[PATCH v3 2/3] drivers: target: target_core_tpg: Pass lockdep expression to RCU lists

Amol Grover
2020-01-17T13:40:43Z

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