-diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
-index 6a68ef5..efb654e 100644
---- a/drivers/md/raid0.c
-+++ b/drivers/md/raid0.c
-@@ -524,6 +524,9 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
- ? (sector & (chunk_sects-1))
- : sector_div(sector, chunk_sects));
-
-+ /* Restore due to sector_div */
-+ sector = bio->bi_iter.bi_sector;
-+
- if (sectors < bio_sectors(bio)) {
- split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);
- bio_chain(split, bio);
-@@ -531,7 +534,6 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
- split = bio;
- }
-
-- sector = bio->bi_iter.bi_sector;
- zone = find_zone(mddev->private, §or);
- tmp_dev = map_sector(mddev, zone, sector, §or);
- split->bi_bdev = tmp_dev->bdev;
+So resync io is waiting for regular write io to complete to
+decrease nr_pending (conf->barrier++ is called before waiting).
+The regular write io splits another bio after call wait_barrier
+which call nr_pending++, then the splitted bio would continue
+with raid10_write_request -> wait_barrier, so the splitted bio
+has to wait for barrier to be zero, then deadlock happens as
+follows.
+
+ resync io regular io
+
+ raise_barrier
+ wait_barrier
+ generic_make_request
+ wait_barrier
+
+To resolve the issue, we need to call allow_barrier to decrease
+nr_pending before generic_make_request since regular IO is not
+issued to underlying devices, and wait_barrier is called again
+to ensure no internal IO happening.
+
+Fixes: fc9977dd069e ("md/raid10: simplify the splitting of requests.")
+Reported-and-tested-by: SiniĊĦa Bandin <sinisa@4net.rs>
+Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
+Signed-off-by: Shaohua Li <shli@fb.com>
+---
+ drivers/md/raid10.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
+index 76c92e31afc0..abb5d382f64d 100644
+--- a/drivers/md/raid10.c
++++ b/drivers/md/raid10.c
+@@ -1209,7 +1209,9 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
+ struct bio *split = bio_split(bio, max_sectors,
+ gfp, &conf->bio_split);
+ bio_chain(split, bio);
++ allow_barrier(conf);
+ generic_make_request(bio);
++ wait_barrier(conf);
+ bio = split;
+ r10_bio->master_bio = bio;
+ r10_bio->sectors = max_sectors;
+@@ -1492,7 +1494,9 @@ retry_write:
+ struct bio *split = bio_split(bio, r10_bio->sectors,
+ GFP_NOIO, &conf->bio_split);
+ bio_chain(split, bio);
++ allow_barrier(conf);
+ generic_make_request(bio);
++ wait_barrier(conf);
+ bio = split;
+ r10_bio->master_bio = bio;
+ }