target: remove the transport_qf_callback se_cmd callback

Remove the need for the transport_qf_callback callback by making
sure we have specific states with specific handlers for the two
queue full cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 37 insertions, 44 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index cb022a1b22b3..4ce205040b15 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -72,9 +72,8 @@ static int transport_generic_write_pending(struct se_cmd *);
 static int transport_processing_thread(void *param);
 static int __transport_execute_tasks(struct se_device *dev);
 static void transport_complete_task_attr(struct se_cmd *cmd);
-static int transport_complete_qf(struct se_cmd *cmd);
 static void transport_handle_queue_full(struct se_cmd *cmd,
-                struct se_device *dev, int (*qf_callback)(struct se_cmd *));
+                struct se_device *dev);
 static void transport_direct_request_timeout(struct se_cmd *cmd);
 static void transport_free_dev_tasks(struct se_cmd *cmd);
 static u32 transport_allocate_tasks(struct se_cmd *cmd,
@@ -969,7 +968,7 @@ static void target_qf_do_work(struct work_struct *work)
 
                 pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
                         " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
-                        (cmd->t_state == TRANSPORT_COMPLETE_OK) ? "COMPLETE_OK" :
+                        (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
                         (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
                         : "UNKNOWN");
                 /*
@@ -1968,8 +1967,8 @@ check_stop:
         return;
 
 queue_full:
-        cmd->t_state = TRANSPORT_COMPLETE_OK;
-        transport_handle_queue_full(cmd, cmd->se_dev, transport_complete_qf);
+        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
+        transport_handle_queue_full(cmd, cmd->se_dev);
 }
 
 static void transport_direct_request_timeout(struct se_cmd *cmd)
@@ -3431,12 +3430,19 @@ static void transport_complete_task_attr(struct se_cmd *cmd)
                 wake_up_interruptible(&dev->dev_queue_obj.thread_wq);
 }
 
-static int transport_complete_qf(struct se_cmd *cmd)
+static void transport_complete_qf(struct se_cmd *cmd)
 {
         int ret = 0;
 
-        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
-                return cmd->se_tfo->queue_status(cmd);
+        transport_stop_all_task_timers(cmd);
+        if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
+                transport_complete_task_attr(cmd);
+
+        if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
+                ret = cmd->se_tfo->queue_status(cmd);
+                if (ret)
+                        goto out;
+        }
 
         switch (cmd->data_direction) {
         case DMA_FROM_DEVICE:
@@ -3446,7 +3452,7 @@ static int transport_complete_qf(struct se_cmd *cmd)
                 if (cmd->t_bidi_data_sg) {
                         ret = cmd->se_tfo->queue_data_in(cmd);
                         if (ret < 0)
-                                return ret;
+                                break;
                 }
                 /* Fall through for DMA_TO_DEVICE */
         case DMA_NONE:
@@ -3456,17 +3462,21 @@ static int transport_complete_qf(struct se_cmd *cmd)
                 break;
         }
 
-        return ret;
+out:
+        if (ret < 0) {
+                transport_handle_queue_full(cmd, cmd->se_dev);
+                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,
-        int (*qf_callback)(struct se_cmd *))
+        struct se_device *dev)
 {
         spin_lock_irq(&dev->qf_cmd_lock);
         cmd->se_cmd_flags |= SCF_EMULATE_QUEUE_FULL;
-        cmd->transport_qf_callback = qf_callback;
         list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
         atomic_inc(&dev->dev_qf_count);
         smp_mb__after_atomic_inc();
@@ -3492,14 +3502,6 @@ static void transport_generic_complete_ok(struct se_cmd *cmd)
         if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
                 schedule_work(&cmd->se_dev->qf_work_queue);
 
-        if (cmd->transport_qf_callback) {
-                ret = cmd->transport_qf_callback(cmd);
-                if (ret < 0)
-                        goto queue_full;
-
-                cmd->transport_qf_callback = NULL;
-                goto done;
-        }
         /*
          * Check if we need to retrieve a sense buffer from
          * the struct se_cmd in question.
@@ -3575,7 +3577,6 @@ static void transport_generic_complete_ok(struct se_cmd *cmd)
                 break;
         }
 
-done:
         transport_lun_remove_cmd(cmd);
         transport_cmd_check_stop_to_fabric(cmd);
         return;
@@ -3583,7 +3584,8 @@ done:
 queue_full:
         pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
                 " data_direction: %d\n", cmd, cmd->data_direction);
-        transport_handle_queue_full(cmd, cmd->se_dev, transport_complete_qf);
+        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
+        transport_handle_queue_full(cmd, cmd->se_dev);
 }
 
 static void transport_free_dev_tasks(struct se_cmd *cmd)
@@ -4110,15 +4112,15 @@ void transport_generic_process_write(struct se_cmd *cmd)
 }
 EXPORT_SYMBOL(transport_generic_process_write);
 
-static int transport_write_pending_qf(struct se_cmd *cmd)
+static void transport_write_pending_qf(struct se_cmd *cmd)
 {
-        return cmd->se_tfo->write_pending(cmd);
+        if (cmd->se_tfo->write_pending(cmd) == -EAGAIN) {
+                pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
+                         cmd);
+                transport_handle_queue_full(cmd, cmd->se_dev);
+        }
 }
 
-/*      transport_generic_write_pending():
- *
- *
- */
 static int transport_generic_write_pending(struct se_cmd *cmd)
 {
         unsigned long flags;
@@ -4128,17 +4130,6 @@ static int transport_generic_write_pending(struct se_cmd *cmd)
         cmd->t_state = TRANSPORT_WRITE_PENDING;
         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
-        if (cmd->transport_qf_callback) {
-                ret = cmd->transport_qf_callback(cmd);
-                if (ret == -EAGAIN)
-                        goto queue_full;
-                else if (ret < 0)
-                        return ret;
-
-                cmd->transport_qf_callback = NULL;
-                return 0;
-        }
-
         /*
          * Clear the se_cmd for WRITE_PENDING status in order to set
          * cmd->t_transport_active=0 so that transport_generic_handle_data
@@ -4163,8 +4154,7 @@ static int transport_generic_write_pending(struct se_cmd *cmd)
 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_write_pending_qf);
+        transport_handle_queue_full(cmd, cmd->se_dev);
         return ret;
 }
 
@@ -4851,7 +4841,10 @@ get_cmd:
                         transport_generic_request_timeout(cmd);
                         break;
                 case TRANSPORT_COMPLETE_QF_WP:
-                        transport_generic_write_pending(cmd);
+                        transport_write_pending_qf(cmd);
+                        break;
+                case TRANSPORT_COMPLETE_QF_OK:
+                        transport_complete_qf(cmd);
                         break;
                 default:
                         pr_err("Unknown t_state: %d deferred_t_state:"
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 16d7a4985639..2d47aa9f762a 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -102,6 +102,7 @@ enum transport_state_table {
         TRANSPORT_NEW_CMD_MAP   = 16,
         TRANSPORT_FREE_CMD_INTR = 17,
         TRANSPORT_COMPLETE_QF_WP = 18,
+        TRANSPORT_COMPLETE_QF_OK = 19,
 };
 
 /* Used for struct se_cmd->se_cmd_flags */
@@ -471,7 +472,6 @@ struct se_cmd {
         struct target_core_fabric_ops *se_tfo;
         int (*transport_emulate_cdb)(struct se_cmd *);
         void (*transport_complete_callback)(struct se_cmd *);
-        int (*transport_qf_callback)(struct se_cmd *);
 
         unsigned char           *t_task_cdb;
         unsigned char           __t_task_cdb[TCM_MAX_COMMAND_SIZE];