could not add page to bio\n");
 			mempool_free(page, &pblk->page_bio_pool);
 			goto err;
 		}
@@ -410,7 +411,7 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
 		line->state = PBLK_LINESTATE_CORRUPT;
 		line->gc_group = PBLK_LINEGC_NONE;
 		move_list =  &l_mg->corrupt_list;
-		pr_err("pblk: corrupted vsc for line %d, vsc:%d (%d/%d/%d)\n",
+		pblk_err(pblk, "corrupted vsc for line %d, vsc:%d (%d/%d/%d)\n",
 						line->id, vsc,
 						line->sec_in_line,
 						lm->high_thrs, lm->mid_thrs);
@@ -430,7 +431,7 @@ void pblk_discard(struct pblk *pblk, struct bio *bio)
 void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd)
 {
 	atomic_long_inc(&pblk->write_failed);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	pblk_print_failed_rqd(pblk, rqd, rqd->error);
 #endif
 }
@@ -452,9 +453,9 @@ void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd)
 		atomic_long_inc(&pblk->read_failed);
 		break;
 	default:
-		pr_err("pblk: unknown read error:%d\n", rqd->error);
+		pblk_err(pblk, "unknown read error:%d\n", rqd->error);
 	}
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	pblk_print_failed_rqd(pblk, rqd, rqd->error);
 #endif
 }
@@ -470,7 +471,7 @@ int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd)
 
 	atomic_inc(&pblk->inflight_io);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	if (pblk_check_io(pblk, rqd))
 		return NVM_IO_ERR;
 #endif
@@ -484,7 +485,7 @@ int pblk_submit_io_sync(struct pblk *pblk, struct nvm_rq *rqd)
 
 	atomic_inc(&pblk->inflight_io);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	if (pblk_check_io(pblk, rqd))
 		return NVM_IO_ERR;
 #endif
@@ -517,7 +518,7 @@ struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 	for (i = 0; i < nr_secs; i++) {
 		page = vmalloc_to_page(kaddr);
 		if (!page) {
-			pr_err("pblk: could not map vmalloc bio\n");
+			pblk_err(pblk, "could not map vmalloc bio\n");
 			bio_put(bio);
 			bio = ERR_PTR(-ENOMEM);
 			goto out;
@@ -525,7 +526,7 @@ struct bio *pblk_bio_map_addr(struct pblk *pblk, void *data,
 
 		ret = bio_add_pc_page(dev->q, bio, page, PAGE_SIZE, 0);
 		if (ret != PAGE_SIZE) {
-			pr_err("pblk: could not add page to bio\n");
+			pblk_err(pblk, "could not add page to bio\n");
 			bio_put(bio);
 			bio = ERR_PTR(-ENOMEM);
 			goto out;
@@ -711,7 +712,7 @@ next_rq:
 			while (test_bit(pos, line->blk_bitmap)) {
 				paddr += min;
 				if (pblk_boundary_paddr_checks(pblk, paddr)) {
-					pr_err("pblk: corrupt emeta line:%d\n",
+					pblk_err(pblk, "corrupt emeta line:%d\n",
 								line->id);
 					bio_put(bio);
 					ret = -EINTR;
@@ -723,7 +724,7 @@ next_rq:
 			}
 
 			if (pblk_boundary_paddr_checks(pblk, paddr + min)) {
-				pr_err("pblk: corrupt emeta line:%d\n",
+				pblk_err(pblk, "corrupt emeta line:%d\n",
 								line->id);
 				bio_put(bio);
 				ret = -EINTR;
@@ -738,7 +739,7 @@ next_rq:
 
 	ret = pblk_submit_io_sync(pblk, &rqd);
 	if (ret) {
-		pr_err("pblk: emeta I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "emeta I/O submission failed: %d\n", ret);
 		bio_put(bio);
 		goto free_rqd_dma;
 	}
@@ -843,7 +844,7 @@ static int pblk_line_submit_smeta_io(struct pblk *pblk, struct pblk_line *line,
 	 */
 	ret = pblk_submit_io_sync(pblk, &rqd);
 	if (ret) {
-		pr_err("pblk: smeta I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "smeta I/O submission failed: %d\n", ret);
 		bio_put(bio);
 		goto free_ppa_list;
 	}
@@ -905,7 +906,7 @@ static int pblk_blk_erase_sync(struct pblk *pblk, struct ppa_addr ppa)
 		struct nvm_tgt_dev *dev = pblk->dev;
 		struct nvm_geo *geo = &dev->geo;
 
-		pr_err("pblk: could not sync erase line:%d,blk:%d\n",
+		pblk_err(pblk, "could not sync erase line:%d,blk:%d\n",
 					pblk_ppa_to_line(ppa),
 					pblk_ppa_to_pos(geo, ppa));
 
@@ -945,7 +946,7 @@ int pblk_line_erase(struct pblk *pblk, struct pblk_line *line)
 
 		ret = pblk_blk_erase_sync(pblk, ppa);
 		if (ret) {
-			pr_err("pblk: failed to erase line %d\n", line->id);
+			pblk_err(pblk, "failed to erase line %d\n", line->id);
 			return ret;
 		}
 	} while (1);
@@ -1012,7 +1013,7 @@ static int pblk_line_init_metadata(struct pblk *pblk, struct pblk_line *line,
 		list_add_tail(&line->list, &l_mg->bad_list);
 		spin_unlock(&l_mg->free_lock);
 
-		pr_debug("pblk: line %d is bad\n", line->id);
+		pblk_debug(pblk, "line %d is bad\n", line->id);
 
 		return 0;
 	}
@@ -1122,7 +1123,7 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 	line->cur_sec = off + lm->smeta_sec;
 
 	if (init && pblk_line_submit_smeta_io(pblk, line, off, PBLK_WRITE)) {
-		pr_debug("pblk: line smeta I/O failed. Retry\n");
+		pblk_debug(pblk, "line smeta I/O failed. Retry\n");
 		return 0;
 	}
 
@@ -1154,7 +1155,7 @@ static int pblk_line_init_bb(struct pblk *pblk, struct pblk_line *line,
 		spin_unlock(&line->lock);
 
 		list_add_tail(&line->list, &l_mg->bad_list);
-		pr_err("pblk: unexpected line %d is bad\n", line->id);
+		pblk_err(pblk, "unexpected line %d is bad\n", line->id);
 
 		return 0;
 	}
@@ -1299,7 +1300,7 @@ struct pblk_line *pblk_line_get(struct pblk *pblk)
 
 retry:
 	if (list_empty(&l_mg->free_list)) {
-		pr_err("pblk: no free lines\n");
+		pblk_err(pblk, "no free lines\n");
 		return NULL;
 	}
 
@@ -1315,7 +1316,7 @@ retry:
 
 		list_add_tail(&line->list, &l_mg->bad_list);
 
-		pr_debug("pblk: line %d is bad\n", line->id);
+		pblk_debug(pblk, "line %d is bad\n", line->id);
 		goto retry;
 	}
 
@@ -1329,7 +1330,7 @@ retry:
 			list_add(&line->list, &l_mg->corrupt_list);
 			goto retry;
 		default:
-			pr_err("pblk: failed to prepare line %d\n", line->id);
+			pblk_err(pblk, "failed to prepare line %d\n", line->id);
 			list_add(&line->list, &l_mg->free_list);
 			l_mg->nr_free_lines++;
 			return NULL;
@@ -1477,7 +1478,7 @@ static void pblk_line_close_meta_sync(struct pblk *pblk)
 
 			ret = pblk_submit_meta_io(pblk, line);
 			if (ret) {
-				pr_err("pblk: sync meta line %d failed (%d)\n",
+				pblk_err(pblk, "sync meta line %d failed (%d)\n",
 							line->id, ret);
 				return;
 			}
@@ -1507,7 +1508,7 @@ void __pblk_pipeline_flush(struct pblk *pblk)
 
 	ret = pblk_recov_pad(pblk);
 	if (ret) {
-		pr_err("pblk: could not close data on teardown(%d)\n", ret);
+		pblk_err(pblk, "could not close data on teardown(%d)\n", ret);
 		return;
 	}
 
@@ -1687,7 +1688,7 @@ int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr ppa)
 		struct nvm_tgt_dev *dev = pblk->dev;
 		struct nvm_geo *geo = &dev->geo;
 
-		pr_err("pblk: could not async erase line:%d,blk:%d\n",
+		pblk_err(pblk, "could not async erase line:%d,blk:%d\n",
 					pblk_ppa_to_line(ppa),
 					pblk_ppa_to_pos(geo, ppa));
 	}
@@ -1726,7 +1727,7 @@ void pblk_line_close(struct pblk *pblk, struct pblk_line *line)
 	struct list_head *move_list;
 	int i;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	WARN(!bitmap_full(line->map_bitmap, lm->sec_per_line),
 				"pblk: corrupt closed line %d\n", line->id);
 #endif
@@ -1856,7 +1857,7 @@ static void __pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list,
 	 * Only send one inflight I/O per LUN. Since we map at a page
 	 * granurality, all ppas in the I/O will map to the same LUN
 	 */
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	int i;
 
 	for (i = 1; i < nr_ppas; i++)
@@ -1866,7 +1867,8 @@ static void __pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list,
 
 	ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(30000));
 	if (ret == -ETIME || ret == -EINTR)
-		pr_err("pblk: taking lun semaphore timed out: err %d\n", -ret);
+		pblk_err(pblk, "taking lun semaphore timed out: err %d\n",
+				-ret);
 }
 
 void pblk_down_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas)
@@ -1901,7 +1903,7 @@ void pblk_up_page(struct pblk *pblk, struct ppa_addr *ppa_list, int nr_ppas)
 	struct pblk_lun *rlun;
 	int pos = pblk_ppa_to_pos(geo, ppa_list[0]);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	int i;
 
 	for (i = 1; i < nr_ppas; i++)
@@ -1951,7 +1953,7 @@ void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa)
 void pblk_update_map_cache(struct pblk *pblk, sector_t lba, struct ppa_addr ppa)
 {
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a cache address */
 	BUG_ON(!pblk_addr_in_cache(ppa));
 	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, pblk_addr_to_cacheline(ppa)));
@@ -1966,7 +1968,7 @@ int pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa_new,
 	struct ppa_addr ppa_l2p, ppa_gc;
 	int ret = 1;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a cache address */
 	BUG_ON(!pblk_addr_in_cache(ppa_new));
 	BUG_ON(pblk_rb_pos_oob(&pblk->rwb, pblk_addr_to_cacheline(ppa_new)));
@@ -2003,14 +2005,14 @@ void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
 {
 	struct ppa_addr ppa_l2p;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a device address */
 	BUG_ON(pblk_addr_in_cache(ppa_mapped));
 #endif
 	/* Invalidate and discard padded entries */
 	if (lba == ADDR_EMPTY) {
 		atomic64_inc(&pblk->pad_wa);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 		atomic_long_inc(&pblk->padded_wb);
 #endif
 		if (!pblk_ppa_empty(ppa_mapped))
@@ -2036,7 +2038,7 @@ void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
 		goto out;
 	}
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	WARN_ON(!pblk_addr_in_cache(ppa_l2p) && !pblk_ppa_empty(ppa_l2p));
 #endif
 

drivers/lightnvm/pblk-gc.c

@@ -90,7 +90,7 @@ static void pblk_gc_line_ws(struct work_struct *work)
 
 	gc_rq->data = vmalloc(array_size(gc_rq->nr_secs, geo->csecs));
 	if (!gc_rq->data) {
-		pr_err("pblk: could not GC line:%d (%d/%d)\n",
+		pblk_err(pblk, "could not GC line:%d (%d/%d)\n",
 					line->id, *line->vsc, gc_rq->nr_secs);
 		goto out;
 	}
@@ -98,7 +98,7 @@ static void pblk_gc_line_ws(struct work_struct *work)
 	/* Read from GC victim block */
 	ret = pblk_submit_read_gc(pblk, gc_rq);
 	if (ret) {
-		pr_err("pblk: failed GC read in line:%d (err:%d)\n",
+		pblk_err(pblk, "failed GC read in line:%d (err:%d)\n",
 								line->id, ret);
 		goto out;
 	}
@@ -146,7 +146,7 @@ static __le64 *get_lba_list_from_emeta(struct pblk *pblk,
 
 	ret = pblk_line_read_emeta(pblk, line, emeta_buf);
 	if (ret) {
-		pr_err("pblk: line %d read emeta failed (%d)\n",
+		pblk_err(pblk, "line %d read emeta failed (%d)\n",
 				line->id, ret);
 		pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
 		return NULL;
@@ -160,7 +160,7 @@ static __le64 *get_lba_list_from_emeta(struct pblk *pblk,
 
 	ret = pblk_recov_check_emeta(pblk, emeta_buf);
 	if (ret) {
-		pr_err("pblk: inconsistent emeta (line %d)\n",
+		pblk_err(pblk, "inconsistent emeta (line %d)\n",
 				line->id);
 		pblk_mfree(emeta_buf, l_mg->emeta_alloc_type);
 		return NULL;
@@ -201,7 +201,7 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
 	} else {
 		lba_list = get_lba_list_from_emeta(pblk, line);
 		if (!lba_list) {
-			pr_err("pblk: could not interpret emeta (line %d)\n",
+			pblk_err(pblk, "could not interpret emeta (line %d)\n",
 					line->id);
 			goto fail_free_invalid_bitmap;
 		}
@@ -213,7 +213,7 @@ static void pblk_gc_line_prepare_ws(struct work_struct *work)
 	spin_unlock(&line->lock);
 
 	if (sec_left < 0) {
-		pr_err("pblk: corrupted GC line (%d)\n", line->id);
+		pblk_err(pblk, "corrupted GC line (%d)\n", line->id);
 		goto fail_free_lba_list;
 	}
 
@@ -289,7 +289,7 @@ fail_free_ws:
 	kref_put(&line->ref, pblk_line_put);
 	atomic_dec(&gc->read_inflight_gc);
 
-	pr_err("pblk: Failed to GC line %d\n", line->id);
+	pblk_err(pblk, "failed to GC line %d\n", line->id);
 }
 
 static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
@@ -297,7 +297,7 @@ static int pblk_gc_line(struct pblk *pblk, struct pblk_line *line)
 	struct pblk_gc *gc = &pblk->gc;
 	struct pblk_line_ws *line_ws;
 
-	pr_debug("pblk: line '%d' being reclaimed for GC\n", line->id);
+	pblk_debug(pblk, "line '%d' being reclaimed for GC\n", line->id);
 
 	line_ws = kmalloc(sizeof(struct pblk_line_ws), GFP_KERNEL);
 	if (!line_ws)
@@ -351,7 +351,7 @@ static int pblk_gc_read(struct pblk *pblk)
 	pblk_gc_kick(pblk);
 
 	if (pblk_gc_line(pblk, line))
-		pr_err("pblk: failed to GC line %d\n", line->id);
+		pblk_err(pblk, "failed to GC line %d\n", line->id);
 
 	return 0;
 }
@@ -522,8 +522,8 @@ static int pblk_gc_reader_ts(void *data)
 		io_schedule();
 	}
 
-#ifdef CONFIG_NVM_DEBUG
-	pr_info("pblk: flushing gc pipeline, %d lines left\n",
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "flushing gc pipeline, %d lines left\n",
 		atomic_read(&gc->pipeline_gc));
 #endif
 
@@ -540,7 +540,7 @@ static int pblk_gc_reader_ts(void *data)
 static void pblk_gc_start(struct pblk *pblk)
 {
 	pblk->gc.gc_active = 1;
-	pr_debug("pblk: gc start\n");
+	pblk_debug(pblk, "gc start\n");
 }
 
 void pblk_gc_should_start(struct pblk *pblk)
@@ -605,14 +605,14 @@ int pblk_gc_init(struct pblk *pblk)
 
 	gc->gc_ts = kthread_create(pblk_gc_ts, pblk, "pblk-gc-ts");
 	if (IS_ERR(gc->gc_ts)) {
-		pr_err("pblk: could not allocate GC main kthread\n");
+		pblk_err(pblk, "could not allocate GC main kthread\n");
 		return PTR_ERR(gc->gc_ts);
 	}
 
 	gc->gc_writer_ts = kthread_create(pblk_gc_writer_ts, pblk,
 							"pblk-gc-writer-ts");
 	if (IS_ERR(gc->gc_writer_ts)) {
-		pr_err("pblk: could not allocate GC writer kthread\n");
+		pblk_err(pblk, "could not allocate GC writer kthread\n");
 		ret = PTR_ERR(gc->gc_writer_ts);
 		goto fail_free_main_kthread;
 	}
@@ -620,7 +620,7 @@ int pblk_gc_init(struct pblk *pblk)
 	gc->gc_reader_ts = kthread_create(pblk_gc_reader_ts, pblk,
 							"pblk-gc-reader-ts");
 	if (IS_ERR(gc->gc_reader_ts)) {
-		pr_err("pblk: could not allocate GC reader kthread\n");
+		pblk_err(pblk, "could not allocate GC reader kthread\n");
 		ret = PTR_ERR(gc->gc_reader_ts);
 		goto fail_free_writer_kthread;
 	}
@@ -641,7 +641,7 @@ int pblk_gc_init(struct pblk *pblk)
 	gc->gc_line_reader_wq = alloc_workqueue("pblk-gc-line-reader-wq",
 			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_GC_MAX_READERS);
 	if (!gc->gc_line_reader_wq) {
-		pr_err("pblk: could not allocate GC line reader workqueue\n");
+		pblk_err(pblk, "could not allocate GC line reader workqueue\n");
 		ret = -ENOMEM;
 		goto fail_free_reader_kthread;
 	}
@@ -650,7 +650,7 @@ int pblk_gc_init(struct pblk *pblk)
 	gc->gc_reader_wq = alloc_workqueue("pblk-gc-line_wq",
 					WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
 	if (!gc->gc_reader_wq) {
-		pr_err("pblk: could not allocate GC reader workqueue\n");
+		pblk_err(pblk, "could not allocate GC reader workqueue\n");
 		ret = -ENOMEM;
 		goto fail_free_reader_line_wq;
 	}

drivers/lightnvm/pblk-init.c

@@ -91,7 +91,7 @@ static size_t pblk_trans_map_size(struct pblk *pblk)
 	return entry_size * pblk->rl.nr_secs;
 }
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 static u32 pblk_l2p_crc(struct pblk *pblk)
 {
 	size_t map_size;
@@ -117,13 +117,13 @@ static int pblk_l2p_recover(struct pblk *pblk, bool factory_init)
 	} else {
 		line = pblk_recov_l2p(pblk);
 		if (IS_ERR(line)) {
-			pr_err("pblk: could not recover l2p table\n");
+			pblk_err(pblk, "could not recover l2p table\n");
 			return -EFAULT;
 		}
 	}
 
-#ifdef CONFIG_NVM_DEBUG
-	pr_info("pblk init: L2P CRC: %x\n", pblk_l2p_crc(pblk));
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "init: L2P CRC: %x\n", pblk_l2p_crc(pblk));
 #endif
 
 	/* Free full lines directly as GC has not been started yet */
@@ -166,7 +166,7 @@ static int pblk_l2p_init(struct pblk *pblk, bool factory_init)
 static void pblk_rwb_free(struct pblk *pblk)
 {
 	if (pblk_rb_tear_down_check(&pblk->rwb))
-		pr_err("pblk: write buffer error on tear down\n");
+		pblk_err(pblk, "write buffer error on tear down\n");
 
 	pblk_rb_data_free(&pblk->rwb);
 	vfree(pblk_rb_entries_ref(&pblk->rwb));
@@ -179,11 +179,14 @@ static int pblk_rwb_init(struct pblk *pblk)
 	struct pblk_rb_entry *entries;
 	unsigned long nr_entries, buffer_size;
 	unsigned int power_size, power_seg_sz;
+	int pgs_in_buffer;
 
-	if (write_buffer_size && (write_buffer_size > pblk->pgs_in_buffer))
+	pgs_in_buffer = max(geo->mw_cunits, geo->ws_opt) * geo->all_luns;
+
+	if (write_buffer_size && (write_buffer_size > pgs_in_buffer))
 		buffer_size = write_buffer_size;
 	else
-		buffer_size = pblk->pgs_in_buffer;
+		buffer_size = pgs_in_buffer;
 
 	nr_entries = pblk_rb_calculate_size(buffer_size);
 
@@ -200,7 +203,8 @@ static int pblk_rwb_init(struct pblk *pblk)
 /* Minimum pages needed within a lun */
 #define ADDR_POOL_SIZE 64
 
-static int pblk_set_addrf_12(struct nvm_geo *geo, struct nvm_addrf_12 *dst)
+static int pblk_set_addrf_12(struct pblk *pblk, struct nvm_geo *geo,
+			     struct nvm_addrf_12 *dst)
 {
 	struct nvm_addrf_12 *src = (struct nvm_addrf_12 *)&geo->addrf;
 	int power_len;
@@ -208,14 +212,14 @@ static int pblk_set_addrf_12(struct nvm_geo *geo, struct nvm_addrf_12 *dst)
 	/* Re-calculate channel and lun format to adapt to configuration */
 	power_len = get_count_order(geo->num_ch);
 	if (1 << power_len != geo->num_ch) {
-		pr_err("pblk: supports only power-of-two channel config.\n");
+		pblk_err(pblk, "supports only power-of-two channel config.\n");
 		return -EINVAL;
 	}
 	dst->ch_len = power_len;
 
 	power_len = get_count_order(geo->num_lun);
 	if (1 << power_len != geo->num_lun) {
-		pr_err("pblk: supports only power-of-two LUN config.\n");
+		pblk_err(pblk, "supports only power-of-two LUN config.\n");
 		return -EINVAL;
 	}
 	dst->lun_len = power_len;
@@ -282,18 +286,19 @@ static int pblk_set_addrf(struct pblk *pblk)
 	case NVM_OCSSD_SPEC_12:
 		div_u64_rem(geo->clba, pblk->min_write_pgs, &mod);
 		if (mod) {
-			pr_err("pblk: bad configuration of sectors/pages\n");
+			pblk_err(pblk, "bad configuration of sectors/pages\n");
 			return -EINVAL;
 		}
 
-		pblk->addrf_len = pblk_set_addrf_12(geo, (void *)&pblk->addrf);
+		pblk->addrf_len = pblk_set_addrf_12(pblk, geo,
+							(void *)&pblk->addrf);
 		break;
 	case NVM_OCSSD_SPEC_20:
 		pblk->addrf_len = pblk_set_addrf_20(geo, (void *)&pblk->addrf,
-								&pblk->uaddrf);
+							&pblk->uaddrf);
 		break;
 	default:
-		pr_err("pblk: OCSSD revision not supported (%d)\n",
+		pblk_err(pblk, "OCSSD revision not supported (%d)\n",
 								geo->version);
 		return -EINVAL;
 	}
@@ -366,15 +371,13 @@ static int pblk_core_init(struct pblk *pblk)
 	atomic64_set(&pblk->nr_flush, 0);
 	pblk->nr_flush_rst = 0;
 
-	pblk->pgs_in_buffer = geo->mw_cunits * geo->all_luns;
-
 	pblk->min_write_pgs = geo->ws_opt * (geo->csecs / PAGE_SIZE);
 	max_write_ppas = pblk->min_write_pgs * geo->all_luns;
 	pblk->max_write_pgs = min_t(int, max_write_ppas, NVM_MAX_VLBA);
 	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);
 
 	if (pblk->max_write_pgs > PBLK_MAX_REQ_ADDRS) {
-		pr_err("pblk: vector list too big(%u > %u)\n",
+		pblk_err(pblk, "vector list too big(%u > %u)\n",
 				pblk->max_write_pgs, PBLK_MAX_REQ_ADDRS);
 		return -EINVAL;
 	}
@@ -607,7 +610,7 @@ static int pblk_luns_init(struct pblk *pblk)
 
 	/* TODO: Implement unbalanced LUN support */
 	if (geo->num_lun < 0) {
-		pr_err("pblk: unbalanced LUN config.\n");
+		pblk_err(pblk, "unbalanced LUN config.\n");
 		return -EINVAL;
 	}
 
@@ -716,10 +719,11 @@ static int pblk_setup_line_meta_12(struct pblk *pblk, struct pblk_line *line,
 
 		/*
 		 * In 1.2 spec. chunk state is not persisted by the device. Thus
-		 * some of the values are reset each time pblk is instantiated.
+		 * some of the values are reset each time pblk is instantiated,
+		 * so we have to assume that the block is closed.
 		 */
 		if (lun_bb_meta[line->id] == NVM_BLK_T_FREE)
-			chunk->state =  NVM_CHK_ST_FREE;
+			chunk->state =  NVM_CHK_ST_CLOSED;
 		else
 			chunk->state = NVM_CHK_ST_OFFLINE;
 
@@ -1026,7 +1030,7 @@ add_emeta_page:
 					lm->emeta_sec[0], geo->clba);
 
 	if (lm->min_blk_line > lm->blk_per_line) {
-		pr_err("pblk: config. not supported. Min. LUN in line:%d\n",
+		pblk_err(pblk, "config. not supported. Min. LUN in line:%d\n",
 							lm->blk_per_line);
 		return -EINVAL;
 	}
@@ -1078,7 +1082,7 @@ static int pblk_lines_init(struct pblk *pblk)
 	}
 
 	if (!nr_free_chks) {
-		pr_err("pblk: too many bad blocks prevent for sane instance\n");
+		pblk_err(pblk, "too many bad blocks prevent for sane instance\n");
 		return -EINTR;
 	}
 
@@ -1108,7 +1112,7 @@ static int pblk_writer_init(struct pblk *pblk)
 		int err = PTR_ERR(pblk->writer_ts);
 
 		if (err != -EINTR)
-			pr_err("pblk: could not allocate writer kthread (%d)\n",
+			pblk_err(pblk, "could not allocate writer kthread (%d)\n",
 					err);
 		return err;
 	}
@@ -1154,7 +1158,7 @@ static void pblk_tear_down(struct pblk *pblk, bool graceful)
 	pblk_rb_sync_l2p(&pblk->rwb);
 	pblk_rl_free(&pblk->rl);
 
-	pr_debug("pblk: consistent tear down (graceful:%d)\n", graceful);
+	pblk_debug(pblk, "consistent tear down (graceful:%d)\n", graceful);
 }
 
 static void pblk_exit(void *private, bool graceful)
@@ -1165,8 +1169,8 @@ static void pblk_exit(void *private, bool graceful)
 	pblk_gc_exit(pblk, graceful);
 	pblk_tear_down(pblk, graceful);
 
-#ifdef CONFIG_NVM_DEBUG
-	pr_info("pblk exit: L2P CRC: %x\n", pblk_l2p_crc(pblk));
+#ifdef CONFIG_NVM_PBLK_DEBUG
+	pblk_info(pblk, "exit: L2P CRC: %x\n", pblk_l2p_crc(pblk));
 #endif
 
 	pblk_free(pblk);
@@ -1189,34 +1193,35 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	struct pblk *pblk;
 	int ret;
 
-	/* pblk supports 1.2 and 2.0 versions */
+	pblk = kzalloc(sizeof(struct pblk), GFP_KERNEL);
+	if (!pblk)
+		return ERR_PTR(-ENOMEM);
+
+	pblk->dev = dev;
+	pblk->disk = tdisk;
+	pblk->state = PBLK_STATE_RUNNING;
+	pblk->gc.gc_enabled = 0;
+
 	if (!(geo->version == NVM_OCSSD_SPEC_12 ||
 					geo->version == NVM_OCSSD_SPEC_20)) {
-		pr_err("pblk: OCSSD version not supported (%u)\n",
+		pblk_err(pblk, "OCSSD version not supported (%u)\n",
 							geo->version);
+		kfree(pblk);
 		return ERR_PTR(-EINVAL);
 	}
 
 	if (geo->version == NVM_OCSSD_SPEC_12 && geo->dom & NVM_RSP_L2P) {
-		pr_err("pblk: host-side L2P table not supported. (%x)\n",
+		pblk_err(pblk, "host-side L2P table not supported. (%x)\n",
 							geo->dom);
+		kfree(pblk);
 		return ERR_PTR(-EINVAL);
 	}
 
-	pblk = kzalloc(sizeof(struct pblk), GFP_KERNEL);
-	if (!pblk)
-		return ERR_PTR(-ENOMEM);
-
-	pblk->dev = dev;
-	pblk->disk = tdisk;
-	pblk->state = PBLK_STATE_RUNNING;
-	pblk->gc.gc_enabled = 0;
-
 	spin_lock_init(&pblk->resubmit_lock);
 	spin_lock_init(&pblk->trans_lock);
 	spin_lock_init(&pblk->lock);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_set(&pblk->inflight_writes, 0);
 	atomic_long_set(&pblk->padded_writes, 0);
 	atomic_long_set(&pblk->padded_wb, 0);
@@ -1241,38 +1246,38 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 
 	ret = pblk_core_init(pblk);
 	if (ret) {
-		pr_err("pblk: could not initialize core\n");
+		pblk_err(pblk, "could not initialize core\n");
 		goto fail;
 	}
 
 	ret = pblk_lines_init(pblk);
 	if (ret) {
-		pr_err("pblk: could not initialize lines\n");
+		pblk_err(pblk, "could not initialize lines\n");
 		goto fail_free_core;
 	}
 
 	ret = pblk_rwb_init(pblk);
 	if (ret) {
-		pr_err("pblk: could not initialize write buffer\n");
+		pblk_err(pblk, "could not initialize write buffer\n");
 		goto fail_free_lines;
 	}
 
 	ret = pblk_l2p_init(pblk, flags & NVM_TARGET_FACTORY);
 	if (ret) {
-		pr_err("pblk: could not initialize maps\n");
+		pblk_err(pblk, "could not initialize maps\n");
 		goto fail_free_rwb;
 	}
 
 	ret = pblk_writer_init(pblk);
 	if (ret) {
 		if (ret != -EINTR)
-			pr_err("pblk: could not initialize write thread\n");
+			pblk_err(pblk, "could not initialize write thread\n");
 		goto fail_free_l2p;
 	}
 
 	ret = pblk_gc_init(pblk);
 	if (ret) {
-		pr_err("pblk: could not initialize gc\n");
+		pblk_err(pblk, "could not initialize gc\n");
 		goto fail_stop_writer;
 	}
 
@@ -1287,8 +1292,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 	blk_queue_max_discard_sectors(tqueue, UINT_MAX >> 9);
 	blk_queue_flag_set(QUEUE_FLAG_DISCARD, tqueue);
 
-	pr_info("pblk(%s): luns:%u, lines:%d, secs:%llu, buf entries:%u\n",
-			tdisk->disk_name,
+	pblk_info(pblk, "luns:%u, lines:%d, secs:%llu, buf entries:%u\n",
 			geo->all_luns, pblk->l_mg.nr_lines,
 			(unsigned long long)pblk->rl.nr_secs,
 			pblk->rwb.nr_entries);

drivers/lightnvm/pblk-rb.c

@@ -111,7 +111,7 @@ int pblk_rb_init(struct pblk_rb *rb, struct pblk_rb_entry *rb_entry_base,
 	} while (iter > 0);
 	up_write(&pblk_rb_lock);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_set(&rb->inflight_flush_point, 0);
 #endif
 
@@ -308,7 +308,7 @@ void pblk_rb_write_entry_user(struct pblk_rb *rb, void *data,
 
 	entry = &rb->entries[ring_pos];
 	flags = READ_ONCE(entry->w_ctx.flags);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Caller must guarantee that the entry is free */
 	BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
 #endif
@@ -332,7 +332,7 @@ void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,
 
 	entry = &rb->entries[ring_pos];
 	flags = READ_ONCE(entry->w_ctx.flags);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Caller must guarantee that the entry is free */
 	BUG_ON(!(flags & PBLK_WRITABLE_ENTRY));
 #endif
@@ -362,7 +362,7 @@ static int pblk_rb_flush_point_set(struct pblk_rb *rb, struct bio *bio,
 		return 0;
 	}
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_inc(&rb->inflight_flush_point);
 #endif
 
@@ -547,7 +547,7 @@ try:
 
 		page = virt_to_page(entry->data);
 		if (!page) {
-			pr_err("pblk: could not allocate write bio page\n");
+			pblk_err(pblk, "could not allocate write bio page\n");
 			flags &= ~PBLK_WRITTEN_DATA;
 			flags |= PBLK_SUBMITTED_ENTRY;
 			/* Release flags on context. Protect from writes */
@@ -557,7 +557,7 @@ try:
 
 		if (bio_add_pc_page(q, bio, page, rb->seg_size, 0) !=
 								rb->seg_size) {
-			pr_err("pblk: could not add page to write bio\n");
+			pblk_err(pblk, "could not add page to write bio\n");
 			flags &= ~PBLK_WRITTEN_DATA;
 			flags |= PBLK_SUBMITTED_ENTRY;
 			/* Release flags on context. Protect from writes */
@@ -576,19 +576,19 @@ try:
 
 	if (pad) {
 		if (pblk_bio_add_pages(pblk, bio, GFP_KERNEL, pad)) {
-			pr_err("pblk: could not pad page in write bio\n");
+			pblk_err(pblk, "could not pad page in write bio\n");
 			return NVM_IO_ERR;
 		}
 
 		if (pad < pblk->min_write_pgs)
 			atomic64_inc(&pblk->pad_dist[pad - 1]);
 		else
-			pr_warn("pblk: padding more than min. sectors\n");
+			pblk_warn(pblk, "padding more than min. sectors\n");
 
 		atomic64_add(pad, &pblk->pad_wa);
 	}
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(pad, &pblk->padded_writes);
 #endif
 
@@ -613,7 +613,7 @@ int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,
 	int ret = 1;
 
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Caller must ensure that the access will not cause an overflow */
 	BUG_ON(pos >= rb->nr_entries);
 #endif
@@ -820,7 +820,7 @@ ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf)
 			rb->subm,
 			rb->sync,
 			rb->l2p_update,
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			atomic_read(&rb->inflight_flush_point),
 #else
 			0,
@@ -838,7 +838,7 @@ ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf)
 			rb->subm,
 			rb->sync,
 			rb->l2p_update,
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			atomic_read(&rb->inflight_flush_point),
 #else
 			0,

drivers/lightnvm/pblk-read.c

@@ -28,7 +28,7 @@ static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
 				sector_t lba, struct ppa_addr ppa,
 				int bio_iter, bool advanced_bio)
 {
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Callers must ensure that the ppa points to a cache address */
 	BUG_ON(pblk_ppa_empty(ppa));
 	BUG_ON(!pblk_addr_in_cache(ppa));
@@ -79,7 +79,7 @@ retry:
 			WARN_ON(test_and_set_bit(i, read_bitmap));
 			meta_list[i].lba = cpu_to_le64(lba);
 			advanced_bio = true;
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			atomic_long_inc(&pblk->cache_reads);
 #endif
 		} else {
@@ -97,7 +97,7 @@ next:
 	else
 		rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(nr_secs, &pblk->inflight_reads);
 #endif
 }
@@ -117,13 +117,13 @@ static void pblk_read_check_seq(struct pblk *pblk, struct nvm_rq *rqd,
 			continue;
 
 		if (lba != blba + i) {
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			struct ppa_addr *p;
 
 			p = (nr_lbas == 1) ? &rqd->ppa_list[i] : &rqd->ppa_addr;
-			print_ppa(&pblk->dev->geo, p, "seq", i);
+			print_ppa(pblk, p, "seq", i);
 #endif
-			pr_err("pblk: corrupted read LBA (%llu/%llu)\n",
+			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
 							lba, (u64)blba + i);
 			WARN_ON(1);
 		}
@@ -149,14 +149,14 @@ static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
 		meta_lba = le64_to_cpu(meta_lba_list[j].lba);
 
 		if (lba != meta_lba) {
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			struct ppa_addr *p;
 			int nr_ppas = rqd->nr_ppas;
 
 			p = (nr_ppas == 1) ? &rqd->ppa_list[j] : &rqd->ppa_addr;
-			print_ppa(&pblk->dev->geo, p, "seq", j);
+			print_ppa(pblk, p, "seq", j);
 #endif
-			pr_err("pblk: corrupted read LBA (%llu/%llu)\n",
+			pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
 								lba, meta_lba);
 			WARN_ON(1);
 		}
@@ -185,7 +185,7 @@ static void pblk_read_put_rqd_kref(struct pblk *pblk, struct nvm_rq *rqd)
 
 static void pblk_end_user_read(struct bio *bio)
 {
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	WARN_ONCE(bio->bi_status, "pblk: corrupted read bio\n");
 #endif
 	bio_endio(bio);
@@ -199,7 +199,7 @@ static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
 	struct bio *int_bio = rqd->bio;
 	unsigned long start_time = r_ctx->start_time;
 
-	generic_end_io_acct(dev->q, READ, &pblk->disk->part0, start_time);
+	generic_end_io_acct(dev->q, REQ_OP_READ, &pblk->disk->part0, start_time);
 
 	if (rqd->error)
 		pblk_log_read_err(pblk, rqd);
@@ -212,7 +212,7 @@ static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
 	if (put_line)
 		pblk_read_put_rqd_kref(pblk, rqd);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
 	atomic_long_sub(rqd->nr_ppas, &pblk->inflight_reads);
 #endif
@@ -231,74 +231,36 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
 	__pblk_end_io_read(pblk, rqd, true);
 }
 
-static int pblk_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
-			     struct bio *orig_bio, unsigned int bio_init_idx,
-			     unsigned long *read_bitmap)
+static void pblk_end_partial_read(struct nvm_rq *rqd)
 {
-	struct pblk_sec_meta *meta_list = rqd->meta_list;
-	struct bio *new_bio;
+	struct pblk *pblk = rqd->private;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_pr_ctx *pr_ctx = r_ctx->private;
+	struct bio *new_bio = rqd->bio;
+	struct bio *bio = pr_ctx->orig_bio;
 	struct bio_vec src_bv, dst_bv;
-	void *ppa_ptr = NULL;
-	void *src_p, *dst_p;
-	dma_addr_t dma_ppa_list = 0;
-	__le64 *lba_list_mem, *lba_list_media;
-	int nr_secs = rqd->nr_ppas;
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	int bio_init_idx = pr_ctx->bio_init_idx;
+	unsigned long *read_bitmap = pr_ctx->bitmap;
+	int nr_secs = pr_ctx->orig_nr_secs;
 	int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
-	int i, ret, hole;
-
-	/* Re-use allocated memory for intermediate lbas */
-	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
-	lba_list_media = (((void *)rqd->ppa_list) + 2 * pblk_dma_ppa_size);
-
-	new_bio = bio_alloc(GFP_KERNEL, nr_holes);
-
-	if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
-		goto fail_add_pages;
-
-	if (nr_holes != new_bio->bi_vcnt) {
-		pr_err("pblk: malformed bio\n");
-		goto fail;
-	}
-
-	for (i = 0; i < nr_secs; i++)
-		lba_list_mem[i] = meta_list[i].lba;
-
-	new_bio->bi_iter.bi_sector = 0; /* internal bio */
-	bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
-
-	rqd->bio = new_bio;
-	rqd->nr_ppas = nr_holes;
-	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
-
-	if (unlikely(nr_holes == 1)) {
-		ppa_ptr = rqd->ppa_list;
-		dma_ppa_list = rqd->dma_ppa_list;
-		rqd->ppa_addr = rqd->ppa_list[0];
-	}
-
-	ret = pblk_submit_io_sync(pblk, rqd);
-	if (ret) {
-		bio_put(rqd->bio);
-		pr_err("pblk: sync read IO submission failed\n");
-		goto fail;
-	}
-
-	if (rqd->error) {
-		atomic_long_inc(&pblk->read_failed);
-#ifdef CONFIG_NVM_DEBUG
-		pblk_print_failed_rqd(pblk, rqd, rqd->error);
-#endif
-	}
+	__le64 *lba_list_mem, *lba_list_media;
+	void *src_p, *dst_p;
+	int hole, i;
 
 	if (unlikely(nr_holes == 1)) {
 		struct ppa_addr ppa;
 
 		ppa = rqd->ppa_addr;
-		rqd->ppa_list = ppa_ptr;
-		rqd->dma_ppa_list = dma_ppa_list;
+		rqd->ppa_list = pr_ctx->ppa_ptr;
+		rqd->dma_ppa_list = pr_ctx->dma_ppa_list;
 		rqd->ppa_list[0] = ppa;
 	}
 
+	/* Re-use allocated memory for intermediate lbas */
+	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
+	lba_list_media = (((void *)rqd->ppa_list) + 2 * pblk_dma_ppa_size);
+
 	for (i = 0; i < nr_secs; i++) {
 		lba_list_media[i] = meta_list[i].lba;
 		meta_list[i].lba = lba_list_mem[i];
@@ -316,7 +278,7 @@ static int pblk_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
 		meta_list[hole].lba = lba_list_media[i];
 
 		src_bv = new_bio->bi_io_vec[i++];
-		dst_bv = orig_bio->bi_io_vec[bio_init_idx + hole];
+		dst_bv = bio->bi_io_vec[bio_init_idx + hole];
 
 		src_p = kmap_atomic(src_bv.bv_page);
 		dst_p = kmap_atomic(dst_bv.bv_page);
@@ -334,19 +296,107 @@ static int pblk_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
 	} while (hole < nr_secs);
 
 	bio_put(new_bio);
+	kfree(pr_ctx);
 
 	/* restore original request */
 	rqd->bio = NULL;
 	rqd->nr_ppas = nr_secs;
 
+	bio_endio(bio);
 	__pblk_end_io_read(pblk, rqd, false);
-	return NVM_IO_DONE;
+}
 
-fail:
-	/* Free allocated pages in new bio */
+static int pblk_setup_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
+			    unsigned int bio_init_idx,
+			    unsigned long *read_bitmap,
+			    int nr_holes)
+{
+	struct pblk_sec_meta *meta_list = rqd->meta_list;
+	struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
+	struct pblk_pr_ctx *pr_ctx;
+	struct bio *new_bio, *bio = r_ctx->private;
+	__le64 *lba_list_mem;
+	int nr_secs = rqd->nr_ppas;
+	int i;
+
+	/* Re-use allocated memory for intermediate lbas */
+	lba_list_mem = (((void *)rqd->ppa_list) + pblk_dma_ppa_size);
+
+	new_bio = bio_alloc(GFP_KERNEL, nr_holes);
+
+	if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
+		goto fail_bio_put;
+
+	if (nr_holes != new_bio->bi_vcnt) {
+		WARN_ONCE(1, "pblk: malformed bio\n");
+		goto fail_free_pages;
+	}
+
+	pr_ctx = kmalloc(sizeof(struct pblk_pr_ctx), GFP_KERNEL);
+	if (!pr_ctx)
+		goto fail_free_pages;
+
+	for (i = 0; i < nr_secs; i++)
+		lba_list_mem[i] = meta_list[i].lba;
+
+	new_bio->bi_iter.bi_sector = 0; /* internal bio */
+	bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
+
+	rqd->bio = new_bio;
+	rqd->nr_ppas = nr_holes;
+	rqd->flags = pblk_set_read_mode(pblk, PBLK_READ_RANDOM);
+
+	pr_ctx->ppa_ptr = NULL;
+	pr_ctx->orig_bio = bio;
+	bitmap_copy(pr_ctx->bitmap, read_bitmap, NVM_MAX_VLBA);
+	pr_ctx->bio_init_idx = bio_init_idx;
+	pr_ctx->orig_nr_secs = nr_secs;
+	r_ctx->private = pr_ctx;
+
+	if (unlikely(nr_holes == 1)) {
+		pr_ctx->ppa_ptr = rqd->ppa_list;
+		pr_ctx->dma_ppa_list = rqd->dma_ppa_list;
+		rqd->ppa_addr = rqd->ppa_list[0];
+	}
+	return 0;
+
+fail_free_pages:
 	pblk_bio_free_pages(pblk, new_bio, 0, new_bio->bi_vcnt);
-fail_add_pages:
-	pr_err("pblk: failed to perform partial read\n");
+fail_bio_put:
+	bio_put(new_bio);
+
+	return -ENOMEM;
+}
+
+static int pblk_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
+				 unsigned int bio_init_idx,
+				 unsigned long *read_bitmap, int nr_secs)
+{
+	int nr_holes;
+	int ret;
+
+	nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
+
+	if (pblk_setup_partial_read(pblk, rqd, bio_init_idx, read_bitmap,
+				    nr_holes))
+		return NVM_IO_ERR;
+
+	rqd->end_io = pblk_end_partial_read;
+
+	ret = pblk_submit_io(pblk, rqd);
+	if (ret) {
+		bio_put(rqd->bio);
+		pblk_err(pblk, "partial read IO submission failed\n");
+		goto err;
+	}
+
+	return NVM_IO_OK;
+
+err:
+	pblk_err(pblk, "failed to perform partial read\n");
+
+	/* Free allocated pages in new bio */
+	pblk_bio_free_pages(pblk, rqd->bio, 0, rqd->bio->bi_vcnt);
 	__pblk_end_io_read(pblk, rqd, false);
 	return NVM_IO_ERR;
 }
@@ -359,7 +409,7 @@ static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd, struct bio *bio,
 
 	pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_inc(&pblk->inflight_reads);
 #endif
 
@@ -382,7 +432,7 @@ retry:
 		WARN_ON(test_and_set_bit(0, read_bitmap));
 		meta_list[0].lba = cpu_to_le64(lba);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 		atomic_long_inc(&pblk->cache_reads);
 #endif
 	} else {
@@ -401,7 +451,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	struct pblk_g_ctx *r_ctx;
 	struct nvm_rq *rqd;
 	unsigned int bio_init_idx;
-	unsigned long read_bitmap; /* Max 64 ppas per request */
+	DECLARE_BITMAP(read_bitmap, NVM_MAX_VLBA);
 	int ret = NVM_IO_ERR;
 
 	/* logic error: lba out-of-bounds. Ignore read request */
@@ -411,9 +461,10 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 		return NVM_IO_ERR;
 	}
 
-	generic_start_io_acct(q, READ, bio_sectors(bio), &pblk->disk->part0);
+	generic_start_io_acct(q, REQ_OP_READ, bio_sectors(bio),
+			      &pblk->disk->part0);
 
-	bitmap_zero(&read_bitmap, nr_secs);
+	bitmap_zero(read_bitmap, nr_secs);
 
 	rqd = pblk_alloc_rqd(pblk, PBLK_READ);
 
@@ -436,7 +487,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
 							&rqd->dma_meta_list);
 	if (!rqd->meta_list) {
-		pr_err("pblk: not able to allocate ppa list\n");
+		pblk_err(pblk, "not able to allocate ppa list\n");
 		goto fail_rqd_free;
 	}
 
@@ -444,32 +495,32 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 		rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
 		rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 
-		pblk_read_ppalist_rq(pblk, rqd, bio, blba, &read_bitmap);
+		pblk_read_ppalist_rq(pblk, rqd, bio, blba, read_bitmap);
 	} else {
-		pblk_read_rq(pblk, rqd, bio, blba, &read_bitmap);
+		pblk_read_rq(pblk, rqd, bio, blba, read_bitmap);
 	}
 
-	if (bitmap_full(&read_bitmap, nr_secs)) {
+	if (bitmap_full(read_bitmap, nr_secs)) {
 		atomic_inc(&pblk->inflight_io);
 		__pblk_end_io_read(pblk, rqd, false);
 		return NVM_IO_DONE;
 	}
 
 	/* All sectors are to be read from the device */
-	if (bitmap_empty(&read_bitmap, rqd->nr_ppas)) {
+	if (bitmap_empty(read_bitmap, rqd->nr_ppas)) {
 		struct bio *int_bio = NULL;
 
 		/* Clone read bio to deal with read errors internally */
 		int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set);
 		if (!int_bio) {
-			pr_err("pblk: could not clone read bio\n");
+			pblk_err(pblk, "could not clone read bio\n");
 			goto fail_end_io;
 		}
 
 		rqd->bio = int_bio;
 
 		if (pblk_submit_io(pblk, rqd)) {
-			pr_err("pblk: read IO submission failed\n");
+			pblk_err(pblk, "read IO submission failed\n");
 			ret = NVM_IO_ERR;
 			goto fail_end_io;
 		}
@@ -480,8 +531,15 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 	/* The read bio request could be partially filled by the write buffer,
 	 * but there are some holes that need to be read from the drive.
 	 */
-	return pblk_partial_read(pblk, rqd, bio, bio_init_idx, &read_bitmap);
+	ret = pblk_partial_read_bio(pblk, rqd, bio_init_idx, read_bitmap,
+				    nr_secs);
+	if (ret)
+		goto fail_meta_free;
+
+	return NVM_IO_OK;
 
+fail_meta_free:
+	nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
 fail_rqd_free:
 	pblk_free_rqd(pblk, rqd, PBLK_READ);
 	return ret;
@@ -514,7 +572,7 @@ static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
 		rqd->ppa_list[valid_secs++] = ppa_list_l2p[i];
 	}
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(valid_secs, &pblk->inflight_reads);
 #endif
 
@@ -548,7 +606,7 @@ static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
 	rqd->ppa_addr = ppa_l2p;
 	valid_secs = 1;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_inc(&pblk->inflight_reads);
 #endif
 
@@ -595,7 +653,8 @@ int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 	bio = pblk_bio_map_addr(pblk, gc_rq->data, gc_rq->secs_to_gc, data_len,
 						PBLK_VMALLOC_META, GFP_KERNEL);
 	if (IS_ERR(bio)) {
-		pr_err("pblk: could not allocate GC bio (%lu)\n", PTR_ERR(bio));
+		pblk_err(pblk, "could not allocate GC bio (%lu)\n",
+				PTR_ERR(bio));
 		goto err_free_dma;
 	}
 
@@ -609,7 +668,7 @@ int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 
 	if (pblk_submit_io_sync(pblk, &rqd)) {
 		ret = -EIO;
-		pr_err("pblk: GC read request failed\n");
+		pblk_err(pblk, "GC read request failed\n");
 		goto err_free_bio;
 	}
 
@@ -619,12 +678,12 @@ int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 
 	if (rqd.error) {
 		atomic_long_inc(&pblk->read_failed_gc);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 		pblk_print_failed_rqd(pblk, &rqd, rqd.error);
 #endif
 	}
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(gc_rq->secs_to_gc, &pblk->sync_reads);
 	atomic_long_add(gc_rq->secs_to_gc, &pblk->recov_gc_reads);
 	atomic_long_sub(gc_rq->secs_to_gc, &pblk->inflight_reads);

drivers/lightnvm/pblk-recovery.c

@@ -77,7 +77,7 @@ static int pblk_recov_l2p_from_emeta(struct pblk *pblk, struct pblk_line *line)
 	}
 
 	if (nr_valid_lbas != nr_lbas)
-		pr_err("pblk: line %d - inconsistent lba list(%llu/%llu)\n",
+		pblk_err(pblk, "line %d - inconsistent lba list(%llu/%llu)\n",
 				line->id, nr_valid_lbas, nr_lbas);
 
 	line->left_msecs = 0;
@@ -184,7 +184,7 @@ next_read_rq:
 	/* If read fails, more padding is needed */
 	ret = pblk_submit_io_sync(pblk, rqd);
 	if (ret) {
-		pr_err("pblk: I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
 		return ret;
 	}
 
@@ -194,7 +194,7 @@ next_read_rq:
 	 * we cannot recover from here. Need FTL log.
 	 */
 	if (rqd->error && rqd->error != NVM_RSP_WARN_HIGHECC) {
-		pr_err("pblk: L2P recovery failed (%d)\n", rqd->error);
+		pblk_err(pblk, "L2P recovery failed (%d)\n", rqd->error);
 		return -EINTR;
 	}
 
@@ -273,7 +273,7 @@ static int pblk_recov_pad_oob(struct pblk *pblk, struct pblk_line *line,
 next_pad_rq:
 	rq_ppas = pblk_calc_secs(pblk, left_ppas, 0);
 	if (rq_ppas < pblk->min_write_pgs) {
-		pr_err("pblk: corrupted pad line %d\n", line->id);
+		pblk_err(pblk, "corrupted pad line %d\n", line->id);
 		goto fail_free_pad;
 	}
 
@@ -342,7 +342,7 @@ next_pad_rq:
 
 	ret = pblk_submit_io(pblk, rqd);
 	if (ret) {
-		pr_err("pblk: I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
 		pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
 		goto fail_free_bio;
 	}
@@ -356,12 +356,12 @@ next_pad_rq:
 
 	if (!wait_for_completion_io_timeout(&pad_rq->wait,
 				msecs_to_jiffies(PBLK_COMMAND_TIMEOUT_MS))) {
-		pr_err("pblk: pad write timed out\n");
+		pblk_err(pblk, "pad write timed out\n");
 		ret = -ETIME;
 	}
 
 	if (!pblk_line_is_full(line))
-		pr_err("pblk: corrupted padded line: %d\n", line->id);
+		pblk_err(pblk, "corrupted padded line: %d\n", line->id);
 
 	vfree(data);
 free_rq:
@@ -461,7 +461,7 @@ next_rq:
 
 	ret = pblk_submit_io_sync(pblk, rqd);
 	if (ret) {
-		pr_err("pblk: I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
 		return ret;
 	}
 
@@ -501,11 +501,11 @@ next_rq:
 
 		ret = pblk_recov_pad_oob(pblk, line, pad_secs);
 		if (ret)
-			pr_err("pblk: OOB padding failed (err:%d)\n", ret);
+			pblk_err(pblk, "OOB padding failed (err:%d)\n", ret);
 
 		ret = pblk_recov_read_oob(pblk, line, p, r_ptr);
 		if (ret)
-			pr_err("pblk: OOB read failed (err:%d)\n", ret);
+			pblk_err(pblk, "OOB read failed (err:%d)\n", ret);
 
 		left_ppas = 0;
 	}
@@ -592,7 +592,7 @@ next_rq:
 
 	ret = pblk_submit_io_sync(pblk, rqd);
 	if (ret) {
-		pr_err("pblk: I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "I/O submission failed: %d\n", ret);
 		bio_put(bio);
 		return ret;
 	}
@@ -671,14 +671,14 @@ static int pblk_recov_l2p_from_oob(struct pblk *pblk, struct pblk_line *line)
 
 	ret = pblk_recov_scan_oob(pblk, line, p, &done);
 	if (ret) {
-		pr_err("pblk: could not recover L2P from OOB\n");
+		pblk_err(pblk, "could not recover L2P from OOB\n");
 		goto out;
 	}
 
 	if (!done) {
 		ret = pblk_recov_scan_all_oob(pblk, line, p);
 		if (ret) {
-			pr_err("pblk: could not recover L2P from OOB\n");
+			pblk_err(pblk, "could not recover L2P from OOB\n");
 			goto out;
 		}
 	}
@@ -737,14 +737,15 @@ static int pblk_recov_check_line_version(struct pblk *pblk,
 	struct line_header *header = &emeta->header;
 
 	if (header->version_major != EMETA_VERSION_MAJOR) {
-		pr_err("pblk: line major version mismatch: %d, expected: %d\n",
-		       header->version_major, EMETA_VERSION_MAJOR);
+		pblk_err(pblk, "line major version mismatch: %d, expected: %d\n",
+			 header->version_major, EMETA_VERSION_MAJOR);
 		return 1;
 	}
 
-#ifdef NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	if (header->version_minor > EMETA_VERSION_MINOR)
-		pr_info("pblk: newer line minor version found: %d\n", line_v);
+		pblk_info(pblk, "newer line minor version found: %d\n",
+				header->version_minor);
 #endif
 
 	return 0;
@@ -851,7 +852,7 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 			continue;
 
 		if (smeta_buf->header.version_major != SMETA_VERSION_MAJOR) {
-			pr_err("pblk: found incompatible line version %u\n",
+			pblk_err(pblk, "found incompatible line version %u\n",
 					smeta_buf->header.version_major);
 			return ERR_PTR(-EINVAL);
 		}
@@ -863,7 +864,7 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 		}
 
 		if (memcmp(pblk->instance_uuid, smeta_buf->header.uuid, 16)) {
-			pr_debug("pblk: ignore line %u due to uuid mismatch\n",
+			pblk_debug(pblk, "ignore line %u due to uuid mismatch\n",
 					i);
 			continue;
 		}
@@ -887,7 +888,7 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 
 		pblk_recov_line_add_ordered(&recov_list, line);
 		found_lines++;
-		pr_debug("pblk: recovering data line %d, seq:%llu\n",
+		pblk_debug(pblk, "recovering data line %d, seq:%llu\n",
 						line->id, smeta_buf->seq_nr);
 	}
 
@@ -947,7 +948,7 @@ next:
 			line->emeta = NULL;
 		} else {
 			if (open_lines > 1)
-				pr_err("pblk: failed to recover L2P\n");
+				pblk_err(pblk, "failed to recover L2P\n");
 
 			open_lines++;
 			line->meta_line = meta_line;
@@ -976,7 +977,7 @@ next:
 
 out:
 	if (found_lines != recovered_lines)
-		pr_err("pblk: failed to recover all found lines %d/%d\n",
+		pblk_err(pblk, "failed to recover all found lines %d/%d\n",
 						found_lines, recovered_lines);
 
 	return data_line;
@@ -999,7 +1000,7 @@ int pblk_recov_pad(struct pblk *pblk)
 
 	ret = pblk_recov_pad_oob(pblk, line, left_msecs);
 	if (ret) {
-		pr_err("pblk: Tear down padding failed (%d)\n", ret);
+		pblk_err(pblk, "tear down padding failed (%d)\n", ret);
 		return ret;
 	}
 

drivers/lightnvm/pblk-sysfs.c

@@ -268,7 +268,7 @@ static ssize_t pblk_sysfs_lines(struct pblk *pblk, char *page)
 	spin_unlock(&l_mg->free_lock);
 
 	if (nr_free_lines != free_line_cnt)
-		pr_err("pblk: corrupted free line list:%d/%d\n",
+		pblk_err(pblk, "corrupted free line list:%d/%d\n",
 						nr_free_lines, free_line_cnt);
 
 	sz = snprintf(page, PAGE_SIZE - sz,
@@ -421,7 +421,7 @@ static ssize_t pblk_sysfs_get_padding_dist(struct pblk *pblk, char *page)
 	return sz;
 }
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 static ssize_t pblk_sysfs_stats_debug(struct pblk *pblk, char *page)
 {
 	return snprintf(page, PAGE_SIZE,
@@ -598,7 +598,7 @@ static struct attribute sys_padding_dist = {
 	.mode = 0644,
 };
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 static struct attribute sys_stats_debug_attr = {
 	.name = "stats",
 	.mode = 0444,
@@ -619,7 +619,7 @@ static struct attribute *pblk_attrs[] = {
 	&sys_write_amp_mileage,
 	&sys_write_amp_trip,
 	&sys_padding_dist,
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	&sys_stats_debug_attr,
 #endif
 	NULL,
@@ -654,7 +654,7 @@ static ssize_t pblk_sysfs_show(struct kobject *kobj, struct attribute *attr,
 		return pblk_sysfs_get_write_amp_trip(pblk, buf);
 	else if (strcmp(attr->name, "padding_dist") == 0)
 		return pblk_sysfs_get_padding_dist(pblk, buf);
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	else if (strcmp(attr->name, "stats") == 0)
 		return pblk_sysfs_stats_debug(pblk, buf);
 #endif
@@ -697,8 +697,7 @@ int pblk_sysfs_init(struct gendisk *tdisk)
 					kobject_get(&parent_dev->kobj),
 					"%s", "pblk");
 	if (ret) {
-		pr_err("pblk: could not register %s/pblk\n",
-						tdisk->disk_name);
+		pblk_err(pblk, "could not register\n");
 		return ret;
 	}
 

drivers/lightnvm/pblk-write.c

@@ -38,7 +38,7 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 			/* Release flags on context. Protect from writes */
 			smp_store_release(&w_ctx->flags, flags);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 			atomic_dec(&rwb->inflight_flush_point);
 #endif
 		}
@@ -51,7 +51,7 @@ static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
 		pblk_bio_free_pages(pblk, rqd->bio, c_ctx->nr_valid,
 							c_ctx->nr_padded);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(rqd->nr_ppas, &pblk->sync_writes);
 #endif
 
@@ -78,7 +78,7 @@ static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
 	unsigned long flags;
 	unsigned long pos;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_sub(c_ctx->nr_valid, &pblk->inflight_writes);
 #endif
 
@@ -196,7 +196,7 @@ static void pblk_queue_resubmit(struct pblk *pblk, struct pblk_c_ctx *c_ctx)
 	list_add_tail(&r_ctx->list, &pblk->resubmit_list);
 	spin_unlock(&pblk->resubmit_lock);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(c_ctx->nr_valid, &pblk->recov_writes);
 #endif
 }
@@ -238,7 +238,7 @@ static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
 
 	recovery = mempool_alloc(&pblk->rec_pool, GFP_ATOMIC);
 	if (!recovery) {
-		pr_err("pblk: could not allocate recovery work\n");
+		pblk_err(pblk, "could not allocate recovery work\n");
 		return;
 	}
 
@@ -258,7 +258,7 @@ static void pblk_end_io_write(struct nvm_rq *rqd)
 		pblk_end_w_fail(pblk, rqd);
 		return;
 	}
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	else
 		WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 #endif
@@ -279,7 +279,7 @@ static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 
 	if (rqd->error) {
 		pblk_log_write_err(pblk, rqd);
-		pr_err("pblk: metadata I/O failed. Line %d\n", line->id);
+		pblk_err(pblk, "metadata I/O failed. Line %d\n", line->id);
 		line->w_err_gc->has_write_err = 1;
 	}
 
@@ -356,11 +356,11 @@ static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 
 	secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	if ((!secs_to_sync && secs_to_flush)
 			|| (secs_to_sync < 0)
 			|| (secs_to_sync > secs_avail && !secs_to_flush)) {
-		pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
+		pblk_err(pblk, "bad sector calculation (a:%d,s:%d,f:%d)\n",
 				secs_avail, secs_to_sync, secs_to_flush);
 	}
 #endif
@@ -397,7 +397,7 @@ int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 	bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
 					l_mg->emeta_alloc_type, GFP_KERNEL);
 	if (IS_ERR(bio)) {
-		pr_err("pblk: failed to map emeta io");
+		pblk_err(pblk, "failed to map emeta io");
 		ret = PTR_ERR(bio);
 		goto fail_free_rqd;
 	}
@@ -428,7 +428,7 @@ int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 
 	ret = pblk_submit_io(pblk, rqd);
 	if (ret) {
-		pr_err("pblk: emeta I/O submission failed: %d\n", ret);
+		pblk_err(pblk, "emeta I/O submission failed: %d\n", ret);
 		goto fail_rollback;
 	}
 
@@ -518,7 +518,7 @@ static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 	/* Assign lbas to ppas and populate request structure */
 	err = pblk_setup_w_rq(pblk, rqd, &erase_ppa);
 	if (err) {
-		pr_err("pblk: could not setup write request: %d\n", err);
+		pblk_err(pblk, "could not setup write request: %d\n", err);
 		return NVM_IO_ERR;
 	}
 
@@ -527,7 +527,7 @@ static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 	/* Submit data write for current data line */
 	err = pblk_submit_io(pblk, rqd);
 	if (err) {
-		pr_err("pblk: data I/O submission failed: %d\n", err);
+		pblk_err(pblk, "data I/O submission failed: %d\n", err);
 		return NVM_IO_ERR;
 	}
 
@@ -549,7 +549,8 @@ static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 		/* Submit metadata write for previous data line */
 		err = pblk_submit_meta_io(pblk, meta_line);
 		if (err) {
-			pr_err("pblk: metadata I/O submission failed: %d", err);
+			pblk_err(pblk, "metadata I/O submission failed: %d",
+					err);
 			return NVM_IO_ERR;
 		}
 	}
@@ -614,7 +615,7 @@ static int pblk_submit_write(struct pblk *pblk)
 		secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail,
 					secs_to_flush);
 		if (secs_to_sync > pblk->max_write_pgs) {
-			pr_err("pblk: bad buffer sync calculation\n");
+			pblk_err(pblk, "bad buffer sync calculation\n");
 			return 1;
 		}
 
@@ -633,14 +634,14 @@ static int pblk_submit_write(struct pblk *pblk)
 
 	if (pblk_rb_read_to_bio(&pblk->rwb, rqd, pos, secs_to_sync,
 								secs_avail)) {
-		pr_err("pblk: corrupted write bio\n");
+		pblk_err(pblk, "corrupted write bio\n");
 		goto fail_put_bio;
 	}
 
 	if (pblk_submit_io_set(pblk, rqd))
 		goto fail_free_bio;
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_long_add(secs_to_sync, &pblk->sub_writes);
 #endif
 

drivers/lightnvm/pblk.h

@@ -119,6 +119,16 @@ struct pblk_g_ctx {
 	u64 lba;
 };
 
+/* partial read context */
+struct pblk_pr_ctx {
+	struct bio *orig_bio;
+	DECLARE_BITMAP(bitmap, NVM_MAX_VLBA);
+	unsigned int orig_nr_secs;
+	unsigned int bio_init_idx;
+	void *ppa_ptr;
+	dma_addr_t dma_ppa_list;
+};
+
 /* Pad context */
 struct pblk_pad_rq {
 	struct pblk *pblk;
@@ -193,7 +203,7 @@ struct pblk_rb {
 	spinlock_t w_lock;		/* Write lock */
 	spinlock_t s_lock;		/* Sync lock */
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	atomic_t inflight_flush_point;	/* Not served REQ_FLUSH | REQ_FUA */
 #endif
 };
@@ -608,9 +618,6 @@ struct pblk {
 
 	int min_write_pgs; /* Minimum amount of pages required by controller */
 	int max_write_pgs; /* Maximum amount of pages supported by controller */
-	int pgs_in_buffer; /* Number of pages that need to be held in buffer to
-			    * guarantee successful reads.
-			    */
 
 	sector_t capacity; /* Device capacity when bad blocks are subtracted */
 
@@ -639,7 +646,7 @@ struct pblk {
 	u64 nr_flush_rst;		/* Flushes reset value for pad dist.*/
 	atomic64_t nr_flush;		/* Number of flush/fua I/O */
 
-#ifdef CONFIG_NVM_DEBUG
+#ifdef CONFIG_NVM_PBLK_DEBUG
 	/* Non-persistent debug counters, 4kb sector I/Os */
 	atomic_long_t inflight_writes;	/* Inflight writes (user and gc) */
 	atomic_long_t padded_writes;	/* Sectors padded due to flush/fua */
@@ -706,6 +713,15 @@ struct pblk_line_ws {
 #define pblk_g_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_g_ctx))
 #define pblk_w_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_c_ctx))
 
+#define pblk_err(pblk, fmt, ...)			\
+	pr_err("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_info(pblk, fmt, ...)			\
+	pr_info("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_warn(pblk, fmt, ...)			\
+	pr_warn("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+#define pblk_debug(pblk, fmt, ...)			\
+	pr_debug("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
+
 /*
  * pblk ring buffer operations
  */
@@ -1282,20 +1298,22 @@ static inline int pblk_io_aligned(struct pblk *pblk, int nr_secs)
 	return !(nr_secs % pblk->min_write_pgs);
 }
 
-#ifdef CONFIG_NVM_DEBUG
-static inline void print_ppa(struct nvm_geo *geo, struct ppa_addr *p,
+#ifdef CONFIG_NVM_PBLK_DEBUG
+static inline void print_ppa(struct pblk *pblk, struct ppa_addr *p,
 			     char *msg, int error)
 {
+	struct nvm_geo *geo = &pblk->dev->geo;
+
 	if (p->c.is_cached) {
-		pr_err("ppa: (%s: %x) cache line: %llu\n",
+		pblk_err(pblk, "ppa: (%s: %x) cache line: %llu\n",
 				msg, error, (u64)p->c.line);
 	} else if (geo->version == NVM_OCSSD_SPEC_12) {
-		pr_err("ppa: (%s: %x):ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d\n",
+		pblk_err(pblk, "ppa: (%s: %x):ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d\n",
 			msg, error,
 			p->g.ch, p->g.lun, p->g.blk,
 			p->g.pg, p->g.pl, p->g.sec);
 	} else {
-		pr_err("ppa: (%s: %x):ch:%d,lun:%d,chk:%d,sec:%d\n",
+		pblk_err(pblk, "ppa: (%s: %x):ch:%d,lun:%d,chk:%d,sec:%d\n",
 			msg, error,
 			p->m.grp, p->m.pu, p->m.chk, p->m.sec);
 	}
@@ -1307,16 +1325,16 @@ static inline void pblk_print_failed_rqd(struct pblk *pblk, struct nvm_rq *rqd,
 	int bit = -1;
 
 	if (rqd->nr_ppas ==  1) {
-		print_ppa(&pblk->dev->geo, &rqd->ppa_addr, "rqd", error);
+		print_ppa(pblk, &rqd->ppa_addr, "rqd", error);
 		return;
 	}
 
 	while ((bit = find_next_bit((void *)&rqd->ppa_status, rqd->nr_ppas,
 						bit + 1)) < rqd->nr_ppas) {
-		print_ppa(&pblk->dev->geo, &rqd->ppa_list[bit], "rqd", error);
+		print_ppa(pblk, &rqd->ppa_list[bit], "rqd", error);
 	}
 
-	pr_err("error:%d, ppa_status:%llx\n", error, rqd->ppa_status);
+	pblk_err(pblk, "error:%d, ppa_status:%llx\n", error, rqd->ppa_status);
 }
 
 static inline int pblk_boundary_ppa_checks(struct nvm_tgt_dev *tgt_dev,
@@ -1347,7 +1365,7 @@ static inline int pblk_boundary_ppa_checks(struct nvm_tgt_dev *tgt_dev,
 				continue;
 		}
 
-		print_ppa(geo, ppa, "boundary", i);
+		print_ppa(tgt_dev->q->queuedata, ppa, "boundary", i);
 
 		return 1;
 	}
@@ -1377,7 +1395,7 @@ static inline int pblk_check_io(struct pblk *pblk, struct nvm_rq *rqd)
 
 			spin_lock(&line->lock);
 			if (line->state != PBLK_LINESTATE_OPEN) {
-				pr_err("pblk: bad ppa: line:%d,state:%d\n",
+				pblk_err(pblk, "bad ppa: line:%d,state:%d\n",
 							line->id, line->state);
 				WARN_ON(1);
 				spin_unlock(&line->lock);

drivers/md/bcache/bcache.h

@@ -328,13 +328,6 @@ struct cached_dev {
 	 */
 	atomic_t		has_dirty;
 
-	/*
-	 * Set to zero by things that touch the backing volume-- except
-	 * writeback.  Incremented by writeback.  Used to determine when to
-	 * accelerate idle writeback.
-	 */
-	atomic_t		backing_idle;
-
 	struct bch_ratelimit	writeback_rate;
 	struct delayed_work	writeback_rate_update;
 
@@ -423,9 +416,9 @@ struct cache {
 	/*
 	 * When allocating new buckets, prio_write() gets first dibs - since we
 	 * may not be allocate at all without writing priorities and gens.
-	 * prio_buckets[] contains the last buckets we wrote priorities to (so
-	 * gc can mark them as metadata), prio_next[] contains the buckets
-	 * allocated for the next prio write.
+	 * prio_last_buckets[] contains the last buckets we wrote priorities to
+	 * (so gc can mark them as metadata), prio_buckets[] contains the
+	 * buckets allocated for the next prio write.
 	 */
 	uint64_t		*prio_buckets;
 	uint64_t		*prio_last_buckets;
@@ -474,6 +467,7 @@ struct cache {
 
 struct gc_stat {
 	size_t			nodes;
+	size_t			nodes_pre;
 	size_t			key_bytes;
 
 	size_t			nkeys;
@@ -514,6 +508,8 @@ struct cache_set {
 	struct cache_accounting accounting;
 
 	unsigned long		flags;
+	atomic_t		idle_counter;
+	atomic_t		at_max_writeback_rate;
 
 	struct cache_sb		sb;
 
@@ -523,8 +519,10 @@ struct cache_set {
 
 	struct bcache_device	**devices;
 	unsigned		devices_max_used;
+	atomic_t		attached_dev_nr;
 	struct list_head	cached_devs;
 	uint64_t		cached_dev_sectors;
+	atomic_long_t		flash_dev_dirty_sectors;
 	struct closure		caching;
 
 	struct closure		sb_write;
@@ -602,6 +600,10 @@ struct cache_set {
 	 * rescale; when it hits 0 we rescale all the bucket priorities.
 	 */
 	atomic_t		rescale;
+	/*
+	 * used for GC, identify if any front side I/Os is inflight
+	 */
+	atomic_t		search_inflight;
 	/*
 	 * When we invalidate buckets, we use both the priority and the amount
 	 * of good data to determine which buckets to reuse first - to weight
@@ -995,7 +997,7 @@ void bch_open_buckets_free(struct cache_set *);
 int bch_cache_allocator_start(struct cache *ca);
 
 void bch_debug_exit(void);
-int bch_debug_init(struct kobject *);
+void bch_debug_init(struct kobject *kobj);
 void bch_request_exit(void);
 int bch_request_init(void);
 

drivers/md/bcache/bset.c

@@ -366,6 +366,10 @@ EXPORT_SYMBOL(bch_btree_keys_init);
 
 /* Binary tree stuff for auxiliary search trees */
 
+/*
+ * return array index next to j when does in-order traverse
+ * of a binary tree which is stored in a linear array
+ */
 static unsigned inorder_next(unsigned j, unsigned size)
 {
 	if (j * 2 + 1 < size) {
@@ -379,6 +383,10 @@ static unsigned inorder_next(unsigned j, unsigned size)
 	return j;
 }
 
+/*
+ * return array index previous to j when does in-order traverse
+ * of a binary tree which is stored in a linear array
+ */
 static unsigned inorder_prev(unsigned j, unsigned size)
 {
 	if (j * 2 < size) {
@@ -421,6 +429,10 @@ static unsigned __to_inorder(unsigned j, unsigned size, unsigned extra)
 	return j;
 }
 
+/*
+ * Return the cacheline index in bset_tree->data, where j is index
+ * from a linear array which stores the auxiliar binary tree
+ */
 static unsigned to_inorder(unsigned j, struct bset_tree *t)
 {
 	return __to_inorder(j, t->size, t->extra);
@@ -441,6 +453,10 @@ static unsigned __inorder_to_tree(unsigned j, unsigned size, unsigned extra)
 	return j;
 }
 
+/*
+ * Return an index from a linear array which stores the auxiliar binary
+ * tree, j is the cacheline index of t->data.
+ */
 static unsigned inorder_to_tree(unsigned j, struct bset_tree *t)
 {
 	return __inorder_to_tree(j, t->size, t->extra);
@@ -546,6 +562,20 @@ static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
 	return low;
 }
 
+/*
+ * Calculate mantissa value for struct bkey_float.
+ * If most significant bit of f->exponent is not set, then
+ *  - f->exponent >> 6 is 0
+ *  - p[0] points to bkey->low
+ *  - p[-1] borrows bits from KEY_INODE() of bkey->high
+ * if most isgnificant bits of f->exponent is set, then
+ *  - f->exponent >> 6 is 1
+ *  - p[0] points to bits from KEY_INODE() of bkey->high
+ *  - p[-1] points to other bits from KEY_INODE() of
+ *    bkey->high too.
+ * See make_bfloat() to check when most significant bit of f->exponent
+ * is set or not.
+ */
 static inline unsigned bfloat_mantissa(const struct bkey *k,
 				       struct bkey_float *f)
 {
@@ -570,6 +600,16 @@ static void make_bfloat(struct bset_tree *t, unsigned j)
 	BUG_ON(m < l || m > r);
 	BUG_ON(bkey_next(p) != m);
 
+	/*
+	 * If l and r have different KEY_INODE values (different backing
+	 * device), f->exponent records how many least significant bits
+	 * are different in KEY_INODE values and sets most significant
+	 * bits to 1 (by +64).
+	 * If l and r have same KEY_INODE value, f->exponent records
+	 * how many different bits in least significant bits of bkey->low.
+	 * See bfloat_mantiss() how the most significant bit of
+	 * f->exponent is used to calculate bfloat mantissa value.
+	 */
 	if (KEY_INODE(l) != KEY_INODE(r))
 		f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
 	else
@@ -633,6 +673,15 @@ void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
 }
 EXPORT_SYMBOL(bch_bset_init_next);
 
+/*
+ * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
+ * accelerate bkey search in a btree node (pointed by bset_tree->data in
+ * memory). After search in the auxiliar tree by calling bset_search_tree(),
+ * a struct bset_search_iter is returned which indicates range [l, r] from
+ * bset_tree->data where the searching bkey might be inside. Then a followed
+ * linear comparison does the exact search, see __bch_bset_search() for how
+ * the auxiliary tree is used.
+ */
 void bch_bset_build_written_tree(struct btree_keys *b)
 {
 	struct bset_tree *t = bset_tree_last(b);
@@ -898,6 +947,17 @@ static struct bset_search_iter bset_search_tree(struct bset_tree *t,
 	unsigned inorder, j, n = 1;
 
 	do {
+		/*
+		 * A bit trick here.
+		 * If p < t->size, (int)(p - t->size) is a minus value and
+		 * the most significant bit is set, right shifting 31 bits
+		 * gets 1. If p >= t->size, the most significant bit is
+		 * not set, right shifting 31 bits gets 0.
+		 * So the following 2 lines equals to
+		 *	if (p >= t->size)
+		 *		p = 0;
+		 * but a branch instruction is avoided.
+		 */
 		unsigned p = n << 4;
 		p &= ((int) (p - t->size)) >> 31;
 
@@ -907,6 +967,9 @@ static struct bset_search_iter bset_search_tree(struct bset_tree *t,
 		f = &t->tree[j];
 
 		/*
+		 * Similar bit trick, use subtract operation to avoid a branch
+		 * instruction.
+		 *
 		 * n = (f->mantissa > bfloat_mantissa())
 		 *	? j * 2
 		 *	: j * 2 + 1;

drivers/md/bcache/btree.c

@@ -90,6 +90,9 @@
 
 #define MAX_NEED_GC		64
 #define MAX_SAVE_PRIO		72
+#define MAX_GC_TIMES		100
+#define MIN_GC_NODES		100
+#define GC_SLEEP_MS		100
 
 #define PTR_DIRTY_BIT		(((uint64_t) 1 << 36))
 
@@ -1008,6 +1011,13 @@ retry:
 		BUG_ON(b->level != level);
 	}
 
+	if (btree_node_io_error(b)) {
+		rw_unlock(write, b);
+		return ERR_PTR(-EIO);
+	}
+
+	BUG_ON(!b->written);
+
 	b->parent = parent;
 	b->accessed = 1;
 
@@ -1019,13 +1029,6 @@ retry:
 	for (; i <= b->keys.nsets; i++)
 		prefetch(b->keys.set[i].data);
 
-	if (btree_node_io_error(b)) {
-		rw_unlock(write, b);
-		return ERR_PTR(-EIO);
-	}
-
-	BUG_ON(!b->written);
-
 	return b;
 }
 
@@ -1520,6 +1523,32 @@ static unsigned btree_gc_count_keys(struct btree *b)
 	return ret;
 }
 
+static size_t btree_gc_min_nodes(struct cache_set *c)
+{
+	size_t min_nodes;
+
+	/*
+	 * Since incremental GC would stop 100ms when front
+	 * side I/O comes, so when there are many btree nodes,
+	 * if GC only processes constant (100) nodes each time,
+	 * GC would last a long time, and the front side I/Os
+	 * would run out of the buckets (since no new bucket
+	 * can be allocated during GC), and be blocked again.
+	 * So GC should not process constant nodes, but varied
+	 * nodes according to the number of btree nodes, which
+	 * realized by dividing GC into constant(100) times,
+	 * so when there are many btree nodes, GC can process
+	 * more nodes each time, otherwise, GC will process less
+	 * nodes each time (but no less than MIN_GC_NODES)
+	 */
+	min_nodes = c->gc_stats.nodes / MAX_GC_TIMES;
+	if (min_nodes < MIN_GC_NODES)
+		min_nodes = MIN_GC_NODES;
+
+	return min_nodes;
+}
+
+
 static int btree_gc_recurse(struct btree *b, struct btree_op *op,
 			    struct closure *writes, struct gc_stat *gc)
 {
@@ -1585,6 +1614,13 @@ static int btree_gc_recurse(struct btree *b, struct btree_op *op,
 		memmove(r + 1, r, sizeof(r[0]) * (GC_MERGE_NODES - 1));
 		r->b = NULL;
 
+		if (atomic_read(&b->c->search_inflight) &&
+		    gc->nodes >= gc->nodes_pre + btree_gc_min_nodes(b->c)) {
+			gc->nodes_pre =  gc->nodes;
+			ret = -EAGAIN;
+			break;
+		}
+
 		if (need_resched()) {
 			ret = -EAGAIN;
 			break;
@@ -1753,7 +1789,10 @@ static void bch_btree_gc(struct cache_set *c)
 		closure_sync(&writes);
 		cond_resched();
 
-		if (ret && ret != -EAGAIN)
+		if (ret == -EAGAIN)
+			schedule_timeout_interruptible(msecs_to_jiffies
+						       (GC_SLEEP_MS));
+		else if (ret)
 			pr_warn("gc failed!");
 	} while (ret && !test_bit(CACHE_SET_IO_DISABLE, &c->flags));
 
@@ -1834,8 +1873,14 @@ static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
 		do {
 			k = bch_btree_iter_next_filter(&iter, &b->keys,
 						       bch_ptr_bad);
-			if (k)
+			if (k) {
 				btree_node_prefetch(b, k);
+				/*
+				 * initiallize c->gc_stats.nodes
+				 * for incremental GC
+				 */
+				b->c->gc_stats.nodes++;
+			}
 
 			if (p)
 				ret = btree(check_recurse, p, b, op);

drivers/md/bcache/btree.h

@@ -152,7 +152,7 @@ static inline bool btree_node_ ## flag(struct btree *b)			\
 {	return test_bit(BTREE_NODE_ ## flag, &b->flags); }		\
 									\
 static inline void set_btree_node_ ## flag(struct btree *b)		\
-{	set_bit(BTREE_NODE_ ## flag, &b->flags); }			\
+{	set_bit(BTREE_NODE_ ## flag, &b->flags); }
 
 enum btree_flags {
 	BTREE_NODE_io_error,

drivers/md/bcache/closure.c

@@ -199,11 +199,16 @@ static const struct file_operations debug_ops = {
 	.release	= single_release
 };
 
-int __init closure_debug_init(void)
+void  __init closure_debug_init(void)
 {
-	closure_debug = debugfs_create_file("closures",
-				0400, bcache_debug, NULL, &debug_ops);
-	return IS_ERR_OR_NULL(closure_debug);
+	if (!IS_ERR_OR_NULL(bcache_debug))
+		/*
+		 * it is unnecessary to check return value of
+		 * debugfs_create_file(), we should not care
+		 * about this.
+		 */
+		closure_debug = debugfs_create_file(
+			"closures", 0400, bcache_debug, NULL, &debug_ops);
 }
 #endif
 

drivers/md/bcache/closure.h

@@ -186,13 +186,13 @@ static inline void closure_sync(struct closure *cl)
 
 #ifdef CONFIG_BCACHE_CLOSURES_DEBUG
 
-int closure_debug_init(void);
+void closure_debug_init(void);
 void closure_debug_create(struct closure *cl);
 void closure_debug_destroy(struct closure *cl);
 
 #else
 
-static inline int closure_debug_init(void) { return 0; }
+static inline void closure_debug_init(void) {}
 static inline void closure_debug_create(struct closure *cl) {}
 static inline void closure_debug_destroy(struct closure *cl) {}
 

drivers/md/bcache/debug.c

@@ -110,11 +110,15 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 	struct bio_vec bv, cbv;
 	struct bvec_iter iter, citer = { 0 };
 
-	check = bio_clone_kmalloc(bio, GFP_NOIO);
+	check = bio_kmalloc(GFP_NOIO, bio_segments(bio));
 	if (!check)
 		return;
+	check->bi_disk = bio->bi_disk;
 	check->bi_opf = REQ_OP_READ;
+	check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
+	check->bi_iter.bi_size = bio->bi_iter.bi_size;
 
+	bch_bio_map(check, NULL);
 	if (bch_bio_alloc_pages(check, GFP_NOIO))
 		goto out_put;
 
@@ -248,11 +252,12 @@ void bch_debug_exit(void)
 		debugfs_remove_recursive(bcache_debug);
 }
 
-int __init bch_debug_init(struct kobject *kobj)
+void __init bch_debug_init(struct kobject *kobj)
 {
-	if (!IS_ENABLED(CONFIG_DEBUG_FS))
-		return 0;
-
+	/*
+	 * it is unnecessary to check return value of
+	 * debugfs_create_file(), we should not care
+	 * about this.
+	 */
 	bcache_debug = debugfs_create_dir("bcache", NULL);
-	return IS_ERR_OR_NULL(bcache_debug);
 }

drivers/md/bcache/journal.c

@@ -828,6 +828,7 @@ void bch_journal_free(struct cache_set *c)
 	free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
 	free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
 	free_fifo(&c->journal.pin);
+	free_heap(&c->flush_btree);
 }
 
 int bch_journal_alloc(struct cache_set *c)

drivers/md/bcache/request.c

@@ -107,7 +107,7 @@ static int bch_keylist_realloc(struct keylist *l, unsigned u64s,
 	/*
 	 * The journalling code doesn't handle the case where the keys to insert
 	 * is bigger than an empty write: If we just return -ENOMEM here,
-	 * bio_insert() and bio_invalidate() will insert the keys created so far
+	 * bch_data_insert_keys() will insert the keys created so far
 	 * and finish the rest when the keylist is empty.
 	 */
 	if (newsize * sizeof(uint64_t) > block_bytes(c) - sizeof(struct jset))
@@ -667,8 +667,7 @@ static void backing_request_endio(struct bio *bio)
 static void bio_complete(struct search *s)
 {
 	if (s->orig_bio) {
-		generic_end_io_acct(s->d->disk->queue,
-				    bio_data_dir(s->orig_bio),
+		generic_end_io_acct(s->d->disk->queue, bio_op(s->orig_bio),
 				    &s->d->disk->part0, s->start_time);
 
 		trace_bcache_request_end(s->d, s->orig_bio);
@@ -702,6 +701,8 @@ static void search_free(struct closure *cl)
 {
 	struct search *s = container_of(cl, struct search, cl);
 
+	atomic_dec(&s->d->c->search_inflight);
+
 	if (s->iop.bio)
 		bio_put(s->iop.bio);
 
@@ -719,6 +720,7 @@ static inline struct search *search_alloc(struct bio *bio,
 
 	closure_init(&s->cl, NULL);
 	do_bio_hook(s, bio, request_endio);
+	atomic_inc(&d->c->search_inflight);
 
 	s->orig_bio		= bio;
 	s->cache_miss		= NULL;
@@ -1062,8 +1064,7 @@ static void detached_dev_end_io(struct bio *bio)
 	bio->bi_end_io = ddip->bi_end_io;
 	bio->bi_private = ddip->bi_private;
 
-	generic_end_io_acct(ddip->d->disk->queue,
-			    bio_data_dir(bio),
+	generic_end_io_acct(ddip->d->disk->queue, bio_op(bio),
 			    &ddip->d->disk->part0, ddip->start_time);
 
 	if (bio->bi_status) {
@@ -1102,6 +1103,44 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio)
 		generic_make_request(bio);
 }
 
+static void quit_max_writeback_rate(struct cache_set *c,
+				    struct cached_dev *this_dc)
+{
+	int i;
+	struct bcache_device *d;
+	struct cached_dev *dc;
+
+	/*
+	 * mutex bch_register_lock may compete with other parallel requesters,
+	 * or attach/detach operations on other backing device. Waiting to
+	 * the mutex lock may increase I/O request latency for seconds or more.
+	 * To avoid such situation, if mutext_trylock() failed, only writeback
+	 * rate of current cached device is set to 1, and __update_write_back()
+	 * will decide writeback rate of other cached devices (remember now
+	 * c->idle_counter is 0 already).
+	 */
+	if (mutex_trylock(&bch_register_lock)) {
+		for (i = 0; i < c->devices_max_used; i++) {
+			if (!c->devices[i])
+				continue;
+
+			if (UUID_FLASH_ONLY(&c->uuids[i]))
+				continue;
+
+			d = c->devices[i];
+			dc = container_of(d, struct cached_dev, disk);
+			/*
+			 * set writeback rate to default minimum value,
+			 * then let update_writeback_rate() to decide the
+			 * upcoming rate.
+			 */
+			atomic_long_set(&dc->writeback_rate.rate, 1);
+		}
+		mutex_unlock(&bch_register_lock);
+	} else
+		atomic_long_set(&this_dc->writeback_rate.rate, 1);
+}
+
 /* Cached devices - read & write stuff */
 
 static blk_qc_t cached_dev_make_request(struct request_queue *q,
@@ -1119,8 +1158,25 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q,
 		return BLK_QC_T_NONE;
 	}
 
-	atomic_set(&dc->backing_idle, 0);
-	generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0);
+	if (likely(d->c)) {
+		if (atomic_read(&d->c->idle_counter))
+			atomic_set(&d->c->idle_counter, 0);
+		/*
+		 * If at_max_writeback_rate of cache set is true and new I/O
+		 * comes, quit max writeback rate of all cached devices
+		 * attached to this cache set, and set at_max_writeback_rate
+		 * to false.
+		 */
+		if (unlikely(atomic_read(&d->c->at_max_writeback_rate) == 1)) {
+			atomic_set(&d->c->at_max_writeback_rate, 0);
+			quit_max_writeback_rate(d->c, dc);
+		}
+	}
+
+	generic_start_io_acct(q,
+			      bio_op(bio),
+			      bio_sectors(bio),
+			      &d->disk->part0);
 
 	bio_set_dev(bio, dc->bdev);
 	bio->bi_iter.bi_sector += dc->sb.data_offset;
@@ -1229,7 +1285,6 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
 	struct search *s;
 	struct closure *cl;
 	struct bcache_device *d = bio->bi_disk->private_data;
-	int rw = bio_data_dir(bio);
 
 	if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) {
 		bio->bi_status = BLK_STS_IOERR;
@@ -1237,7 +1292,7 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
 		return BLK_QC_T_NONE;
 	}
 
-	generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0);
+	generic_start_io_acct(q, bio_op(bio), bio_sectors(bio), &d->disk->part0);
 
 	s = search_alloc(bio, d);
 	cl = &s->cl;
@@ -1254,7 +1309,7 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
 				      flash_dev_nodata,
 				      bcache_wq);
 		return BLK_QC_T_NONE;
-	} else if (rw) {
+	} else if (bio_data_dir(bio)) {
 		bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys,
 					&KEY(d->id, bio->bi_iter.bi_sector, 0),
 					&KEY(d->id, bio_end_sector(bio), 0));

drivers/md/bcache/super.c

@@ -181,7 +181,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
 		goto err;
 	}
 
-	sb->last_mount = get_seconds();
+	sb->last_mount = (u32)ktime_get_real_seconds();
 	err = NULL;
 
 	get_page(bh->b_page);
@@ -696,12 +696,14 @@ static void bcache_device_detach(struct bcache_device *d)
 {
 	lockdep_assert_held(&bch_register_lock);
 
+	atomic_dec(&d->c->attached_dev_nr);
+
 	if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) {
 		struct uuid_entry *u = d->c->uuids + d->id;
 
 		SET_UUID_FLASH_ONLY(u, 0);
 		memcpy(u->uuid, invalid_uuid, 16);
-		u->invalidated = cpu_to_le32(get_seconds());
+		u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds());
 		bch_uuid_write(d->c);
 	}
 
@@ -796,11 +798,12 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 		return idx;
 
 	if (bioset_init(&d->bio_split, 4, offsetof(struct bbio, bio),
-			BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) ||
-	    !(d->disk = alloc_disk(BCACHE_MINORS))) {
-		ida_simple_remove(&bcache_device_idx, idx);
-		return -ENOMEM;
-	}
+			BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER))
+		goto err;
+
+	d->disk = alloc_disk(BCACHE_MINORS);
+	if (!d->disk)
+		goto err;
 
 	set_capacity(d->disk, sectors);
 	snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", idx);
@@ -834,6 +837,11 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 	blk_queue_write_cache(q, true, true);
 
 	return 0;
+
+err:
+	ida_simple_remove(&bcache_device_idx, idx);
+	return -ENOMEM;
+
 }
 
 /* Cached device */
@@ -1027,7 +1035,7 @@ void bch_cached_dev_detach(struct cached_dev *dc)
 int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 			  uint8_t *set_uuid)
 {
-	uint32_t rtime = cpu_to_le32(get_seconds());
+	uint32_t rtime = cpu_to_le32((u32)ktime_get_real_seconds());
 	struct uuid_entry *u;
 	struct cached_dev *exist_dc, *t;
 
@@ -1070,7 +1078,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	    (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
 	     BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
 		memcpy(u->uuid, invalid_uuid, 16);
-		u->invalidated = cpu_to_le32(get_seconds());
+		u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds());
 		u = NULL;
 	}
 
@@ -1138,6 +1146,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 
 	bch_cached_dev_run(dc);
 	bcache_device_link(&dc->disk, c, "bdev");
+	atomic_inc(&c->attached_dev_nr);
 
 	/* Allow the writeback thread to proceed */
 	up_write(&dc->writeback_lock);
@@ -1285,6 +1294,7 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 	pr_info("registered backing device %s", dc->backing_dev_name);
 
 	list_add(&dc->list, &uncached_devices);
+	/* attach to a matched cache set if it exists */
 	list_for_each_entry(c, &bch_cache_sets, list)
 		bch_cached_dev_attach(dc, c, NULL);
 
@@ -1311,6 +1321,8 @@ static void flash_dev_free(struct closure *cl)
 {
 	struct bcache_device *d = container_of(cl, struct bcache_device, cl);
 	mutex_lock(&bch_register_lock);
+	atomic_long_sub(bcache_dev_sectors_dirty(d),
+			&d->c->flash_dev_dirty_sectors);
 	bcache_device_free(d);
 	mutex_unlock(&bch_register_lock);
 	kobject_put(&d->kobj);
@@ -1390,7 +1402,7 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size)
 
 	get_random_bytes(u->uuid, 16);
 	memset(u->label, 0, 32);
-	u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
+	u->first_reg = u->last_reg = cpu_to_le32((u32)ktime_get_real_seconds());
 
 	SET_UUID_FLASH_ONLY(u, 1);
 	u->sectors = size >> 9;
@@ -1687,6 +1699,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
 	c->block_bits		= ilog2(sb->block_size);
 	c->nr_uuids		= bucket_bytes(c) / sizeof(struct uuid_entry);
 	c->devices_max_used	= 0;
+	atomic_set(&c->attached_dev_nr, 0);
 	c->btree_pages		= bucket_pages(c);
 	if (c->btree_pages > BTREE_MAX_PAGES)
 		c->btree_pages = max_t(int, c->btree_pages / 4,
@@ -1894,7 +1907,7 @@ static void run_cache_set(struct cache_set *c)
 		goto err;
 
 	closure_sync(&cl);
-	c->sb.last_mount = get_seconds();
+	c->sb.last_mount = (u32)ktime_get_real_seconds();
 	bcache_write_super(c);
 
 	list_for_each_entry_safe(dc, t, &uncached_devices, list)
@@ -2163,8 +2176,12 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 	if (!try_module_get(THIS_MODULE))
 		return -EBUSY;
 
-	if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
-	    !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
+	path = kstrndup(buffer, size, GFP_KERNEL);
+	if (!path)
+		goto err;
+
+	sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL);
+	if (!sb)
 		goto err;
 
 	err = "failed to open device";
@@ -2324,13 +2341,21 @@ static int __init bcache_init(void)
 		return bcache_major;
 	}
 
-	if (!(bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) ||
-	    !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
-	    bch_request_init() ||
-	    bch_debug_init(bcache_kobj) || closure_debug_init() ||
+	bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0);
+	if (!bcache_wq)
+		goto err;
+
+	bcache_kobj = kobject_create_and_add("bcache", fs_kobj);
+	if (!bcache_kobj)
+		goto err;
+
+	if (bch_request_init() ||
 	    sysfs_create_files(bcache_kobj, files))
 		goto err;
 
+	bch_debug_init(bcache_kobj);
+	closure_debug_init();
+
 	return 0;
 err:
 	bcache_exit();

drivers/md/bcache/sysfs.c

@@ -149,6 +149,7 @@ SHOW(__bch_cached_dev)
 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 					     disk.kobj);
 	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
+	int wb = dc->writeback_running;
 
 #define var(stat)		(dc->stat)
 
@@ -170,7 +171,8 @@ SHOW(__bch_cached_dev)
 	var_printf(writeback_running,	"%i");
 	var_print(writeback_delay);
 	var_print(writeback_percent);
-	sysfs_hprint(writeback_rate,	dc->writeback_rate.rate << 9);
+	sysfs_hprint(writeback_rate,
+		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
 	sysfs_hprint(io_errors,		atomic_read(&dc->io_errors));
 	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
 	sysfs_printf(io_disable,	"%i", dc->io_disable);
@@ -188,15 +190,22 @@ SHOW(__bch_cached_dev)
 		char change[20];
 		s64 next_io;
 
-		bch_hprint(rate,	dc->writeback_rate.rate << 9);
-		bch_hprint(dirty,	bcache_dev_sectors_dirty(&dc->disk) << 9);
-		bch_hprint(target,	dc->writeback_rate_target << 9);
-		bch_hprint(proportional,dc->writeback_rate_proportional << 9);
-		bch_hprint(integral,	dc->writeback_rate_integral_scaled << 9);
-		bch_hprint(change,	dc->writeback_rate_change << 9);
-
-		next_io = div64_s64(dc->writeback_rate.next - local_clock(),
-				    NSEC_PER_MSEC);
+		/*
+		 * Except for dirty and target, other values should
+		 * be 0 if writeback is not running.
+		 */
+		bch_hprint(rate,
+			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
+			      : 0);
+		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
+		bch_hprint(target, dc->writeback_rate_target << 9);
+		bch_hprint(proportional,
+			   wb ? dc->writeback_rate_proportional << 9 : 0);
+		bch_hprint(integral,
+			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
+		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
+		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
+					 NSEC_PER_MSEC) : 0;
 
 		return sprintf(buf,
 			       "rate:\t\t%s/sec\n"
@@ -255,8 +264,19 @@ STORE(__cached_dev)
 
 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
 
-	sysfs_strtoul_clamp(writeback_rate,
-			    dc->writeback_rate.rate, 1, INT_MAX);
+	if (attr == &sysfs_writeback_rate) {
+		ssize_t ret;
+		long int v = atomic_long_read(&dc->writeback_rate.rate);
+
+		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
+
+		if (!ret) {
+			atomic_long_set(&dc->writeback_rate.rate, v);
+			ret = size;
+		}
+
+		return ret;
+	}
 
 	sysfs_strtoul_clamp(writeback_rate_update_seconds,
 			    dc->writeback_rate_update_seconds,
@@ -338,8 +358,8 @@ STORE(__cached_dev)
 			if (!v)
 				return size;
 		}
-
-		pr_err("Can't attach %s: cache set not found", buf);
+		if (v == -ENOENT)
+			pr_err("Can't attach %s: cache set not found", buf);
 		return v;
 	}
 

drivers/md/bcache/util.c

@@ -200,7 +200,7 @@ uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
 {
 	uint64_t now = local_clock();
 
-	d->next += div_u64(done * NSEC_PER_SEC, d->rate);
+	d->next += div_u64(done * NSEC_PER_SEC, atomic_long_read(&d->rate));
 
 	/* Bound the time.  Don't let us fall further than 2 seconds behind
 	 * (this prevents unnecessary backlog that would make it impossible

drivers/md/bcache/util.h

@@ -442,7 +442,7 @@ struct bch_ratelimit {
 	 * Rate at which we want to do work, in units per second
 	 * The units here correspond to the units passed to bch_next_delay()
 	 */
-	uint32_t		rate;
+	atomic_long_t		rate;
 };
 
 static inline void bch_ratelimit_reset(struct bch_ratelimit *d)