From: Zhang Yi Before submitting I/O and allocating blocks with the EXT4_GET_BLOCKS_PRE_IO flag set, ext4_split_convert_extents() may convert the target extent range to initialized due to ENOSPC, ENOMEM, or EQUOTA errors. However, it still marks the mapping as incorrectly unwritten. Although this may not seem to cause any practical problems, it will result in an unnecessary extent conversion operation after I/O completion. Therefore, it's better to correct the returned mapping status. Signed-off-by: Zhang Yi --- fs/ext4/extents.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 2db84f6b0056..19338f488550 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3916,6 +3916,8 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, /* get_block() before submitting IO, split the extent */ if (flags & EXT4_GET_BLOCKS_PRE_IO) { + int depth; + path = ext4_split_convert_extents(handle, inode, map, path, flags, allocated); if (IS_ERR(path)) @@ -3931,7 +3933,13 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, err = -EFSCORRUPTED; goto errout; } - map->m_flags |= EXT4_MAP_UNWRITTEN; + /* Don't mark unwritten if the extent has been zeroed out. */ + path = ext4_find_extent(inode, map->m_lblk, path, flags); + if (IS_ERR(path)) + return path; + depth = ext_depth(inode); + if (ext4_ext_is_unwritten(path[depth].p_ext)) + map->m_flags |= EXT4_MAP_UNWRITTEN; goto out; } /* IO end_io complete, convert the filled extent to written */ -- 2.46.1