Commit ae9e9c6a authored Oct 30, 2014 by Jan Kara Committed by Theodore Ts'o Oct 30, 2014

ext4: make ext4_ext_convert_to_initialized() return proper number of blocks



ext4_ext_convert_to_initialized() can return more blocks than are
actually allocated from map->m_lblk in case where initial part of the
on-disk extent is zeroed out. Luckily this doesn't have serious
consequences because the caller currently uses the return value
only to unmap metadata buffers. Anyway this is a data
corruption/exposure problem waiting to happen so fix it.

Coverity-id: 1226848
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent 4f879ca6

fs/ext4/extents.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -3603,11 +3603,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
		}
		}

		allocated = ext4_split_extent(handle, inode, ppath,
		&split_map, split_flag, flags);
		if (allocated < 0)
		err = allocated;

		err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
		flags);
		if (err > 0)
		err = 0;
		out:
		/* If we have gotten a failure, don't zero out status tree */
		if (!err)

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