From: NeilBrown Date: Thu, 16 Oct 2025 13:49:58 +0000 (-0400) Subject: nfsd: stop pretending that we cache the SEQUENCE reply. X-Git-Tag: v6.19-rc1~77^2~18 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fceb8734e7f1e5dd698c03403ff500923e0fd612;p=thirdparty%2Fkernel%2Flinux.git nfsd: stop pretending that we cache the SEQUENCE reply. nfsd does not cache the reply to a SEQUENCE. As the comment above nfsd4_replay_cache_entry() says: * The sequence operation is not cached because we can use the slot and * session values. The comment above nfsd4_cache_this() suggests otherwise. * The session reply cache only needs to cache replies that the client * actually asked us to. But it's almost free for us to cache compounds * consisting of only a SEQUENCE op, so we may as well cache those too. * Also, the protocol doesn't give us a convenient response in the case * of a replay of a solo SEQUENCE op that wasn't cached The code in nfsd4_store_cache_entry() makes it clear that only responses beyond 'cstate.data_offset' are actually cached, and data_offset is set at the end of nfsd4_encode_sequence() *after* the sequence response has been encoded. This patch simplifies code and removes the confusing comments. - nfsd4_is_solo_sequence() is discarded as not-useful. - nfsd4_cache_this() is now trivial so it too is discarded with the code placed in-line at the one call-site in nfsd4_store_cache_entry(). - nfsd4_enc_sequence_replay() is open-coded in to nfsd4_replay_cache_entry(), and then simplified to (hopefully) make the process of replaying a reply clearer. Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever --- diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 085f5ef12230d..35004568d43eb 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3508,7 +3508,7 @@ nfsd4_store_cache_entry(struct nfsd4_compoundres *resp) free_svc_cred(&slot->sl_cred); copy_cred(&slot->sl_cred, &resp->rqstp->rq_cred); - if (!nfsd4_cache_this(resp)) { + if (!(resp->cstate.slot->sl_flags & NFSD4_SLOT_CACHETHIS)) { slot->sl_flags &= ~NFSD4_SLOT_CACHED; return; } @@ -3522,41 +3522,6 @@ nfsd4_store_cache_entry(struct nfsd4_compoundres *resp) return; } -/* - * Encode the replay sequence operation from the slot values. - * If cachethis is FALSE encode the uncached rep error on the next - * operation which sets resp->p and increments resp->opcnt for - * nfs4svc_encode_compoundres. - * - */ -static __be32 -nfsd4_enc_sequence_replay(struct nfsd4_compoundargs *args, - struct nfsd4_compoundres *resp) -{ - struct nfsd4_op *op; - struct nfsd4_slot *slot = resp->cstate.slot; - - /* Encode the replayed sequence operation */ - op = &args->ops[resp->opcnt - 1]; - nfsd4_encode_operation(resp, op); - - if (slot->sl_flags & NFSD4_SLOT_CACHED) - return op->status; - if (args->opcnt == 1) { - /* - * The original operation wasn't a solo sequence--we - * always cache those--so this retry must not match the - * original: - */ - op->status = nfserr_seq_false_retry; - } else { - op = &args->ops[resp->opcnt++]; - op->status = nfserr_retry_uncached_rep; - nfsd4_encode_operation(resp, op); - } - return op->status; -} - /* * The sequence operation is not cached because we can use the slot and * session values. @@ -3565,17 +3530,30 @@ static __be32 nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp, struct nfsd4_sequence *seq) { + struct nfsd4_compoundargs *args = resp->rqstp->rq_argp; struct nfsd4_slot *slot = resp->cstate.slot; struct xdr_stream *xdr = resp->xdr; __be32 *p; - __be32 status; dprintk("--> %s slot %p\n", __func__, slot); - status = nfsd4_enc_sequence_replay(resp->rqstp->rq_argp, resp); - if (status) - return status; + /* Always encode the SEQUENCE response. */ + nfsd4_encode_operation(resp, &args->ops[0]); + if (args->opcnt == 1) + /* A solo SEQUENCE - nothing was cached */ + return args->ops[0].status; + + if (!(slot->sl_flags & NFSD4_SLOT_CACHED)) { + /* We weren't asked to cache this. */ + struct nfsd4_op *op; + + op = &args->ops[resp->opcnt++]; + op->status = nfserr_retry_uncached_rep; + nfsd4_encode_operation(resp, op); + return op->status; + } + /* return reply from cache */ p = xdr_reserve_space(xdr, slot->sl_datalen); if (!p) { WARN_ON_ONCE(1); diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index 1ce8e12ae3354..ae75846b3cd71 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -924,27 +924,6 @@ struct nfsd4_compoundres { struct nfsd4_compound_state cstate; }; -static inline bool nfsd4_is_solo_sequence(struct nfsd4_compoundres *resp) -{ - struct nfsd4_compoundargs *args = resp->rqstp->rq_argp; - return resp->opcnt == 1 && args->ops[0].opnum == OP_SEQUENCE; -} - -/* - * The session reply cache only needs to cache replies that the client - * actually asked us to. But it's almost free for us to cache compounds - * consisting of only a SEQUENCE op, so we may as well cache those too. - * Also, the protocol doesn't give us a convenient response in the case - * of a replay of a solo SEQUENCE op that wasn't cached - * (RETRY_UNCACHED_REP can only be returned in the second op of a - * compound). - */ -static inline bool nfsd4_cache_this(struct nfsd4_compoundres *resp) -{ - return (resp->cstate.slot->sl_flags & NFSD4_SLOT_CACHETHIS) - || nfsd4_is_solo_sequence(resp); -} - static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp) { struct nfsd4_compoundres *resp = rqstp->rq_resp;