On Wed, May 10 2017, shli@xxxxxxxxxx wrote:
> From: Shaohua Li <shli@xxxxxx>
>
> If we add bios to block plugging list, locking is unnecessry, since the block
> unplug is guaranteed not to run at that time.
Yes, that make sense. Thanks
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
>
> Cc: NeilBrown <neilb@xxxxxxxx>
> Signed-off-by: Shaohua Li <shli@xxxxxx>
> ---
> drivers/md/raid1.c | 7 +++----
> drivers/md/raid10.c | 7 +++----
> 2 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index 7c1f73398800..a17ed6218d51 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1529,17 +1529,16 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
> plug = container_of(cb, struct raid1_plug_cb, cb);
> else
> plug = NULL;
> - spin_lock_irqsave(&conf->device_lock, flags);
> if (plug) {
> bio_list_add(&plug->pending, mbio);
> plug->pending_cnt++;
> } else {
> + spin_lock_irqsave(&conf->device_lock, flags);
> bio_list_add(&conf->pending_bio_list, mbio);
> conf->pending_count++;
> - }
> - spin_unlock_irqrestore(&conf->device_lock, flags);
> - if (!plug)
> + spin_unlock_irqrestore(&conf->device_lock, flags);
> md_wakeup_thread(mddev->thread);
> + }
> }
>
> r1_bio_write_done(r1_bio);
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index 6b86a0032cf8..4343d7ff9916 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -1282,17 +1282,16 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
> plug = container_of(cb, struct raid10_plug_cb, cb);
> else
> plug = NULL;
> - spin_lock_irqsave(&conf->device_lock, flags);
> if (plug) {
> bio_list_add(&plug->pending, mbio);
> plug->pending_cnt++;
> } else {
> + spin_lock_irqsave(&conf->device_lock, flags);
> bio_list_add(&conf->pending_bio_list, mbio);
> conf->pending_count++;
> - }
> - spin_unlock_irqrestore(&conf->device_lock, flags);
> - if (!plug)
> + spin_unlock_irqrestore(&conf->device_lock, flags);
> md_wakeup_thread(mddev->thread);
> + }
> }
>
> static void raid10_write_request(struct mddev *mddev, struct bio *bio,
> --
> 2.11.0
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