On 3/7/25 10:00 AM, Jeff Layton wrote: > On Sat, 2025-03-01 at 13:31 -0500, cel@xxxxxxxxxx wrote: >> From: Chuck Lever <chuck.lever@xxxxxxxxxx> >> >> I've built a naive proof-of-concept of the csa_referring_call_list >> argument of the CB_SEQUENCE operation, and hooked it up for the >> CB_OFFLOAD callback operation. >> >> This has been pushed to my kernel.org "fix-async-copy" branch for >> folks to play around with. >> >> I've done some basic testing with a server that ensures the >> CB_OFFLOAD callback is sent before the COPY reply, while running a >> network capture. Operation appears correct, Wireshark is happy >> with the construction of the XDR, and the CB_SEQUENCE arguments >> match the SEQUENCE operation in the COPY COMPOUND. >> >> I'd like to include this series in nfsd-testing. >> >> Changes since RFC: >> - Add a field to struct nfsd4_slot that records its table index >> - Include a few additional COPY-related fixes >> - Some operational testing has been done >> >> Chuck Lever (5): >> NFSD: OFFLOAD_CANCEL should mark an async COPY as completed >> NFSD: Shorten CB_OFFLOAD response to NFS4ERR_DELAY >> NFSD: Implement CB_SEQUENCE referring call lists >> NFSD: Record each NFSv4 call's session slot index >> NFSD: Use a referring call list for CB_OFFLOAD >> >> fs/nfsd/nfs4callback.c | 132 +++++++++++++++++++++++++++++++++++++++-- >> fs/nfsd/nfs4proc.c | 16 ++++- >> fs/nfsd/nfs4state.c | 38 ++++++------ >> fs/nfsd/state.h | 23 +++++++ >> fs/nfsd/xdr4.h | 4 ++ >> fs/nfsd/xdr4cb.h | 5 +- >> 6 files changed, 193 insertions(+), 25 deletions(-) >> > > I think this all looks good for a first pass, and should be OK for > COPY. You can add: > > > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> Thanks! > I think we'll eventually want this for longer-lived stateids too. > Specifically: > > CB_RECALL > CB_LAYOUTRECALL > CB_NOTIFY_LOCK > > The main thing missing for that is the ability to free referring call > records once we ensure that the client has seen the reply. For > instance, if nfsd records a referring call on slot:seq 1:2, then once > it sees a SEQUENCE for 1:3, then it doesn't need to keep around the > referring call for 1:2. The server knows that call is no longer in > flight so it's no longer needed. > > If we don't do that, then we could end up with rather long referring > call lists, with a bunch of long-completed calls. Agreed that RCLs will have uses outside of COPY. I don't have a good understanding of the use cases you mention above, so it would delay RCL support in CB_OFFLOAD quite a bit if we were to wait for the implementation of the other use cases. -- Chuck Lever
