On Tue, Jul 21, 2020 at 05:42:40PM +0200, Christoph Hellwig wrote: > On Tue, Jul 21, 2020 at 04:31:36PM +0100, Matthew Wilcox wrote: > > > Umm, no. -ENOTBLK is internal - the file systems will retry using > > > buffered I/O and the error shall never escape to userspace (or even the > > > VFS for that matter). > > > > Ah, I made the mistake of believing the comments that I could see in > > your patch instead of reading the code. > > > > Can I suggest deleting this comment: > > > > /* > > * No fallback to buffered IO on errors for XFS, direct IO will either > > * complete fully or fail. > > */ > > > > and rewording this one: > > > > /* > > * Allow a directio write to fall back to a buffered > > * write *only* in the case that we're doing a reflink > > * CoW. In all other directio scenarios we do not > > * allow an operation to fall back to buffered mode. > > */ > > > > as part of your revised patchset? > > That isn't actually true. In current mainline we only fallback on > reflink RMW cases, but with this series we also fall back for > invalidation failures. ... that's why I'm suggesting that you delete the first one and rewrite the second one. Because they aren't true.