Do not unlock all_mddevs_lock in md_seq_show() and keep the lock until
md_seq_stop().
The list of all_mddevs may be deleted in md_seq_show() because
all_mddevs_lock is temporarily unlocked.
The list should not be deleted while iterating over all_mddevs.
(Just as the list should not be deleted during list_for_each_entry().)
Fixes: cf1b6d4441ff ("md: simplify md_seq_ops")
Signed-off-by: Yuya Fujita <fujita.yuya-00@xxxxxxxxxxx>
---
drivers/md/md.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c94373d64f2c..97ef08608848 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8293,7 +8293,6 @@ static int md_seq_show(struct seq_file *seq, void *v)
if (!mddev_get(mddev))
return 0;
- spin_unlock(&all_mddevs_lock);
spin_lock(&mddev->lock);
if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
seq_printf(seq, "%s : %sactive", mdname(mddev),
@@ -8364,7 +8363,6 @@ static int md_seq_show(struct seq_file *seq, void *v)
seq_printf(seq, "\n");
}
spin_unlock(&mddev->lock);
- spin_lock(&all_mddevs_lock);
if (atomic_dec_and_test(&mddev->active))
__mddev_put(mddev);
--
2.31.1
