block: pass 'op' to blk_queue_enter()

We need to check if the request to be allocated is PREEMPT_ONLY,
and have to pass REQ_PREEEMPT flag to blk_queue_eneter(), so pass
'op' to blk_queue_enter() directly.

Change-Id: I53bafb80d59917f65b5855571489638d9fe507c3
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Patch-mainline: linux-block@vger.kernel.org @ 03/10/2017, 22:04
Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>

block/blk-core.c

@@ -816,14 +816,14 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask)
 }
 EXPORT_SYMBOL(blk_alloc_queue);
 
-int blk_queue_enter(struct request_queue *q, bool nowait)
+int blk_queue_enter(struct request_queue *q, unsigned int op)
 {
 	while (true) {
 
 		if (percpu_ref_tryget_live(&q->q_usage_counter))
 			return 0;
 
-		if (nowait)
+		if (op & REQ_NOWAIT)
 			return -EBUSY;
 
 		/*
@@ -1457,8 +1457,8 @@ static struct request *blk_old_get_request(struct request_queue *q,
 	/* create ioc upfront */
 	create_io_context(gfp_mask, q->node);
 
-	ret = blk_queue_enter(q, !(gfp_mask & __GFP_DIRECT_RECLAIM) ||
-			      (op & REQ_NOWAIT));
+	ret = blk_queue_enter(q, (gfp_mask & __GFP_DIRECT_RECLAIM) ? op :
+			      op | REQ_NOWAIT);
 	if (ret)
 		return ERR_PTR(ret);
 	spin_lock_irq(q->queue_lock);
@@ -1485,6 +1485,7 @@ struct request *blk_get_request(struct request_queue *q, unsigned int op,
 		req = blk_mq_alloc_request(q, op,
 			(gfp_mask & __GFP_DIRECT_RECLAIM) ?
 				0 : BLK_MQ_REQ_NOWAIT);
+
 		if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
 			q->mq_ops->initialize_rq_fn(req);
 	} else {
@@ -2234,7 +2235,7 @@ blk_qc_t generic_make_request(struct bio *bio)
 		flags = BLK_MQ_REQ_NOWAIT;
 	if (bio_flagged(bio, BIO_QUEUE_ENTERED))
 		blk_queue_enter_live(q);
-	else if (blk_queue_enter(q, flags) < 0) {
+	else if (blk_queue_enter(q, bio->bi_opf) < 0) {
 		if (!blk_queue_dying(q) && (bio->bi_opf & REQ_NOWAIT))
 			bio_wouldblock_error(bio);
 		else
@@ -2287,7 +2288,7 @@ blk_qc_t generic_make_request(struct bio *bio)
 			flags = 0;
 			if (bio->bi_opf & REQ_NOWAIT)
 				flags = BLK_MQ_REQ_NOWAIT;
-			if (blk_queue_enter(q, flags) < 0)
+			if (blk_queue_enter(q, bio->bi_opf) < 0)
 				enter_succeeded = false;
 		}
 

block/blk-mq.c

@@ -405,7 +405,8 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
 	struct request *rq;
 	int ret;
 
-	ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
+	ret = blk_queue_enter(q, !(flags & BLK_MQ_REQ_NOWAIT) ? op :
+			op | REQ_NOWAIT);
 	if (ret)
 		return ERR_PTR(ret);
 

fs/block_dev.c

@@ -689,7 +689,7 @@ int bdev_read_page(struct block_device *bdev, sector_t sector,
 	if (!ops->rw_page || bdev_get_integrity(bdev))
 		return result;
 
-	result = blk_queue_enter(bdev->bd_queue, false);
+	result = blk_queue_enter(bdev->bd_queue, 0);
 	if (result)
 		return result;
 	result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, false);
@@ -725,7 +725,7 @@ int bdev_write_page(struct block_device *bdev, sector_t sector,
 
 	if (!ops->rw_page || bdev_get_integrity(bdev))
 		return -EOPNOTSUPP;
-	result = blk_queue_enter(bdev->bd_queue, false);
+	result = blk_queue_enter(bdev->bd_queue, 0);
 	if (result)
 		return result;
 

include/linux/blkdev.h

@@ -987,7 +987,7 @@ extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 			 struct scsi_ioctl_command __user *);
 
-extern int blk_queue_enter(struct request_queue *q, bool nowait);
+extern int blk_queue_enter(struct request_queue *q, unsigned int op);
 extern void blk_queue_exit(struct request_queue *q);
 extern void blk_start_queue(struct request_queue *q);
 extern void blk_start_queue_async(struct request_queue *q);