1 files changed, 208 insertions, 148 deletions

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 54263679a7b1..c6f7129e43d3 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2010-2011 Neil Brown
  * Copyright (C) 2010-2018 Red Hat, Inc. All rights reserved.
@@ -29,10 +30,10 @@
  */
 #define	MIN_RAID456_JOURNAL_SPACE (4*2048)
 
-static bool devices_handle_discard_safely = false;
+static bool devices_handle_discard_safely;
 
 /*
- * The following flags are used by dm-raid.c to set up the array state.
+ * The following flags are used by dm-raid to set up the array state.
  * They must be cleared before md_run is called.
  */
 #define FirstUse 10		/* rdev flag */
@@ -212,6 +213,7 @@ struct raid_dev {
 #define RT_FLAG_RS_IN_SYNC		6
 #define RT_FLAG_RS_RESYNCING		7
 #define RT_FLAG_RS_GROW			8
+#define RT_FLAG_RS_FROZEN		9
 
 /* Array elements of 64 bit needed for rebuild/failed disk bits */
 #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
@@ -253,7 +255,7 @@ struct raid_set {
 		int mode;
 	} journal_dev;
 
-	struct raid_dev dev[];
+	struct raid_dev dev[] __counted_by(raid_disks);
 };
 
 static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
@@ -362,8 +364,8 @@ static struct {
 	const int mode;
 	const char *param;
 } _raid456_journal_mode[] = {
-	{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
-	{ R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
+	{ R5C_JOURNAL_MODE_WRITE_THROUGH, "writethrough" },
+	{ R5C_JOURNAL_MODE_WRITE_BACK,    "writeback" }
 };
 
 /* Return MD raid4/5/6 journal mode for dm @journal_mode one */
@@ -436,7 +438,7 @@ static bool rs_is_reshapable(struct raid_set *rs)
 /* Return true, if raid set in @rs is recovering */
 static bool rs_is_recovering(struct raid_set *rs)
 {
-	return rs->md.recovery_cp < rs->md.dev_sectors;
+	return rs->md.resync_offset < rs->md.dev_sectors;
 }
 
 /* Return true, if raid set in @rs is reshaping */
@@ -748,7 +750,11 @@ static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *r
 		return ERR_PTR(-ENOMEM);
 	}
 
-	mddev_init(&rs->md);
+	if (mddev_init(&rs->md)) {
+		kfree(rs);
+		ti->error = "Cannot initialize raid context";
+		return ERR_PTR(-ENOMEM);
+	}
 
 	rs->raid_disks = raid_devs;
 	rs->delta_disks = 0;
@@ -762,7 +768,7 @@ static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *r
 	rs->md.layout = raid_type->algorithm;
 	rs->md.new_layout = rs->md.layout;
 	rs->md.delta_disks = 0;
-	rs->md.recovery_cp = MaxSector;
+	rs->md.resync_offset = MaxSector;
 
 	for (i = 0; i < raid_devs; i++)
 		md_rdev_init(&rs->dev[i].rdev);
@@ -797,6 +803,7 @@ static void raid_set_free(struct raid_set *rs)
 			dm_put_device(rs->ti, rs->dev[i].data_dev);
 	}
 
+	mddev_destroy(&rs->md);
 	kfree(rs);
 }
 
@@ -905,7 +912,7 @@ static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 		rs->md.external = 0;
 		rs->md.persistent = 1;
 		rs->md.major_version = 2;
-	} else if (rebuild && !rs->md.recovery_cp) {
+	} else if (rebuild && !rs->md.resync_offset) {
 		/*
 		 * Without metadata, we will not be able to tell if the array
 		 * is in-sync or not - we must assume it is not.  Therefore,
@@ -1081,7 +1088,7 @@ static int validate_raid_redundancy(struct raid_set *rs)
 			if ((!rs->dev[i].rdev.sb_page ||
 			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
 			    (++rebuilds_per_group >= copies))
-					goto too_many;
+				goto too_many;
 		}
 		break;
 	default:
@@ -1114,7 +1121,7 @@ too_many:
  *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
  *    [region_size <sectors>]		Defines granularity of bitmap
  *    [journal_dev <dev>]		raid4/5/6 journaling deviice
- *    					(i.e. write hole closing log)
+ *					(i.e. write hole closing log)
  *
  * RAID10-only options:
  *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
@@ -1348,11 +1355,7 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
 				return -EINVAL;
 			}
 
-			/*
-			 * In device-mapper, we specify things in sectors, but
-			 * MD records this value in kB
-			 */
-			if (value < 0 || value / 2 > COUNTER_MAX) {
+			if (value < 0) {
 				rs->ti->error = "Max write-behind limit out of range";
 				return -EINVAL;
 			}
@@ -1619,6 +1622,23 @@ static int _check_data_dev_sectors(struct raid_set *rs)
 	return 0;
 }
 
+/* Get reshape sectors from data_offsets or raid set */
+static sector_t _get_reshape_sectors(struct raid_set *rs)
+{
+	struct md_rdev *rdev;
+	sector_t reshape_sectors = 0;
+
+	rdev_for_each(rdev, &rs->md)
+		if (!test_bit(Journal, &rdev->flags)) {
+			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
+					rdev->data_offset - rdev->new_data_offset :
+					rdev->new_data_offset - rdev->data_offset;
+			break;
+		}
+
+	return max(reshape_sectors, (sector_t) rs->data_offset);
+}
+
 /* Calculate the sectors per device and per array used for @rs */
 static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
 {
@@ -1649,7 +1669,7 @@ static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, b
 		if (sector_div(dev_sectors, data_stripes))
 			goto bad;
 
-		array_sectors = (data_stripes + delta_disks) * dev_sectors;
+		array_sectors = (data_stripes + delta_disks) * (dev_sectors - _get_reshape_sectors(rs));
 		if (sector_div(array_sectors, rs->raid10_copies))
 			goto bad;
 
@@ -1658,7 +1678,7 @@ static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, b
 
 	else
 		/* Striped layouts */
-		array_sectors = (data_stripes + delta_disks) * dev_sectors;
+		array_sectors = (data_stripes + delta_disks) * (dev_sectors - _get_reshape_sectors(rs));
 
 	mddev->array_sectors = array_sectors;
 	mddev->dev_sectors = dev_sectors;
@@ -1675,20 +1695,20 @@ static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
 {
 	/* raid0 does not recover */
 	if (rs_is_raid0(rs))
-		rs->md.recovery_cp = MaxSector;
+		rs->md.resync_offset = MaxSector;
 	/*
 	 * A raid6 set has to be recovered either
 	 * completely or for the grown part to
 	 * ensure proper parity and Q-Syndrome
 	 */
 	else if (rs_is_raid6(rs))
-		rs->md.recovery_cp = dev_sectors;
+		rs->md.resync_offset = dev_sectors;
 	/*
 	 * Other raid set types may skip recovery
 	 * depending on the 'nosync' flag.
 	 */
 	else
-		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
+		rs->md.resync_offset = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
 				     ? MaxSector : dev_sectors;
 }
 
@@ -1697,11 +1717,20 @@ static void do_table_event(struct work_struct *ws)
 	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 
 	smp_rmb(); /* Make sure we access most actual mddev properties */
-	if (!rs_is_reshaping(rs)) {
+
+	/* Only grow size resulting from added stripe(s) after reshape ended. */
+	if (!rs_is_reshaping(rs) &&
+	    rs->array_sectors > rs->md.array_sectors &&
+	    !rs->md.delta_disks &&
+	    rs->md.raid_disks == rs->raid_disks) {
+		/* The raid10 personality doesn't provide proper device sizes -> correct. */
 		if (rs_is_raid10(rs))
 			rs_set_rdev_sectors(rs);
+
+		rs->md.array_sectors = rs->array_sectors;
 		rs_set_capacity(rs);
 	}
+
 	dm_table_event(rs->ti->table);
 }
 
@@ -1988,7 +2017,7 @@ struct dm_raid_superblock {
 	__le64 sectors; /* Used device size in sectors */
 
 	/*
-	 * Additonal Bit field of devices indicating failures to support
+	 * Additional Bit field of devices indicating failures to support
 	 * up to 256 devices with the 1.9.0 on-disk metadata format
 	 */
 	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
@@ -2114,7 +2143,7 @@ static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 	sb->events = cpu_to_le64(mddev->events);
 
 	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
-	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
+	sb->array_resync_offset = cpu_to_le64(mddev->resync_offset);
 
 	sb->level = cpu_to_le32(mddev->level);
 	sb->layout = cpu_to_le32(mddev->layout);
@@ -2208,7 +2237,6 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 {
 	int role;
-	unsigned int d;
 	struct mddev *mddev = &rs->md;
 	uint64_t events_sb;
 	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
@@ -2306,24 +2334,23 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 	}
 
 	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
-		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
+		mddev->resync_offset = le64_to_cpu(sb->array_resync_offset);
 
 	/*
 	 * During load, we set FirstUse if a new superblock was written.
 	 * There are two reasons we might not have a superblock:
 	 * 1) The raid set is brand new - in which case, all of the
 	 *    devices must have their In_sync bit set.	Also,
-	 *    recovery_cp must be 0, unless forced.
+	 *    resync_offset must be 0, unless forced.
 	 * 2) This is a new device being added to an old raid set
 	 *    and the new device needs to be rebuilt - in which
 	 *    case the In_sync bit will /not/ be set and
-	 *    recovery_cp must be MaxSector.
+	 *    resync_offset must be MaxSector.
 	 * 3) This is/are a new device(s) being added to an old
 	 *    raid set during takeover to a higher raid level
 	 *    to provide capacity for redundancy or during reshape
 	 *    to add capacity to grow the raid set.
 	 */
-	d = 0;
 	rdev_for_each(r, mddev) {
 		if (test_bit(Journal, &rdev->flags))
 			continue;
@@ -2339,8 +2366,6 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 			if (test_bit(FirstUse, &r->flags))
 				rebuild_and_new++;
 		}
-
-		d++;
 	}
 
 	if (new_devs == rs->raid_disks || !rebuilds) {
@@ -2365,8 +2390,8 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 			      new_devs > 1 ? "s" : "");
 			return -EINVAL;
 		} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
-			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
-			      (unsigned long long) mddev->recovery_cp);
+			DMERR("'rebuild' specified while raid set is not in-sync (resync_offset=%llu)",
+			      (unsigned long long) mddev->resync_offset);
 			return -EINVAL;
 		} else if (rs_is_reshaping(rs)) {
 			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
@@ -2381,7 +2406,7 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
 	 */
 	sb_retrieve_failed_devices(sb, failed_devices);
 	rdev_for_each(r, mddev) {
-		if (test_bit(Journal, &rdev->flags) ||
+		if (test_bit(Journal, &r->flags) ||
 		    !r->sb_page)
 			continue;
 		sb2 = page_address(r->sb_page);
@@ -2490,7 +2515,7 @@ static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
 		rdev->saved_raid_disk = rdev->raid_disk;
 	}
 
-	/* Reshape support -> restore repective data offsets */
+	/* Reshape support -> restore respective data offsets */
 	rdev->data_offset = le64_to_cpu(sb->data_offset);
 	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
 
@@ -2506,6 +2531,10 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 	struct md_rdev *rdev, *freshest;
 	struct mddev *mddev = &rs->md;
 
+	/* Respect resynchronization requested with "sync" argument. */
+	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
+		set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
+
 	freshest = NULL;
 	rdev_for_each(rdev, mddev) {
 		if (test_bit(Journal, &rdev->flags))
@@ -2671,11 +2700,11 @@ static int rs_adjust_data_offsets(struct raid_set *rs)
 	}
 out:
 	/*
-	 * Raise recovery_cp in case data_offset != 0 to
+	 * Raise resync_offset in case data_offset != 0 to
 	 * avoid false recovery positives in the constructor.
 	 */
-	if (rs->md.recovery_cp < rs->md.dev_sectors)
-		rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
+	if (rs->md.resync_offset < rs->md.dev_sectors)
+		rs->md.resync_offset += rs->dev[0].rdev.data_offset;
 
 	/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
 	rdev_for_each(rdev, &rs->md) {
@@ -2730,7 +2759,7 @@ static int rs_setup_takeover(struct raid_set *rs)
 	}
 
 	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
-	mddev->recovery_cp = MaxSector;
+	mddev->resync_offset = MaxSector;
 
 	while (d--) {
 		rdev = &rs->dev[d].rdev;
@@ -2738,7 +2767,7 @@ static int rs_setup_takeover(struct raid_set *rs)
 		if (test_bit(d, (void *) rs->rebuild_disks)) {
 			clear_bit(In_sync, &rdev->flags);
 			clear_bit(Faulty, &rdev->flags);
-			mddev->recovery_cp = rdev->recovery_offset = 0;
+			mddev->resync_offset = rdev->recovery_offset = 0;
 			/* Bitmap has to be created when we do an "up" takeover */
 			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 		}
@@ -2808,23 +2837,6 @@ static int rs_prepare_reshape(struct raid_set *rs)
 	return 0;
 }
 
-/* Get reshape sectors from data_offsets or raid set */
-static sector_t _get_reshape_sectors(struct raid_set *rs)
-{
-	struct md_rdev *rdev;
-	sector_t reshape_sectors = 0;
-
-	rdev_for_each(rdev, &rs->md)
-		if (!test_bit(Journal, &rdev->flags)) {
-			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
-					rdev->data_offset - rdev->new_data_offset :
-					rdev->new_data_offset - rdev->data_offset;
-			break;
-		}
-
-	return max(reshape_sectors, (sector_t) rs->data_offset);
-}
-
 /*
  * Reshape:
  * - change raid layout
@@ -2855,7 +2867,7 @@ static int rs_setup_reshape(struct raid_set *rs)
 	 *
 	 * - in case of adding disk(s), array size has
 	 *   to grow after the disk adding reshape,
-	 *   which'll hapen in the event handler;
+	 *   which'll happen in the event handler;
 	 *   reshape will happen forward, so space has to
 	 *   be available at the beginning of each disk
 	 *
@@ -3148,7 +3160,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		 * If a takeover is needed, userspace sets any additional
 		 * devices to rebuild and we can check for a valid request here.
 		 *
-		 * If acceptible, set the level to the new requested
+		 * If acceptable, set the level to the new requested
 		 * one, prohibit requesting recovery, allow the raid
 		 * set to run and store superblocks during resume.
 		 */
@@ -3183,12 +3195,12 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		/* Out-of-place space has to be available to allow for a reshape unless raid1! */
 		if (reshape_sectors || rs_is_raid1(rs)) {
 			/*
-			  * We can only prepare for a reshape here, because the
-			  * raid set needs to run to provide the repective reshape
-			  * check functions via its MD personality instance.
-			  *
-			  * So do the reshape check after md_run() succeeded.
-			  */
+			 * We can only prepare for a reshape here, because the
+			 * raid set needs to run to provide the respective reshape
+			 * check functions via its MD personality instance.
+			 *
+			 * So do the reshape check after md_run() succeeded.
+			 */
 			r = rs_prepare_reshape(rs);
 			if (r)
 				goto bad;
@@ -3213,7 +3225,7 @@ size_check:
 			if (r)
 				goto bad;
 
-			rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
+			rs_setup_recovery(rs, rs->md.resync_offset < rs->md.dev_sectors ? rs->md.resync_offset : rs->md.dev_sectors);
 		} else {
 			/* This is no size change or it is shrinking, update size and record in superblocks */
 			r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
@@ -3235,14 +3247,15 @@ size_check:
 	rs_reset_inconclusive_reshape(rs);
 
 	/* Start raid set read-only and assumed clean to change in raid_resume() */
-	rs->md.ro = 1;
+	rs->md.ro = MD_RDONLY;
 	rs->md.in_sync = 1;
 
+	/* Has to be held on running the array */
+	mddev_suspend_and_lock_nointr(&rs->md);
+
 	/* Keep array frozen until resume. */
-	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
+	md_frozen_sync_thread(&rs->md);
 
-	/* Has to be held on running the array */
-	mddev_lock_nointr(&rs->md);
 	r = md_run(&rs->md);
 	rs->md.in_sync = 0; /* Assume already marked dirty */
 	if (r) {
@@ -3254,8 +3267,7 @@ size_check:
 	r = md_start(&rs->md);
 	if (r) {
 		ti->error = "Failed to start raid array";
-		mddev_unlock(&rs->md);
-		goto bad_md_start;
+		goto bad_unlock;
 	}
 
 	/* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
@@ -3263,26 +3275,24 @@ size_check:
 		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
 		if (r) {
 			ti->error = "Failed to set raid4/5/6 journal mode";
-			mddev_unlock(&rs->md);
-			goto bad_journal_mode_set;
+			goto bad_unlock;
 		}
 	}
 
-	mddev_suspend(&rs->md);
 	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
 
 	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
 	if (rs_is_raid456(rs)) {
 		r = rs_set_raid456_stripe_cache(rs);
 		if (r)
-			goto bad_stripe_cache;
+			goto bad_unlock;
 	}
 
 	/* Now do an early reshape check */
 	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
 		r = rs_check_reshape(rs);
 		if (r)
-			goto bad_check_reshape;
+			goto bad_unlock;
 
 		/* Restore new, ctr requested layout to perform check */
 		rs_config_restore(rs, &rs_layout);
@@ -3291,22 +3301,21 @@ size_check:
 			r = rs->md.pers->check_reshape(&rs->md);
 			if (r) {
 				ti->error = "Reshape check failed";
-				goto bad_check_reshape;
+				goto bad_unlock;
 			}
 		}
 	}
 
 	/* Disable/enable discard support on raid set. */
 	configure_discard_support(rs);
+	rs->md.dm_gendisk = dm_disk(dm_table_get_md(ti->table));
 
 	mddev_unlock(&rs->md);
 	return 0;
 
-bad_md_start:
-bad_journal_mode_set:
-bad_stripe_cache:
-bad_check_reshape:
+bad_unlock:
 	md_stop(&rs->md);
+	mddev_unlock(&rs->md);
 bad:
 	raid_set_free(rs);
 
@@ -3317,7 +3326,13 @@ static void raid_dtr(struct dm_target *ti)
 {
 	struct raid_set *rs = ti->private;
 
+	mddev_lock_nointr(&rs->md);
 	md_stop(&rs->md);
+	rs->md.dm_gendisk = NULL;
+	mddev_unlock(&rs->md);
+
+	if (work_pending(&rs->md.event_work))
+		flush_work(&rs->md.event_work);
 	raid_set_free(rs);
 }
 
@@ -3327,17 +3342,18 @@ static int raid_map(struct dm_target *ti, struct bio *bio)
 	struct mddev *mddev = &rs->md;
 
 	/*
-	 * If we're reshaping to add disk(s)), ti->len and
+	 * If we're reshaping to add disk(s), ti->len and
 	 * mddev->array_sectors will differ during the process
 	 * (ti->len > mddev->array_sectors), so we have to requeue
 	 * bios with addresses > mddev->array_sectors here or
 	 * there will occur accesses past EOD of the component
 	 * data images thus erroring the raid set.
 	 */
-	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
+	if (unlikely(bio_has_data(bio) && bio_end_sector(bio) > mddev->array_sectors))
 		return DM_MAPIO_REQUEUE;
 
-	md_handle_request(mddev, bio);
+	if (unlikely(!md_handle_request(mddev, bio)))
+		return DM_MAPIO_REQUEUE;
 
 	return DM_MAPIO_SUBMITTED;
 }
@@ -3369,7 +3385,7 @@ static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long r
 	/* The MD sync thread can be done with io or be interrupted but still be running */
 	if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
 	    (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
-	     (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
+	     (md_is_rdwr(mddev) && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
 		if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
 			return st_reshape;
 
@@ -3433,7 +3449,7 @@ static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
 
 	} else {
 		if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
-			r = mddev->recovery_cp;
+			r = mddev->resync_offset;
 		else
 			r = mddev->curr_resync_completed;
 
@@ -3537,7 +3553,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 		recovery = rs->md.recovery;
 		state = decipher_sync_action(mddev, recovery);
 		progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
-		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
+		resync_mismatches = mddev->last_sync_action == ACTION_CHECK ?
 				    atomic64_read(&mddev->resync_mismatches) : 0;
 
 		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
@@ -3712,26 +3728,37 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 }
 
 static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
-			char *result, unsigned maxlen)
+			char *result, unsigned int maxlen)
 {
 	struct raid_set *rs = ti->private;
 	struct mddev *mddev = &rs->md;
+	int ret = 0;
 
 	if (!mddev->pers || !mddev->pers->sync_request)
 		return -EINVAL;
 
-	if (!strcasecmp(argv[0], "frozen"))
-		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-	else
-		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags) ||
+	    test_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags))
+		return -EBUSY;
 
-	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
-		if (mddev->sync_thread) {
-			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
-			md_unregister_thread(&mddev->sync_thread);
-			md_reap_sync_thread(mddev);
-		}
-	} else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
+	if (!strcasecmp(argv[0], "frozen")) {
+		ret = mddev_lock(mddev);
+		if (ret)
+			return ret;
+
+		md_frozen_sync_thread(mddev);
+		mddev_unlock(mddev);
+	} else if (!strcasecmp(argv[0], "idle")) {
+		ret = mddev_lock(mddev);
+		if (ret)
+			return ret;
+
+		md_idle_sync_thread(mddev);
+		mddev_unlock(mddev);
+	}
+
+	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
 		return -EBUSY;
 	else if (!strcasecmp(argv[0], "resync"))
 		; /* MD_RECOVERY_NEEDED set below */
@@ -3748,16 +3775,16 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
 		} else
 			return -EINVAL;
 	}
-	if (mddev->ro == 2) {
+	if (mddev->ro == MD_AUTO_READ) {
 		/* A write to sync_action is enough to justify
 		 * canceling read-auto mode
 		 */
-		mddev->ro = 0;
-		if (!mddev->suspended && mddev->sync_thread)
+		mddev->ro = MD_RDWR;
+		if (!mddev->suspended)
 			md_wakeup_thread(mddev->sync_thread);
 	}
 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-	if (!mddev->suspended && mddev->thread)
+	if (!mddev->suspended)
 		md_wakeup_thread(mddev->thread);
 
 	return 0;
@@ -3786,8 +3813,40 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
 	struct raid_set *rs = ti->private;
 	unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
 
-	blk_limits_io_min(limits, chunk_size_bytes);
-	blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
+	if (chunk_size_bytes) {
+		limits->io_min = chunk_size_bytes;
+		limits->io_opt = chunk_size_bytes * mddev_data_stripes(rs);
+	}
+}
+
+static void raid_presuspend(struct dm_target *ti)
+{
+	struct raid_set *rs = ti->private;
+	struct mddev *mddev = &rs->md;
+
+	/*
+	 * From now on, disallow raid_message() to change sync_thread until
+	 * resume, raid_postsuspend() is too late.
+	 */
+	set_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags);
+
+	if (!reshape_interrupted(mddev))
+		return;
+
+	/*
+	 * For raid456, if reshape is interrupted, IO across reshape position
+	 * will never make progress, while caller will wait for IO to be done.
+	 * Inform raid456 to handle those IO to prevent deadlock.
+	 */
+	if (mddev->pers && mddev->pers->prepare_suspend)
+		mddev->pers->prepare_suspend(mddev);
+}
+
+static void raid_presuspend_undo(struct dm_target *ti)
+{
+	struct raid_set *rs = ti->private;
+
+	clear_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags);
 }
 
 static void raid_postsuspend(struct dm_target *ti)
@@ -3795,13 +3854,13 @@ static void raid_postsuspend(struct dm_target *ti)
 	struct raid_set *rs = ti->private;
 
 	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
-		/* Writes have to be stopped before suspending to avoid deadlocks. */
-		if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
-			md_stop_writes(&rs->md);
-
-		mddev_lock_nointr(&rs->md);
-		mddev_suspend(&rs->md);
-		mddev_unlock(&rs->md);
+		/*
+		 * sync_thread must be stopped during suspend, and writes have
+		 * to be stopped before suspending to avoid deadlocks.
+		 */
+		md_stop_writes(&rs->md);
+		mddev_suspend(&rs->md, false);
+		rs->md.ro = MD_RDONLY;
 	}
 }
 
@@ -3895,9 +3954,13 @@ static int __load_dirty_region_bitmap(struct raid_set *rs)
 	/* Try loading the bitmap unless "raid0", which does not have one */
 	if (!rs_is_raid0(rs) &&
 	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
-		r = md_bitmap_load(&rs->md);
-		if (r)
-			DMERR("Failed to load bitmap");
+		struct mddev *mddev = &rs->md;
+
+		if (md_bitmap_enabled(mddev, false)) {
+			r = mddev->bitmap_ops->load(mddev);
+			if (r)
+				DMERR("Failed to load bitmap");
+		}
 	}
 
 	return r;
@@ -3910,7 +3973,7 @@ static void rs_update_sbs(struct raid_set *rs)
 	int ro = mddev->ro;
 
 	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
-	mddev->ro = 0;
+	mddev->ro = MD_RDWR;
 	md_update_sb(mddev, 1);
 	mddev->ro = ro;
 }
@@ -3978,6 +4041,11 @@ static int raid_preresume(struct dm_target *ti)
 	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
 		return 0;
 
+	/* If different and no explicit grow request, expose MD array size as of superblock. */
+	if (!test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) &&
+	    rs->array_sectors != mddev->array_sectors)
+		rs_set_capacity(rs);
+
 	/*
 	 * The superblocks need to be updated on disk if the
 	 * array is new or new devices got added (thus zeroed
@@ -4001,23 +4069,24 @@ static int raid_preresume(struct dm_target *ti)
 	}
 
 	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
-        if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
+	if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
 	    (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
 	     (rs->requested_bitmap_chunk_sectors &&
 	       mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
 		int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
 
-		r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
-		if (r)
-			DMERR("Failed to resize bitmap");
+		if (md_bitmap_enabled(mddev, false)) {
+			r = mddev->bitmap_ops->resize(mddev, mddev->dev_sectors,
+						      chunksize);
+			if (r)
+				DMERR("Failed to resize bitmap");
+		}
 	}
 
 	/* Check for any resize/reshape on @rs and adjust/initiate */
-	/* Be prepared for mddev_resume() in raid_resume() */
-	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
+	if (mddev->resync_offset && mddev->resync_offset < MaxSector) {
 		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
-		mddev->resync_min = mddev->recovery_cp;
+		mddev->resync_min = mddev->resync_offset;
 		if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
 			mddev->resync_max_sectors = mddev->dev_sectors;
 	}
@@ -4048,7 +4117,9 @@ static void raid_resume(struct dm_target *ti)
 		 * Take this opportunity to check whether any failed
 		 * devices are reachable again.
 		 */
+		mddev_lock_nointr(mddev);
 		attempt_restore_of_faulty_devices(rs);
+		mddev_unlock(mddev);
 	}
 
 	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
@@ -4057,11 +4128,14 @@ static void raid_resume(struct dm_target *ti)
 			rs_set_capacity(rs);
 
 		mddev_lock_nointr(mddev);
-		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-		mddev->ro = 0;
+		WARN_ON_ONCE(!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery));
+		WARN_ON_ONCE(rcu_dereference_protected(mddev->sync_thread,
+						       lockdep_is_held(&mddev->reconfig_mutex)));
+		clear_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags);
+		mddev->ro = MD_RDWR;
 		mddev->in_sync = 0;
-		mddev_resume(mddev);
-		mddev_unlock(mddev);
+		md_unfrozen_sync_thread(mddev);
+		mddev_unlock_and_resume(mddev);
 	}
 }
 
@@ -4076,27 +4150,13 @@ static struct target_type raid_target = {
 	.message = raid_message,
 	.iterate_devices = raid_iterate_devices,
 	.io_hints = raid_io_hints,
+	.presuspend = raid_presuspend,
+	.presuspend_undo = raid_presuspend_undo,
 	.postsuspend = raid_postsuspend,
 	.preresume = raid_preresume,
 	.resume = raid_resume,
 };
-
-static int __init dm_raid_init(void)
-{
-	DMINFO("Loading target version %u.%u.%u",
-	       raid_target.version[0],
-	       raid_target.version[1],
-	       raid_target.version[2]);
-	return dm_register_target(&raid_target);
-}
-
-static void __exit dm_raid_exit(void)
-{
-	dm_unregister_target(&raid_target);
-}
-
-module_init(dm_raid_init);
-module_exit(dm_raid_exit);
+module_dm(raid);
 
 module_param(devices_handle_discard_safely, bool, 0644);
 MODULE_PARM_DESC(devices_handle_discard_safely,
@@ -4109,6 +4169,6 @@ MODULE_ALIAS("dm-raid10");
 MODULE_ALIAS("dm-raid4");
 MODULE_ALIAS("dm-raid5");
 MODULE_ALIAS("dm-raid6");
-MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
-MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
+MODULE_AUTHOR("Neil Brown <dm-devel@lists.linux.dev>");
+MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@lists.linux.dev>");
 MODULE_LICENSE("GPL");