1 files changed, 44 insertions, 21 deletions

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index a38f36b68060..24f06fba4309 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -64,7 +64,7 @@ struct io_worker {
 
 	union {
 		struct rcu_head rcu;
-		struct work_struct work;
+		struct delayed_work work;
 	};
 };
 
@@ -160,9 +160,9 @@ static inline struct io_wq_acct *io_get_acct(struct io_wq *wq, bool bound)
 }
 
 static inline struct io_wq_acct *io_work_get_acct(struct io_wq *wq,
-						  struct io_wq_work *work)
+						  unsigned int work_flags)
 {
-	return io_get_acct(wq, !(atomic_read(&work->flags) & IO_WQ_WORK_UNBOUND));
+	return io_get_acct(wq, !(work_flags & IO_WQ_WORK_UNBOUND));
 }
 
 static inline struct io_wq_acct *io_wq_get_acct(struct io_worker *worker)
@@ -452,9 +452,14 @@ static void __io_worker_idle(struct io_wq *wq, struct io_worker *worker)
 	}
 }
 
+static inline unsigned int __io_get_work_hash(unsigned int work_flags)
+{
+	return work_flags >> IO_WQ_HASH_SHIFT;
+}
+
 static inline unsigned int io_get_work_hash(struct io_wq_work *work)
 {
-	return atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT;
+	return __io_get_work_hash(atomic_read(&work->flags));
 }
 
 static bool io_wait_on_hash(struct io_wq *wq, unsigned int hash)
@@ -484,17 +489,19 @@ static struct io_wq_work *io_get_next_work(struct io_wq_acct *acct,
 	struct io_wq *wq = worker->wq;
 
 	wq_list_for_each(node, prev, &acct->work_list) {
+		unsigned int work_flags;
 		unsigned int hash;
 
 		work = container_of(node, struct io_wq_work, list);
 
 		/* not hashed, can run anytime */
-		if (!io_wq_is_hashed(work)) {
+		work_flags = atomic_read(&work->flags);
+		if (!__io_wq_is_hashed(work_flags)) {
 			wq_list_del(&acct->work_list, node, prev);
 			return work;
 		}
 
-		hash = io_get_work_hash(work);
+		hash = __io_get_work_hash(work_flags);
 		/* all items with this hash lie in [work, tail] */
 		tail = wq->hash_tail[hash];
 
@@ -591,12 +598,15 @@ static void io_worker_handle_work(struct io_wq_acct *acct,
 		/* handle a whole dependent link */
 		do {
 			struct io_wq_work *next_hashed, *linked;
-			unsigned int hash = io_get_work_hash(work);
+			unsigned int work_flags = atomic_read(&work->flags);
+			unsigned int hash = __io_wq_is_hashed(work_flags)
+				? __io_get_work_hash(work_flags)
+				: -1U;
 
 			next_hashed = wq_next_work(work);
 
 			if (do_kill &&
-			    (atomic_read(&work->flags) & IO_WQ_WORK_UNBOUND))
+			    (work_flags & IO_WQ_WORK_UNBOUND))
 				atomic_or(IO_WQ_WORK_CANCEL, &work->flags);
 			wq->do_work(work);
 			io_assign_current_work(worker, NULL);
@@ -634,7 +644,7 @@ static int io_wq_worker(void *data)
 	struct io_wq_acct *acct = io_wq_get_acct(worker);
 	struct io_wq *wq = worker->wq;
 	bool exit_mask = false, last_timeout = false;
-	char buf[TASK_COMM_LEN];
+	char buf[TASK_COMM_LEN] = {};
 
 	set_mask_bits(&worker->flags, 0,
 		      BIT(IO_WORKER_F_UP) | BIT(IO_WORKER_F_RUNNING));
@@ -770,6 +780,18 @@ static inline bool io_should_retry_thread(struct io_worker *worker, long err)
 	}
 }
 
+static void queue_create_worker_retry(struct io_worker *worker)
+{
+	/*
+	 * We only bother retrying because there's a chance that the
+	 * failure to create a worker is due to some temporary condition
+	 * in the forking task (e.g. outstanding signal); give the task
+	 * some time to clear that condition.
+	 */
+	schedule_delayed_work(&worker->work,
+			      msecs_to_jiffies(worker->init_retries * 5));
+}
+
 static void create_worker_cont(struct callback_head *cb)
 {
 	struct io_worker *worker;
@@ -809,12 +831,13 @@ static void create_worker_cont(struct callback_head *cb)
 
 	/* re-create attempts grab a new worker ref, drop the existing one */
 	io_worker_release(worker);
-	schedule_work(&worker->work);
+	queue_create_worker_retry(worker);
 }
 
 static void io_workqueue_create(struct work_struct *work)
 {
-	struct io_worker *worker = container_of(work, struct io_worker, work);
+	struct io_worker *worker = container_of(work, struct io_worker,
+						work.work);
 	struct io_wq_acct *acct = io_wq_get_acct(worker);
 
 	if (!io_queue_worker_create(worker, acct, create_worker_cont))
@@ -855,8 +878,8 @@ fail:
 		kfree(worker);
 		goto fail;
 	} else {
-		INIT_WORK(&worker->work, io_workqueue_create);
-		schedule_work(&worker->work);
+		INIT_DELAYED_WORK(&worker->work, io_workqueue_create);
+		queue_create_worker_retry(worker);
 	}
 
 	return true;
@@ -903,19 +926,19 @@ static void io_run_cancel(struct io_wq_work *work, struct io_wq *wq)
 	} while (work);
 }
 
-static void io_wq_insert_work(struct io_wq *wq, struct io_wq_work *work)
+static void io_wq_insert_work(struct io_wq *wq, struct io_wq_acct *acct,
+			      struct io_wq_work *work, unsigned int work_flags)
 {
-	struct io_wq_acct *acct = io_work_get_acct(wq, work);
 	unsigned int hash;
 	struct io_wq_work *tail;
 
-	if (!io_wq_is_hashed(work)) {
+	if (!__io_wq_is_hashed(work_flags)) {
 append:
 		wq_list_add_tail(&work->list, &acct->work_list);
 		return;
 	}
 
-	hash = io_get_work_hash(work);
+	hash = __io_get_work_hash(work_flags);
 	tail = wq->hash_tail[hash];
 	wq->hash_tail[hash] = work;
 	if (!tail)
@@ -931,8 +954,8 @@ static bool io_wq_work_match_item(struct io_wq_work *work, void *data)
 
 void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
 {
-	struct io_wq_acct *acct = io_work_get_acct(wq, work);
 	unsigned int work_flags = atomic_read(&work->flags);
+	struct io_wq_acct *acct = io_work_get_acct(wq, work_flags);
 	struct io_cb_cancel_data match = {
 		.fn		= io_wq_work_match_item,
 		.data		= work,
@@ -951,7 +974,7 @@ void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
 	}
 
 	raw_spin_lock(&acct->lock);
-	io_wq_insert_work(wq, work);
+	io_wq_insert_work(wq, acct, work, work_flags);
 	clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
 	raw_spin_unlock(&acct->lock);
 
@@ -1021,10 +1044,10 @@ static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
 }
 
 static inline void io_wq_remove_pending(struct io_wq *wq,
+					struct io_wq_acct *acct,
 					 struct io_wq_work *work,
 					 struct io_wq_work_node *prev)
 {
-	struct io_wq_acct *acct = io_work_get_acct(wq, work);
 	unsigned int hash = io_get_work_hash(work);
 	struct io_wq_work *prev_work = NULL;
 
@@ -1051,7 +1074,7 @@ static bool io_acct_cancel_pending_work(struct io_wq *wq,
 		work = container_of(node, struct io_wq_work, list);
 		if (!match->fn(work, match->data))
 			continue;
-		io_wq_remove_pending(wq, work, prev);
+		io_wq_remove_pending(wq, acct, work, prev);
 		raw_spin_unlock(&acct->lock);
 		io_run_cancel(work, wq);
 		match->nr_pending++;