target: make more use of the task_flags field in se_task
Christoph Hellwig [Wed, 12 Oct 2011 15:07:03 +0000 (11:07 -0400)]
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>

drivers/target/target_core_tmr.c
drivers/target/target_core_transport.c
include/target/target_core_base.h

index b8dc10f..b5c1864 100644 (file)
@@ -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);
 
index c935c72..165a60c 100644 (file)
@@ -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);
index 6c49db4..5e3dd14 100644 (file)
@@ -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;