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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d04b779..d4e99e9 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3312,10 +3312,10 @@
* 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;