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From:   Dinghao Liu <dinghao.liu@zju.edu.cn>
To:     dinghao.liu@zju.edu.cn, kjlu@umn.edu
Cc:     Alasdair Kergon <agk@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>, dm-devel@redhat.com,
        Heinz Mauelshagen <heinzm@redhat.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] dm raid: add missed unlock in raid_ctr
Date:   Fri,  3 Sep 2021 15:55:30 +0800
Message-Id: <20210903075531.20310-1-dinghao.liu@zju.edu.cn>
Precedence: bulk

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@zju.edu.cn>
---
 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