target: Fix remote-port TMR ABORT + se_cmd fabric stop
[firefly-linux-kernel-4.4.55.git] / drivers / target / target_core_transport.c
index 4fdcee2006d1698f4b4e8689c7976ea161a34685..c1f4cb4103f79357aa5c74c81127c904750e6754 100644 (file)
@@ -528,9 +528,6 @@ void transport_deregister_session(struct se_session *se_sess)
 }
 EXPORT_SYMBOL(transport_deregister_session);
 
-/*
- * Called with cmd->t_state_lock held.
- */
 static void target_remove_from_state_list(struct se_cmd *cmd)
 {
        struct se_device *dev = cmd->se_dev;
@@ -555,10 +552,6 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&cmd->t_state_lock, flags);
-       if (write_pending)
-               cmd->t_state = TRANSPORT_WRITE_PENDING;
-
        if (remove_from_lists) {
                target_remove_from_state_list(cmd);
 
@@ -568,6 +561,10 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
                cmd->se_lun = NULL;
        }
 
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       if (write_pending)
+               cmd->t_state = TRANSPORT_WRITE_PENDING;
+
        /*
         * Determine if frontend context caller is requesting the stopping of
         * this command for frontend exceptions.
@@ -621,6 +618,8 @@ static void transport_lun_remove_cmd(struct se_cmd *cmd)
 
 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 {
+       bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
+
        if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
                transport_lun_remove_cmd(cmd);
        /*
@@ -632,7 +631,7 @@ void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
 
        if (transport_cmd_check_stop_to_fabric(cmd))
                return;
-       if (remove)
+       if (remove && ack_kref)
                transport_put_cmd(cmd);
 }
 
@@ -700,7 +699,7 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
         * Check for case where an explicit ABORT_TASK has been received
         * and transport_wait_for_tasks() will be waiting for completion..
         */
-       if (cmd->transport_state & CMD_T_ABORTED &&
+       if (cmd->transport_state & CMD_T_ABORTED ||
            cmd->transport_state & CMD_T_STOP) {
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                complete_all(&cmd->t_transport_stop_comp);
@@ -2213,20 +2212,14 @@ static inline void transport_free_pages(struct se_cmd *cmd)
 }
 
 /**
- * transport_release_cmd - free a command
- * @cmd:       command to free
+ * transport_put_cmd - release a reference to a command
+ * @cmd:       command to release
  *
- * This routine unconditionally frees a command, and reference counting
- * or list removal must be done in the caller.
+ * This routine releases our reference to the command and frees it if possible.
  */
-static int transport_release_cmd(struct se_cmd *cmd)
+static int transport_put_cmd(struct se_cmd *cmd)
 {
        BUG_ON(!cmd->se_tfo);
-
-       if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
-               core_tmr_release_req(cmd->se_tmr_req);
-       if (cmd->t_task_cdb != cmd->__t_task_cdb)
-               kfree(cmd->t_task_cdb);
        /*
         * If this cmd has been setup with target_get_sess_cmd(), drop
         * the kref and call ->release_cmd() in kref callback.
@@ -2234,18 +2227,6 @@ static int transport_release_cmd(struct se_cmd *cmd)
        return target_put_sess_cmd(cmd);
 }
 
-/**
- * transport_put_cmd - release a reference to a command
- * @cmd:       command to release
- *
- * This routine releases our reference to the command and frees it if possible.
- */
-static int transport_put_cmd(struct se_cmd *cmd)
-{
-       transport_free_pages(cmd);
-       return transport_release_cmd(cmd);
-}
-
 void *transport_kmap_data_sg(struct se_cmd *cmd)
 {
        struct scatterlist *sg = cmd->t_data_sg;
@@ -2441,34 +2422,58 @@ static void transport_write_pending_qf(struct se_cmd *cmd)
        }
 }
 
-int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
+static bool
+__transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
+                          unsigned long *flags);
+
+static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
 {
        unsigned long flags;
+
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       __transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
+       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+}
+
+int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
+{
        int ret = 0;
+       bool aborted = false, tas = false;
 
        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
                if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
-                        transport_wait_for_tasks(cmd);
+                       target_wait_free_cmd(cmd, &aborted, &tas);
 
-               ret = transport_release_cmd(cmd);
+               if (!aborted || tas)
+                       ret = transport_put_cmd(cmd);
        } else {
                if (wait_for_tasks)
-                       transport_wait_for_tasks(cmd);
+                       target_wait_free_cmd(cmd, &aborted, &tas);
                /*
                 * Handle WRITE failure case where transport_generic_new_cmd()
                 * has already added se_cmd to state_list, but fabric has
                 * failed command before I/O submission.
                 */
-               if (cmd->state_active) {
-                       spin_lock_irqsave(&cmd->t_state_lock, flags);
+               if (cmd->state_active)
                        target_remove_from_state_list(cmd);
-                       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-               }
 
                if (cmd->se_lun)
                        transport_lun_remove_cmd(cmd);
 
-               ret = transport_put_cmd(cmd);
+               if (!aborted || tas)
+                       ret = transport_put_cmd(cmd);
+       }
+       /*
+        * If the task has been internally aborted due to TMR ABORT_TASK
+        * or LUN_RESET, target_core_tmr.c is responsible for performing
+        * the remaining calls to target_put_sess_cmd(), and not the
+        * callers of this function.
+        */
+       if (aborted) {
+               pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
+               wait_for_completion(&cmd->cmd_wait_comp);
+               cmd->se_tfo->release_cmd(cmd);
+               ret = 1;
        }
        return ret;
 }
@@ -2508,26 +2513,46 @@ out:
 }
 EXPORT_SYMBOL(target_get_sess_cmd);
 
+static void target_free_cmd_mem(struct se_cmd *cmd)
+{
+       transport_free_pages(cmd);
+
+       if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
+               core_tmr_release_req(cmd->se_tmr_req);
+       if (cmd->t_task_cdb != cmd->__t_task_cdb)
+               kfree(cmd->t_task_cdb);
+}
+
 static void target_release_cmd_kref(struct kref *kref)
 {
        struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
        struct se_session *se_sess = se_cmd->se_sess;
        unsigned long flags;
+       bool fabric_stop;
 
        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
        if (list_empty(&se_cmd->se_cmd_list)) {
                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+               target_free_cmd_mem(se_cmd);
                se_cmd->se_tfo->release_cmd(se_cmd);
                return;
        }
-       if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
+
+       spin_lock(&se_cmd->t_state_lock);
+       fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP);
+       spin_unlock(&se_cmd->t_state_lock);
+
+       if (se_cmd->cmd_wait_set || fabric_stop) {
+               list_del_init(&se_cmd->se_cmd_list);
                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+               target_free_cmd_mem(se_cmd);
                complete(&se_cmd->cmd_wait_comp);
                return;
        }
-       list_del(&se_cmd->se_cmd_list);
+       list_del_init(&se_cmd->se_cmd_list);
        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 
+       target_free_cmd_mem(se_cmd);
        se_cmd->se_tfo->release_cmd(se_cmd);
 }
 
@@ -2539,6 +2564,7 @@ int target_put_sess_cmd(struct se_cmd *se_cmd)
        struct se_session *se_sess = se_cmd->se_sess;
 
        if (!se_sess) {
+               target_free_cmd_mem(se_cmd);
                se_cmd->se_tfo->release_cmd(se_cmd);
                return 1;
        }
@@ -2555,6 +2581,7 @@ void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
 {
        struct se_cmd *se_cmd;
        unsigned long flags;
+       int rc;
 
        spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
        if (se_sess->sess_tearing_down) {
@@ -2564,8 +2591,15 @@ void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
        se_sess->sess_tearing_down = 1;
        list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
 
-       list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
-               se_cmd->cmd_wait_set = 1;
+       list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
+               rc = kref_get_unless_zero(&se_cmd->cmd_kref);
+               if (rc) {
+                       se_cmd->cmd_wait_set = 1;
+                       spin_lock(&se_cmd->t_state_lock);
+                       se_cmd->transport_state |= CMD_T_FABRIC_STOP;
+                       spin_unlock(&se_cmd->t_state_lock);
+               }
+       }
 
        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 }
@@ -2578,15 +2612,25 @@ void target_wait_for_sess_cmds(struct se_session *se_sess)
 {
        struct se_cmd *se_cmd, *tmp_cmd;
        unsigned long flags;
+       bool tas;
 
        list_for_each_entry_safe(se_cmd, tmp_cmd,
                                &se_sess->sess_wait_list, se_cmd_list) {
-               list_del(&se_cmd->se_cmd_list);
+               list_del_init(&se_cmd->se_cmd_list);
 
                pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
                        " %d\n", se_cmd, se_cmd->t_state,
                        se_cmd->se_tfo->get_cmd_state(se_cmd));
 
+               spin_lock_irqsave(&se_cmd->t_state_lock, flags);
+               tas = (se_cmd->transport_state & CMD_T_TAS);
+               spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
+
+               if (!target_put_sess_cmd(se_cmd)) {
+                       if (tas)
+                               target_put_sess_cmd(se_cmd);
+               }
+
                wait_for_completion(&se_cmd->cmd_wait_comp);
                pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
                        " fabric state: %d\n", se_cmd, se_cmd->t_state,
@@ -2608,53 +2652,75 @@ void transport_clear_lun_ref(struct se_lun *lun)
        wait_for_completion(&lun->lun_ref_comp);
 }
 
-/**
- * transport_wait_for_tasks - wait for completion to occur
- * @cmd:       command to wait
- *
- * Called from frontend fabric context to wait for storage engine
- * to pause and/or release frontend generated struct se_cmd.
- */
-bool transport_wait_for_tasks(struct se_cmd *cmd)
+static bool
+__transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
+                          bool *aborted, bool *tas, unsigned long *flags)
+       __releases(&cmd->t_state_lock)
+       __acquires(&cmd->t_state_lock)
 {
-       unsigned long flags;
 
-       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       assert_spin_locked(&cmd->t_state_lock);
+       WARN_ON_ONCE(!irqs_disabled());
+
+       if (fabric_stop)
+               cmd->transport_state |= CMD_T_FABRIC_STOP;
+
+       if (cmd->transport_state & CMD_T_ABORTED)
+               *aborted = true;
+
+       if (cmd->transport_state & CMD_T_TAS)
+               *tas = true;
+
        if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
-           !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
-               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+           !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
                return false;
-       }
 
        if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
-           !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
-               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+           !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
                return false;
-       }
 
-       if (!(cmd->transport_state & CMD_T_ACTIVE)) {
-               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+       if (!(cmd->transport_state & CMD_T_ACTIVE))
+               return false;
+
+       if (fabric_stop && *aborted)
                return false;
-       }
 
        cmd->transport_state |= CMD_T_STOP;
 
-       pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d, t_state: %d, CMD_T_STOP\n",
-               cmd, cmd->tag, cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
+       pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
+                " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
+                cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
 
-       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+       spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
 
        wait_for_completion(&cmd->t_transport_stop_comp);
 
-       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       spin_lock_irqsave(&cmd->t_state_lock, *flags);
        cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
 
-       pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->t_transport_stop_comp) for ITT: 0x%08llx\n",
-               cmd->tag);
+       pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
+                "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
+
+       return true;
+}
+
+/**
+ * transport_wait_for_tasks - wait for completion to occur
+ * @cmd:       command to wait
+ *
+ * Called from frontend fabric context to wait for storage engine
+ * to pause and/or release frontend generated struct se_cmd.
+ */
+bool transport_wait_for_tasks(struct se_cmd *cmd)
+{
+       unsigned long flags;
+       bool ret, aborted = false, tas = false;
 
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
-       return true;
+       return ret;
 }
 EXPORT_SYMBOL(transport_wait_for_tasks);
 
@@ -2900,8 +2966,17 @@ static void target_tmr_work(struct work_struct *work)
        struct se_cmd *cmd = container_of(work, struct se_cmd, work);
        struct se_device *dev = cmd->se_dev;
        struct se_tmr_req *tmr = cmd->se_tmr_req;
+       unsigned long flags;
        int ret;
 
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       if (cmd->transport_state & CMD_T_ABORTED) {
+               tmr->response = TMR_FUNCTION_REJECTED;
+               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               goto check_stop;
+       }
+       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
        switch (tmr->function) {
        case TMR_ABORT_TASK:
                core_tmr_abort_task(dev, tmr, cmd->se_sess);
@@ -2934,9 +3009,17 @@ static void target_tmr_work(struct work_struct *work)
                break;
        }
 
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       if (cmd->transport_state & CMD_T_ABORTED) {
+               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               goto check_stop;
+       }
        cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
+       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
        cmd->se_tfo->queue_tm_rsp(cmd);
 
+check_stop:
        transport_cmd_check_stop_to_fabric(cmd);
 }