target: Add se_node_acl->acl_free_comp for NodeACL release path
Nicholas Bellinger [Sat, 10 Mar 2012 22:32:52 +0000 (14:32 -0800)]
Add se_node_acl->acl_free_comp for NodeACL release path to wait for outstanding
fabric session shutdown to complete in transport_deregister_session() before
finishing NodeACL release from configfs process context.

Also make transport_deregister_session() clear the comp_nacl bit
to skip se_node_acl->acl_free_comp completion for dynamically generated
NodeACL during fabric session shutdown.

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Joern Engel <joern@logfs.org>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_tpg.c
drivers/target/target_core_transport.c
include/target/target_core_base.h

index 3215340..9cdfd06 100644 (file)
@@ -274,6 +274,7 @@ struct se_node_acl *core_tpg_check_initiator_node_acl(
 
        INIT_LIST_HEAD(&acl->acl_list);
        INIT_LIST_HEAD(&acl->acl_sess_list);
+       init_completion(&acl->acl_free_comp);
        spin_lock_init(&acl->device_list_lock);
        spin_lock_init(&acl->nacl_sess_lock);
        atomic_set(&acl->acl_pr_ref_count, 0);
@@ -402,6 +403,7 @@ struct se_node_acl *core_tpg_add_initiator_node_acl(
 
        INIT_LIST_HEAD(&acl->acl_list);
        INIT_LIST_HEAD(&acl->acl_sess_list);
+       init_completion(&acl->acl_free_comp);
        spin_lock_init(&acl->device_list_lock);
        spin_lock_init(&acl->nacl_sess_lock);
        atomic_set(&acl->acl_pr_ref_count, 0);
index 7badc87..9e61abc 100644 (file)
@@ -372,13 +372,16 @@ EXPORT_SYMBOL(transport_free_session);
 void transport_deregister_session(struct se_session *se_sess)
 {
        struct se_portal_group *se_tpg = se_sess->se_tpg;
+       struct target_core_fabric_ops *se_tfo;
        struct se_node_acl *se_nacl;
        unsigned long flags;
+       bool comp_nacl = true;
 
        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);
@@ -391,29 +394,34 @@ void transport_deregister_session(struct se_session *se_sess)
         * struct se_node_acl if it had been previously dynamically generated.
         */
        se_nacl = se_sess->se_node_acl;
-       if (se_nacl) {
-               spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
-               if (se_nacl->dynamic_node_acl) {
-                       if (!se_tpg->se_tpg_tfo->tpg_check_demo_mode_cache(
-                                       se_tpg)) {
-                               list_del(&se_nacl->acl_list);
-                               se_tpg->num_node_acls--;
-                               spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
-
-                               core_tpg_wait_for_nacl_pr_ref(se_nacl);
-                               core_free_device_list_for_node(se_nacl, se_tpg);
-                               se_tpg->se_tpg_tfo->tpg_release_fabric_acl(se_tpg,
-                                               se_nacl);
-                               spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
-                       }
+
+       spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
+       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--;
+                       spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
+                       core_tpg_wait_for_nacl_pr_ref(se_nacl);
+                       core_free_device_list_for_node(se_nacl, se_tpg);
+                       se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
+
+                       comp_nacl = false;
+                       spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
                }
-               spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
        }
+       spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
 
        transport_free_session(se_sess);
 
        pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
                se_tpg->se_tpg_tfo->get_fabric_name());
+       /*
+        * Awake sleeping ->acl_free_comp caller from configfs se_node_acl
+        * removal context
+        */
+       if (se_nacl && comp_nacl == true)
+               complete(&se_nacl->acl_free_comp);
+
 }
 EXPORT_SYMBOL(transport_deregister_session);
 
index d630794..f8aa300 100644 (file)
@@ -641,6 +641,7 @@ struct se_node_acl {
        struct config_group     *acl_default_groups[5];
        struct list_head        acl_list;
        struct list_head        acl_sess_list;
+       struct completion       acl_free_comp;
 };
 
 struct se_session {