[PATCH v9 3/8] block: Add bdev atomic write limits helpers

From: John Garry
Date: Wed Oct 16 2024 - 06:05:16 EST


Add helpers to get atomic write limits for a bdev, so that we don't access
request_queue helpers outside the block layer.

We check if the bdev can actually atomic write in these helpers, so we
can avoid users missing using this check.

Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
include/linux/blkdev.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 50c3b959da28..c2cc3c146d74 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1674,6 +1674,22 @@ static inline bool bdev_can_atomic_write(struct block_device *bdev)
return true;
}

+static inline unsigned int
+bdev_atomic_write_unit_min_bytes(struct block_device *bdev)
+{
+ if (!bdev_can_atomic_write(bdev))
+ return 0;
+ return queue_atomic_write_unit_min_bytes(bdev_get_queue(bdev));
+}
+
+static inline unsigned int
+bdev_atomic_write_unit_max_bytes(struct block_device *bdev)
+{
+ if (!bdev_can_atomic_write(bdev))
+ return 0;
+ return queue_atomic_write_unit_max_bytes(bdev_get_queue(bdev));
+}
+
#define DEFINE_IO_COMP_BATCH(name) struct io_comp_batch name = { }

#endif /* _LINUX_BLKDEV_H */
--
2.31.1