Merge tag 'for-linus-20180504' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A collection of fixes that should to into this release. This contains:

   - Set of bcache fixes from Coly, fixing regression in patches that
     went into this series.

   - Set of NVMe fixes by way of Keith.

   - Set of bdi related fixes, one from Jan and two from Tetsuo Handa,
     fixing various issues around device addition/removal.

   - Two block inflight fixes from Omar, fixing issues around the
     transition to using tags for blk-mq inflight accounting that we
     did a few releases ago"

* tag 'for-linus-20180504' of git://git.kernel.dk/linux-block:
  bdi: Fix oops in wb_workfn()
  nvmet: switch loopback target state to connecting when resetting
  nvme/multipath: Fix multipath disabled naming collisions
  nvme/multipath: Disable runtime writable enabling parameter
  nvme: Set integrity flag for user passthrough commands
  nvme: fix potential memory leak in option parsing
  bdi: Fix use after free bug in debugfs_remove()
  bdi: wake up concurrent wb_shutdown() callers.
  bcache: use pr_info() to inform duplicated CACHE_SET_IO_DISABLE set
  bcache: set dc->io_disable to true in conditional_stop_bcache_device()
  bcache: add wait_for_kthread_stop() in bch_allocator_thread()
  bcache: count backing device I/O error for writeback I/O
  bcache: set CACHE_SET_IO_DISABLE in bch_cached_dev_error()
  bcache: store disk name in struct cache and struct cached_dev
  blk-mq: fix sysfs inflight counter
  blk-mq: count allocated but not started requests in iostats inflight

block/blk-mq.c

@@ -95,18 +95,15 @@ static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
 {
 	struct mq_inflight *mi = priv;
 
-	if (blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) {
-		/*
-		 * index[0] counts the specific partition that was asked
-		 * for. index[1] counts the ones that are active on the
-		 * whole device, so increment that if mi->part is indeed
-		 * a partition, and not a whole device.
-		 */
-		if (rq->part == mi->part)
-			mi->inflight[0]++;
-		if (mi->part->partno)
-			mi->inflight[1]++;
-	}
+	/*
+	 * index[0] counts the specific partition that was asked for. index[1]
+	 * counts the ones that are active on the whole device, so increment
+	 * that if mi->part is indeed a partition, and not a whole device.
+	 */
+	if (rq->part == mi->part)
+		mi->inflight[0]++;
+	if (mi->part->partno)
+		mi->inflight[1]++;
 }
 
 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
@@ -118,6 +115,25 @@ void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
 	blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
 }
 
+static void blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx,
+				     struct request *rq, void *priv,
+				     bool reserved)
+{
+	struct mq_inflight *mi = priv;
+
+	if (rq->part == mi->part)
+		mi->inflight[rq_data_dir(rq)]++;
+}
+
+void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+			 unsigned int inflight[2])
+{
+	struct mq_inflight mi = { .part = part, .inflight = inflight, };
+
+	inflight[0] = inflight[1] = 0;
+	blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi);
+}
+
 void blk_freeze_queue_start(struct request_queue *q)
 {
 	int freeze_depth;

block/blk-mq.h

@@ -188,7 +188,9 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 }
 
 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
-			unsigned int inflight[2]);
+		      unsigned int inflight[2]);
+void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+			 unsigned int inflight[2]);
 
 static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx)
 {

block/genhd.c

@@ -82,6 +82,18 @@ void part_in_flight(struct request_queue *q, struct hd_struct *part,
 	}
 }
 
+void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+		       unsigned int inflight[2])
+{
+	if (q->mq_ops) {
+		blk_mq_in_flight_rw(q, part, inflight);
+		return;
+	}
+
+	inflight[0] = atomic_read(&part->in_flight[0]);
+	inflight[1] = atomic_read(&part->in_flight[1]);
+}
+
 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
 {
 	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);

block/partition-generic.c

@@ -145,13 +145,15 @@ ssize_t part_stat_show(struct device *dev,
 		jiffies_to_msecs(part_stat_read(p, time_in_queue)));
 }
 
-ssize_t part_inflight_show(struct device *dev,
-			struct device_attribute *attr, char *buf)
+ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
+	struct request_queue *q = part_to_disk(p)->queue;
+	unsigned int inflight[2];
 
-	return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
-		atomic_read(&p->in_flight[1]));
+	part_in_flight_rw(q, p, inflight);
+	return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
 }
 
 #ifdef CONFIG_FAIL_MAKE_REQUEST

drivers/md/bcache/alloc.c

@@ -290,7 +290,7 @@ do {									\
 		if (kthread_should_stop() ||				\
 		    test_bit(CACHE_SET_IO_DISABLE, &ca->set->flags)) {	\
 			set_current_state(TASK_RUNNING);		\
-			return 0;					\
+			goto out;					\
 		}							\
 									\
 		schedule();						\
@@ -378,6 +378,9 @@ retry_invalidate:
 			bch_prio_write(ca);
 		}
 	}
+out:
+	wait_for_kthread_stop();
+	return 0;
 }
 
 /* Allocation */

drivers/md/bcache/bcache.h

@@ -392,6 +392,8 @@ struct cached_dev {
 #define DEFAULT_CACHED_DEV_ERROR_LIMIT	64
 	atomic_t		io_errors;
 	unsigned		error_limit;
+
+	char			backing_dev_name[BDEVNAME_SIZE];
 };
 
 enum alloc_reserve {
@@ -464,6 +466,8 @@ struct cache {
 	atomic_long_t		meta_sectors_written;
 	atomic_long_t		btree_sectors_written;
 	atomic_long_t		sectors_written;
+
+	char			cache_dev_name[BDEVNAME_SIZE];
 };
 
 struct gc_stat {

drivers/md/bcache/debug.c

@@ -106,7 +106,6 @@ void bch_btree_verify(struct btree *b)
 
 void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 {
-	char name[BDEVNAME_SIZE];
 	struct bio *check;
 	struct bio_vec bv, cbv;
 	struct bvec_iter iter, citer = { 0 };
@@ -134,7 +133,7 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio)
 					bv.bv_len),
 				 dc->disk.c,
 				 "verify failed at dev %s sector %llu",
-				 bdevname(dc->bdev, name),
+				 dc->backing_dev_name,
 				 (uint64_t) bio->bi_iter.bi_sector);
 
 		kunmap_atomic(p1);

drivers/md/bcache/io.c

@@ -52,7 +52,6 @@ void bch_submit_bbio(struct bio *bio, struct cache_set *c,
 /* IO errors */
 void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio)
 {
-	char buf[BDEVNAME_SIZE];
 	unsigned errors;
 
 	WARN_ONCE(!dc, "NULL pointer of struct cached_dev");
@@ -60,7 +59,7 @@ void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio)
 	errors = atomic_add_return(1, &dc->io_errors);
 	if (errors < dc->error_limit)
 		pr_err("%s: IO error on backing device, unrecoverable",
-			bio_devname(bio, buf));
+			dc->backing_dev_name);
 	else
 		bch_cached_dev_error(dc);
 }
@@ -105,19 +104,18 @@ void bch_count_io_errors(struct cache *ca,
 	}
 
 	if (error) {
-		char buf[BDEVNAME_SIZE];
 		unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT,
 						    &ca->io_errors);
 		errors >>= IO_ERROR_SHIFT;
 
 		if (errors < ca->set->error_limit)
 			pr_err("%s: IO error on %s%s",
-			       bdevname(ca->bdev, buf), m,
+			       ca->cache_dev_name, m,
 			       is_read ? ", recovering." : ".");
 		else
 			bch_cache_set_error(ca->set,
 					    "%s: too many IO errors %s",
-					    bdevname(ca->bdev, buf), m);
+					    ca->cache_dev_name, m);
 	}
 }
 

drivers/md/bcache/request.c

@@ -649,11 +649,8 @@ static void backing_request_endio(struct bio *bio)
 		 */
 		if (unlikely(s->iop.writeback &&
 			     bio->bi_opf & REQ_PREFLUSH)) {
-			char buf[BDEVNAME_SIZE];
-
-			bio_devname(bio, buf);
 			pr_err("Can't flush %s: returned bi_status %i",
-				buf, bio->bi_status);
+				dc->backing_dev_name, bio->bi_status);
 		} else {
 			/* set to orig_bio->bi_status in bio_complete() */
 			s->iop.status = bio->bi_status;

drivers/md/bcache/super.c

@@ -936,7 +936,6 @@ static void cancel_writeback_rate_update_dwork(struct cached_dev *dc)
 static void cached_dev_detach_finish(struct work_struct *w)
 {
 	struct cached_dev *dc = container_of(w, struct cached_dev, detach);
-	char buf[BDEVNAME_SIZE];
 	struct closure cl;
 	closure_init_stack(&cl);
 
@@ -967,7 +966,7 @@ static void cached_dev_detach_finish(struct work_struct *w)
 
 	mutex_unlock(&bch_register_lock);
 
-	pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
+	pr_info("Caching disabled for %s", dc->backing_dev_name);
 
 	/* Drop ref we took in cached_dev_detach() */
 	closure_put(&dc->disk.cl);
@@ -999,29 +998,28 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 {
 	uint32_t rtime = cpu_to_le32(get_seconds());
 	struct uuid_entry *u;
-	char buf[BDEVNAME_SIZE];
 	struct cached_dev *exist_dc, *t;
 
-	bdevname(dc->bdev, buf);
-
 	if ((set_uuid && memcmp(set_uuid, c->sb.set_uuid, 16)) ||
 	    (!set_uuid && memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16)))
 		return -ENOENT;
 
 	if (dc->disk.c) {
-		pr_err("Can't attach %s: already attached", buf);
+		pr_err("Can't attach %s: already attached",
+		       dc->backing_dev_name);
 		return -EINVAL;
 	}
 
 	if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
-		pr_err("Can't attach %s: shutting down", buf);
+		pr_err("Can't attach %s: shutting down",
+		       dc->backing_dev_name);
 		return -EINVAL;
 	}
 
 	if (dc->sb.block_size < c->sb.block_size) {
 		/* Will die */
 		pr_err("Couldn't attach %s: block size less than set's block size",
-		       buf);
+		       dc->backing_dev_name);
 		return -EINVAL;
 	}
 
@@ -1029,7 +1027,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	list_for_each_entry_safe(exist_dc, t, &c->cached_devs, list) {
 		if (!memcmp(dc->sb.uuid, exist_dc->sb.uuid, 16)) {
 			pr_err("Tried to attach %s but duplicate UUID already attached",
-				buf);
+				dc->backing_dev_name);
 
 			return -EINVAL;
 		}
@@ -1047,13 +1045,15 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 
 	if (!u) {
 		if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
-			pr_err("Couldn't find uuid for %s in set", buf);
+			pr_err("Couldn't find uuid for %s in set",
+			       dc->backing_dev_name);
 			return -ENOENT;
 		}
 
 		u = uuid_find_empty(c);
 		if (!u) {
-			pr_err("Not caching %s, no room for UUID", buf);
+			pr_err("Not caching %s, no room for UUID",
+			       dc->backing_dev_name);
 			return -EINVAL;
 		}
 	}
@@ -1112,7 +1112,8 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	up_write(&dc->writeback_lock);
 
 	pr_info("Caching %s as %s on set %pU",
-		bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
+		dc->backing_dev_name,
+		dc->disk.disk->disk_name,
 		dc->disk.c->sb.set_uuid);
 	return 0;
 }
@@ -1225,10 +1226,10 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 				 struct block_device *bdev,
 				 struct cached_dev *dc)
 {
-	char name[BDEVNAME_SIZE];
 	const char *err = "cannot allocate memory";
 	struct cache_set *c;
 
+	bdevname(bdev, dc->backing_dev_name);
 	memcpy(&dc->sb, sb, sizeof(struct cache_sb));
 	dc->bdev = bdev;
 	dc->bdev->bd_holder = dc;
@@ -1237,6 +1238,7 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 	bio_first_bvec_all(&dc->sb_bio)->bv_page = sb_page;
 	get_page(sb_page);
 
+
 	if (cached_dev_init(dc, sb->block_size << 9))
 		goto err;
 
@@ -1247,7 +1249,7 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 	if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
 		goto err;
 
-	pr_info("registered backing device %s", bdevname(bdev, name));
+	pr_info("registered backing device %s", dc->backing_dev_name);
 
 	list_add(&dc->list, &uncached_devices);
 	list_for_each_entry(c, &bch_cache_sets, list)
@@ -1259,7 +1261,7 @@ static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 
 	return;
 err:
-	pr_notice("error %s: %s", bdevname(bdev, name), err);
+	pr_notice("error %s: %s", dc->backing_dev_name, err);
 	bcache_device_stop(&dc->disk);
 }
 
@@ -1367,7 +1369,7 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size)
 
 bool bch_cached_dev_error(struct cached_dev *dc)
 {
-	char name[BDEVNAME_SIZE];
+	struct cache_set *c;
 
 	if (!dc || test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
 		return false;
@@ -1377,7 +1379,22 @@ bool bch_cached_dev_error(struct cached_dev *dc)
 	smp_mb();
 
 	pr_err("stop %s: too many IO errors on backing device %s\n",
-		dc->disk.disk->disk_name, bdevname(dc->bdev, name));
+		dc->disk.disk->disk_name, dc->backing_dev_name);
+
+	/*
+	 * If the cached device is still attached to a cache set,
+	 * even dc->io_disable is true and no more I/O requests
+	 * accepted, cache device internal I/O (writeback scan or
+	 * garbage collection) may still prevent bcache device from
+	 * being stopped. So here CACHE_SET_IO_DISABLE should be
+	 * set to c->flags too, to make the internal I/O to cache
+	 * device rejected and stopped immediately.
+	 * If c is NULL, that means the bcache device is not attached
+	 * to any cache set, then no CACHE_SET_IO_DISABLE bit to set.
+	 */
+	c = dc->disk.c;
+	if (c && test_and_set_bit(CACHE_SET_IO_DISABLE, &c->flags))
+		pr_info("CACHE_SET_IO_DISABLE already set");
 
 	bcache_device_stop(&dc->disk);
 	return true;
@@ -1395,7 +1412,7 @@ bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
 		return false;
 
 	if (test_and_set_bit(CACHE_SET_IO_DISABLE, &c->flags))
-		pr_warn("CACHE_SET_IO_DISABLE already set");
+		pr_info("CACHE_SET_IO_DISABLE already set");
 
 	/* XXX: we can be called from atomic context
 	acquire_console_sem();
@@ -1539,6 +1556,20 @@ static void conditional_stop_bcache_device(struct cache_set *c,
 		 */
 		pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.",
 			d->disk->disk_name);
+			/*
+			 * There might be a small time gap that cache set is
+			 * released but bcache device is not. Inside this time
+			 * gap, regular I/O requests will directly go into
+			 * backing device as no cache set attached to. This
+			 * behavior may also introduce potential inconsistence
+			 * data in writeback mode while cache is dirty.
+			 * Therefore before calling bcache_device_stop() due
+			 * to a broken cache device, dc->io_disable should be
+			 * explicitly set to true.
+			 */
+			dc->io_disable = true;
+			/* make others know io_disable is true earlier */
+			smp_mb();
 			bcache_device_stop(d);
 	} else {
 		/*
@@ -2003,12 +2034,10 @@ static int cache_alloc(struct cache *ca)
 static int register_cache(struct cache_sb *sb, struct page *sb_page,
 				struct block_device *bdev, struct cache *ca)
 {
-	char name[BDEVNAME_SIZE];
 	const char *err = NULL; /* must be set for any error case */
 	int ret = 0;
 
-	bdevname(bdev, name);
-
+	bdevname(bdev, ca->cache_dev_name);
 	memcpy(&ca->sb, sb, sizeof(struct cache_sb));
 	ca->bdev = bdev;
 	ca->bdev->bd_holder = ca;
@@ -2045,14 +2074,14 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
 		goto out;
 	}
 
-	pr_info("registered cache device %s", name);
+	pr_info("registered cache device %s", ca->cache_dev_name);
 
 out:
 	kobject_put(&ca->kobj);
 
 err:
 	if (err)
-		pr_notice("error %s: %s", name, err);
+		pr_notice("error %s: %s", ca->cache_dev_name, err);
 
 	return ret;
 }

drivers/md/bcache/writeback.c

@@ -244,8 +244,10 @@ static void dirty_endio(struct bio *bio)
 	struct keybuf_key *w = bio->bi_private;
 	struct dirty_io *io = w->private;
 
-	if (bio->bi_status)
+	if (bio->bi_status) {
 		SET_KEY_DIRTY(&w->key, false);
+		bch_count_backing_io_errors(io->dc, bio);
+	}
 
 	closure_put(&io->cl);
 }

drivers/nvme/host/core.c

@@ -764,6 +764,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
 				ret = PTR_ERR(meta);
 				goto out_unmap;
 			}
+			req->cmd_flags |= REQ_INTEGRITY;
 		}
 	}
 
@@ -2997,31 +2998,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 	if (nvme_init_ns_head(ns, nsid, id))
 		goto out_free_id;
 	nvme_setup_streams_ns(ctrl, ns);
-	
-#ifdef CONFIG_NVME_MULTIPATH
-	/*
-	 * If multipathing is enabled we need to always use the subsystem
-	 * instance number for numbering our devices to avoid conflicts
-	 * between subsystems that have multiple controllers and thus use
-	 * the multipath-aware subsystem node and those that have a single
-	 * controller and use the controller node directly.
-	 */
-	if (ns->head->disk) {
-		sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
-				ctrl->cntlid, ns->head->instance);
-		flags = GENHD_FL_HIDDEN;
-	} else {
-		sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
-				ns->head->instance);
-	}
-#else
-	/*
-	 * But without the multipath code enabled, multiple controller per
-	 * subsystems are visible as devices and thus we cannot use the
-	 * subsystem instance.
-	 */
-	sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
-#endif
+	nvme_set_disk_name(disk_name, ns, ctrl, &flags);
 
 	if ((ctrl->quirks & NVME_QUIRK_LIGHTNVM) && id->vs[0] == 0x1) {
 		if (nvme_nvm_register(ns, disk_name, node)) {

drivers/nvme/host/fabrics.c

@@ -668,6 +668,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -ENOMEM;
 				goto out;
 			}
+			kfree(opts->transport);
 			opts->transport = p;
 			break;
 		case NVMF_OPT_NQN:
@@ -676,6 +677,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -ENOMEM;
 				goto out;
 			}
+			kfree(opts->subsysnqn);
 			opts->subsysnqn = p;
 			nqnlen = strlen(opts->subsysnqn);
 			if (nqnlen >= NVMF_NQN_SIZE) {
@@ -698,6 +700,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -ENOMEM;
 				goto out;
 			}
+			kfree(opts->traddr);
 			opts->traddr = p;
 			break;
 		case NVMF_OPT_TRSVCID:
@@ -706,6 +709,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -ENOMEM;
 				goto out;
 			}
+			kfree(opts->trsvcid);
 			opts->trsvcid = p;
 			break;
 		case NVMF_OPT_QUEUE_SIZE:
@@ -792,6 +796,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -EINVAL;
 				goto out;
 			}
+			nvmf_host_put(opts->host);
 			opts->host = nvmf_host_add(p);
 			kfree(p);
 			if (!opts->host) {
@@ -817,6 +822,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 				ret = -ENOMEM;
 				goto out;
 			}
+			kfree(opts->host_traddr);
 			opts->host_traddr = p;
 			break;
 		case NVMF_OPT_HOST_ID:

drivers/nvme/host/multipath.c

@@ -15,10 +15,32 @@
 #include "nvme.h"
 
 static bool multipath = true;
-module_param(multipath, bool, 0644);
+module_param(multipath, bool, 0444);
 MODULE_PARM_DESC(multipath,
 	"turn on native support for multiple controllers per subsystem");
 
+/*
+ * If multipathing is enabled we need to always use the subsystem instance
+ * number for numbering our devices to avoid conflicts between subsystems that
+ * have multiple controllers and thus use the multipath-aware subsystem node
+ * and those that have a single controller and use the controller node
+ * directly.
+ */
+void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
+			struct nvme_ctrl *ctrl, int *flags)
+{
+	if (!multipath) {
+		sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
+	} else if (ns->head->disk) {
+		sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
+				ctrl->cntlid, ns->head->instance);
+		*flags = GENHD_FL_HIDDEN;
+	} else {
+		sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
+				ns->head->instance);
+	}
+}
+
 void nvme_failover_req(struct request *req)
 {
 	struct nvme_ns *ns = req->q->queuedata;

drivers/nvme/host/nvme.h

@@ -436,6 +436,8 @@ extern const struct attribute_group nvme_ns_id_attr_group;
 extern const struct block_device_operations nvme_ns_head_ops;
 
 #ifdef CONFIG_NVME_MULTIPATH
+void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
+			struct nvme_ctrl *ctrl, int *flags);
 void nvme_failover_req(struct request *req);
 bool nvme_req_needs_failover(struct request *req, blk_status_t error);
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
@@ -461,6 +463,16 @@ static inline void nvme_mpath_check_last_path(struct nvme_ns *ns)
 }
 
 #else
+/*
+ * Without the multipath code enabled, multiple controller per subsystems are
+ * visible as devices and thus we cannot use the subsystem instance.
+ */
+static inline void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
+				      struct nvme_ctrl *ctrl, int *flags)
+{
+	sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
+}
+
 static inline void nvme_failover_req(struct request *req)
 {
 }

drivers/nvme/target/loop.c

@@ -469,6 +469,12 @@ static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 	nvme_stop_ctrl(&ctrl->ctrl);
 	nvme_loop_shutdown_ctrl(ctrl);
 
+	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
+		/* state change failure should never happen */
+		WARN_ON_ONCE(1);
+		return;
+	}
+
 	ret = nvme_loop_configure_admin_queue(ctrl);
 	if (ret)
 		goto out_disable;

fs/fs-writeback.c

@@ -1961,7 +1961,7 @@ void wb_workfn(struct work_struct *work)
 	}
 
 	if (!list_empty(&wb->work_list))
-		mod_delayed_work(bdi_wq, &wb->dwork, 0);
+		wb_wakeup(wb);
 	else if (wb_has_dirty_io(wb) && dirty_writeback_interval)
 		wb_wakeup_delayed(wb);
 

include/linux/genhd.h

@@ -368,7 +368,9 @@ static inline void free_part_stats(struct hd_struct *part)
 	part_stat_add(cpu, gendiskp, field, -subnd)
 
 void part_in_flight(struct request_queue *q, struct hd_struct *part,
-			unsigned int inflight[2]);
+		    unsigned int inflight[2]);
+void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
+		       unsigned int inflight[2]);
 void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
 			int rw);
 void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,

include/linux/wait_bit.h

@@ -305,4 +305,21 @@ do {									\
 	__ret;								\
 })
 
+/**
+ * clear_and_wake_up_bit - clear a bit and wake up anyone waiting on that bit
+ *
+ * @bit: the bit of the word being waited on
+ * @word: the word being waited on, a kernel virtual address
+ *
+ * You can use this helper if bitflags are manipulated atomically rather than
+ * non-atomically under a lock.
+ */
+static inline void clear_and_wake_up_bit(int bit, void *word)
+{
+	clear_bit_unlock(bit, word);
+	/* See wake_up_bit() for which memory barrier you need to use. */
+	smp_mb__after_atomic();
+	wake_up_bit(word, bit);
+}
+
 #endif /* _LINUX_WAIT_BIT_H */

mm/backing-dev.c

@@ -115,6 +115,7 @@ static int bdi_debug_register(struct backing_dev_info *bdi, const char *name)
 					       bdi, &bdi_debug_stats_fops);
 	if (!bdi->debug_stats) {
 		debugfs_remove(bdi->debug_dir);
+		bdi->debug_dir = NULL;
 		return -ENOMEM;
 	}
 
@@ -383,7 +384,7 @@ static void wb_shutdown(struct bdi_writeback *wb)
 	 * the barrier provided by test_and_clear_bit() above.
 	 */
 	smp_wmb();
-	clear_bit(WB_shutting_down, &wb->state);
+	clear_and_wake_up_bit(WB_shutting_down, &wb->state);
 }
 
 static void wb_exit(struct bdi_writeback *wb)