On 5/6/25 4:10 AM, Christoph Hellwig wrote: > On Sun, Apr 27, 2025 at 12:39:14PM -0400, cel@xxxxxxxxxx wrote: >> NFSD can return 0 here, as at least one client implementation we >> are aware of (the Linux NFS client) treats 0 as meaning "CLONE has >> no alignment restrictions". > > Usually clone does have a restriction, though. Then should this patch extract that block size and report it? Pointer to sample code would kickstart me to get that done. >> Meanwhile we need to consult the nfsv4 Working Group to clarify the >> meaning and use of the value of this attribute. > > Yeah, the attribute seems to be severely underspecified, i.e. it does > not even provide a unit that the value is in. Agreed. Everyone is /assuming/ bytes, for now. > I think the only sane way out is an errate that makes 0 mean > "not specified" and then provides the byte unit and maybe some > other quirks. > >> + /* Linux filesystems have no clone alignment restrictions */ > > That is absolutely untrue as said above. -- Chuck Lever
