From 4911096f1a5df73c12c287a42ece4e7b5d9c19ec Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Thu, 14 Jan 2010 17:45:08 -0500 Subject: [PATCH] nfs41: back channel drc minimal implementation For now the back channel ca_maxresponsesize_cached is 0 and there is no backchannel DRC. Return NFS4ERR_REP_TOO_BIG_TO_CACHE when a cb_sequence cachethis is true. When it is false, return NFS4ERR_RETRY_UNCACHED_REP as the next operation error. Remember the replay error accross compound operation processing. Signed-off-by: Andy Adamson Signed-off-by: Trond Myklebust --- fs/nfs/callback_proc.c | 25 +++++++++++++++++-------- fs/nfs/callback_xdr.c | 19 +++++++++++++++---- 2 files changed, 32 insertions(+), 12 deletions(-) diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 3d7edd65577b..4062f7690a33 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -143,9 +143,8 @@ int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const n * Return success if the sequenceID is one more than what we last saw on * this slot, accounting for wraparound. Increments the slot's sequence. * - * We don't yet implement a duplicate request cache, so at this time - * we will log replays, and process them as if we had not seen them before, - * but we don't bump the sequence in the slot. Not too worried about it, + * We don't yet implement a duplicate request cache, instead we set the + * back channel ca_maxresponsesize_cached to zero. This is OK for now * since we only currently implement idempotent callbacks anyway. * * We have a single slot backchannel at this time, so we don't bother @@ -174,9 +173,15 @@ validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args) /* Replay */ if (args->csa_sequenceid == slot->seq_nr) { - dprintk("%s seqid %d is a replay - no DRC available\n", + dprintk("%s seqid %d is a replay\n", __func__, args->csa_sequenceid); - return htonl(NFS4_OK); + /* Signal process_op to set this error on next op */ + if (args->csa_cachethis == 0) + return htonl(NFS4ERR_RETRY_UNCACHED_REP); + + /* The ca_maxresponsesize_cached is 0 with no DRC */ + else if (args->csa_cachethis == 1) + return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE); } /* Wraparound */ @@ -319,9 +324,13 @@ out: kfree(args->csa_rclists[i].rcl_refcalls); kfree(args->csa_rclists); - dprintk("%s: exit with status = %d\n", __func__, ntohl(status)); - res->csr_status = status; - return res->csr_status; + if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) + res->csr_status = 0; + else + res->csr_status = status; + dprintk("%s: exit with status = %d res->csr_status %d\n", __func__, + ntohl(status), ntohl(res->csr_status)); + return status; } unsigned nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy) diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c index a6f2ded72b17..08b430d922c4 100644 --- a/fs/nfs/callback_xdr.c +++ b/fs/nfs/callback_xdr.c @@ -605,7 +605,7 @@ preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op) static __be32 process_op(uint32_t minorversion, int nop, struct svc_rqst *rqstp, struct xdr_stream *xdr_in, void *argp, - struct xdr_stream *xdr_out, void *resp) + struct xdr_stream *xdr_out, void *resp, int* drc_status) { struct callback_op *op = &callback_ops[0]; unsigned int op_nr; @@ -628,6 +628,11 @@ static __be32 process_op(uint32_t minorversion, int nop, if (status) goto encode_hdr; + if (*drc_status) { + status = *drc_status; + goto encode_hdr; + } + maxlen = xdr_out->end - xdr_out->p; if (maxlen > 0 && maxlen < PAGE_SIZE) { status = op->decode_args(rqstp, xdr_in, argp); @@ -636,6 +641,12 @@ static __be32 process_op(uint32_t minorversion, int nop, } else status = htonl(NFS4ERR_RESOURCE); + /* Only set by OP_CB_SEQUENCE processing */ + if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) { + *drc_status = status; + status = 0; + } + encode_hdr: res = encode_op_hdr(xdr_out, op_nr, status); if (unlikely(res)) @@ -655,7 +666,7 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r struct cb_compound_hdr_res hdr_res = { NULL }; struct xdr_stream xdr_in, xdr_out; __be32 *p; - __be32 status; + __be32 status, drc_status = 0; unsigned int nops = 0; dprintk("%s: start\n", __func__); @@ -675,8 +686,8 @@ static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *r return rpc_system_err; while (status == 0 && nops != hdr_arg.nops) { - status = process_op(hdr_arg.minorversion, nops, - rqstp, &xdr_in, argp, &xdr_out, resp); + status = process_op(hdr_arg.minorversion, nops, rqstp, + &xdr_in, argp, &xdr_out, resp, &drc_status); nops++; }