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-rw-r--r--include/sys/taskq.h9
-rw-r--r--module/spl/spl-taskq.c70
2 files changed, 58 insertions, 21 deletions
diff --git a/include/sys/taskq.h b/include/sys/taskq.h
index a43a86da6..5830fe2dd 100644
--- a/include/sys/taskq.h
+++ b/include/sys/taskq.h
@@ -55,6 +55,14 @@
#define TQ_NEW 0x04000000
#define TQ_FRONT 0x08000000
+/* spin_lock(lock) and spin_lock_nested(lock,0) are equivalent,
+ * so TQ_LOCK_DYNAMIC must not evaluate to 0
+ */
+typedef enum tq_lock_role {
+ TQ_LOCK_GENERAL = 0,
+ TQ_LOCK_DYNAMIC = 1,
+} tq_lock_role_t;
+
typedef unsigned long taskqid_t;
typedef void (task_func_t)(void *);
@@ -81,6 +89,7 @@ typedef struct taskq {
struct list_head tq_delay_list; /* delayed task_t's */
wait_queue_head_t tq_work_waitq; /* new work waitq */
wait_queue_head_t tq_wait_waitq; /* wait waitq */
+ tq_lock_role_t tq_lock_class; /* class used when taking tq_lock */
} taskq_t;
typedef struct taskq_ent {
diff --git a/module/spl/spl-taskq.c b/module/spl/spl-taskq.c
index 2c2e3ad46..588dbc8a4 100644
--- a/module/spl/spl-taskq.c
+++ b/module/spl/spl-taskq.c
@@ -113,7 +113,8 @@ retry:
*/
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
schedule_timeout(HZ / 100);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
if (count < 100) {
count++;
goto retry;
@@ -122,7 +123,8 @@ retry:
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
t = kmem_alloc(sizeof(taskq_ent_t), task_km_flags(flags));
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
if (t) {
taskq_init_ent(t);
@@ -188,7 +190,8 @@ task_expire(unsigned long data)
taskq_t *tq = t->tqent_taskq;
struct list_head *l;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
if (t->tqent_flags & TQENT_FLAG_CANCEL) {
ASSERT(list_empty(&t->tqent_list));
@@ -379,7 +382,8 @@ taskq_wait_id_check(taskq_t *tq, taskqid_t id)
int active = 0;
int rc;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
rc = (taskq_find(tq, id, &active) == NULL);
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
@@ -402,7 +406,8 @@ taskq_wait_outstanding_check(taskq_t *tq, taskqid_t id)
{
int rc;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
rc = (id < tq->tq_lowest_id);
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
@@ -429,7 +434,8 @@ taskq_wait_check(taskq_t *tq)
{
int rc;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
rc = (tq->tq_lowest_id == tq->tq_next_id);
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
@@ -474,7 +480,8 @@ taskq_member(taskq_t *tq, void *t)
{
int found;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
found = taskq_member_impl(tq, t);
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
@@ -497,7 +504,8 @@ taskq_cancel_id(taskq_t *tq, taskqid_t id)
ASSERT(tq);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
t = taskq_find(tq, id, &active);
if (t && !active) {
list_del_init(&t->tqent_list);
@@ -519,7 +527,8 @@ taskq_cancel_id(taskq_t *tq, taskqid_t id)
if (timer_pending(&t->tqent_timer)) {
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
del_timer_sync(&t->tqent_timer);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock,
+ tq->tq_lock_flags, tq->tq_lock_class);
}
if (!(t->tqent_flags & TQENT_FLAG_PREALLOC))
@@ -549,7 +558,8 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
ASSERT(tq);
ASSERT(func);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
/* Taskq being destroyed and all tasks drained */
if (!(tq->tq_flags & TASKQ_ACTIVE))
@@ -605,7 +615,8 @@ taskq_dispatch_delay(taskq_t *tq, task_func_t func, void *arg,
ASSERT(tq);
ASSERT(func);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
/* Taskq being destroyed and all tasks drained */
if (!(tq->tq_flags & TASKQ_ACTIVE))
@@ -648,7 +659,8 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
ASSERT(tq);
ASSERT(func);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
/* Taskq being destroyed and all tasks drained */
if (!(tq->tq_flags & TASKQ_ACTIVE)) {
@@ -740,13 +752,14 @@ taskq_thread_spawn_task(void *arg)
(void) taskq_thread_create(tq);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
tq->tq_nspawn--;
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
}
/*
- * Spawn addition threads for dynamic taskqs (TASKQ_DYNMAIC) the current
+ * Spawn addition threads for dynamic taskqs (TASKQ_DYNAMIC) the current
* number of threads is insufficient to handle the pending tasks. These
* new threads must be created by the dedicated dynamic_taskq to avoid
* deadlocks between thread creation and memory reclaim. The system_taskq
@@ -810,6 +823,7 @@ taskq_thread(void *args)
int seq_tasks = 0;
ASSERT(tqt);
+ ASSERT(tqt->tqt_tq);
tq = tqt->tqt_tq;
current->flags |= PF_NOFREEZE;
@@ -821,7 +835,8 @@ taskq_thread(void *args)
sigprocmask(SIG_BLOCK, &blocked, NULL);
flush_signals(current);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
/* Immediately exit if more threads than allowed were created. */
if (tq->tq_nthreads >= tq->tq_maxthreads)
@@ -848,7 +863,8 @@ taskq_thread(void *args)
schedule();
seq_tasks = 0;
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock,
+ tq->tq_lock_flags, tq->tq_lock_class);
remove_wait_queue(&tq->tq_work_waitq, &wait);
} else {
__set_current_state(TASK_RUNNING);
@@ -877,7 +893,8 @@ taskq_thread(void *args)
/* Perform the requested task */
t->tqent_func(t->tqent_arg);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock,
+ tq->tq_lock_flags, tq->tq_lock_class);
tq->tq_nactive--;
list_del_init(&tqt->tqt_active_list);
tqt->tqt_task = NULL;
@@ -999,9 +1016,11 @@ taskq_create(const char *name, int nthreads, pri_t pri,
INIT_LIST_HEAD(&tq->tq_delay_list);
init_waitqueue_head(&tq->tq_work_waitq);
init_waitqueue_head(&tq->tq_wait_waitq);
+ tq->tq_lock_class = TQ_LOCK_GENERAL;
if (flags & TASKQ_PREPOPULATE) {
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
for (i = 0; i < minalloc; i++)
task_done(tq, task_alloc(tq, TQ_PUSHPAGE | TQ_NEW));
@@ -1040,7 +1059,8 @@ taskq_destroy(taskq_t *tq)
taskq_ent_t *t;
ASSERT(tq);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
tq->tq_flags &= ~TASKQ_ACTIVE;
spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
@@ -1053,7 +1073,8 @@ taskq_destroy(taskq_t *tq)
taskq_wait(tq);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
/*
* Signal each thread to exit and block until it does. Each thread
@@ -1069,7 +1090,8 @@ taskq_destroy(taskq_t *tq)
kthread_stop(thread);
- spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+ spin_lock_irqsave_nested(&tq->tq_lock, tq->tq_lock_flags,
+ tq->tq_lock_class);
}
while (!list_empty(&tq->tq_free_list)) {
@@ -1113,6 +1135,12 @@ spl_taskq_init(void)
return (1);
}
+ /* This is used to annotate tq_lock, so
+ * taskq_dispatch -> taskq_thread_spawn -> taskq_dispatch
+ * does not trigger a lockdep warning re: possible recursive locking
+ */
+ dynamic_taskq->tq_lock_class = TQ_LOCK_DYNAMIC;
+
return (0);
}