Commit 5f0aa21d authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Shaohua Li
Browse files

md-cluster: protect md_find_rdev_nr_rcu with rcu lock 



We need to use rcu_read_lock/unlock to avoid potential
race.

Reported-by: default avatarShaohua Li <shli@fb.com>
Reviewed-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent c20c33f0

drivers/md/md-cluster.c

+8 −4
Original line number Diff line number Diff line
@@ -489,9 +489,10 @@ static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg 


static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)

{

	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,

						   le32_to_cpu(msg->raid_slot));

	struct md_rdev *rdev;



	rcu_read_lock();

	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));

	if (rdev) {

		set_bit(ClusterRemove, &rdev->flags);

		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -500,18 +501,21 @@ static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg) 
	else

		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",

			__func__, __LINE__, le32_to_cpu(msg->raid_slot));

	rcu_read_unlock();

}



static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)

{

	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,

						   le32_to_cpu(msg->raid_slot));

	struct md_rdev *rdev;



	rcu_read_lock();

	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));

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

		clear_bit(Faulty, &rdev->flags);

	else

		pr_warn("%s: %d Could not find disk(%d) which is faulty",

			__func__, __LINE__, le32_to_cpu(msg->raid_slot));

	rcu_read_unlock();

}



static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)