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: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index 67a7358..b4dc211 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -489,9 +489,10 @@
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 @@
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)