fs: Add helper to clean bdev aliases under a bh and use it

Add a helper function that clears buffer heads from a block device
aliasing passed bh. Use this helper function from filesystems instead of
the original unmap_underlying_metadata() to save some boiler plate code
and also have a better name for the functionalily since it is not
unmapping anything for a *long* time.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 9c9c73ce7d4f..d1ab91fc6d43 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -171,6 +171,10 @@ int sync_mapping_buffers(struct address_space *mapping);
 void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
 void clean_bdev_aliases(struct block_device *bdev, sector_t block,
 			sector_t len);
+static inline void clean_bdev_bh_alias(struct buffer_head *bh)
+{
+	clean_bdev_aliases(bh->b_bdev, bh->b_blocknr, 1);
+}
 
 void mark_buffer_async_write(struct buffer_head *bh);
 void __wait_on_buffer(struct buffer_head *);