1 files changed, 169 insertions, 98 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8cdca0296749..41c050b59ec4 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -69,7 +69,7 @@
 
 #include <trace/events/block.h>
 #include "md.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "md-cluster.h"
 
 #ifndef MODULE
@@ -266,6 +266,52 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
  * call has finished, the bio has been linked into some internal structure
  * and so is visible to ->quiesce(), so we don't need the refcount any more.
  */
+static bool is_suspended(struct mddev *mddev, struct bio *bio)
+{
+	if (mddev->suspended)
+		return true;
+	if (bio_data_dir(bio) != WRITE)
+		return false;
+	if (mddev->suspend_lo >= mddev->suspend_hi)
+		return false;
+	if (bio->bi_iter.bi_sector >= mddev->suspend_hi)
+		return false;
+	if (bio_end_sector(bio) < mddev->suspend_lo)
+		return false;
+	return true;
+}
+
+void md_handle_request(struct mddev *mddev, struct bio *bio)
+{
+check_suspended:
+	rcu_read_lock();
+	if (is_suspended(mddev, bio)) {
+		DEFINE_WAIT(__wait);
+		for (;;) {
+			prepare_to_wait(&mddev->sb_wait, &__wait,
+					TASK_UNINTERRUPTIBLE);
+			if (!is_suspended(mddev, bio))
+				break;
+			rcu_read_unlock();
+			schedule();
+			rcu_read_lock();
+		}
+		finish_wait(&mddev->sb_wait, &__wait);
+	}
+	atomic_inc(&mddev->active_io);
+	rcu_read_unlock();
+
+	if (!mddev->pers->make_request(mddev, bio)) {
+		atomic_dec(&mddev->active_io);
+		wake_up(&mddev->sb_wait);
+		goto check_suspended;
+	}
+
+	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
+		wake_up(&mddev->sb_wait);
+}
+EXPORT_SYMBOL(md_handle_request);
+
 static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 {
 	const int rw = bio_data_dir(bio);
@@ -285,23 +331,6 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio)
 		bio_endio(bio);
 		return BLK_QC_T_NONE;
 	}
-check_suspended:
-	rcu_read_lock();
-	if (mddev->suspended) {
-		DEFINE_WAIT(__wait);
-		for (;;) {
-			prepare_to_wait(&mddev->sb_wait, &__wait,
-					TASK_UNINTERRUPTIBLE);
-			if (!mddev->suspended)
-				break;
-			rcu_read_unlock();
-			schedule();
-			rcu_read_lock();
-		}
-		finish_wait(&mddev->sb_wait, &__wait);
-	}
-	atomic_inc(&mddev->active_io);
-	rcu_read_unlock();
 
 	/*
 	 * save the sectors now since our bio can
@@ -310,20 +339,14 @@ check_suspended:
 	sectors = bio_sectors(bio);
 	/* bio could be mergeable after passing to underlayer */
 	bio->bi_opf &= ~REQ_NOMERGE;
-	if (!mddev->pers->make_request(mddev, bio)) {
-		atomic_dec(&mddev->active_io);
-		wake_up(&mddev->sb_wait);
-		goto check_suspended;
-	}
+
+	md_handle_request(mddev, bio);
 
 	cpu = part_stat_lock();
 	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
 	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors);
 	part_stat_unlock();
 
-	if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
-		wake_up(&mddev->sb_wait);
-
 	return BLK_QC_T_NONE;
 }
 
@@ -336,12 +359,17 @@ check_suspended:
 void mddev_suspend(struct mddev *mddev)
 {
 	WARN_ON_ONCE(mddev->thread && current == mddev->thread->tsk);
+	lockdep_assert_held(&mddev->reconfig_mutex);
 	if (mddev->suspended++)
 		return;
 	synchronize_rcu();
 	wake_up(&mddev->sb_wait);
+	set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags);
+	smp_mb__after_atomic();
 	wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
 	mddev->pers->quiesce(mddev, 1);
+	clear_bit_unlock(MD_ALLOW_SB_UPDATE, &mddev->flags);
+	wait_event(mddev->sb_wait, !test_bit(MD_UPDATING_SB, &mddev->flags));
 
 	del_timer_sync(&mddev->safemode_timer);
 }
@@ -349,6 +377,7 @@ EXPORT_SYMBOL_GPL(mddev_suspend);
 
 void mddev_resume(struct mddev *mddev)
 {
+	lockdep_assert_held(&mddev->reconfig_mutex);
 	if (--mddev->suspended)
 		return;
 	wake_up(&mddev->sb_wait);
@@ -422,7 +451,7 @@ static void submit_flushes(struct work_struct *ws)
 			bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
 			bi->bi_end_io = md_end_flush;
 			bi->bi_private = rdev;
-			bi->bi_bdev = rdev->bdev;
+			bio_set_dev(bi, rdev->bdev);
 			bi->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 			atomic_inc(&mddev->flush_pending);
 			submit_bio(bi);
@@ -439,16 +468,22 @@ static void md_submit_flush_data(struct work_struct *ws)
 	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
 	struct bio *bio = mddev->flush_bio;
 
+	/*
+	 * must reset flush_bio before calling into md_handle_request to avoid a
+	 * deadlock, because other bios passed md_handle_request suspend check
+	 * could wait for this and below md_handle_request could wait for those
+	 * bios because of suspend check
+	 */
+	mddev->flush_bio = NULL;
+	wake_up(&mddev->sb_wait);
+
 	if (bio->bi_iter.bi_size == 0)
 		/* an empty barrier - all done */
 		bio_endio(bio);
 	else {
 		bio->bi_opf &= ~REQ_PREFLUSH;
-		mddev->pers->make_request(mddev, bio);
+		md_handle_request(mddev, bio);
 	}
-
-	mddev->flush_bio = NULL;
-	wake_up(&mddev->sb_wait);
 }
 
 void md_flush_request(struct mddev *mddev, struct bio *bio)
@@ -506,7 +541,7 @@ static void mddev_put(struct mddev *mddev)
 		bioset_free(sync_bs);
 }
 
-static void md_safemode_timeout(unsigned long data);
+static void md_safemode_timeout(struct timer_list *t);
 
 void mddev_init(struct mddev *mddev)
 {
@@ -515,8 +550,7 @@ void mddev_init(struct mddev *mddev)
 	mutex_init(&mddev->bitmap_info.mutex);
 	INIT_LIST_HEAD(&mddev->disks);
 	INIT_LIST_HEAD(&mddev->all_mddevs);
-	setup_timer(&mddev->safemode_timer, md_safemode_timeout,
-		    (unsigned long) mddev);
+	timer_setup(&mddev->safemode_timer, md_safemode_timeout, 0);
 	atomic_set(&mddev->active, 1);
 	atomic_set(&mddev->openers, 0);
 	atomic_set(&mddev->active_io, 0);
@@ -649,6 +683,7 @@ void mddev_unlock(struct mddev *mddev)
 	 */
 	spin_lock(&pers_lock);
 	md_wakeup_thread(mddev->thread);
+	wake_up(&mddev->sb_wait);
 	spin_unlock(&pers_lock);
 }
 EXPORT_SYMBOL_GPL(mddev_unlock);
@@ -772,7 +807,7 @@ void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
 
 	atomic_inc(&rdev->nr_pending);
 
-	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
+	bio_set_dev(bio, rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev);
 	bio->bi_iter.bi_sector = sector;
 	bio_add_page(bio, page, size, 0);
 	bio->bi_private = rdev;
@@ -803,8 +838,10 @@ int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
 	struct bio *bio = md_bio_alloc_sync(rdev->mddev);
 	int ret;
 
-	bio->bi_bdev = (metadata_op && rdev->meta_bdev) ?
-		rdev->meta_bdev : rdev->bdev;
+	if (metadata_op && rdev->meta_bdev)
+		bio_set_dev(bio, rdev->meta_bdev);
+	else
+		bio_set_dev(bio, rdev->bdev);
 	bio_set_op_attrs(bio, op, op_flags);
 	if (metadata_op)
 		bio->bi_iter.bi_sector = sector + rdev->sb_start;
@@ -1536,7 +1573,8 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
 	} else if (sb->bblog_offset != 0)
 		rdev->badblocks.shift = 0;
 
-	if (le32_to_cpu(sb->feature_map) & MD_FEATURE_PPL) {
+	if ((le32_to_cpu(sb->feature_map) &
+	    (MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS))) {
 		rdev->ppl.offset = (__s16)le16_to_cpu(sb->ppl.offset);
 		rdev->ppl.size = le16_to_cpu(sb->ppl.size);
 		rdev->ppl.sector = rdev->sb_start + rdev->ppl.offset;
@@ -1655,10 +1693,15 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
 		if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
 			set_bit(MD_HAS_JOURNAL, &mddev->flags);
 
-		if (le32_to_cpu(sb->feature_map) & MD_FEATURE_PPL) {
+		if (le32_to_cpu(sb->feature_map) &
+		    (MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS)) {
 			if (le32_to_cpu(sb->feature_map) &
 			    (MD_FEATURE_BITMAP_OFFSET | MD_FEATURE_JOURNAL))
 				return -EINVAL;
+			if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_PPL) &&
+			    (le32_to_cpu(sb->feature_map) &
+					    MD_FEATURE_MULTIPLE_PPLS))
+				return -EINVAL;
 			set_bit(MD_HAS_PPL, &mddev->flags);
 		}
 	} else if (mddev->pers == NULL) {
@@ -1875,7 +1918,11 @@ retry:
 		sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
 
 	if (test_bit(MD_HAS_PPL, &mddev->flags)) {
-		sb->feature_map |= cpu_to_le32(MD_FEATURE_PPL);
+		if (test_bit(MD_HAS_MULTIPLE_PPLS, &mddev->flags))
+			sb->feature_map |=
+			    cpu_to_le32(MD_FEATURE_MULTIPLE_PPLS);
+		else
+			sb->feature_map |= cpu_to_le32(MD_FEATURE_PPL);
 		sb->ppl.offset = cpu_to_le16(rdev->ppl.offset);
 		sb->ppl.size = cpu_to_le16(rdev->ppl.size);
 	}
@@ -2287,7 +2334,7 @@ static void export_array(struct mddev *mddev)
 
 static bool set_in_sync(struct mddev *mddev)
 {
-	WARN_ON_ONCE(!spin_is_locked(&mddev->lock));
+	lockdep_assert_held(&mddev->lock);
 	if (!mddev->in_sync) {
 		mddev->sync_checkers++;
 		spin_unlock(&mddev->lock);
@@ -2406,10 +2453,18 @@ repeat:
 		}
 	}
 
-	/* First make sure individual recovery_offsets are correct */
+	/*
+	 * First make sure individual recovery_offsets are correct
+	 * curr_resync_completed can only be used during recovery.
+	 * During reshape/resync it might use array-addresses rather
+	 * that device addresses.
+	 */
 	rdev_for_each(rdev, mddev) {
 		if (rdev->raid_disk >= 0 &&
 		    mddev->delta_disks >= 0 &&
+		    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
+		    test_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
+		    !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
 		    !test_bit(Journal, &rdev->flags) &&
 		    !test_bit(In_sync, &rdev->flags) &&
 		    mddev->curr_resync_completed > rdev->recovery_offset)
@@ -2625,7 +2680,7 @@ state_show(struct md_rdev *rdev, char *page)
 {
 	char *sep = ",";
 	size_t len = 0;
-	unsigned long flags = ACCESS_ONCE(rdev->flags);
+	unsigned long flags = READ_ONCE(rdev->flags);
 
 	if (test_bit(Faulty, &flags) ||
 	    (!test_bit(ExternalBbl, &flags) &&
@@ -4283,6 +4338,8 @@ new_dev_store(struct mddev *mddev, const char *buf, size_t len)
 	if (err)
 		export_rdev(rdev);
 	mddev_unlock(mddev);
+	if (!err)
+		md_new_event(mddev);
 	return err ? err : len;
 }
 
@@ -4796,7 +4853,7 @@ suspend_lo_show(struct mddev *mddev, char *page)
 static ssize_t
 suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
 {
-	unsigned long long old, new;
+	unsigned long long new;
 	int err;
 
 	err = kstrtoull(buf, 10, &new);
@@ -4812,16 +4869,10 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
 	if (mddev->pers == NULL ||
 	    mddev->pers->quiesce == NULL)
 		goto unlock;
-	old = mddev->suspend_lo;
+	mddev_suspend(mddev);
 	mddev->suspend_lo = new;
-	if (new >= old)
-		/* Shrinking suspended region */
-		mddev->pers->quiesce(mddev, 2);
-	else {
-		/* Expanding suspended region - need to wait */
-		mddev->pers->quiesce(mddev, 1);
-		mddev->pers->quiesce(mddev, 0);
-	}
+	mddev_resume(mddev);
+
 	err = 0;
 unlock:
 	mddev_unlock(mddev);
@@ -4839,7 +4890,7 @@ suspend_hi_show(struct mddev *mddev, char *page)
 static ssize_t
 suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
 {
-	unsigned long long old, new;
+	unsigned long long new;
 	int err;
 
 	err = kstrtoull(buf, 10, &new);
@@ -4852,19 +4903,13 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
 	if (err)
 		return err;
 	err = -EINVAL;
-	if (mddev->pers == NULL ||
-	    mddev->pers->quiesce == NULL)
+	if (mddev->pers == NULL)
 		goto unlock;
-	old = mddev->suspend_hi;
+
+	mddev_suspend(mddev);
 	mddev->suspend_hi = new;
-	if (new <= old)
-		/* Shrinking suspended region */
-		mddev->pers->quiesce(mddev, 2);
-	else {
-		/* Expanding suspended region - need to wait */
-		mddev->pers->quiesce(mddev, 1);
-		mddev->pers->quiesce(mddev, 0);
-	}
+	mddev_resume(mddev);
+
 	err = 0;
 unlock:
 	mddev_unlock(mddev);
@@ -5329,7 +5374,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
 	return NULL;
 }
 
-static int add_named_array(const char *val, struct kernel_param *kp)
+static int add_named_array(const char *val, const struct kernel_param *kp)
 {
 	/*
 	 * val must be "md_*" or "mdNNN".
@@ -5358,9 +5403,9 @@ static int add_named_array(const char *val, struct kernel_param *kp)
 	return -EINVAL;
 }
 
-static void md_safemode_timeout(unsigned long data)
+static void md_safemode_timeout(struct timer_list *t)
 {
-	struct mddev *mddev = (struct mddev *) data;
+	struct mddev *mddev = from_timer(mddev, t, safemode_timer);
 
 	mddev->safemode = 1;
 	if (mddev->external)
@@ -5806,8 +5851,14 @@ void md_stop(struct mddev *mddev)
 	 * This is called from dm-raid
 	 */
 	__md_stop(mddev);
-	if (mddev->bio_set)
+	if (mddev->bio_set) {
 		bioset_free(mddev->bio_set);
+		mddev->bio_set = NULL;
+	}
+	if (mddev->sync_set) {
+		bioset_free(mddev->sync_set);
+		mddev->sync_set = NULL;
+	}
 }
 
 EXPORT_SYMBOL_GPL(md_stop);
@@ -6334,7 +6385,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
 					break;
 				}
 			}
-			if (has_journal) {
+			if (has_journal || mddev->bitmap) {
 				export_rdev(rdev);
 				return -EBUSY;
 			}
@@ -6590,22 +6641,26 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
 		return -ENOENT; /* cannot remove what isn't there */
 	err = 0;
 	if (mddev->pers) {
-		mddev->pers->quiesce(mddev, 1);
 		if (fd >= 0) {
 			struct bitmap *bitmap;
 
 			bitmap = bitmap_create(mddev, -1);
+			mddev_suspend(mddev);
 			if (!IS_ERR(bitmap)) {
 				mddev->bitmap = bitmap;
 				err = bitmap_load(mddev);
 			} else
 				err = PTR_ERR(bitmap);
-		}
-		if (fd < 0 || err) {
+			if (err) {
+				bitmap_destroy(mddev);
+				fd = -1;
+			}
+			mddev_resume(mddev);
+		} else if (fd < 0) {
+			mddev_suspend(mddev);
 			bitmap_destroy(mddev);
-			fd = -1; /* make sure to put the file */
+			mddev_resume(mddev);
 		}
-		mddev->pers->quiesce(mddev, 0);
 	}
 	if (fd < 0) {
 		struct file *f = mddev->bitmap_info.file;
@@ -6707,7 +6762,7 @@ static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
 
 void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
 {
-	WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
+	lockdep_assert_held(&mddev->reconfig_mutex);
 
 	if (mddev->external_size)
 		return;
@@ -6889,8 +6944,8 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
 				mddev->bitmap_info.default_offset;
 			mddev->bitmap_info.space =
 				mddev->bitmap_info.default_space;
-			mddev->pers->quiesce(mddev, 1);
 			bitmap = bitmap_create(mddev, -1);
+			mddev_suspend(mddev);
 			if (!IS_ERR(bitmap)) {
 				mddev->bitmap = bitmap;
 				rv = bitmap_load(mddev);
@@ -6898,7 +6953,7 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
 				rv = PTR_ERR(bitmap);
 			if (rv)
 				bitmap_destroy(mddev);
-			mddev->pers->quiesce(mddev, 0);
+			mddev_resume(mddev);
 		} else {
 			/* remove the bitmap */
 			if (!mddev->bitmap) {
@@ -6921,9 +6976,9 @@ static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
 				mddev->bitmap_info.nodes = 0;
 				md_cluster_ops->leave(mddev);
 			}
-			mddev->pers->quiesce(mddev, 1);
+			mddev_suspend(mddev);
 			bitmap_destroy(mddev);
-			mddev->pers->quiesce(mddev, 0);
+			mddev_resume(mddev);
 			mddev->bitmap_info.offset = 0;
 		}
 	}
@@ -7440,8 +7495,8 @@ void md_wakeup_thread(struct md_thread *thread)
 {
 	if (thread) {
 		pr_debug("md: waking up MD thread %s.\n", thread->tsk->comm);
-		if (!test_and_set_bit(THREAD_WAKEUP, &thread->flags))
-			wake_up(&thread->wqueue);
+		set_bit(THREAD_WAKEUP, &thread->flags);
+		wake_up(&thread->wqueue);
 	}
 }
 EXPORT_SYMBOL(md_wakeup_thread);
@@ -7836,7 +7891,7 @@ static const struct file_operations md_seq_fops = {
 	.open           = md_seq_open,
 	.read           = seq_read,
 	.llseek         = seq_lseek,
-	.release	= seq_release_private,
+	.release	= seq_release,
 	.poll		= mdstat_poll,
 };
 
@@ -7996,7 +8051,7 @@ bool md_write_start(struct mddev *mddev, struct bio *bi)
 	if (mddev->safemode == 1)
 		mddev->safemode = 0;
 	/* sync_checkers is always 0 when writes_pending is in per-cpu mode */
-	if (mddev->in_sync || !mddev->sync_checkers) {
+	if (mddev->in_sync || mddev->sync_checkers) {
 		spin_lock(&mddev->lock);
 		if (mddev->in_sync) {
 			mddev->in_sync = 0;
@@ -8011,7 +8066,8 @@ bool 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) && !mddev->suspended);
+		   !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;
@@ -8082,7 +8138,6 @@ void md_allow_write(struct mddev *mddev)
 		sysfs_notify_dirent_safe(mddev->sysfs_state);
 		/* wait for the dirty state to be recorded in the metadata */
 		wait_event(mddev->sb_wait,
-			   !test_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags) &&
 			   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
 	} else
 		spin_unlock(&mddev->lock);
@@ -8449,16 +8504,19 @@ void md_do_sync(struct md_thread *thread)
 		} else {
 			if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
 				mddev->curr_resync = MaxSector;
-			rcu_read_lock();
-			rdev_for_each_rcu(rdev, mddev)
-				if (rdev->raid_disk >= 0 &&
-				    mddev->delta_disks >= 0 &&
-				    !test_bit(Journal, &rdev->flags) &&
-				    !test_bit(Faulty, &rdev->flags) &&
-				    !test_bit(In_sync, &rdev->flags) &&
-				    rdev->recovery_offset < mddev->curr_resync)
-					rdev->recovery_offset = mddev->curr_resync;
-			rcu_read_unlock();
+			if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+			    test_bit(MD_RECOVERY_RECOVER, &mddev->recovery)) {
+				rcu_read_lock();
+				rdev_for_each_rcu(rdev, mddev)
+					if (rdev->raid_disk >= 0 &&
+					    mddev->delta_disks >= 0 &&
+					    !test_bit(Journal, &rdev->flags) &&
+					    !test_bit(Faulty, &rdev->flags) &&
+					    !test_bit(In_sync, &rdev->flags) &&
+					    rdev->recovery_offset < mddev->curr_resync)
+						rdev->recovery_offset = mddev->curr_resync;
+				rcu_read_unlock();
+			}
 		}
 	}
  skip:
@@ -8656,6 +8714,9 @@ void md_check_recovery(struct mddev *mddev)
 	if (mddev_trylock(mddev)) {
 		int spares = 0;
 
+		if (!mddev->external && mddev->safemode == 1)
+			mddev->safemode = 0;
+
 		if (mddev->ro) {
 			struct md_rdev *rdev;
 			if (!mddev->external && mddev->in_sync)
@@ -8782,6 +8843,16 @@ void md_check_recovery(struct mddev *mddev)
 	unlock:
 		wake_up(&mddev->sb_wait);
 		mddev_unlock(mddev);
+	} else if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags) && mddev->sb_flags) {
+		/* Write superblock - thread that called mddev_suspend()
+		 * holds reconfig_mutex for us.
+		 */
+		set_bit(MD_UPDATING_SB, &mddev->flags);
+		smp_mb__after_atomic();
+		if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags))
+			md_update_sb(mddev, 0);
+		clear_bit_unlock(MD_UPDATING_SB, &mddev->flags);
+		wake_up(&mddev->sb_wait);
 	}
 }
 EXPORT_SYMBOL(md_check_recovery);
@@ -9243,11 +9314,11 @@ static __exit void md_exit(void)
 subsys_initcall(md_init);
 module_exit(md_exit)
 
-static int get_ro(char *buffer, struct kernel_param *kp)
+static int get_ro(char *buffer, const struct kernel_param *kp)
 {
 	return sprintf(buffer, "%d", start_readonly);
 }
-static int set_ro(const char *val, struct kernel_param *kp)
+static int set_ro(const char *val, const struct kernel_param *kp)
 {
 	return kstrtouint(val, 10, (unsigned int *)&start_readonly);
 }