Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d44b0a92 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md/raid10: add rcu protection in raid10_status. 



mirrors[].rdev can become NULL at any point unless:
 - a counted reference is held
 - ->reconfig_mutex is held, or
 - rcu_read_lock() is held

raid10_status holds none of these.  So add rcu_read_lock()
protection.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 83f1261f

drivers/md/raid10.c

+6 −4
Original line number Diff line number Diff line
@@ -1495,10 +1495,12 @@ static void raid10_status(struct seq_file *seq, struct mddev *mddev) 
	}

	seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,

					conf->geo.raid_disks - mddev->degraded);

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

		seq_printf(seq, "%s",

			      conf->mirrors[i].rdev &&

			      test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");

	rcu_read_lock();

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

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

		seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");

	}

	rcu_read_unlock();

	seq_printf(seq, "]");

}