diff mbox series

md: fix bi_status reporting in md_end_clone_io

Message ID 20231118003958.2740032-1-song@kernel.org (mailing list archive)
State Accepted, archived
Delegated to: Song Liu
Headers show
Series md: fix bi_status reporting in md_end_clone_io | expand

Commit Message

Song Liu Nov. 18, 2023, 12:39 a.m. UTC
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")
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>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
---
 drivers/md/md.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Yu Kuai Nov. 20, 2023, 1:05 a.m. UTC | #1
在 2023/11/18 8:39, Song Liu 写道:
> 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().

LGTM
Reviewed-by: Yu Kuai <yukuai3@huawei.com>

> 
> Fixes: 10764815ff47 ("md: add io accounting for raid0 and raid5")
> 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>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> ---
>   drivers/md/md.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 4ee4593c874a..c94373d64f2c 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -8666,7 +8666,8 @@ static void md_end_clone_io(struct bio *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);
>
Guoqing Jiang Nov. 20, 2023, 1:31 a.m. UTC | #2
On 11/18/23 08:39, Song Liu wrote:
> 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().

DRBD has the similar change.

> Fixes: 10764815ff47 ("md: add io accounting for raid0 and raid5")
> 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>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> ---
>   drivers/md/md.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 4ee4593c874a..c94373d64f2c 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -8666,7 +8666,8 @@ static void md_end_clone_io(struct bio *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;

Thanks for the fix!

Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>

Guoqing
Guoqing Jiang Nov. 20, 2023, 1:40 a.m. UTC | #3
On 11/18/23 08:39, Song Liu wrote:
> 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().

DRBD has the similar change.

> Fixes: 10764815ff47 ("md: add io accounting for raid0 and raid5")
> 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>
> Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
> ---
>   drivers/md/md.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 4ee4593c874a..c94373d64f2c 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -8666,7 +8666,8 @@ static void md_end_clone_io(struct bio *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;

Thanks for the fix!

Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>

Guoqing
diff mbox series

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4ee4593c874a..c94373d64f2c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8666,7 +8666,8 @@  static void md_end_clone_io(struct bio *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);