Commit 23b245c0 authored by Shaohua Li's avatar Shaohua Li
Browse files

md/raid1/10: avoid unnecessary locking 



If we add bios to block plugging list, locking is unnecessry, since the block
unplug is guaranteed not to run at that time.

Reviewed-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent bb3338d3

drivers/md/raid1.c

+3 −4
Original line number Diff line number Diff line
@@ -1529,18 +1529,17 @@ 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)

			md_wakeup_thread(mddev->thread);

		}

	}



	r1_bio_write_done(r1_bio);

drivers/md/raid10.c

+3 −4
Original line number Diff line number Diff line
@@ -1282,18 +1282,17 @@ 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)

		md_wakeup_thread(mddev->thread);

	}

}



static void raid10_write_request(struct mddev *mddev, struct bio *bio,

				 struct r10bio *r10_bio)