Commit 93dec51e authored by Yu Kuai's avatar Yu Kuai
Browse files

md/raid1: fix data lost for writemostly rdev 



If writemostly is enabled, alloc_behind_master_bio() will allocate a new
bio for rdev, with bi_opf set to 0. Later, raid1_write_request() will
clone from this bio, hence bi_opf is still 0 for the cloned bio. Submit
this cloned bio will end up to be read, causing write data lost.

Fix this problem by inheriting bi_opf from original bio for
behind_mast_bio.

Fixes: e879a0d9 ("md/raid1,raid10: don't ignore IO flags")
Reported-and-tested-by: default avatarIan Dall <ian@beware.dropbear.id.au>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220507
Link: https://lore.kernel.org/linux-raid/20250903014140.3690499-1-yukuai1@huaweicloud.com


Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarLi Nan <linan122@huawei.com>
parent 95a7c500

drivers/md/raid1.c

+1 −1
Original line number Diff line number Diff line
@@ -1225,7 +1225,7 @@ static void alloc_behind_master_bio(struct r1bio *r1_bio, 
	int i = 0;

	struct bio *behind_bio = NULL;



	behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,

	behind_bio = bio_alloc_bioset(NULL, vcnt, bio->bi_opf, GFP_NOIO,

				      &r1_bio->mddev->bio_set);



	/* discard op, we don't support writezero/writesame yet */