diff options
| -rw-r--r-- | drivers/md/raid10.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 16977e8e075d..d5d92337e35e 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1712,6 +1712,11 @@ retry_discard: } else r10_bio->master_bio = (struct bio *)first_r10bio; + /* + * first select target devices under rcu_lock and + * inc refcount on their rdev. Record them by setting + * bios[x] to bio + */ rcu_read_lock(); for (disk = 0; disk < geo->raid_disks; disk++) { struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev); @@ -1743,9 +1748,6 @@ retry_discard: for (disk = 0; disk < geo->raid_disks; disk++) { sector_t dev_start, dev_end; struct bio *mbio, *rbio = NULL; - struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev); - struct md_rdev *rrdev = rcu_dereference( - conf->mirrors[disk].replacement); /* * Now start to calculate the start and end address for each disk. @@ -1775,9 +1777,12 @@ retry_discard: /* * It only handles discard bio which size is >= stripe size, so - * dev_end > dev_start all the time + * dev_end > dev_start all the time. + * It doesn't need to use rcu lock to get rdev here. We already + * add rdev->nr_pending in the first loop. */ if (r10_bio->devs[disk].bio) { + struct md_rdev *rdev = conf->mirrors[disk].rdev; mbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set); mbio->bi_end_io = raid10_end_discard_request; mbio->bi_private = r10_bio; @@ -1790,6 +1795,7 @@ retry_discard: bio_endio(mbio); } if (r10_bio->devs[disk].repl_bio) { + struct md_rdev *rrdev = conf->mirrors[disk].replacement; rbio = bio_clone_fast(bio, GFP_NOIO, &mddev->bio_set); rbio->bi_end_io = raid10_end_discard_request; rbio->bi_private = r10_bio; |