On Fri, Oct 26, 2018 at 11:04 AM Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > > > > On Oct 26, 2018, at 8:54 AM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote: > > > > Hi Chuck, > > > > In the context of doing a copy between different "types" of > > filesystems, it was pointed out to me that NFS has many types: > > nfs4_fs_type, nfs4_remote_fs_type, nfs4_remote_referral_fs_type, > > nfs4_referral_fs_type. So doing a simple check that fs type of "in" > > and "out" might not be sufficient. Do you see any issues allowing a > > copy offload between different types? Basically checking that "in" and > > "out" descriptions come from any of the these types? > > I'm no expert... so what follows is an uninformed opinion. I was wondering if there was anything different about the migrated/replicated filesystem that maybe say they are typically read-only and thus doing a copy there wouldn't be appropriate. But it sounds like you don't see anything special about doing a copy from nfs4_fs_type to say nfs_remote_fs_type? > All of these are NFSv4 file systems. But I don't think that's an > adequate check (it's necessary, but not sufficient). > The minor version of the mount point has to be 2 or higher, and > the client must confirm that the mounted server supports copy > offload (because all NFSv4.2 features are OPTIONAL). I agree that we should check for 4.2 versioning but the latter I don't think is necessary, as the COPY call will just gets not supported error (we already have the capability check for CAP_COPY inside of nfs42_proc_copy , just in case we already sent one copy and then negated the capabilities). > > > -- > Chuck Lever > > >
