[NFS-Ganesha-Devel] Re: Better interop for NFS/SMB file share mode/reservation

Jeremy Allison wrote: > On Wed, Mar 06, 2019 at 03:31:08PM -0500, Jeff Layton wrote: >> On Wed, 2019-03-06 at 10:11 -0500, J. Bruce Fields wrote: >>> >>> Jeff, wasn't there some work (on Ceph maybe?) on a userspace delegation >>> API? Is that close to what's needed? >>> >> >> Here's the C headers for that stuff: >> >> https://github.com/ceph/ceph/blob/7ba6bece4187eda5d05a9b84211fe6ba8dd287b... >> >> It's simple enough and works for us in ganesha, and I think we can >> probably adapt it to samba without too much difficulty. The callback >> doesn't seem like it'll do for a kernel API though -- you'd almost >> certainly need to do something different there (signals? inotify?). > > SMB3 leases have R/RW and Handle-based leases. Just to be precise: SMB2.1+ has R, RH, RW and RWH leases. > Handle leases allow multiple opens of the same pathname > that get different handles to share the lease, allowing > a client redirector to delay opens or closes locally > so long as it has a handle lease. That'a a propertly of leases in general, not just H-leases. The client provides a lease key which is a GUID with each lease request > > Here are the semantics: > > https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/d8df... > > I'm not sure a simple file-descriptor based API is > enough for us. Can he have a uuid or token based > API instead where the server can chose what fd's > to cover with a token ? Yes, that would be ideal.