On Tue, Jan 14, 2020 at 04:50:23PM -0500, Theodore Y. Ts'o wrote: > I note that you've dropped the inode_dio_wait() in ext4's ZERO_RANGE, > COLLAPSE_RANGE, INSERT_RANGE, etc. We had added these to avoid > problems when various fallocate operations which modify the inode's > logical->physical block mapping racing with direct I/O (both reads or > writes). > > I don't see a replacement protection in this patch series. How does > are file systems supported to protect against such races? By holding i_rwsem until the direct I/O operations are finished, and not just until they are sumbitted.