[v2,2/4] md/raid10: improve code of mrdev in raid10_sync_request
Commit Message
From: Li Nan <linan122@huawei.com>
'need_recover' and 'mrdev' are equivalent in raid10_sync_request(), and
inc mrdev->nr_pending is unreasonable if don't need recovery. Replace
'need_recover' with 'mrdev', and only inc nr_pending when needed.
Suggested-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Li Nan <linan122@huawei.com>
---
drivers/md/raid10.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
Comments
在 2023/05/26 15:45, linan666@huaweicloud.com 写道:
> From: Li Nan <linan122@huawei.com>
>
> 'need_recover' and 'mrdev' are equivalent in raid10_sync_request(), and
> inc mrdev->nr_pending is unreasonable if don't need recovery. Replace
> 'need_recover' with 'mrdev', and only inc nr_pending when needed.
LGTM, feel free to add:
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
>
> Suggested-by: Yu Kuai <yukuai3@huawei.com>
> Signed-off-by: Li Nan <linan122@huawei.com>
> ---
> drivers/md/raid10.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index e21502c03b45..9de9eabff209 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -3437,7 +3437,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> sector_t sect;
> int must_sync;
> int any_working;
> - int need_recover = 0;
> struct raid10_info *mirror = &conf->mirrors[i];
> struct md_rdev *mrdev, *mreplace;
>
> @@ -3446,14 +3445,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> mreplace = rcu_dereference(mirror->replacement);
>
> if (mrdev != NULL &&
> - !test_bit(Faulty, &mrdev->flags) &&
> - !test_bit(In_sync, &mrdev->flags))
> - need_recover = 1;
> + (test_bit(Faulty, &mrdev->flags) ||
> + test_bit(In_sync, &mrdev->flags)))
> + mrdev = NULL;
> if (mreplace != NULL &&
> test_bit(Faulty, &mreplace->flags))
> mreplace = NULL;
>
> - if (!need_recover && !mreplace) {
> + if (!mrdev && !mreplace) {
> rcu_read_unlock();
> continue;
> }
> @@ -3487,7 +3486,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> rcu_read_unlock();
> continue;
> }
> - atomic_inc(&mrdev->nr_pending);
> + if (mrdev)
> + atomic_inc(&mrdev->nr_pending);
> if (mreplace)
> atomic_inc(&mreplace->nr_pending);
> rcu_read_unlock();
> @@ -3574,7 +3574,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> r10_bio->devs[1].devnum = i;
> r10_bio->devs[1].addr = to_addr;
>
> - if (need_recover) {
> + if (mrdev) {
> bio = r10_bio->devs[1].bio;
> bio->bi_next = biolist;
> biolist = bio;
> @@ -3619,7 +3619,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> for (k = 0; k < conf->copies; k++)
> if (r10_bio->devs[k].devnum == i)
> break;
> - if (!test_bit(In_sync,
> + if (mrdev && !test_bit(In_sync,
> &mrdev->flags)
> && !rdev_set_badblocks(
> mrdev,
> @@ -3645,12 +3645,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
> if (rb2)
> atomic_dec(&rb2->remaining);
> r10_bio = rb2;
> - rdev_dec_pending(mrdev, mddev);
> + if (mrdev)
> + rdev_dec_pending(mrdev, mddev);
> if (mreplace)
> rdev_dec_pending(mreplace, mddev);
> break;
> }
> - rdev_dec_pending(mrdev, mddev);
> + if (mrdev)
> + rdev_dec_pending(mrdev, mddev);
> if (mreplace)
> rdev_dec_pending(mreplace, mddev);
> if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) {
>
@@ -3437,7 +3437,6 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
sector_t sect;
int must_sync;
int any_working;
- int need_recover = 0;
struct raid10_info *mirror = &conf->mirrors[i];
struct md_rdev *mrdev, *mreplace;
@@ -3446,14 +3445,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
mreplace = rcu_dereference(mirror->replacement);
if (mrdev != NULL &&
- !test_bit(Faulty, &mrdev->flags) &&
- !test_bit(In_sync, &mrdev->flags))
- need_recover = 1;
+ (test_bit(Faulty, &mrdev->flags) ||
+ test_bit(In_sync, &mrdev->flags)))
+ mrdev = NULL;
if (mreplace != NULL &&
test_bit(Faulty, &mreplace->flags))
mreplace = NULL;
- if (!need_recover && !mreplace) {
+ if (!mrdev && !mreplace) {
rcu_read_unlock();
continue;
}
@@ -3487,7 +3486,8 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
rcu_read_unlock();
continue;
}
- atomic_inc(&mrdev->nr_pending);
+ if (mrdev)
+ atomic_inc(&mrdev->nr_pending);
if (mreplace)
atomic_inc(&mreplace->nr_pending);
rcu_read_unlock();
@@ -3574,7 +3574,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
r10_bio->devs[1].devnum = i;
r10_bio->devs[1].addr = to_addr;
- if (need_recover) {
+ if (mrdev) {
bio = r10_bio->devs[1].bio;
bio->bi_next = biolist;
biolist = bio;
@@ -3619,7 +3619,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
for (k = 0; k < conf->copies; k++)
if (r10_bio->devs[k].devnum == i)
break;
- if (!test_bit(In_sync,
+ if (mrdev && !test_bit(In_sync,
&mrdev->flags)
&& !rdev_set_badblocks(
mrdev,
@@ -3645,12 +3645,14 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
if (rb2)
atomic_dec(&rb2->remaining);
r10_bio = rb2;
- rdev_dec_pending(mrdev, mddev);
+ if (mrdev)
+ rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
break;
}
- rdev_dec_pending(mrdev, mddev);
+ if (mrdev)
+ rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) {