[PATCH] dm raid: add missed unlock in raid_ctr

From: Dinghao Liu
Date: Fri Sep 03 2021 - 03:55:45 EST


mddev_unlock() is called on all paths after we call mddev_lock_nointr(),
except for three error handling paths, which may cause a deadlock. This
bug is suggested by a static analysis tool, please advise.

Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
---
drivers/md/dm-raid.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index d9ef52159a22..79f36a806082 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3276,15 +3276,19 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
if (rs_is_raid456(rs)) {
r = rs_set_raid456_stripe_cache(rs);
- if (r)
+ if (r) {
+ mddev_unlock(&rs->md);
goto bad_stripe_cache;
+ }
}

/* Now do an early reshape check */
if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
r = rs_check_reshape(rs);
- if (r)
+ if (r) {
+ mddev_unlock(&rs->md);
goto bad_check_reshape;
+ }

/* Restore new, ctr requested layout to perform check */
rs_config_restore(rs, &rs_layout);
@@ -3293,6 +3297,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
r = rs->md.pers->check_reshape(&rs->md);
if (r) {
ti->error = "Reshape check failed";
+ mddev_unlock(&rs->md);
goto bad_check_reshape;
}
}
--
2.17.1