> > ./run --ov=0 --samefs rename-new-pop-dir > > Fix attached. So, is sync_filesystem(sb); in ovl_remount() needed or not? Note that ./run --ov=0 rename-mass-4 does pass but hits a WARN_ON: [ 735.666817] WARNING: CPU: 1 PID: 7 at /home/amir/build/src/linux/fs/overlayfs/file.c:913 ovl_writepage+0x71/0x113 The WARN_ON is also hit by xfstest overlay/030. In both cases its an extending write where pos == size It seems to me that simple_write_end() is indeed too simple and compared to __generic_write_end() it is missing at least pagecache_isize_extended() which seems related to the WARN_ON. I tried several fixes, but gave up. I found one fix for overlay/001 failure: @@ -65,7 +65,8 @@ static struct file *ovl_open_upper(const struct file *file, ovl_path_upper(file_dentry(file), &realpath); old_cred = ovl_override_creds(inode->i_sb); - realfile = open_with_fake_path(&realpath, O_RDWR | O_NOATIME, + realfile = open_with_fake_path(&realpath, + O_RDWR | O_LARGEFILE | O_NOATIME, realinode, current_cred()); Other xfstests failures: overlay/032 overlay/047 overlay/050 overlay/051 Thanks, Amir.