target: Convert ACL change queue_depth se_session reference usage
authorNicholas Bellinger <nab@linux-iscsi.org>
Fri, 8 Jan 2016 06:15:06 +0000 (22:15 -0800)
committerNicholas Bellinger <nab@linux-iscsi.org>
Wed, 20 Jan 2016 09:34:14 +0000 (01:34 -0800)
This patch converts core_tpg_set_initiator_node_queue_depth()
to use struct se_node_acl->acl_sess_list when performing
explicit se_tpg_tfo->shutdown_session() for active sessions,
in order for new se_node_acl->queue_depth to take effect.

This follows how core_tpg_del_initiator_node_acl() currently
works when invoking se_tpg_tfo->shutdown-session(), and ahead
of the next patch to take se_node_acl->acl_kref during lookup,
the extra get_initiator_node_acl() can go away. In order to
achieve this, go ahead and change target_get_session() to use
kref_get_unless_zero() and propigate up the return value
to know when a session is already being released.

This is because se_node_acl->acl_group is already protecting
se_node_acl->acl_group reference via configfs, and shutdown
within core_tpg_del_initiator_node_acl() won't occur until
sys_write() to core_tpg_set_initiator_node_queue_depth()
attribute returns back to user-space.

Also, drop the left-over iscsi-target hack, and obtain
se_portal_group->session_lock in lio_tpg_shutdown_session()
internally. Remove iscsi-target wrapper and unused se_tpg +
force parameters and associated code.

Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
drivers/target/iscsi/iscsi_target_configfs.c
drivers/target/iscsi/iscsi_target_tpg.c
drivers/target/iscsi/iscsi_target_tpg.h
drivers/target/target_core_tpg.c
drivers/target/target_core_transport.c
include/target/target_core_fabric.h

index b4bfd706ac9422705a35fc879705f46d6787fc13..2f821de6304985d552fba6f2d68cdd9f49707b7c 100644 (file)
@@ -725,11 +725,8 @@ static ssize_t lio_target_nacl_cmdsn_depth_store(struct config_item *item,
 
        if (iscsit_get_tpg(tpg) < 0)
                return -EINVAL;
-       /*
-        * iscsit_tpg_set_initiator_node_queue_depth() assumes force=1
-        */
-       ret = iscsit_tpg_set_initiator_node_queue_depth(tpg,
-                               config_item_name(acl_ci), cmdsn_depth, 1);
+
+       ret = core_tpg_set_initiator_node_queue_depth(se_nacl, cmdsn_depth);
 
        pr_debug("LIO_Target_ConfigFS: %s/%s Set CmdSN Window: %u for"
                "InitiatorName: %s\n", config_item_name(wwn_ci),
@@ -1593,42 +1590,30 @@ static int lio_tpg_check_prot_fabric_only(
 }
 
 /*
- * Called with spin_lock_irq(struct se_portal_group->session_lock) held
- * or not held.
- *
- * Also, this function calls iscsit_inc_session_usage_count() on the
+ * This function calls iscsit_inc_session_usage_count() on the
  * struct iscsi_session in question.
  */
 static int lio_tpg_shutdown_session(struct se_session *se_sess)
 {
        struct iscsi_session *sess = se_sess->fabric_sess_ptr;
-       struct se_portal_group *se_tpg = se_sess->se_tpg;
-       bool local_lock = false;
-
-       if (!spin_is_locked(&se_tpg->session_lock)) {
-               spin_lock_irq(&se_tpg->session_lock);
-               local_lock = true;
-       }
+       struct se_portal_group *se_tpg = &sess->tpg->tpg_se_tpg;
 
+       spin_lock_bh(&se_tpg->session_lock);
        spin_lock(&sess->conn_lock);
        if (atomic_read(&sess->session_fall_back_to_erl0) ||
            atomic_read(&sess->session_logout) ||
            (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
                spin_unlock(&sess->conn_lock);
-               if (local_lock)
-                       spin_unlock_irq(&sess->conn_lock);
+               spin_unlock_bh(&se_tpg->session_lock);
                return 0;
        }
        atomic_set(&sess->session_reinstatement, 1);
        spin_unlock(&sess->conn_lock);
 
        iscsit_stop_time2retain_timer(sess);
-       spin_unlock_irq(&se_tpg->session_lock);
+       spin_unlock_bh(&se_tpg->session_lock);
 
        iscsit_stop_session(sess, 1, 1);
-       if (!local_lock)
-               spin_lock_irq(&se_tpg->session_lock);
-
        return 1;
 }
 
index 23c95cd14167a2705b773d0c7155567af331eb33..0814e5894a9616ffcc79fb0d0f086f718a971fd7 100644 (file)
@@ -590,16 +590,6 @@ int iscsit_tpg_del_network_portal(
        return iscsit_tpg_release_np(tpg_np, tpg, np);
 }
 
-int iscsit_tpg_set_initiator_node_queue_depth(
-       struct iscsi_portal_group *tpg,
-       unsigned char *initiatorname,
-       u32 queue_depth,
-       int force)
-{
-       return core_tpg_set_initiator_node_queue_depth(&tpg->tpg_se_tpg,
-               initiatorname, queue_depth, force);
-}
-
 int iscsit_ta_authentication(struct iscsi_portal_group *tpg, u32 authentication)
 {
        unsigned char buf1[256], buf2[256], *none = NULL;
index 9db32bd24cd46d65c5b0050374d0fd6118ac9d32..2da211920c186215e740d1aaa47f781999d1fb71 100644 (file)
@@ -26,8 +26,6 @@ extern struct iscsi_tpg_np *iscsit_tpg_add_network_portal(struct iscsi_portal_gr
                        int);
 extern int iscsit_tpg_del_network_portal(struct iscsi_portal_group *,
                        struct iscsi_tpg_np *);
-extern int iscsit_tpg_set_initiator_node_queue_depth(struct iscsi_portal_group *,
-                       unsigned char *, u32, int);
 extern int iscsit_ta_authentication(struct iscsi_portal_group *, u32);
 extern int iscsit_ta_login_timeout(struct iscsi_portal_group *, u32);
 extern int iscsit_ta_netif_timeout(struct iscsi_portal_group *, u32);
index 62103a8cbe72e406f5a9d54ce488743fd63356e8..67be44da29ff9d614291f82a34da795cb67be127 100644 (file)
@@ -157,28 +157,25 @@ void core_tpg_add_node_to_devs(
        mutex_unlock(&tpg->tpg_lun_mutex);
 }
 
-/*      core_set_queue_depth_for_node():
- *
- *
- */
-static int core_set_queue_depth_for_node(
-       struct se_portal_group *tpg,
-       struct se_node_acl *acl)
+static void
+target_set_nacl_queue_depth(struct se_portal_group *tpg,
+                           struct se_node_acl *acl, u32 queue_depth)
 {
+       acl->queue_depth = queue_depth;
+
        if (!acl->queue_depth) {
-               pr_err("Queue depth for %s Initiator Node: %s is 0,"
+               pr_warn("Queue depth for %s Initiator Node: %s is 0,"
                        "defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
                        acl->initiatorname);
                acl->queue_depth = 1;
        }
-
-       return 0;
 }
 
 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
                const unsigned char *initiatorname)
 {
        struct se_node_acl *acl;
+       u32 queue_depth;
 
        acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
                        GFP_KERNEL);
@@ -193,24 +190,20 @@ static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
        spin_lock_init(&acl->nacl_sess_lock);
        mutex_init(&acl->lun_entry_mutex);
        atomic_set(&acl->acl_pr_ref_count, 0);
+
        if (tpg->se_tpg_tfo->tpg_get_default_depth)
-               acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
+               queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
        else
-               acl->queue_depth = 1;
+               queue_depth = 1;
+       target_set_nacl_queue_depth(tpg, acl, queue_depth);
+
        snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
        acl->se_tpg = tpg;
        acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
 
        tpg->se_tpg_tfo->set_default_node_attributes(acl);
 
-       if (core_set_queue_depth_for_node(tpg, acl) < 0)
-               goto out_free_acl;
-
        return acl;
-
-out_free_acl:
-       kfree(acl);
-       return NULL;
 }
 
 static void target_add_node_acl(struct se_node_acl *acl)
@@ -327,7 +320,8 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
                if (sess->sess_tearing_down != 0)
                        continue;
 
-               target_get_session(sess);
+               if (!target_get_session(sess))
+                       continue;
                list_move(&sess->sess_acl_list, &sess_list);
        }
        spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
@@ -364,108 +358,52 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
  *
  */
 int core_tpg_set_initiator_node_queue_depth(
-       struct se_portal_group *tpg,
-       unsigned char *initiatorname,
-       u32 queue_depth,
-       int force)
+       struct se_node_acl *acl,
+       u32 queue_depth)
 {
-       struct se_session *sess, *init_sess = NULL;
-       struct se_node_acl *acl;
+       LIST_HEAD(sess_list);
+       struct se_portal_group *tpg = acl->se_tpg;
+       struct se_session *sess, *sess_tmp;
        unsigned long flags;
-       int dynamic_acl = 0;
-
-       mutex_lock(&tpg->acl_node_mutex);
-       acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
-       if (!acl) {
-               pr_err("Access Control List entry for %s Initiator"
-                       " Node %s does not exists for TPG %hu, ignoring"
-                       " request.\n", tpg->se_tpg_tfo->get_fabric_name(),
-                       initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
-               mutex_unlock(&tpg->acl_node_mutex);
-               return -ENODEV;
-       }
-       if (acl->dynamic_node_acl) {
-               acl->dynamic_node_acl = 0;
-               dynamic_acl = 1;
-       }
-       mutex_unlock(&tpg->acl_node_mutex);
-
-       spin_lock_irqsave(&tpg->session_lock, flags);
-       list_for_each_entry(sess, &tpg->tpg_sess_list, sess_list) {
-               if (sess->se_node_acl != acl)
-                       continue;
-
-               if (!force) {
-                       pr_err("Unable to change queue depth for %s"
-                               " Initiator Node: %s while session is"
-                               " operational.  To forcefully change the queue"
-                               " depth and force session reinstatement"
-                               " use the \"force=1\" parameter.\n",
-                               tpg->se_tpg_tfo->get_fabric_name(), initiatorname);
-                       spin_unlock_irqrestore(&tpg->session_lock, flags);
-
-                       mutex_lock(&tpg->acl_node_mutex);
-                       if (dynamic_acl)
-                               acl->dynamic_node_acl = 1;
-                       mutex_unlock(&tpg->acl_node_mutex);
-                       return -EEXIST;
-               }
-               /*
-                * Determine if the session needs to be closed by our context.
-                */
-               if (!tpg->se_tpg_tfo->shutdown_session(sess))
-                       continue;
-
-               init_sess = sess;
-               break;
-       }
+       int rc;
 
        /*
         * User has requested to change the queue depth for a Initiator Node.
         * Change the value in the Node's struct se_node_acl, and call
-        * core_set_queue_depth_for_node() to add the requested queue depth.
-        *
-        * Finally call  tpg->se_tpg_tfo->close_session() to force session
-        * reinstatement to occur if there is an active session for the
-        * $FABRIC_MOD Initiator Node in question.
+        * target_set_nacl_queue_depth() to set the new queue depth.
         */
-       acl->queue_depth = queue_depth;
+       target_set_nacl_queue_depth(tpg, acl, queue_depth);
+
+       spin_lock_irqsave(&acl->nacl_sess_lock, flags);
+       list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
+                                sess_acl_list) {
+               if (sess->sess_tearing_down != 0)
+                       continue;
+               if (!target_get_session(sess))
+                       continue;
+               spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 
-       if (core_set_queue_depth_for_node(tpg, acl) < 0) {
-               spin_unlock_irqrestore(&tpg->session_lock, flags);
                /*
-                * Force session reinstatement if
-                * core_set_queue_depth_for_node() failed, because we assume
-                * the $FABRIC_MOD has already the set session reinstatement
-                * bit from tpg->se_tpg_tfo->shutdown_session() called above.
+                * Finally call tpg->se_tpg_tfo->close_session() to force session
+                * reinstatement to occur if there is an active session for the
+                * $FABRIC_MOD Initiator Node in question.
                 */
-               if (init_sess)
-                       tpg->se_tpg_tfo->close_session(init_sess);
-
-               mutex_lock(&tpg->acl_node_mutex);
-               if (dynamic_acl)
-                       acl->dynamic_node_acl = 1;
-               mutex_unlock(&tpg->acl_node_mutex);
-               return -EINVAL;
+               rc = tpg->se_tpg_tfo->shutdown_session(sess);
+               target_put_session(sess);
+               if (!rc) {
+                       spin_lock_irqsave(&acl->nacl_sess_lock, flags);
+                       continue;
+               }
+               target_put_session(sess);
+               spin_lock_irqsave(&acl->nacl_sess_lock, flags);
        }
-       spin_unlock_irqrestore(&tpg->session_lock, flags);
-       /*
-        * If the $FABRIC_MOD session for the Initiator Node ACL exists,
-        * forcefully shutdown the $FABRIC_MOD session/nexus.
-        */
-       if (init_sess)
-               tpg->se_tpg_tfo->close_session(init_sess);
+       spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 
        pr_debug("Successfully changed queue depth to: %d for Initiator"
-               " Node: %s on %s Target Portal Group: %u\n", queue_depth,
-               initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
+               " Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
+               acl->initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
                tpg->se_tpg_tfo->tpg_get_tag(tpg));
 
-       mutex_lock(&tpg->acl_node_mutex);
-       if (dynamic_acl)
-               acl->dynamic_node_acl = 1;
-       mutex_unlock(&tpg->acl_node_mutex);
-
        return 0;
 }
 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
index eb7aaf022df51184a2ff2cce7eea8f7fcecb1566..7b05ebf8053cadd35c6d55bcac5d715e8a3c2b2a 100644 (file)
@@ -384,9 +384,9 @@ static void target_release_session(struct kref *kref)
        se_tpg->se_tpg_tfo->close_session(se_sess);
 }
 
-void target_get_session(struct se_session *se_sess)
+int target_get_session(struct se_session *se_sess)
 {
-       kref_get(&se_sess->sess_kref);
+       return kref_get_unless_zero(&se_sess->sess_kref);
 }
 EXPORT_SYMBOL(target_get_session);
 
index de21130cc9bc909c93456da898c0d09c0b798472..48e002f86893b386c3e2d0e59462aa9dd6346c20 100644 (file)
@@ -117,7 +117,7 @@ void        __transport_register_session(struct se_portal_group *,
                struct se_node_acl *, struct se_session *, void *);
 void   transport_register_session(struct se_portal_group *,
                struct se_node_acl *, struct se_session *, void *);
-void   target_get_session(struct se_session *);
+int    target_get_session(struct se_session *);
 void   target_put_session(struct se_session *);
 ssize_t        target_show_dynamic_sessions(struct se_portal_group *, char *);
 void   transport_free_session(struct se_session *);
@@ -171,8 +171,7 @@ struct se_node_acl *core_tpg_get_initiator_node_acl(struct se_portal_group *tpg,
                unsigned char *);
 struct se_node_acl *core_tpg_check_initiator_node_acl(struct se_portal_group *,
                unsigned char *);
-int    core_tpg_set_initiator_node_queue_depth(struct se_portal_group *,
-               unsigned char *, u32, int);
+int    core_tpg_set_initiator_node_queue_depth(struct se_node_acl *, u32);
 int    core_tpg_set_initiator_node_tag(struct se_portal_group *,
                struct se_node_acl *, const char *);
 int    core_tpg_register(struct se_wwn *, struct se_portal_group *, int);