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, 5 insertions, 5 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 760b2c552197..19d80b82d344 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1159,7 +1159,7 @@ static ssize_t fuse_file_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 = 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)
@@ -1464,7 +1464,7 @@ static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
 {
         struct inode *inode = req->inode;
         struct fuse_inode *fi = get_fuse_inode(inode);
-        struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info;
+        struct backing_dev_info *bdi = inode_to_bdi(inode);
         int i;
 
         list_del(&req->writepages_entry);
@@ -1658,7 +1658,7 @@ static int fuse_writepage_locked(struct page *page)
         req->end = fuse_writepage_end;
         req->inode = inode;
 
-        inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
+        inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
         inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
 
         spin_lock(&fc->lock);
@@ -1768,7 +1768,7 @@ static bool fuse_writepage_in_flight(struct fuse_req *new_req,
 
         if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT ||
                                         old_req->state == FUSE_REQ_PENDING)) {
-                struct backing_dev_info *bdi = page->mapping->backing_dev_info;
+                struct backing_dev_info *bdi = inode_to_bdi(page->mapping->host);
 
                 copy_highpage(old_req->pages[0], page);
                 spin_unlock(&fc->lock);
@@ -1872,7 +1872,7 @@ static int fuse_writepages_fill(struct page *page,
         req->page_descs[req->num_pages].offset = 0;
         req->page_descs[req->num_pages].length = PAGE_SIZE;
 
-        inc_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK);
+        inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
         inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
 
         err = 0;