6.6-stable review patch. If anyone has any objections, please let me know.
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From: Song Liu song@kernel.org
commit 45b478951b2ba5aea70b2850c49c1aa83aedd0d2 upstream.
md_end_clone_io() may overwrite error status in orig_bio->bi_status with BLK_STS_OK. This could happen when orig_bio has BIO_CHAIN (split by md_submit_bio => bio_split_to_limits, for example). As a result, upper layer may miss error reported from md (or the device) and consider the failed IO was successful.
Fix this by only update orig_bio->bi_status when current bio reports error and orig_bio is BLK_STS_OK. This is the same behavior as __bio_chain_endio().
Fixes: 10764815ff47 ("md: add io accounting for raid0 and raid5") Cc: stable@vger.kernel.org # v5.14+ Reported-by: Bhanu Victor DiCara 00bvd0+linux@gmail.com Closes: https://lore.kernel.org/regressions/5727380.DvuYhMxLoT@bvd0/ Signed-off-by: Song Liu song@kernel.org Tested-by: Xiao Ni xni@redhat.com Reviewed-by: Yu Kuai yukuai3@huawei.com Acked-by: Guoqing Jiang guoqing.jiang@linux.dev Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/md.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8669,7 +8669,8 @@ static void md_end_clone_io(struct bio * struct bio *orig_bio = md_io_clone->orig_bio; struct mddev *mddev = md_io_clone->mddev;
- orig_bio->bi_status = bio->bi_status; + if (bio->bi_status && !orig_bio->bi_status) + orig_bio->bi_status = bio->bi_status;
if (md_io_clone->start_time) bio_end_io_acct(orig_bio, md_io_clone->start_time);