fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info

Now that we got rid of the bdi abuse on character devices we can always use
sb->s_bdi to get at the backing_dev_info for a file, except for the block
device special case.  Export inode_to_bdi and replace uses of
mapping->backing_dev_info with it to prepare for the removal of
mapping->backing_dev_info.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ce74b394b49d..905986dd4c3c 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -945,7 +945,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
         mutex_lock(&inode->i_mutex);
 
         /* We can write back this queue in page reclaim */
-        current->backing_dev_info = file->f_mapping->backing_dev_info;
+        current->backing_dev_info = inode_to_bdi(inode);
 
         err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
         if (err)