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From:   Amol Grover <frextrite@gmail.com>
To:     "Martin K. Petersen" <martin.petersen@oracle.com>
Cc:     linux-scsi@vger.kernel.org, target-devel@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Joel Fernandes <joel@joelfernandes.org>,
        Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Amol Grover <frextrite@gmail.com>
Subject: [PATCH v3 2/3] drivers: target: target_core_tpg: Pass lockdep expression to RCU lists
Date:   Fri, 17 Jan 2020 19:08:55 +0530
Message-Id: <20200117133854.32550-2-frextrite@gmail.com>
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tpg->tpg_lun_hlist is traversed with hlist_for_each_entry_rcu
outside an RCU read-side critical section but under the
protection of tpg->tpg_lun_mutex.

Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and
harden RCU lists.

Signed-off-by: Amol Grover <frextrite@gmail.com>
---
 drivers/target/target_core_tpg.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index d24e0a3ba3ff..7aa0240a7948 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -110,7 +110,8 @@ void core_tpg_add_node_to_devs(
 	struct se_device *dev;
 
 	mutex_lock(&tpg->tpg_lun_mutex);
-	hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
+	hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link,
+				 lockdep_is_held(&tpg->tpg_lun_mutex)) {
 		if (lun_orig && lun != lun_orig)
 			continue;
 
-- 
2.24.1