drivers: target: target_core_device: Pass lockdep expression to RCU lists

PATCH New Amol Grover 1 participant 3 messages Jan 17, 2020

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Amol Grover

author

2020-01-17 13:40 UTC #0 lore raw

PATCH v3 1/3 drivers: target: target_core_device: Pass lockdep expression to RCU lists

nacl->lun_entry_hlist is traversed with hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of nacl->lun_entry_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 <[email protected]>

---
v3:
- Remove rcu_read_lock_held() from lockdep expression since it is implicitly checked for.
- Remove unintended macro usage.

v2:
- Fix sparse error
CHECK: Alignment should match open parenthesis

 drivers/target/target_core_device.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

drivers/target/target_core_device.c +6 -3

index 2d19f0e332b0..306c626183d5 100644
@@ -247,7 +247,8 @@ void core_free_device_list_for_node(
 	struct se_dev_entry *deve;
 
 	mutex_lock(&nacl->lun_entry_mutex);
-	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
+	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link,
+				 lockdep_is_held(&nacl->lun_entry_mutex)) {
 		struct se_lun *lun = rcu_dereference_check(deve->se_lun,
 					lockdep_is_held(&nacl->lun_entry_mutex));
 		core_disable_device_list_for_node(lun, deve, nacl, tpg);

@@ -276,7 +277,8 @@ struct se_dev_entry *target_nacl_find_deve(struct se_node_acl *nacl, u64 mapped_
 {
 	struct se_dev_entry *deve;
 
-	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
+	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link,
+				 lockdep_is_held(&nacl->lun_entry_mutex))
 		if (deve->mapped_lun == mapped_lun)
 			return deve;

@@ -460,7 +462,8 @@ void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
 	list_for_each_entry(nacl, &tpg->acl_node_list, acl_list) {
 
 		mutex_lock(&nacl->lun_entry_mutex);
-		hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
+		hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link,
+					 lockdep_is_held(&nacl->lun_entry_mutex)) {
 			struct se_lun *tmp_lun = rcu_dereference_check(deve->se_lun,
 					lockdep_is_held(&nacl->lun_entry_mutex));

Signature · 1 line

2.24.1

Amol Grover

author

2020-01-17 13:40 UTC #1 lore raw

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

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 <[email protected]>

---
 drivers/target/target_core_tpg.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

drivers/target/target_core_tpg.c +2 -1

index d24e0a3ba3ff..7aa0240a7948 100644
@@ -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;

Signature · 1 line

2.24.1

Amol Grover

author

2020-01-17 13:41 UTC #2 lore raw

PATCH v3 3/3 drivers: target: tcm_fc: tfc_sess: Pass lockdep expression to RCU lists

In reply to Amol Grover

head is traversed with hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of ft_lport_lock.

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 <[email protected]>

---
 drivers/target/tcm_fc/tfc_sess.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

drivers/target/tcm_fc/tfc_sess.c +8 -4

index 4fd6a1de947c..bb70f61237a6 100644
@@ -170,7 +170,8 @@ static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 	}
 
 	head = &tport->hash[ft_sess_hash(port_id)];
-	hlist_for_each_entry_rcu(sess, head, hash) {
+	hlist_for_each_entry_rcu(sess, head, hash,
+				 lockdep_is_held(&ft_lport_lock)) {
 		if (sess->port_id == port_id) {
 			kref_get(&sess->kref);
 			rcu_read_unlock();

@@ -215,7 +216,8 @@ static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 	ft_format_wwn(&initiatorname[0], TRANSPORT_IQN_LEN, rdata->ids.port_name);
 
 	head = &tport->hash[ft_sess_hash(port_id)];
-	hlist_for_each_entry_rcu(sess, head, hash)
+	hlist_for_each_entry_rcu(sess, head, hash,
+				 lockdep_is_held(&ft_lport_lock))
 		if (sess->port_id == port_id)
 			return sess;

@@ -264,7 +266,8 @@ static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
 	struct ft_sess *sess;
 
 	head = &tport->hash[ft_sess_hash(port_id)];
-	hlist_for_each_entry_rcu(sess, head, hash) {
+	hlist_for_each_entry_rcu(sess, head, hash,
+				 lockdep_is_held(&ft_lport_lock)) {
 		if (sess->port_id == port_id) {
 			ft_sess_unhash(sess);
 			return sess;

@@ -291,7 +294,8 @@ static void ft_sess_delete_all(struct ft_tport *tport)
 
 	for (head = tport->hash;
 	     head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
-		hlist_for_each_entry_rcu(sess, head, hash) {
+		hlist_for_each_entry_rcu(sess, head, hash,
+					 lockdep_is_held(&ft_lport_lock)) {
 			ft_sess_unhash(sess);
 			ft_close_sess(sess);	/* release from table */
 		}

Signature · 1 line

2.24.1