On Tue, May 06, 2025 at 09:45:56AM -0400, Chuck Lever wrote: > 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. I think reporting 0 as unknown makes perfect sense, just don't claim that there is no limitation. The generic remap range checks for file system block size alignment: if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_out, bs)) return -EINVAL; in generic_remap_checks.
