btrfs: Change submit_bio_hook to taking an inode directly

The only possible 'private_data' that is passed to this function is
actually an inode. Make that explicit by changing the signature of the
call back. No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -885,11 +885,10 @@ static int check_async_write(struct btrfs_inode *bi)
 	return 1;
 }
 
-static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
+static blk_status_t btree_submit_bio_hook(struct inode *inode, struct bio *bio,
 					  int mirror_num, unsigned long bio_flags,
 					  u64 bio_offset)
 {
-	struct inode *inode = private_data;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	int async = check_async_write(BTRFS_I(inode));
 	blk_status_t ret;
@@ -915,7 +914,7 @@ static blk_status_t btree_submit_bio_hook(void *private_data, struct bio *bio,
 		 * checksumming can happen in parallel across all CPUs
 		 */
 		ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, 0,
-					  bio_offset, private_data,
+					  bio_offset, inode,
 					  btree_submit_bio_start);
 	}
 

fs/btrfs/extent_io.h

@@ -104,7 +104,7 @@ struct extent_io_ops {
 	 * The following callbacks must be always defined, the function
 	 * pointer will be called unconditionally.
 	 */
-	blk_status_t (*submit_bio_hook)(void *private_data, struct bio *bio,
+	blk_status_t (*submit_bio_hook)(struct inode *inode, struct bio *bio,
 					int mirror_num, unsigned long bio_flags,
 					u64 bio_offset);
 	int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,

fs/btrfs/inode.c

@@ -1953,11 +1953,10 @@ static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
  *
  *    c-3) otherwise:			async submit
  */
-static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
+static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags,
 				 u64 bio_offset)
 {
-	struct inode *inode = private_data;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;