On Fri, 2021-01-08 at 13:08 -0500, bfields@xxxxxxxxxxxx wrote: > On Fri, Jan 08, 2021 at 04:35:50PM +0000, Trond Myklebust wrote: > > Just ignore generic/465. As far as NFS is concerned, the test has > > utterly borked assumptions about O_DIRECT ordering. > > Thanks, adding to my list of tests to skip. Should we report it as > an > xfstests bug? > > (Is the test just wrong, or is this some non-standard but documented > NFS > behavior, or something else?) > > --b. I'm not sure who decided the ordering requirements for O_DIRECT, but in order to fix the generic/465 case, I'd either have to order all reads with all outstanding writes or implement some kind of range locking to do it in a more fine-grained way. We do order buffered I/O and O_DIRECT, so that backup programs can do their thing on databases that use O_DIRECT. However we do assume that anyone using O_DIRECT for I/O is doing their own synchronisation. -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
