Commit e50d3992 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md/raid5: add rcu protection to rdev accesses in handle_failed_sync. 



The rdev could be freed while handle_failed_sync is running, so
rcu protection is needed.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 707a6a42

drivers/md/raid5.c

+4 −2
Original line number Diff line number Diff line
@@ -3210,15 +3210,16 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh, 
		/* During recovery devices cannot be removed, so

		 * locking and refcounting of rdevs is not needed

		 */

		rcu_read_lock();

		for (i = 0; i < conf->raid_disks; i++) {

			struct md_rdev *rdev = conf->disks[i].rdev;

			struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);

			if (rdev

			    && !test_bit(Faulty, &rdev->flags)

			    && !test_bit(In_sync, &rdev->flags)

			    && !rdev_set_badblocks(rdev, sh->sector,

						   STRIPE_SECTORS, 0))

				abort = 1;

			rdev = conf->disks[i].replacement;

			rdev = rcu_dereference(conf->disks[i].replacement);

			if (rdev

			    && !test_bit(Faulty, &rdev->flags)

			    && !test_bit(In_sync, &rdev->flags)
@@ -3226,6 +3227,7 @@ handle_failed_sync(struct r5conf *conf, struct stripe_head *sh, 
						   STRIPE_SECTORS, 0))

				abort = 1;

		}

		rcu_read_unlock();

		if (abort)

			conf->recovery_disabled =

				conf->mddev->recovery_disabled;