target: make more use of the task_flags field in se_task

Replace various atomic_t variables that were mostly under t_state_lock
with new flags in task_flags.  Note that the execution error path
didn't take t_state_lock before, so add it there.

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

3 files changed, 43 insertions, 44 deletions

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index b8dc10fd4ef..b5c18648fa2 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -259,8 +259,8 @@ static void core_tmr_drain_task_list(
                         atomic_read(&cmd->t_transport_stop),
                         atomic_read(&cmd->t_transport_sent));
 
-                if (atomic_read(&task->task_active)) {
-                        atomic_set(&task->task_stop, 1);
+                if (task->task_flags & TF_ACTIVE) {
+                        task->task_flags |= TF_REQUEST_STOP;
                         spin_unlock_irqrestore(
                                 &cmd->t_state_lock, flags);
 
@@ -269,11 +269,10 @@ static void core_tmr_drain_task_list(
                         wait_for_completion(&task->task_stop_comp);
                         pr_debug("LUN_RESET Completed task: %p shutdown for"
                                 " dev: %p\n", task, dev);
+
                         spin_lock_irqsave(&cmd->t_state_lock, flags);
                         atomic_dec(&cmd->t_task_cdbs_left);
-
-                        atomic_set(&task->task_active, 0);
-                        atomic_set(&task->task_stop, 0);
+                        task->task_flags &= ~(TF_ACTIVE | TF_REQUEST_STOP);
                 }
                 __transport_stop_task_timer(task, &flags);
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index c935c72da7b..165a60c875a 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -440,7 +440,7 @@ static void transport_all_task_dev_remove_state(struct se_cmd *cmd)
                 return;
 
         list_for_each_entry(task, &cmd->t_task_list, t_list) {
-                if (atomic_read(&task->task_active))
+                if (task->task_flags & TF_ACTIVE)
                         continue;
 
                 if (!atomic_read(&task->task_state_active))
@@ -718,7 +718,7 @@ void transport_complete_task(struct se_task *task, int success)
                 atomic_inc(&dev->depth_left);
 
         spin_lock_irqsave(&cmd->t_state_lock, flags);
-        atomic_set(&task->task_active, 0);
+        task->task_flags &= ~TF_ACTIVE;
 
         /*
          * See if any sense data exists, if so set the TASK_SENSE flag.
@@ -737,14 +737,14 @@ void transport_complete_task(struct se_task *task, int success)
          * See if we are waiting for outstanding struct se_task
          * to complete for an exception condition
          */
-        if (atomic_read(&task->task_stop)) {
+        if (task->task_flags & TF_REQUEST_STOP) {
                 /*
                  * Decrement cmd->t_se_count if this task had
                  * previously thrown its timeout exception handler.
                  */
-                if (atomic_read(&task->task_timeout)) {
+                if (task->task_flags & TF_TIMEOUT) {
                         atomic_dec(&cmd->t_se_count);
-                        atomic_set(&task->task_timeout, 0);
+                        task->task_flags &= ~TF_TIMEOUT;
                 }
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
@@ -756,7 +756,7 @@ void transport_complete_task(struct se_task *task, int success)
          * left counter to determine when the struct se_cmd is ready to be queued to
          * the processing thread.
          */
-        if (atomic_read(&task->task_timeout)) {
+        if (task->task_flags & TF_TIMEOUT) {
                 if (!atomic_dec_and_test(
                                 &cmd->t_task_cdbs_timeout_left)) {
                         spin_unlock_irqrestore(&cmd->t_state_lock,
@@ -1793,8 +1793,7 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd)
                  * If the struct se_task has not been sent and is not active,
                  * remove the struct se_task from the execution queue.
                  */
-                if (!atomic_read(&task->task_sent) &&
-                    !atomic_read(&task->task_active)) {
+                if (!(task->task_flags & (TF_ACTIVE | TF_SENT))) {
                         spin_unlock_irqrestore(&cmd->t_state_lock,
                                         flags);
                         transport_remove_task_from_execute_queue(task,
@@ -1810,8 +1809,8 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd)
                  * If the struct se_task is active, sleep until it is returned
                  * from the plugin.
                  */
-                if (atomic_read(&task->task_active)) {
-                        atomic_set(&task->task_stop, 1);
+                if (task->task_flags & TF_ACTIVE) {
+                        task->task_flags |= TF_REQUEST_STOP;
                         spin_unlock_irqrestore(&cmd->t_state_lock,
                                         flags);
 
@@ -1823,9 +1822,7 @@ static int transport_stop_tasks_for_cmd(struct se_cmd *cmd)
 
                         spin_lock_irqsave(&cmd->t_state_lock, flags);
                         atomic_dec(&cmd->t_task_cdbs_left);
-
-                        atomic_set(&task->task_active, 0);
-                        atomic_set(&task->task_stop, 0);
+                        task->task_flags &= ~(TF_ACTIVE | TF_REQUEST_STOP);
                 } else {
                         pr_debug("task_no[%d] - Did nothing\n", task->task_no);
                         ret++;
@@ -2074,18 +2071,18 @@ static void transport_task_timeout_handler(unsigned long data)
         pr_debug("transport task timeout fired! task: %p cmd: %p\n", task, cmd);
 
         spin_lock_irqsave(&cmd->t_state_lock, flags);
-        if (task->task_flags & TF_STOP) {
+        if (task->task_flags & TF_TIMER_STOP) {
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                 return;
         }
-        task->task_flags &= ~TF_RUNNING;
+        task->task_flags &= ~TF_TIMER_RUNNING;
 
         /*
          * Determine if transport_complete_task() has already been called.
          */
-        if (!atomic_read(&task->task_active)) {
-                pr_debug("transport task: %p cmd: %p timeout task_active"
-                                " == 0\n", task, cmd);
+        if (!(task->task_flags & TF_ACTIVE)) {
+                pr_debug("transport task: %p cmd: %p timeout !TF_ACTIVE\n",
+                         task, cmd);
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                 return;
         }
@@ -2094,12 +2091,12 @@ static void transport_task_timeout_handler(unsigned long data)
         atomic_inc(&cmd->t_transport_timeout);
         cmd->t_tasks_failed = 1;
 
-        atomic_set(&task->task_timeout, 1);
+        task->task_flags |= TF_TIMEOUT;
         task->task_error_status = PYX_TRANSPORT_TASK_TIMEOUT;
         task->task_scsi_status = 1;
 
-        if (atomic_read(&task->task_stop)) {
-                pr_debug("transport task: %p cmd: %p timeout task_stop"
+        if (task->task_flags & TF_REQUEST_STOP) {
+                pr_debug("transport task: %p cmd: %p timeout TF_REQUEST_STOP"
                                 " == 1\n", task, cmd);
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                 complete(&task->task_stop_comp);
@@ -2129,7 +2126,7 @@ static void transport_start_task_timer(struct se_task *task)
         struct se_device *dev = task->task_se_cmd->se_dev;
         int timeout;
 
-        if (task->task_flags & TF_RUNNING)
+        if (task->task_flags & TF_TIMER_RUNNING)
                 return;
         /*
          * If the task_timeout is disabled, exit now.
@@ -2143,7 +2140,7 @@ static void transport_start_task_timer(struct se_task *task)
         task->task_timer.data = (unsigned long) task;
         task->task_timer.function = transport_task_timeout_handler;
 
-        task->task_flags |= TF_RUNNING;
+        task->task_flags |= TF_TIMER_RUNNING;
         add_timer(&task->task_timer);
 #if 0
         pr_debug("Starting task timer for cmd: %p task: %p seconds:"
@@ -2158,17 +2155,17 @@ void __transport_stop_task_timer(struct se_task *task, unsigned long *flags)
 {
         struct se_cmd *cmd = task->task_se_cmd;
 
-        if (!task->task_flags & TF_RUNNING)
+        if (!(task->task_flags & TF_TIMER_RUNNING))
                 return;
 
-        task->task_flags |= TF_STOP;
+        task->task_flags |= TF_TIMER_STOP;
         spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
 
         del_timer_sync(&task->task_timer);
 
         spin_lock_irqsave(&cmd->t_state_lock, *flags);
-        task->task_flags &= ~TF_RUNNING;
-        task->task_flags &= ~TF_STOP;
+        task->task_flags &= ~TF_TIMER_RUNNING;
+        task->task_flags &= ~TF_TIMER_STOP;
 }
 
 static void transport_stop_all_task_timers(struct se_cmd *cmd)
@@ -2360,8 +2357,7 @@ check_depth:
         cmd = task->task_se_cmd;
 
         spin_lock_irqsave(&cmd->t_state_lock, flags);
-        atomic_set(&task->task_active, 1);
-        atomic_set(&task->task_sent, 1);
+        task->task_flags |= (TF_ACTIVE | TF_SENT);
         atomic_inc(&cmd->t_task_cdbs_sent);
 
         if (atomic_read(&cmd->t_task_cdbs_sent) ==
@@ -2379,7 +2375,9 @@ check_depth:
                 error = cmd->transport_emulate_cdb(cmd);
                 if (error != 0) {
                         cmd->transport_error_status = error;
-                        atomic_set(&task->task_active, 0);
+                        spin_lock_irqsave(&cmd->t_state_lock, flags);
+                        task->task_flags &= ~TF_ACTIVE;
+                        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                         atomic_set(&cmd->transport_sent, 0);
                         transport_stop_tasks_for_cmd(cmd);
                         transport_generic_request_failure(cmd, dev, 0, 1);
@@ -2415,7 +2413,9 @@ check_depth:
 
                 if (error != 0) {
                         cmd->transport_error_status = error;
-                        atomic_set(&task->task_active, 0);
+                        spin_lock_irqsave(&cmd->t_state_lock, flags);
+                        task->task_flags &= ~TF_ACTIVE;
+                        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                         atomic_set(&cmd->transport_sent, 0);
                         transport_stop_tasks_for_cmd(cmd);
                         transport_generic_request_failure(cmd, dev, 0, 1);
@@ -3613,7 +3613,7 @@ static void transport_free_dev_tasks(struct se_cmd *cmd)
         spin_lock_irqsave(&cmd->t_state_lock, flags);
         list_for_each_entry_safe(task, task_tmp,
                                 &cmd->t_task_list, t_list) {
-                if (atomic_read(&task->task_active))
+                if (task->task_flags & TF_ACTIVE)
                         continue;
 
                 kfree(task->task_sg_bidi);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 6c49db40320..5e3dd1418ba 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -72,9 +72,13 @@ enum transport_tpg_type_table {
 };
 
 /* Used for generate timer flags */
-enum timer_flags_table {
-        TF_RUNNING      = 0x01,
-        TF_STOP         = 0x02,
+enum se_task_flags {
+        TF_ACTIVE               = (1 << 0),
+        TF_SENT                 = (1 << 1),
+        TF_TIMEOUT              = (1 << 2),
+        TF_REQUEST_STOP         = (1 << 3),
+        TF_TIMER_RUNNING        = (1 << 4),
+        TF_TIMER_STOP           = (1 << 5),
 };
 
 /* Special transport agnostic struct se_cmd->t_states */
@@ -413,11 +417,7 @@ struct se_task {
         enum dma_data_direction task_data_direction;
         struct se_cmd *task_se_cmd;
         struct completion       task_stop_comp;
-        atomic_t        task_active;
         atomic_t        task_execute_queue;
-        atomic_t        task_timeout;
-        atomic_t        task_sent;
-        atomic_t        task_stop;
         atomic_t        task_state_active;
         struct timer_list       task_timer;
         struct list_head t_list;