Commit 0568c518 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: down i_data_sem only for read when walking tree for fiemap 



Not sure why I put this in as down_write originally; all we are
doing is walking the tree, nothing will change under us and
concurrent reads should be no problem.

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 6fd058f7

fs/ext4/extents.c

+2 −2
Original line number Diff line number Diff line
@@ -3312,10 +3312,10 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 
		 * Walk the extent tree gathering extent information.

		 * ext4_ext_fiemap_cb will push extents back to user.

		 */

		down_write(&EXT4_I(inode)->i_data_sem);

		down_read(&EXT4_I(inode)->i_data_sem);

		error = ext4_ext_walk_space(inode, start_blk, len_blks,

					  ext4_ext_fiemap_cb, fieinfo);

		up_write(&EXT4_I(inode)->i_data_sem);

		up_read(&EXT4_I(inode)->i_data_sem);

	}



	return error;