md/raid10: fix writes_pending and barrier reference leaks on discard failures

raid10_make_request() acquires a writes_pending reference with
md_write_start() before calling raid10_handle_discard(). Several failure
paths in raid10_handle_discard() complete the bio and return without
releasing the corresponding reference, causing md_write_end() to be
skipped.

Call md_write_end() before returning from these failure paths to keep
writes_pending accounting balanced.

Additionally, discard split allocation failures can occur after
wait_barrier() succeeds. Those paths return without calling
allow_barrier(), leaking the associated barrier reference.

Release the barrier before returning from those paths.

Fixes: c9aa889b03 ("md: raid10 add nowait support")
Fixes: 4cf58d9529 ("md/raid10: Handle bio_split() errors")
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Link: https://patch.msgid.link/20260613182810.1317258-4-abd.masalkhi@gmail.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>
This commit is contained in:
Abd-Alrhman Masalkhi 2026-06-13 18:28:09 +00:00 committed by Yu Kuai
parent e045d6ed33
commit 393d687131

View File

@ -1639,6 +1639,7 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
md_write_end(mddev);
return 0;
}
@ -1681,6 +1682,8 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
if (IS_ERR(split)) {
bio->bi_status = errno_to_blk_status(PTR_ERR(split));
bio_endio(bio);
md_write_end(mddev);
allow_barrier(conf);
return 0;
}
@ -1698,6 +1701,8 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
if (IS_ERR(split)) {
bio->bi_status = errno_to_blk_status(PTR_ERR(split));
bio_endio(bio);
md_write_end(mddev);
allow_barrier(conf);
return 0;
}