Commit 779e2651 authored by Eric Whitney's avatar Eric Whitney Committed by Theodore Ts'o
Browse files

ext4: clean up GET_BLOCKS_PRE_IO error handling 



If the call to ext4_split_convert_extents() fails in the
EXT4_GET_BLOCKS_PRE_IO case within ext4_ext_handle_unwritten_extents(),
error out through the exit point at function end rather than jumping
through an intermediate point.  Fix the error handling in the event
ext4_split_convert_extents() returns 0, which it shouldn't do when
splitting an existing extent.  The current code returns the passed in
value of allocated (which is likely non-zero) while failing to set
m_flags, m_pblk, and m_len.

Signed-off-by: default avatarEric Whitney <enwlinux@gmail.com>
Link: https://lore.kernel.org/r/20200430185320.23001-4-enwlinux@gmail.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent bee6cf00

fs/ext4/extents.c

+20 −6
Original line number Diff line number Diff line
@@ -3818,12 +3818,25 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, 
	trace_ext4_ext_handle_unwritten_extents(inode, map, flags,

						    allocated, newblock);



	/* get_block() before submit the IO, split the extent */

	/* get_block() before submitting IO, split the extent */

	if (flags & EXT4_GET_BLOCKS_PRE_IO) {

		ret = ext4_split_convert_extents(handle, inode, map, ppath,

					 flags | EXT4_GET_BLOCKS_CONVERT);

		if (ret <= 0)

			goto out;

		if (ret < 0) {

			err = ret;

			goto out2;

		}

		/*

		 * shouldn't get a 0 return when splitting an extent unless

		 * m_len is 0 (bug) or extent has been corrupted

		 */

		if (unlikely(ret == 0)) {

			EXT4_ERROR_INODE(inode,

					 "unexpected ret == 0, m_len = %u",

					 map->m_len);

			err = -EFSCORRUPTED;

			goto out2;

		}

		map->m_flags |= EXT4_MAP_UNWRITTEN;

		goto out;

	}
@@ -3863,11 +3876,12 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, 
	ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);

	if (ret >= 0)

		ext4_update_inode_fsync_trans(handle, inode, 1);

out:



	if (ret <= 0) {

		err = ret;

		goto out2;

	} else

	}

out:

	allocated = ret;

	map->m_flags |= EXT4_MAP_NEW;

map_out: