[PATCH 14/27] block: add a bdev_stable_writes helper

[Christoph Hellwig]

Add a helper to check the stable writes flag based on the block_device
instead of having to poke into the block layer internal request_queue.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>
---
 drivers/md/dm-table.c  | 4 +---
 fs/super.c             | 2 +-
 include/linux/blkdev.h | 6 ++++++
 mm/swapfile.c          | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 5e38d0dd009d5..d46839faa0ca5 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1950,9 +1950,7 @@ static int device_requires_stable_pages(struct dm_target *ti,
 					struct dm_dev *dev, sector_t start,
 					sector_t len, void *data)
 {
-	struct request_queue *q = bdev_get_queue(dev->bdev);
-
-	return blk_queue_stable_writes(q);
+	return bdev_stable_writes(dev->bdev);
 }
 
 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
diff --git a/fs/super.c b/fs/super.c
index f1d4a193602d6..60f57c7bc0a69 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1204,7 +1204,7 @@ static int set_bdev_super(struct super_block *s, void *data)
 	s->s_dev = s->s_bdev->bd_dev;
 	s->s_bdi = bdi_get(s->s_bdev->bd_disk->bdi);
 
-	if (blk_queue_stable_writes(s->s_bdev->bd_disk->queue))
+	if (bdev_stable_writes(s->s_bdev))
 		s->s_iflags |= SB_I_STABLE_WRITES;
 	return 0;
 }
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 075b16d4560e7..a433798c3343e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1330,6 +1330,12 @@ static inline bool bdev_nonrot(struct block_device *bdev)
 	return blk_queue_nonrot(bdev_get_queue(bdev));
 }
 
+static inline bool bdev_stable_writes(struct block_device *bdev)
+{
+	return test_bit(QUEUE_FLAG_STABLE_WRITES,
+			&bdev_get_queue(bdev)->queue_flags);
+}
+
 static inline bool bdev_write_cache(struct block_device *bdev)
 {
 	return test_bit(QUEUE_FLAG_WC, &bdev_get_queue(bdev)->queue_flags);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index d5ab7ec4d92ca..4069f17a82c8e 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3065,7 +3065,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		goto bad_swap_unlock_inode;
 	}
 
-	if (p->bdev && blk_queue_stable_writes(p->bdev->bd_disk->queue))
+	if (p->bdev && bdev_stable_writes(p->bdev))
 		p->flags |= SWP_STABLE_WRITES;
 
 	if (p->bdev && p->bdev->bd_disk->fops->rw_page)
-- 
2.30.2