From 40cf2123c57928c3ec0626c49bef97ebdbce008e Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 2 Jun 2016 16:19:52 +1000 Subject: md/multipath: add rcu protection to rdev access in multipath_status. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li --- drivers/md/multipath.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/md/multipath.c') diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c index dd483bb2e111..69244de2036b 100644 --- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -141,17 +141,19 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio) return; } -static void multipath_status (struct seq_file *seq, struct mddev *mddev) +static void multipath_status(struct seq_file *seq, struct mddev *mddev) { struct mpconf *conf = mddev->private; int i; seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); - for (i = 0; i < conf->raid_disks; i++) - seq_printf (seq, "%s", - conf->multipaths[i].rdev && - test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); + rcu_read_lock(); + for (i = 0; i < conf->raid_disks; i++) { + struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev); + seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); + } + rcu_read_unlock(); seq_printf (seq, "]"); } -- cgit v1.2.3