On Tue, Jun 10, 2025 at 04:57:36PM -0400, Mike Snitzer wrote: > IO must be aligned, otherwise it falls back to using buffered IO. > > RWF_DONTCACHE is _not_ currently used for misaligned IO (even when > nfsd/enable-dontcache=1) because it works against us (due to RMW > needing to read without benefit of cache), whereas buffered IO enables > misaligned IO to be more performant. This seems to "randomly" mix direct I/O and buffered I/O on a file. That's basically asking for data corruption due to invalidation races. But maybe also explain what this is trying to address to start with?