From 5fd133511d5f2a9167573d100e14fddd9c621581 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 2 Jun 2016 16:19:52 +1000 Subject: [PATCH] md/raid5: add rcu protection to rdev accesses in raid5_status. Signed-off-by: NeilBrown Signed-off-by: Shaohua Li --- drivers/md/raid5.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 198b2a9eef98..c07b22e8d946 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7069,10 +7069,12 @@ static void raid5_status(struct seq_file *seq, struct mddev *mddev) seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level, conf->chunk_sectors / 2, mddev->layout); 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->disks[i].rdev && - test_bit(In_sync, &conf->disks[i].rdev->flags) ? "U" : "_"); + rcu_read_lock(); + for (i = 0; i < conf->raid_disks; i++) { + struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev); + seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); + } + rcu_read_unlock(); seq_printf (seq, "]"); }