Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

Pull MD update from Shaohua Li:

 - fixed deadlock in MD suspend and a potential bug in bio allocation
   (Neil Brown)

 - fixed signal issue (Mikulas Patocka)

 - fixed typo in FailFast test (Guoqing Jiang)

 - other trival fixes

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  MD: fix sleep in atomic
  MD: fix a null dereference
  md: use a separate bio_set for synchronous IO.
  md: change the initialization value for a spare device spot to MD_DISK_ROLE_SPARE
  md/raid1: remove unused bio in sync_request_write
  md/raid10: fix FailFast test for wrong device
  md: don't use flush_signals in userspace processes
  md: fix deadlock between mddev_suspend() and md_write_start()

drivers/md/faulty.c

@@ -170,7 +170,7 @@ static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
 		conf->nfaults = n+1;
 }
 
-static void faulty_make_request(struct mddev *mddev, struct bio *bio)
+static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
 {
 	struct faulty_conf *conf = mddev->private;
 	int failit = 0;
@@ -182,7 +182,7 @@ static void faulty_make_request(struct mddev *mddev, struct bio *bio)
 			 * just fail immediately
 			 */
 			bio_io_error(bio);
-			return;
+			return true;
 		}
 
 		if (check_sector(conf, bio->bi_iter.bi_sector,
@@ -224,6 +224,7 @@ static void faulty_make_request(struct mddev *mddev, struct bio *bio)
 		bio->bi_bdev = conf->rdev->bdev;
 
 	generic_make_request(bio);
+	return true;
 }
 
 static void faulty_status(struct seq_file *seq, struct mddev *mddev)

drivers/md/linear.c

@@ -245,7 +245,7 @@ static void linear_free(struct mddev *mddev, void *priv)
 	kfree(conf);
 }
 
-static void linear_make_request(struct mddev *mddev, struct bio *bio)
+static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 {
 	char b[BDEVNAME_SIZE];
 	struct dev_info *tmp_dev;
@@ -254,7 +254,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
 		md_flush_request(mddev, bio);
-		return;
+		return true;
 	}
 
 	tmp_dev = which_dev(mddev, bio_sector);
@@ -292,7 +292,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
 		mddev_check_write_zeroes(mddev, bio);
 		generic_make_request(bio);
 	}
-	return;
+	return true;
 
 out_of_bounds:
 	pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %s: %llu sectors, offset %llu\n",
@@ -302,6 +302,7 @@ out_of_bounds:
 	       (unsigned long long)tmp_dev->rdev->sectors,
 	       (unsigned long long)start_sector);
 	bio_io_error(bio);
+	return true;
 }
 
 static void linear_status (struct seq_file *seq, struct mddev *mddev)

drivers/md/md.c

@@ -203,6 +203,14 @@ struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
 }
 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
 
+static struct bio *md_bio_alloc_sync(struct mddev *mddev)
+{
+	if (!mddev || !mddev->sync_set)
+		return bio_alloc(GFP_NOIO, 1);
+
+	return bio_alloc_bioset(GFP_NOIO, 1, mddev->sync_set);
+}
+
 /*
  * We have a system wide 'event count' that is incremented
  * on any 'interesting' event, and readers of /proc/mdstat
@@ -277,7 +285,7 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 		bio_endio(bio);
 		return BLK_QC_T_NONE;
 	}
-	smp_rmb(); /* Ensure implications of  'active' are visible */
+check_suspended:
 	rcu_read_lock();
 	if (mddev->suspended) {
 		DEFINE_WAIT(__wait);
@@ -302,7 +310,11 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 	sectors = bio_sectors(bio);
 	/* bio could be mergeable after passing to underlayer */
 	bio->bi_opf &= ~REQ_NOMERGE;
-	mddev->pers->make_request(mddev, bio);
+	if (!mddev->pers->make_request(mddev, bio)) {
+		atomic_dec(&mddev->active_io);
+		wake_up(&mddev->sb_wait);
+		goto check_suspended;
+	}
 
 	cpu = part_stat_lock();
 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
@@ -327,6 +339,7 @@ void mddev_suspend(struct mddev *mddev)
 	if (mddev->suspended++)
 		return;
 	synchronize_rcu();
+	wake_up(&mddev->sb_wait);
 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
 	mddev->pers->quiesce(mddev, 1);
 
@@ -462,7 +475,7 @@ static void mddev_delayed_delete(struct work_struct *ws);
 
 static void mddev_put(struct mddev *mddev)
 {
-	struct bio_set *bs = NULL;
+	struct bio_set *bs = NULL, *sync_bs = NULL;
 
 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
 		return;
@@ -472,7 +485,9 @@ static void mddev_put(struct mddev *mddev)
 		 * so destroy it */
 		list_del_init(&mddev->all_mddevs);
 		bs = mddev->bio_set;
+		sync_bs = mddev->sync_set;
 		mddev->bio_set = NULL;
+		mddev->sync_set = NULL;
 		if (mddev->gendisk) {
 			/* We did a probe so need to clean up.  Call
 			 * queue_work inside the spinlock so that
@@ -487,6 +502,8 @@ static void mddev_put(struct mddev *mddev)
 	spin_unlock(&all_mddevs_lock);
 	if (bs)
 		bioset_free(bs);
+	if (sync_bs)
+		bioset_free(sync_bs);
 }
 
 static void md_safemode_timeout(unsigned long data);
@@ -751,7 +768,7 @@ void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
 	if (test_bit(Faulty, &rdev->flags))
 		return;
 
-	bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
+	bio = md_bio_alloc_sync(mddev);
 
 	atomic_inc(&rdev->nr_pending);
 
@@ -783,7 +800,7 @@ int md_super_wait(struct mddev *mddev)
 int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
 		 struct page *page, int op, int op_flags, bool metadata_op)
 {
-	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
+	struct bio *bio = md_bio_alloc_sync(rdev->mddev);
 	int ret;
 
 	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
@@ -1852,7 +1869,7 @@ retry:
 		max_dev = le32_to_cpu(sb->max_dev);
 
 	for (i=0; i<max_dev;i++)
-		sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
+		sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
 
 	if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
 		sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
@@ -5432,6 +5449,11 @@ int md_run(struct mddev *mddev)
 		if (!mddev->bio_set)
 			return -ENOMEM;
 	}
+	if (mddev->sync_set == NULL) {
+		mddev->sync_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
+		if (!mddev->sync_set)
+			return -ENOMEM;
+	}
 
 	spin_lock(&pers_lock);
 	pers = find_pers(mddev->level, mddev->clevel);
@@ -7950,12 +7972,14 @@ EXPORT_SYMBOL(md_done_sync);
  * If we need to update some array metadata (e.g. 'active' flag
  * in superblock) before writing, schedule a superblock update
  * and wait for it to complete.
+ * A return value of 'false' means that the write wasn't recorded
+ * and cannot proceed as the array is being suspend.
  */
-void md_write_start(struct mddev *mddev, struct bio *bi)
+bool md_write_start(struct mddev *mddev, struct bio *bi)
 {
 	int did_change = 0;
 	if (bio_data_dir(bi) != WRITE)
-		return;
+		return true;
 
 	BUG_ON(mddev->ro == 1);
 	if (mddev->ro == 2) {
@@ -7987,7 +8011,12 @@ void md_write_start(struct mddev *mddev, struct bio *bi)
 	if (did_change)
 		sysfs_notify_dirent_safe(mddev->sysfs_state);
 	wait_event(mddev->sb_wait,
-		   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
+		   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) && !mddev->suspended);
+	if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
+		percpu_ref_put(&mddev->writes_pending);
+		return false;
+	}
+	return true;
 }
 EXPORT_SYMBOL(md_write_start);
 

drivers/md/md.h

@@ -444,6 +444,9 @@ struct mddev {
 	struct attribute_group		*to_remove;
 
 	struct bio_set			*bio_set;
+	struct bio_set			*sync_set; /* for sync operations like
+						   * metadata and bitmap writes
+						   */
 
 	/* Generic flush handling.
 	 * The last to finish preflush schedules a worker to submit
@@ -510,7 +513,7 @@ struct md_personality
 	int level;
 	struct list_head list;
 	struct module *owner;
-	void (*make_request)(struct mddev *mddev, struct bio *bio);
+	bool (*make_request)(struct mddev *mddev, struct bio *bio);
 	int (*run)(struct mddev *mddev);
 	void (*free)(struct mddev *mddev, void *priv);
 	void (*status)(struct seq_file *seq, struct mddev *mddev);
@@ -649,7 +652,7 @@ extern void md_wakeup_thread(struct md_thread *thread);
 extern void md_check_recovery(struct mddev *mddev);
 extern void md_reap_sync_thread(struct mddev *mddev);
 extern int mddev_init_writes_pending(struct mddev *mddev);
-extern void md_write_start(struct mddev *mddev, struct bio *bi);
+extern bool md_write_start(struct mddev *mddev, struct bio *bi);
 extern void md_write_inc(struct mddev *mddev, struct bio *bi);
 extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);

drivers/md/multipath.c

@@ -106,7 +106,7 @@ static void multipath_end_request(struct bio *bio)
 	rdev_dec_pending(rdev, conf->mddev);
 }
 
-static void multipath_make_request(struct mddev *mddev, struct bio * bio)
+static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
 {
 	struct mpconf *conf = mddev->private;
 	struct multipath_bh * mp_bh;
@@ -114,7 +114,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
 		md_flush_request(mddev, bio);
-		return;
+		return true;
 	}
 
 	mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
@@ -126,7 +126,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
 	if (mp_bh->path < 0) {
 		bio_io_error(bio);
 		mempool_free(mp_bh, conf->pool);
-		return;
+		return true;
 	}
 	multipath = conf->multipaths + mp_bh->path;
 
@@ -141,7 +141,7 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
 	mddev_check_writesame(mddev, &mp_bh->bio);
 	mddev_check_write_zeroes(mddev, &mp_bh->bio);
 	generic_make_request(&mp_bh->bio);
-	return;
+	return true;
 }
 
 static void multipath_status(struct seq_file *seq, struct mddev *mddev)

drivers/md/raid0.c

@@ -548,7 +548,7 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
 	bio_endio(bio);
 }
 
-static void raid0_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
 {
 	struct strip_zone *zone;
 	struct md_rdev *tmp_dev;
@@ -559,12 +559,12 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
 		md_flush_request(mddev, bio);
-		return;
+		return true;
 	}
 
 	if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
 		raid0_handle_discard(mddev, bio);
-		return;
+		return true;
 	}
 
 	bio_sector = bio->bi_iter.bi_sector;
@@ -599,6 +599,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
 	mddev_check_writesame(mddev, bio);
 	mddev_check_write_zeroes(mddev, bio);
 	generic_make_request(bio);
+	return true;
 }
 
 static void raid0_status(struct seq_file *seq, struct mddev *mddev)

drivers/md/raid1.c

@@ -1321,7 +1321,6 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 	 * Continue immediately if no resync is active currently.
 	 */
 
-	md_write_start(mddev, bio); /* wait on superblock update early */
 
 	if ((bio_end_sector(bio) > mddev->suspend_lo &&
 	    bio->bi_iter.bi_sector < mddev->suspend_hi) ||
@@ -1335,7 +1334,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 		 */
 		DEFINE_WAIT(w);
 		for (;;) {
-			flush_signals(current);
+			sigset_t full, old;
 			prepare_to_wait(&conf->wait_barrier,
 					&w, TASK_INTERRUPTIBLE);
 			if (bio_end_sector(bio) <= mddev->suspend_lo ||
@@ -1345,7 +1344,10 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 				     bio->bi_iter.bi_sector,
 				     bio_end_sector(bio))))
 				break;
+			sigfillset(&full);
+			sigprocmask(SIG_BLOCK, &full, &old);
 			schedule();
+			sigprocmask(SIG_SETMASK, &old, NULL);
 		}
 		finish_wait(&conf->wait_barrier, &w);
 	}
@@ -1550,13 +1552,13 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 	wake_up(&conf->wait_barrier);
 }
 
-static void raid1_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
 {
 	sector_t sectors;
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
 		md_flush_request(mddev, bio);
-		return;
+		return true;
 	}
 
 	/*
@@ -1571,8 +1573,12 @@ static void raid1_make_request(struct mddev *mddev, struct bio *bio)
 
 	if (bio_data_dir(bio) == READ)
 		raid1_read_request(mddev, bio, sectors, NULL);
-	else
+	else {
+		if (!md_write_start(mddev,bio))
+			return false;
 		raid1_write_request(mddev, bio, sectors);
+	}
+	return true;
 }
 
 static void raid1_status(struct seq_file *seq, struct mddev *mddev)
@@ -2165,9 +2171,7 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
 	struct r1conf *conf = mddev->private;
 	int i;
 	int disks = conf->raid_disks * 2;
-	struct bio *bio, *wbio;
-
-	bio = r1_bio->bios[r1_bio->read_disk];
+	struct bio *wbio;
 
 	if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
 		/* ouch - failed to read all of that. */

drivers/md/raid10.c

@@ -1303,8 +1303,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 	sector_t sectors;
 	int max_sectors;
 
-	md_write_start(mddev, bio);
-
 	/*
 	 * Register the new request and wait if the reconstruction
 	 * thread has put up a bar for new requests.
@@ -1525,7 +1523,7 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
 		raid10_write_request(mddev, bio, r10_bio);
 }
 
-static void raid10_make_request(struct mddev *mddev, struct bio *bio)
+static bool raid10_make_request(struct mddev *mddev, struct bio *bio)
 {
 	struct r10conf *conf = mddev->private;
 	sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
@@ -1534,9 +1532,12 @@ static void raid10_make_request(struct mddev *mddev, struct bio *bio)
 
 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
 		md_flush_request(mddev, bio);
-		return;
+		return true;
 	}
 
+	if (!md_write_start(mddev, bio))
+		return false;
+
 	/*
 	 * If this request crosses a chunk boundary, we need to split
 	 * it.
@@ -1553,6 +1554,7 @@ static void raid10_make_request(struct mddev *mddev, struct bio *bio)
 
 	/* In case raid10d snuck in to freeze_array */
 	wake_up(&conf->wait_barrier);
+	return true;
 }
 
 static void raid10_status(struct seq_file *seq, struct mddev *mddev)
@@ -3293,7 +3295,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
 			biolist = bio;
 			bio->bi_end_io = end_sync_read;
 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
-			if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
+			if (test_bit(FailFast, &rdev->flags))
 				bio->bi_opf |= MD_FAILFAST;
 			bio->bi_iter.bi_sector = sector + rdev->data_offset;
 			bio->bi_bdev = rdev->bdev;
@@ -3305,7 +3307,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
 				continue;
 			}
 			atomic_inc(&rdev->nr_pending);
-			rcu_read_unlock();
 
 			/* Need to set up for writing to the replacement */
 			bio = r10_bio->devs[i].repl_bio;
@@ -3316,11 +3317,12 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
 			biolist = bio;
 			bio->bi_end_io = end_sync_write;
 			bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-			if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
+			if (test_bit(FailFast, &rdev->flags))
 				bio->bi_opf |= MD_FAILFAST;
 			bio->bi_iter.bi_sector = sector + rdev->data_offset;
 			bio->bi_bdev = rdev->bdev;
 			count++;
+			rcu_read_unlock();
 		}
 
 		if (count < 2) {

drivers/md/raid5.c

@@ -5479,7 +5479,6 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi)
 	last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
 
 	bi->bi_next = NULL;
-	md_write_start(mddev, bi);
 
 	stripe_sectors = conf->chunk_sectors *
 		(conf->raid_disks - conf->max_degraded);
@@ -5549,11 +5548,10 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi)
 		release_stripe_plug(mddev, sh);
 	}
 
-	md_write_end(mddev);
 	bio_endio(bi);
 }
 
-static void raid5_make_request(struct mddev *mddev, struct bio * bi)
+static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
 {
 	struct r5conf *conf = mddev->private;
 	int dd_idx;
@@ -5569,10 +5567,10 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
 		int ret = r5l_handle_flush_request(conf->log, bi);
 
 		if (ret == 0)
-			return;
+			return true;
 		if (ret == -ENODEV) {
 			md_flush_request(mddev, bi);
-			return;
+			return true;
 		}
 		/* ret == -EAGAIN, fallback */
 		/*
@@ -5582,6 +5580,8 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
 		do_flush = bi->bi_opf & REQ_PREFLUSH;
 	}
 
+	if (!md_write_start(mddev, bi))
+		return false;
 	/*
 	 * If array is degraded, better not do chunk aligned read because
 	 * later we might have to read it again in order to reconstruct
@@ -5591,18 +5591,18 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
 	    mddev->reshape_position == MaxSector) {
 		bi = chunk_aligned_read(mddev, bi);
 		if (!bi)
-			return;
+			return true;
 	}
 
 	if (unlikely(bio_op(bi) == REQ_OP_DISCARD)) {
 		make_discard_request(mddev, bi);
-		return;
+		md_write_end(mddev);
+		return true;
 	}
 
 	logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
 	last_sector = bio_end_sector(bi);
 	bi->bi_next = NULL;
-	md_write_start(mddev, bi);
 
 	prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
 	for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
@@ -5693,12 +5693,15 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
 				 * userspace, we want an interruptible
 				 * wait.
 				 */
-				flush_signals(current);
 				prepare_to_wait(&conf->wait_for_overlap,
 						&w, TASK_INTERRUPTIBLE);
 				if (logical_sector >= mddev->suspend_lo &&
 				    logical_sector < mddev->suspend_hi) {
+					sigset_t full, old;
+					sigfillset(&full);
+					sigprocmask(SIG_BLOCK, &full, &old);
 					schedule();
+					sigprocmask(SIG_SETMASK, &old, NULL);
 					do_prepare = true;
 				}
 				goto retry;
@@ -5740,6 +5743,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
 	if (rw == WRITE)
 		md_write_end(mddev);
 	bio_endio(bi);
+	return true;
 }
 
 static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);