Imported Upstream version 0.6.5.8

[mirror_spl-debian.git] / module / spl / spl-taskq.c

diff --git a/module/spl/spl-taskq.c b/module/spl/spl-taskq.c
index 7d233c23e40d2425f252165c22ca0d3495ac1986..017b410ac03a6384a7a004b432aef3ff20bc6609 100644 (file)
--- a/module/spl/spl-taskq.c
+++ b/module/spl/spl-taskq.c
@@ -419,8 +419,8 @@ taskq_wait_outstanding_check(taskq_t *tq, taskqid_t id)
 void
 taskq_wait_outstanding(taskq_t *tq, taskqid_t id)
 {
-       wait_event(tq->tq_wait_waitq,
-           taskq_wait_outstanding_check(tq, id ? id : tq->tq_next_id - 1));
+       id = id ? id : tq->tq_next_id - 1;
+       wait_event(tq->tq_wait_waitq, taskq_wait_outstanding_check(tq, id));
 }
 EXPORT_SYMBOL(taskq_wait_outstanding);
 
@@ -738,11 +738,12 @@ taskq_thread_spawn_task(void *arg)
 {
        taskq_t *tq = (taskq_t *)arg;
 
-       (void) taskq_thread_create(tq);
-
-       spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
-       tq->tq_nspawn--;
-       spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
+       if (taskq_thread_create(tq) == NULL) {
+               /* restore spawning count if failed */
+               spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+               tq->tq_nspawn--;
+               spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
+       }
 }
 
 /*
@@ -820,6 +821,14 @@ taskq_thread(void *args)
        flush_signals(current);
 
        spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+       /*
+        * If we are dynamically spawned, decrease spawning count. Note that
+        * we could be created during taskq_create, in which case we shouldn't
+        * do the decrement. But it's fine because taskq_create will reset
+        * tq_nspawn later.
+        */
+       if (tq->tq_flags & TASKQ_DYNAMIC)
+               tq->tq_nspawn--;
 
        /* Immediately exit if more threads than allowed were created. */
        if (tq->tq_nthreads >= tq->tq_maxthreads)
@@ -1020,6 +1029,11 @@ taskq_create(const char *name, int nthreads, pri_t pri,
 
        /* Wait for all threads to be started before potential destroy */
        wait_event(tq->tq_wait_waitq, tq->tq_nthreads == count);
+       /*
+        * taskq_thread might have touched nspawn, but we don't want them to
+        * because they're not dynamically spawned. So we reset it to 0
+        */
+       tq->tq_nspawn = 0;
 
        if (rc) {
                taskq_destroy(tq);
@@ -1052,6 +1066,12 @@ taskq_destroy(taskq_t *tq)
        taskq_wait(tq);
 
        spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+       /* wait for spawning threads to insert themselves to the list */
+       while (tq->tq_nspawn) {
+               spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
+               schedule_timeout_interruptible(1);
+               spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+       }
 
        /*
         * Signal each thread to exit and block until it does.  Each thread