2 files changed, 69 insertions, 34 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index b1a3cdb29468..a0cd56ee5fe9 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -64,8 +64,9 @@ struct kmem_cache *t10_alua_lba_map_cache;
 struct kmem_cache *t10_alua_lba_map_mem_cache;
 
 static void transport_complete_task_attr(struct se_cmd *cmd);
+static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
 static void transport_handle_queue_full(struct se_cmd *cmd,
-                struct se_device *dev);
+                struct se_device *dev, int err, bool write_pending);
 static int transport_put_cmd(struct se_cmd *cmd);
 static void target_complete_ok_work(struct work_struct *work);
 
@@ -804,7 +805,8 @@ void target_qf_do_work(struct work_struct *work)
 
                 if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
                         transport_write_pending_qf(cmd);
-                else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
+                else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
+                         cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
                         transport_complete_qf(cmd);
         }
 }
@@ -1719,7 +1721,7 @@ void transport_generic_request_failure(struct se_cmd *cmd,
                 }
                 trace_target_cmd_complete(cmd);
                 ret = cmd->se_tfo->queue_status(cmd);
-                if (ret == -EAGAIN || ret == -ENOMEM)
+                if (ret)
                         goto queue_full;
                 goto check_stop;
         default:
@@ -1730,7 +1732,7 @@ void transport_generic_request_failure(struct se_cmd *cmd,
         }
 
         ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
-        if (ret == -EAGAIN || ret == -ENOMEM)
+        if (ret)
                 goto queue_full;
 
 check_stop:
@@ -1739,8 +1741,7 @@ check_stop:
         return;
 
 queue_full:
-        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
-        transport_handle_queue_full(cmd, cmd->se_dev);
+        transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
 }
 EXPORT_SYMBOL(transport_generic_request_failure);
 
@@ -1977,13 +1978,29 @@ static void transport_complete_qf(struct se_cmd *cmd)
         int ret = 0;
 
         transport_complete_task_attr(cmd);
+        /*
+         * If a fabric driver ->write_pending() or ->queue_data_in() callback
+         * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
+         * the same callbacks should not be retried.  Return CHECK_CONDITION
+         * if a scsi_status is not already set.
+         *
+         * If a fabric driver ->queue_status() has returned non zero, always
+         * keep retrying no matter what..
+         */
+        if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
+                if (cmd->scsi_status)
+                        goto queue_status;
 
-        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
-                trace_target_cmd_complete(cmd);
-                ret = cmd->se_tfo->queue_status(cmd);
-                goto out;
+                cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
+                cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
+                cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
+                translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
+                goto queue_status;
         }
 
+        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
+                goto queue_status;
+
         switch (cmd->data_direction) {
         case DMA_FROM_DEVICE:
                 if (cmd->scsi_status)
@@ -2007,19 +2024,33 @@ queue_status:
                 break;
         }
 
-out:
         if (ret < 0) {
-                transport_handle_queue_full(cmd, cmd->se_dev);
+                transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
                 return;
         }
         transport_lun_remove_cmd(cmd);
         transport_cmd_check_stop_to_fabric(cmd);
 }
 
-static void transport_handle_queue_full(
-        struct se_cmd *cmd,
-        struct se_device *dev)
+static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
+                                        int err, bool write_pending)
 {
+        /*
+         * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
+         * ->queue_data_in() callbacks from new process context.
+         *
+         * Otherwise for other errors, transport_complete_qf() will send
+         * CHECK_CONDITION via ->queue_status() instead of attempting to
+         * retry associated fabric driver data-transfer callbacks.
+         */
+        if (err == -EAGAIN || err == -ENOMEM) {
+                cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
+                                                 TRANSPORT_COMPLETE_QF_OK;
+        } else {
+                pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
+                cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
+        }
+
         spin_lock_irq(&dev->qf_cmd_lock);
         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
         atomic_inc_mb(&dev->dev_qf_count);
@@ -2083,7 +2114,7 @@ static void target_complete_ok_work(struct work_struct *work)
                 WARN_ON(!cmd->scsi_status);
                 ret = transport_send_check_condition_and_sense(
                                         cmd, 0, 1);
-                if (ret == -EAGAIN || ret == -ENOMEM)
+                if (ret)
                         goto queue_full;
 
                 transport_lun_remove_cmd(cmd);
@@ -2109,7 +2140,7 @@ static void target_complete_ok_work(struct work_struct *work)
                 } else if (rc) {
                         ret = transport_send_check_condition_and_sense(cmd,
                                                 rc, 0);
-                        if (ret == -EAGAIN || ret == -ENOMEM)
+                        if (ret)
                                 goto queue_full;
 
                         transport_lun_remove_cmd(cmd);
@@ -2134,7 +2165,7 @@ queue_rsp:
                 if (target_read_prot_action(cmd)) {
                         ret = transport_send_check_condition_and_sense(cmd,
                                                 cmd->pi_err, 0);
-                        if (ret == -EAGAIN || ret == -ENOMEM)
+                        if (ret)
                                 goto queue_full;
 
                         transport_lun_remove_cmd(cmd);
@@ -2144,7 +2175,7 @@ queue_rsp:
 
                 trace_target_cmd_complete(cmd);
                 ret = cmd->se_tfo->queue_data_in(cmd);
-                if (ret == -EAGAIN || ret == -ENOMEM)
+                if (ret)
                         goto queue_full;
                 break;
         case DMA_TO_DEVICE:
@@ -2157,7 +2188,7 @@ queue_rsp:
                         atomic_long_add(cmd->data_length,
                                         &cmd->se_lun->lun_stats.tx_data_octets);
                         ret = cmd->se_tfo->queue_data_in(cmd);
-                        if (ret == -EAGAIN || ret == -ENOMEM)
+                        if (ret)
                                 goto queue_full;
                         break;
                 }
@@ -2166,7 +2197,7 @@ queue_rsp:
 queue_status:
                 trace_target_cmd_complete(cmd);
                 ret = cmd->se_tfo->queue_status(cmd);
-                if (ret == -EAGAIN || ret == -ENOMEM)
+                if (ret)
                         goto queue_full;
                 break;
         default:
@@ -2180,8 +2211,8 @@ queue_status:
 queue_full:
         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
                 " data_direction: %d\n", cmd, cmd->data_direction);
-        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
-        transport_handle_queue_full(cmd, cmd->se_dev);
+
+        transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
 }
 
 void target_free_sgl(struct scatterlist *sgl, int nents)
@@ -2449,18 +2480,14 @@ transport_generic_new_cmd(struct se_cmd *cmd)
         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
         ret = cmd->se_tfo->write_pending(cmd);
-        if (ret == -EAGAIN || ret == -ENOMEM)
+        if (ret)
                 goto queue_full;
 
-        /* fabric drivers should only return -EAGAIN or -ENOMEM as error */
-        WARN_ON(ret);
-
-        return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+        return 0;
 
 queue_full:
         pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
-        cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
-        transport_handle_queue_full(cmd, cmd->se_dev);
+        transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
         return 0;
 }
 EXPORT_SYMBOL(transport_generic_new_cmd);
@@ -2470,10 +2497,10 @@ static void transport_write_pending_qf(struct se_cmd *cmd)
         int ret;
 
         ret = cmd->se_tfo->write_pending(cmd);
-        if (ret == -EAGAIN || ret == -ENOMEM) {
+        if (ret) {
                 pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
                          cmd);
-                transport_handle_queue_full(cmd, cmd->se_dev);
+                transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
         }
 }
 
@@ -3011,6 +3038,8 @@ static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
         __releases(&cmd->t_state_lock)
         __acquires(&cmd->t_state_lock)
 {
+        int ret;
+
         assert_spin_locked(&cmd->t_state_lock);
         WARN_ON_ONCE(!irqs_disabled());
 
@@ -3034,7 +3063,9 @@ static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
         trace_target_cmd_complete(cmd);
 
         spin_unlock_irq(&cmd->t_state_lock);
-        cmd->se_tfo->queue_status(cmd);
+        ret = cmd->se_tfo->queue_status(cmd);
+        if (ret)
+                transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
         spin_lock_irq(&cmd->t_state_lock);
 
         return 1;
@@ -3055,6 +3086,7 @@ EXPORT_SYMBOL(transport_check_aborted_status);
 void transport_send_task_abort(struct se_cmd *cmd)
 {
         unsigned long flags;
+        int ret;
 
         spin_lock_irqsave(&cmd->t_state_lock, flags);
         if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
@@ -3090,7 +3122,9 @@ send_abort:
                  cmd->t_task_cdb[0], cmd->tag);
 
         trace_target_cmd_complete(cmd);
-        cmd->se_tfo->queue_status(cmd);
+        ret = cmd->se_tfo->queue_status(cmd);
+        if (ret)
+                transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
 }
 
 static void target_tmr_work(struct work_struct *work)
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 2e282461cfa5..730ed3055336 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -117,6 +117,7 @@ enum transport_state_table {
         TRANSPORT_ISTATE_PROCESSING = 11,
         TRANSPORT_COMPLETE_QF_WP = 18,
         TRANSPORT_COMPLETE_QF_OK = 19,
+        TRANSPORT_COMPLETE_QF_ERR = 20,
 };
 
 /* Used for struct se_cmd->se_cmd_flags */