ext4: clean up GET_BLOCKS_PRE_IO error handling (779e2651) · Commits · 戴 / test

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:

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

Theodore Ts'o <tytso@mit.edu>

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:

Admin message