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-rw-r--r--drivers/target/iscsi/iscsi_target.c2
-rw-r--r--drivers/target/target_core_device.c10
-rw-r--r--drivers/target/target_core_tpg.c45
-rw-r--r--drivers/target/target_core_transport.c116
4 files changed, 136 insertions, 37 deletions
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index bd810c109277..6ed80b05d674 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3436,7 +3436,7 @@ iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
if ((tpg->tpg_attrib.generate_node_acls == 0) &&
(tpg->tpg_attrib.demo_mode_discovery == 0) &&
- (!core_tpg_get_initiator_node_acl(&tpg->tpg_se_tpg,
+ (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
cmd->conn->sess->sess_ops->InitiatorName))) {
continue;
}
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 356c80fbb304..bb6a6c35324a 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -77,12 +77,16 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
&deve->read_bytes);
se_lun = rcu_dereference(deve->se_lun);
+
+ if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
+ se_lun = NULL;
+ goto out_unlock;
+ }
+
se_cmd->se_lun = rcu_dereference(deve->se_lun);
se_cmd->pr_res_key = deve->pr_res_key;
se_cmd->orig_fe_lun = unpacked_lun;
se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
-
- percpu_ref_get(&se_lun->lun_ref);
se_cmd->lun_ref_active = true;
if ((se_cmd->data_direction == DMA_TO_DEVICE) &&
@@ -96,6 +100,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
goto ref_dev;
}
}
+out_unlock:
rcu_read_unlock();
if (!se_lun) {
@@ -826,6 +831,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
xcopy_lun = &dev->xcopy_lun;
rcu_assign_pointer(xcopy_lun->lun_se_dev, dev);
init_completion(&xcopy_lun->lun_ref_comp);
+ init_completion(&xcopy_lun->lun_shutdown_comp);
INIT_LIST_HEAD(&xcopy_lun->lun_deve_list);
INIT_LIST_HEAD(&xcopy_lun->lun_dev_link);
mutex_init(&xcopy_lun->lun_tg_pt_md_mutex);
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index 5fb9dd7f08bb..2794c6ec5c3c 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -75,9 +75,21 @@ struct se_node_acl *core_tpg_get_initiator_node_acl(
unsigned char *initiatorname)
{
struct se_node_acl *acl;
-
+ /*
+ * Obtain se_node_acl->acl_kref using fabric driver provided
+ * initiatorname[] during node acl endpoint lookup driven by
+ * new se_session login.
+ *
+ * The reference is held until se_session shutdown -> release
+ * occurs via fabric driver invoked transport_deregister_session()
+ * or transport_free_session() code.
+ */
mutex_lock(&tpg->acl_node_mutex);
acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
+ if (acl) {
+ if (!kref_get_unless_zero(&acl->acl_kref))
+ acl = NULL;
+ }
mutex_unlock(&tpg->acl_node_mutex);
return acl;
@@ -232,6 +244,25 @@ static void target_add_node_acl(struct se_node_acl *acl)
acl->initiatorname);
}
+bool target_tpg_has_node_acl(struct se_portal_group *tpg,
+ const char *initiatorname)
+{
+ struct se_node_acl *acl;
+ bool found = false;
+
+ mutex_lock(&tpg->acl_node_mutex);
+ list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
+ if (!strcmp(acl->initiatorname, initiatorname)) {
+ found = true;
+ break;
+ }
+ }
+ mutex_unlock(&tpg->acl_node_mutex);
+
+ return found;
+}
+EXPORT_SYMBOL(target_tpg_has_node_acl);
+
struct se_node_acl *core_tpg_check_initiator_node_acl(
struct se_portal_group *tpg,
unsigned char *initiatorname)
@@ -248,6 +279,15 @@ struct se_node_acl *core_tpg_check_initiator_node_acl(
acl = target_alloc_node_acl(tpg, initiatorname);
if (!acl)
return NULL;
+ /*
+ * When allocating a dynamically generated node_acl, go ahead
+ * and take the extra kref now before returning to the fabric
+ * driver caller.
+ *
+ * Note this reference will be released at session shutdown
+ * time within transport_free_session() code.
+ */
+ kref_get(&acl->acl_kref);
acl->dynamic_node_acl = 1;
/*
@@ -499,7 +539,7 @@ static void core_tpg_lun_ref_release(struct percpu_ref *ref)
{
struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
- complete(&lun->lun_ref_comp);
+ complete(&lun->lun_shutdown_comp);
}
int core_tpg_register(
@@ -626,6 +666,7 @@ struct se_lun *core_tpg_alloc_lun(
lun->lun_link_magic = SE_LUN_LINK_MAGIC;
atomic_set(&lun->lun_acl_count, 0);
init_completion(&lun->lun_ref_comp);
+ init_completion(&lun->lun_shutdown_comp);
INIT_LIST_HEAD(&lun->lun_deve_list);
INIT_LIST_HEAD(&lun->lun_dev_link);
atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index aa517c4fadb9..df2059984e14 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -341,7 +341,6 @@ void __transport_register_session(
&buf[0], PR_REG_ISID_LEN);
se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
}
- kref_get(&se_nacl->acl_kref);
spin_lock_irq(&se_nacl->nacl_sess_lock);
/*
@@ -424,14 +423,27 @@ static void target_complete_nacl(struct kref *kref)
{
struct se_node_acl *nacl = container_of(kref,
struct se_node_acl, acl_kref);
+ struct se_portal_group *se_tpg = nacl->se_tpg;
- complete(&nacl->acl_free_comp);
+ if (!nacl->dynamic_stop) {
+ complete(&nacl->acl_free_comp);
+ return;
+ }
+
+ mutex_lock(&se_tpg->acl_node_mutex);
+ list_del(&nacl->acl_list);
+ mutex_unlock(&se_tpg->acl_node_mutex);
+
+ core_tpg_wait_for_nacl_pr_ref(nacl);
+ core_free_device_list_for_node(nacl, se_tpg);
+ kfree(nacl);
}
void target_put_nacl(struct se_node_acl *nacl)
{
kref_put(&nacl->acl_kref, target_complete_nacl);
}
+EXPORT_SYMBOL(target_put_nacl);
void transport_deregister_session_configfs(struct se_session *se_sess)
{
@@ -464,6 +476,42 @@ EXPORT_SYMBOL(transport_deregister_session_configfs);
void transport_free_session(struct se_session *se_sess)
{
+ struct se_node_acl *se_nacl = se_sess->se_node_acl;
+
+ /*
+ * Drop the se_node_acl->nacl_kref obtained from within
+ * core_tpg_get_initiator_node_acl().
+ */
+ if (se_nacl) {
+ struct se_portal_group *se_tpg = se_nacl->se_tpg;
+ const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
+ unsigned long flags;
+
+ se_sess->se_node_acl = NULL;
+
+ /*
+ * Also determine if we need to drop the extra ->cmd_kref if
+ * it had been previously dynamically generated, and
+ * the endpoint is not caching dynamic ACLs.
+ */
+ mutex_lock(&se_tpg->acl_node_mutex);
+ if (se_nacl->dynamic_node_acl &&
+ !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
+ spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
+ if (list_empty(&se_nacl->acl_sess_list))
+ se_nacl->dynamic_stop = true;
+ spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
+
+ if (se_nacl->dynamic_stop)
+ list_del(&se_nacl->acl_list);
+ }
+ mutex_unlock(&se_tpg->acl_node_mutex);
+
+ if (se_nacl->dynamic_stop)
+ target_put_nacl(se_nacl);
+
+ target_put_nacl(se_nacl);
+ }
if (se_sess->sess_cmd_map) {
percpu_ida_destroy(&se_sess->sess_tag_pool);
kvfree(se_sess->sess_cmd_map);
@@ -475,16 +523,12 @@ EXPORT_SYMBOL(transport_free_session);
void transport_deregister_session(struct se_session *se_sess)
{
struct se_portal_group *se_tpg = se_sess->se_tpg;
- const struct target_core_fabric_ops *se_tfo;
- struct se_node_acl *se_nacl;
unsigned long flags;
- bool comp_nacl = true, drop_nacl = false;
if (!se_tpg) {
transport_free_session(se_sess);
return;
}
- se_tfo = se_tpg->se_tpg_tfo;
spin_lock_irqsave(&se_tpg->session_lock, flags);
list_del(&se_sess->sess_list);
@@ -492,37 +536,16 @@ void transport_deregister_session(struct se_session *se_sess)
se_sess->fabric_sess_ptr = NULL;
spin_unlock_irqrestore(&se_tpg->session_lock, flags);
- /*
- * Determine if we need to do extra work for this initiator node's
- * struct se_node_acl if it had been previously dynamically generated.
- */
- se_nacl = se_sess->se_node_acl;
-
- mutex_lock(&se_tpg->acl_node_mutex);
- if (se_nacl && se_nacl->dynamic_node_acl) {
- if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
- list_del(&se_nacl->acl_list);
- se_tpg->num_node_acls--;
- drop_nacl = true;
- }
- }
- mutex_unlock(&se_tpg->acl_node_mutex);
-
- if (drop_nacl) {
- core_tpg_wait_for_nacl_pr_ref(se_nacl);
- core_free_device_list_for_node(se_nacl, se_tpg);
- kfree(se_nacl);
- comp_nacl = false;
- }
pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
se_tpg->se_tpg_tfo->get_fabric_name());
/*
* If last kref is dropping now for an explicit NodeACL, awake sleeping
* ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
- * removal context.
+ * removal context from within transport_free_session() code.
+ *
+ * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
+ * to release all remaining generate_node_acl=1 created ACL resources.
*/
- if (se_nacl && comp_nacl)
- target_put_nacl(se_nacl);
transport_free_session(se_sess);
}
@@ -2657,10 +2680,39 @@ void target_wait_for_sess_cmds(struct se_session *se_sess)
}
EXPORT_SYMBOL(target_wait_for_sess_cmds);
+static void target_lun_confirm(struct percpu_ref *ref)
+{
+ struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
+
+ complete(&lun->lun_ref_comp);
+}
+
void transport_clear_lun_ref(struct se_lun *lun)
{
- percpu_ref_kill(&lun->lun_ref);
+ /*
+ * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
+ * the initial reference and schedule confirm kill to be
+ * executed after one full RCU grace period has completed.
+ */
+ percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
+ /*
+ * The first completion waits for percpu_ref_switch_to_atomic_rcu()
+ * to call target_lun_confirm after lun->lun_ref has been marked
+ * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
+ * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
+ * fails for all new incoming I/O.
+ */
wait_for_completion(&lun->lun_ref_comp);
+ /*
+ * The second completion waits for percpu_ref_put_many() to
+ * invoke ->release() after lun->lun_ref has switched to
+ * atomic_t mode, and lun->lun_ref.count has reached zero.
+ *
+ * At this point all target-core lun->lun_ref references have
+ * been dropped via transport_lun_remove_cmd(), and it's safe
+ * to proceed with the remaining LUN shutdown.
+ */
+ wait_for_completion(&lun->lun_shutdown_comp);
}
static bool