diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1d54109..0466ee2 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * raid1.c : Multiple Devices driver for Linux
  *
@@ -20,15 +21,6 @@
  *
  * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
  * - persistent bitmap code
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * You should have received a copy of the GNU General Public License
- * (for example /usr/src/linux/COPYING); if not, write to the Free
- * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <linux/slab.h>
@@ -50,31 +42,6 @@
 	 (1L << MD_HAS_PPL) |		\
 	 (1L << MD_HAS_MULTIPLE_PPLS))
 
-/*
- * Number of guaranteed r1bios in case of extreme VM load:
- */
-#define	NR_RAID1_BIOS 256
-
-/* when we get a read error on a read-only array, we redirect to another
- * device without failing the first device, or trying to over-write to
- * correct the read error.  To keep track of bad blocks on a per-bio
- * level, we store IO_BLOCKED in the appropriate 'bios' pointer
- */
-#define IO_BLOCKED ((struct bio *)1)
-/* When we successfully write to a known bad-block, we need to remove the
- * bad-block marking which must be done from process context.  So we record
- * the success by setting devs[n].bio to IO_MADE_GOOD
- */
-#define IO_MADE_GOOD ((struct bio *)2)
-
-#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
-
-/* When there are this many requests queue to be written by
- * the raid1 thread, we become 'congested' to provide back-pressure
- * for writeback.
- */
-static int max_queued_requests = 1024;
-
 static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
 static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
 
@@ -83,6 +50,57 @@
 
 #include "raid1-10.c"
 
+static int check_and_add_wb(struct md_rdev *rdev, sector_t lo, sector_t hi)
+{
+	struct wb_info *wi, *temp_wi;
+	unsigned long flags;
+	int ret = 0;
+	struct mddev *mddev = rdev->mddev;
+
+	wi = mempool_alloc(mddev->wb_info_pool, GFP_NOIO);
+
+	spin_lock_irqsave(&rdev->wb_list_lock, flags);
+	list_for_each_entry(temp_wi, &rdev->wb_list, list) {
+		/* collision happened */
+		if (hi > temp_wi->lo && lo < temp_wi->hi) {
+			ret = -EBUSY;
+			break;
+		}
+	}
+
+	if (!ret) {
+		wi->lo = lo;
+		wi->hi = hi;
+		list_add(&wi->list, &rdev->wb_list);
+	} else
+		mempool_free(wi, mddev->wb_info_pool);
+	spin_unlock_irqrestore(&rdev->wb_list_lock, flags);
+
+	return ret;
+}
+
+static void remove_wb(struct md_rdev *rdev, sector_t lo, sector_t hi)
+{
+	struct wb_info *wi;
+	unsigned long flags;
+	int found = 0;
+	struct mddev *mddev = rdev->mddev;
+
+	spin_lock_irqsave(&rdev->wb_list_lock, flags);
+	list_for_each_entry(wi, &rdev->wb_list, list)
+		if (hi == wi->hi && lo == wi->lo) {
+			list_del(&wi->list);
+			mempool_free(wi, mddev->wb_info_pool);
+			found = 1;
+			break;
+		}
+
+	if (!found)
+		WARN(1, "The write behind IO is not recorded\n");
+	spin_unlock_irqrestore(&rdev->wb_list_lock, flags);
+	wake_up(&rdev->wb_io_wait);
+}
+
 /*
  * for resync bio, r1bio pointer can be retrieved from the per-bio
  * 'struct resync_pages'.
@@ -101,11 +119,6 @@
 	return kzalloc(size, gfp_flags);
 }
 
-static void r1bio_pool_free(void *r1_bio, void *data)
-{
-	kfree(r1_bio);
-}
-
 #define RESYNC_DEPTH 32
 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
 #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
@@ -181,7 +194,7 @@
 	kfree(rps);
 
 out_free_r1bio:
-	r1bio_pool_free(r1_bio, data);
+	rbio_pool_free(r1_bio, data);
 	return NULL;
 }
 
@@ -201,7 +214,7 @@
 	/* resync pages array stored in the 1st bio's .bi_private */
 	kfree(rp);
 
-	r1bio_pool_free(r1bio, data);
+	rbio_pool_free(r1bio, data);
 }
 
 static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
@@ -434,19 +447,21 @@
 		    /* We never try FailFast to WriteMostly devices */
 		    !test_bit(WriteMostly, &rdev->flags)) {
 			md_error(r1_bio->mddev, rdev);
-			if (!test_bit(Faulty, &rdev->flags))
-				/* This is the only remaining device,
-				 * We need to retry the write without
-				 * FailFast
-				 */
-				set_bit(R1BIO_WriteError, &r1_bio->state);
-			else {
-				/* Finished with this branch */
-				r1_bio->bios[mirror] = NULL;
-				to_put = bio;
-			}
-		} else
+		}
+
+		/*
+		 * When the device is faulty, it is not necessary to
+		 * handle write error.
+		 * For failfast, this is the only remaining device,
+		 * We need to retry the write without FailFast.
+		 */
+		if (!test_bit(Faulty, &rdev->flags))
 			set_bit(R1BIO_WriteError, &r1_bio->state);
+		else {
+			/* Finished with this branch */
+			r1_bio->bios[mirror] = NULL;
+			to_put = bio;
+		}
 	} else {
 		/*
 		 * Set R1BIO_Uptodate in our master bio, so that we
@@ -484,6 +499,12 @@
 	}
 
 	if (behind) {
+		if (test_bit(WBCollisionCheck, &rdev->flags)) {
+			sector_t lo = r1_bio->sector;
+			sector_t hi = r1_bio->sector + r1_bio->sectors;
+
+			remove_wb(rdev, lo, hi);
+		}
 		if (test_bit(WriteMostly, &rdev->flags))
 			atomic_dec(&r1_bio->behind_remaining);
 
@@ -853,8 +874,11 @@
  * backgroup IO calls must call raise_barrier.  Once that returns
  *    there is no normal IO happeing.  It must arrange to call
  *    lower_barrier when the particular background IO completes.
+ *
+ * If resync/recovery is interrupted, returns -EINTR;
+ * Otherwise, returns 0.
  */
-static sector_t raise_barrier(struct r1conf *conf, sector_t sector_nr)
+static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
 {
 	int idx = sector_to_idx(sector_nr);
 
@@ -1457,7 +1481,6 @@
 		if (!r1_bio->bios[i])
 			continue;
 
-
 		if (first_clone) {
 			/* do behind I/O ?
 			 * Not if there are too many, or cannot
@@ -1482,7 +1505,16 @@
 			mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set);
 
 		if (r1_bio->behind_master_bio) {
-			if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
+			struct md_rdev *rdev = conf->mirrors[i].rdev;
+
+			if (test_bit(WBCollisionCheck, &rdev->flags)) {
+				sector_t lo = r1_bio->sector;
+				sector_t hi = r1_bio->sector + r1_bio->sectors;
+
+				wait_event(rdev->wb_io_wait,
+					   check_and_add_wb(rdev, lo, hi) == 0);
+			}
+			if (test_bit(WriteMostly, &rdev->flags))
 				atomic_inc(&r1_bio->behind_remaining);
 		}
 
@@ -1585,12 +1617,12 @@
 
 	/*
 	 * If it is not operational, then we have already marked it as dead
-	 * else if it is the last working disks, ignore the error, let the
-	 * next level up know.
+	 * else if it is the last working disks with "fail_last_dev == false",
+	 * ignore the error, let the next level up know.
 	 * else mark the drive as failed
 	 */
 	spin_lock_irqsave(&conf->device_lock, flags);
-	if (test_bit(In_sync, &rdev->flags)
+	if (test_bit(In_sync, &rdev->flags) && !mddev->fail_last_dev
 	    && (conf->raid_disks - mddev->degraded) == 1) {
 		/*
 		 * Don't fail the drive, act as though we were just a
@@ -1603,11 +1635,9 @@
 		return;
 	}
 	set_bit(Blocked, &rdev->flags);
-	if (test_and_clear_bit(In_sync, &rdev->flags)) {
+	if (test_and_clear_bit(In_sync, &rdev->flags))
 		mddev->degraded++;
-		set_bit(Faulty, &rdev->flags);
-	} else
-		set_bit(Faulty, &rdev->flags);
+	set_bit(Faulty, &rdev->flags);
 	spin_unlock_irqrestore(&conf->device_lock, flags);
 	/*
 	 * if recovery is running, make sure it aborts.
@@ -1739,9 +1769,8 @@
 		first = last = rdev->saved_raid_disk;
 
 	for (mirror = first; mirror <= last; mirror++) {
-		p = conf->mirrors+mirror;
+		p = conf->mirrors + mirror;
 		if (!p->rdev) {
-
 			if (mddev->gendisk)
 				disk_stack_limits(mddev->gendisk, rdev->bdev,
 						  rdev->data_offset << 9);
@@ -1863,6 +1892,36 @@
 		reschedule_retry(r1_bio);
 }
 
+static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
+{
+	sector_t sync_blocks = 0;
+	sector_t s = r1_bio->sector;
+	long sectors_to_go = r1_bio->sectors;
+
+	/* make sure these bits don't get cleared. */
+	do {
+		md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
+		s += sync_blocks;
+		sectors_to_go -= sync_blocks;
+	} while (sectors_to_go > 0);
+}
+
+static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
+{
+	if (atomic_dec_and_test(&r1_bio->remaining)) {
+		struct mddev *mddev = r1_bio->mddev;
+		int s = r1_bio->sectors;
+
+		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+		    test_bit(R1BIO_WriteError, &r1_bio->state))
+			reschedule_retry(r1_bio);
+		else {
+			put_buf(r1_bio);
+			md_done_sync(mddev, s, uptodate);
+		}
+	}
+}
+
 static void end_sync_write(struct bio *bio)
 {
 	int uptodate = !bio->bi_status;
@@ -1874,15 +1933,7 @@
 	struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
 
 	if (!uptodate) {
-		sector_t sync_blocks = 0;
-		sector_t s = r1_bio->sector;
-		long sectors_to_go = r1_bio->sectors;
-		/* make sure these bits doesn't get cleared. */
-		do {
-			md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
-			s += sync_blocks;
-			sectors_to_go -= sync_blocks;
-		} while (sectors_to_go > 0);
+		abort_sync_write(mddev, r1_bio);
 		set_bit(WriteErrorSeen, &rdev->flags);
 		if (!test_and_set_bit(WantReplacement, &rdev->flags))
 			set_bit(MD_RECOVERY_NEEDED, &
@@ -1897,16 +1948,7 @@
 		)
 		set_bit(R1BIO_MadeGood, &r1_bio->state);
 
-	if (atomic_dec_and_test(&r1_bio->remaining)) {
-		int s = r1_bio->sectors;
-		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
-		    test_bit(R1BIO_WriteError, &r1_bio->state))
-			reschedule_retry(r1_bio);
-		else {
-			put_buf(r1_bio);
-			md_done_sync(mddev, s, uptodate);
-		}
-	}
+	put_sync_write_buf(r1_bio, uptodate);
 }
 
 static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
@@ -2106,7 +2148,7 @@
 		}
 	r1_bio->read_disk = primary;
 	for (i = 0; i < conf->raid_disks * 2; i++) {
-		int j;
+		int j = 0;
 		struct bio *pbio = r1_bio->bios[primary];
 		struct bio *sbio = r1_bio->bios[i];
 		blk_status_t status = sbio->bi_status;
@@ -2114,14 +2156,15 @@
 		struct page **spages = get_resync_pages(sbio)->pages;
 		struct bio_vec *bi;
 		int page_len[RESYNC_PAGES] = { 0 };
+		struct bvec_iter_all iter_all;
 
 		if (sbio->bi_end_io != end_sync_read)
 			continue;
 		/* Now we can 'fixup' the error value */
 		sbio->bi_status = 0;
 
-		bio_for_each_segment_all(bi, sbio, j)
-			page_len[j] = bi->bv_len;
+		bio_for_each_segment_all(bi, sbio, iter_all)
+			page_len[j++] = bi->bv_len;
 
 		if (!status) {
 			for (j = vcnt; j-- ; ) {
@@ -2172,8 +2215,10 @@
 		     (i == r1_bio->read_disk ||
 		      !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
 			continue;
-		if (test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+		if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
+			abort_sync_write(mddev, r1_bio);
 			continue;
+		}
 
 		bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
 		if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
@@ -2186,17 +2231,7 @@
 		generic_make_request(wbio);
 	}
 
-	if (atomic_dec_and_test(&r1_bio->remaining)) {
-		/* if we're here, all write(s) have completed, so clean up */
-		int s = r1_bio->sectors;
-		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
-		    test_bit(R1BIO_WriteError, &r1_bio->state))
-			reschedule_retry(r1_bio);
-		else {
-			put_buf(r1_bio);
-			md_done_sync(mddev, s, 1);
-		}
-	}
+	put_sync_write_buf(r1_bio, 1);
 }
 
 /*
@@ -2889,7 +2924,6 @@
 		if (read_targets == 1)
 			bio->bi_opf &= ~MD_FAILFAST;
 		generic_make_request(bio);
-
 	}
 	return nr_sectors;
 }
@@ -2948,8 +2982,8 @@
 	if (!conf->poolinfo)
 		goto abort;
 	conf->poolinfo->raid_disks = mddev->raid_disks * 2;
-	err = mempool_init(&conf->r1bio_pool, NR_RAID1_BIOS, r1bio_pool_alloc,
-			   r1bio_pool_free, conf->poolinfo);
+	err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
+			   rbio_pool_free, conf->poolinfo);
 	if (err)
 		goto abort;
 
@@ -3090,11 +3124,18 @@
 	}
 
 	mddev->degraded = 0;
-	for (i=0; i < conf->raid_disks; i++)
+	for (i = 0; i < conf->raid_disks; i++)
 		if (conf->mirrors[i].rdev == NULL ||
 		    !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
 		    test_bit(Faulty, &conf->mirrors[i].rdev->flags))
 			mddev->degraded++;
+	/*
+	 * RAID1 needs at least one disk in active
+	 */
+	if (conf->raid_disks - mddev->degraded < 1) {
+		ret = -EINVAL;
+		goto abort;
+	}
 
 	if (conf->raid_disks - mddev->degraded == 1)
 		mddev->recovery_cp = MaxSector;
@@ -3125,11 +3166,15 @@
 						  mddev->queue);
 	}
 
-	ret =  md_integrity_register(mddev);
+	ret = md_integrity_register(mddev);
 	if (ret) {
 		md_unregister_thread(&mddev->thread);
-		raid1_free(mddev, conf);
+		goto abort;
 	}
+	return 0;
+
+abort:
+	raid1_free(mddev, conf);
 	return ret;
 }
 
@@ -3233,8 +3278,8 @@
 	newpoolinfo->mddev = mddev;
 	newpoolinfo->raid_disks = raid_disks * 2;
 
-	ret = mempool_init(&newpool, NR_RAID1_BIOS, r1bio_pool_alloc,
-			   r1bio_pool_free, newpoolinfo);
+	ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
+			   rbio_pool_free, newpoolinfo);
 	if (ret) {
 		kfree(newpoolinfo);
 		return ret;