---

yaml
---
r: 320913
b: refs/heads/master
c: a06e05e
h: refs/heads/master
i:
  320911: 26464ef
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 86072d8112595ea1b6beeb33f578e7c2839e014e
+refs/heads/master: a06e05e6afab70b4b23c0a7975aaeae24b195cd6

trunk/block/blk-core.c

@@ -837,7 +837,7 @@ static struct io_context *rq_ioc(struct bio *bio)
 }
 
 /**
- * get_request - get a free request
+ * __get_request - get a free request
  * @q: request_queue to allocate request from
  * @rw_flags: RW and SYNC flags
  * @bio: bio to allocate request for (can be %NULL)
@@ -850,8 +850,8 @@ static struct io_context *rq_ioc(struct bio *bio)
  * Returns %NULL on failure, with @q->queue_lock held.
  * Returns !%NULL on success, with @q->queue_lock *not held*.
  */
-static struct request *get_request(struct request_queue *q, int rw_flags,
-				   struct bio *bio, gfp_t gfp_mask)
+static struct request *__get_request(struct request_queue *q, int rw_flags,
+				     struct bio *bio, gfp_t gfp_mask)
 {
 	struct request *rq;
 	struct request_list *rl = &q->rq;
@@ -1029,56 +1029,55 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 }
 
 /**
- * get_request_wait - get a free request with retry
+ * get_request - get a free request
  * @q: request_queue to allocate request from
  * @rw_flags: RW and SYNC flags
  * @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
  *
- * Get a free request from @q.  This function keeps retrying under memory
- * pressure and fails iff @q is dead.
+ * Get a free request from @q.  If %__GFP_WAIT is set in @gfp_mask, this
+ * function keeps retrying under memory pressure and fails iff @q is dead.
  *
  * Must be callled with @q->queue_lock held and,
  * Returns %NULL on failure, with @q->queue_lock held.
  * Returns !%NULL on success, with @q->queue_lock *not held*.
  */
-static struct request *get_request_wait(struct request_queue *q, int rw_flags,
-					struct bio *bio)
+static struct request *get_request(struct request_queue *q, int rw_flags,
+				   struct bio *bio, gfp_t gfp_mask)
 {
 	const bool is_sync = rw_is_sync(rw_flags) != 0;
+	DEFINE_WAIT(wait);
+	struct request_list *rl = &q->rq;
 	struct request *rq;
+retry:
+	rq = __get_request(q, rw_flags, bio, gfp_mask);
+	if (rq)
+		return rq;
 
-	rq = get_request(q, rw_flags, bio, GFP_NOIO);
-	while (!rq) {
-		DEFINE_WAIT(wait);
-		struct request_list *rl = &q->rq;
-
-		if (unlikely(blk_queue_dead(q)))
-			return NULL;
-
-		prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
-				TASK_UNINTERRUPTIBLE);
+	if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dead(q)))
+		return NULL;
 
-		trace_block_sleeprq(q, bio, rw_flags & 1);
+	/* wait on @rl and retry */
+	prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
+				  TASK_UNINTERRUPTIBLE);
 
-		spin_unlock_irq(q->queue_lock);
-		io_schedule();
+	trace_block_sleeprq(q, bio, rw_flags & 1);
 
-		/*
-		 * After sleeping, we become a "batching" process and
-		 * will be able to allocate at least one request, and
-		 * up to a big batch of them for a small period time.
-		 * See ioc_batching, ioc_set_batching
-		 */
-		create_io_context(GFP_NOIO, q->node);
-		ioc_set_batching(q, current->io_context);
+	spin_unlock_irq(q->queue_lock);
+	io_schedule();
 
-		spin_lock_irq(q->queue_lock);
-		finish_wait(&rl->wait[is_sync], &wait);
+	/*
+	 * After sleeping, we become a "batching" process and will be able
+	 * to allocate at least one request, and up to a big batch of them
+	 * for a small period time.  See ioc_batching, ioc_set_batching
+	 */
+	create_io_context(GFP_NOIO, q->node);
+	ioc_set_batching(q, current->io_context);
 
-		rq = get_request(q, rw_flags, bio, GFP_NOIO);
-	};
+	spin_lock_irq(q->queue_lock);
+	finish_wait(&rl->wait[is_sync], &wait);
 
-	return rq;
+	goto retry;
 }
 
 struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
@@ -1088,10 +1087,7 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
 	BUG_ON(rw != READ && rw != WRITE);
 
 	spin_lock_irq(q->queue_lock);
-	if (gfp_mask & __GFP_WAIT)
-		rq = get_request_wait(q, rw, NULL);
-	else
-		rq = get_request(q, rw, NULL, gfp_mask);
+	rq = get_request(q, rw, NULL, gfp_mask);
 	if (!rq)
 		spin_unlock_irq(q->queue_lock);
 	/* q->queue_lock is unlocked at this point */
@@ -1481,7 +1477,7 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio)
 	 * Grab a free request. This is might sleep but can not fail.
 	 * Returns with the queue unlocked.
 	 */
-	req = get_request_wait(q, rw_flags, bio);
+	req = get_request(q, rw_flags, bio, GFP_NOIO);
 	if (unlikely(!req)) {
 		bio_endio(bio, -ENODEV);	/* @q is dead */
 		goto out_unlock;