block: add a bdev_fua helper

Add a helper to check the FUA flag based on the block_device instead of
having to poke into the block layer internal request_queue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-14-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/rnbd/rnbd-srv.c

@@ -533,7 +533,6 @@ static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 					struct rnbd_srv_sess_dev *sess_dev)
 {
 	struct rnbd_dev *rnbd_dev = sess_dev->rnbd_dev;
-	struct request_queue *q = bdev_get_queue(rnbd_dev->bdev);
 
 	rsp->hdr.type = cpu_to_le16(RNBD_MSG_OPEN_RSP);
 	rsp->device_id =
@@ -560,7 +559,7 @@ static void rnbd_srv_fill_msg_open_rsp(struct rnbd_msg_open_rsp *rsp,
 	rsp->cache_policy = 0;
 	if (bdev_write_cache(rnbd_dev->bdev))
 		rsp->cache_policy |= RNBD_WRITEBACK;
-	if (blk_queue_fua(q))
+	if (bdev_fua(rnbd_dev->bdev))
 		rsp->cache_policy |= RNBD_FUA;
 }
 

drivers/target/target_core_iblock.c

@@ -727,14 +727,13 @@ iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 
 	if (data_direction == DMA_TO_DEVICE) {
 		struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
-		struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 		/*
 		 * Force writethrough using REQ_FUA if a volatile write cache
 		 * is not enabled, or if initiator set the Force Unit Access bit.
 		 */
 		opf = REQ_OP_WRITE;
 		miter_dir = SG_MITER_TO_SG;
-		if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
+		if (bdev_fua(ib_dev->ibd_bd)) {
 			if (cmd->se_cmd_flags & SCF_FUA)
 				opf |= REQ_FUA;
 			else if (!bdev_write_cache(ib_dev->ibd_bd))

fs/iomap/direct-io.c

@@ -265,8 +265,7 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 		 * cache flushes on IO completion.
 		 */
 		if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
-		    (dio->flags & IOMAP_DIO_WRITE_FUA) &&
-		    blk_queue_fua(bdev_get_queue(iomap->bdev)))
+		    (dio->flags & IOMAP_DIO_WRITE_FUA) && bdev_fua(iomap->bdev))
 			use_fua = true;
 	}
 

include/linux/blkdev.h

@@ -602,7 +602,6 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
 			     REQ_FAILFAST_DRIVER))
 #define blk_queue_quiesced(q)	test_bit(QUEUE_FLAG_QUIESCED, &(q)->queue_flags)
 #define blk_queue_pm_only(q)	atomic_read(&(q)->pm_only)
-#define blk_queue_fua(q)	test_bit(QUEUE_FLAG_FUA, &(q)->queue_flags)
 #define blk_queue_registered(q)	test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags)
 #define blk_queue_nowait(q)	test_bit(QUEUE_FLAG_NOWAIT, &(q)->queue_flags)
 
@@ -1336,6 +1335,11 @@ static inline bool bdev_write_cache(struct block_device *bdev)
 	return test_bit(QUEUE_FLAG_WC, &bdev_get_queue(bdev)->queue_flags);
 }
 
+static inline bool bdev_fua(struct block_device *bdev)
+{
+	return test_bit(QUEUE_FLAG_FUA, &bdev_get_queue(bdev)->queue_flags);
+}
+
 static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);