From 5f0aa21da6cc620b08e5f69f51db29cb1f722174 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Fri, 12 Aug 2016 13:42:39 +0800 Subject: [PATCH] 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 Reviewed-by: NeilBrown Signed-off-by: Guoqing Jiang Signed-off-by: Shaohua Li --- drivers/md/md-cluster.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index 67a735840639..b4dc211923c7 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -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) -- 2.39.5