Hi all, With ext2 driven by ext4 module (or ext4 without journal, I haven't tested ext2 module, but I guess the result is the same), v4.14-rc1 kernel starts to fail fstests generic/441 as: +First fsync after reopen of fd[0] failed: Input/output error git bisect shows that this is uncovered by commit ffb959bbdf92 ("mm: remove optimizations based on i_size in mapping writeback waits"), which removed (i_size == 0) check in filemap_fdatawait(). I say "uncovered" because test fails with 4.13 kernel too if we re-open the test file without O_TRUNC flag in src/fsync-err.c (so file size is not zero, and fails the i_size == 0 check). The EIO was returned by sync_inode_metadata() in __generic_file_fsync(), the call trace is like: do_fsync vfs_fsync_range ext4_sync_file __generic_file_fsync sync_inode_metadata writeback_single_inode __writeback_single_inode filemap_fdatawait => EIO here Thanks, Eryu