2009-05-18 14:23:24

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [pnfs] [PATCH 07/31] nfsd41: replay solo and embedded create session

On Mon, May 18, 2009 at 10:02:25AM -0400, William A. (Andy) Adamson wrote:
> On Fri, May 15, 2009 at 7:08 PM, J. Bruce Fields <[email protected]> wrote:
> > On Tue, Apr 28, 2009 at 12:59:41PM -0400, [email protected] wrote:
> >> From: Andy Adamson <[email protected]>
> >>
> >> CREATE_SESSION can be preceeded by a SEQUENCE operation (an embedded
> >> CREATE_SESSION) and the create session single slot cache must be maintained.
> >> Always replay a create session from nfsd4_replay_create_session(). Leave
> >> nfsd4_store_cache_entry() for session (sequence operation) replays.
> >>
> >> Set cstate->status to a new internal error, nfserr_replay_clientid_cache, and
> >> change the logic in nfsd4_proc_compound so that CREATE_SESSION replays replace
> >> encode_operation.
> >> The new internal error is needed to differentiate between an embedded
> >> CREATE_SESSION replay and a SEQUENCE replay.
> >
> > And making the clientid_cache cache just the unencoded
> > nfsd4_create_session would avoid the need for this special case, since
> > it would look to nfsd4_proc_compound() like any other create_session.
>
> I believe we will still need the new internal case.
> When the sequence operation replay case gets hit in
> nfsd4_proc_compound, the entire reply has been constructed from the
> cache, so the sequence operation replay exits nfsd4_proc_compound
> processing.
>
> In the create session replay case, only the create session operation
> will be reconstructed from the cache, and it might be an embedded
> create session (part of another sessions sequence compound) and so the
> rest of the operations in that compound would need to be processed.
> So, the create session replay does not exit nfsd4_proc_compound
> processing.

Right--and in that respect it's just like any other (non-replay) case.

So you'd still need the sequence case, but you wouldn't need the
replay_clientid_cache case, which would be encoded normally--the only
"replay" would be done inside create_session's proc function, which
would restore the saved values to the struct nfsd4_create_session.

Where possible, I'm happier keeping special cases inside the individual
op functions rather than in nfsd_proc_compound.

--b.

>
> -->Andy
> >
> > --b.
> >
> >>
> >> Signed-off-by: Andy Adamson <[email protected]>
> >> ---
> >> fs/nfsd/nfs4proc.c | 9 +++++++--
> >> fs/nfsd/nfs4state.c | 5 +++++
> >> fs/nfsd/nfs4xdr.c | 17 +++++++++++++++++
> >> include/linux/nfsd/nfsd.h | 2 ++
> >> include/linux/nfsd/xdr4.h | 2 ++
> >> 5 files changed, 33 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> >> index b2883e9..32d5866 100644
> >> --- a/fs/nfsd/nfs4proc.c
> >> +++ b/fs/nfsd/nfs4proc.c
> >> @@ -996,7 +996,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
> >> BUG_ON(op->status == nfs_ok);
> >>
> >> encode_op:
> >> - /* Only from SEQUENCE or CREATE_SESSION */
> >> + /* Only from SEQUENCE */
> >> if (resp->cstate.status == nfserr_replay_cache) {
> >> dprintk("%s NFS4.1 replay from cache\n", __func__);
> >> if (nfsd4_not_cached(resp))
> >> @@ -1005,7 +1005,12 @@ encode_op:
> >> status = op->status;
> >> goto out;
> >> }
> >> - if (op->status == nfserr_replay_me) {
> >> + /* Only from CREATE_SESSION */
> >> + if (resp->cstate.status == nfserr_replay_clientid_cache) {
> >> + dprintk("%s NFS4.1 replay from clientid cache\n",
> >> + __func__);
> >> + status = op->status;
> >> + } else if (op->status == nfserr_replay_me) {
> >> op->replay = &cstate->replay_owner->so_replay;
> >> nfsd4_encode_replay(resp, op);
> >> status = op->status = op->replay->rp_status;
> >> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> >> index de7cc51..e216169 100644
> >> --- a/fs/nfsd/nfs4state.c
> >> +++ b/fs/nfsd/nfs4state.c
> >> @@ -1350,6 +1350,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
> >> struct nfsd4_create_session *cr_ses)
> >> {
> >> u32 ip_addr = svc_addr_in(rqstp)->sin_addr.s_addr;
> >> + struct nfsd4_compoundres *resp = rqstp->rq_resp;
> >> struct nfs4_client *conf, *unconf;
> >> struct nfsd4_clid_slot *slot = NULL;
> >> int status = 0;
> >> @@ -1364,6 +1365,10 @@ nfsd4_create_session(struct svc_rqst *rqstp,
> >> if (status == nfserr_replay_cache) {
> >> dprintk("Got a create_session replay! seqid= %d\n",
> >> slot->sl_seqid);
> >> + cstate->status = nfserr_replay_clientid_cache;
> >> + /* Return the cached reply status */
> >> + status = nfsd4_replay_create_session(resp, slot);
> >> + goto out;
> >> } else if (cr_ses->seqid != conf->cl_slot.sl_seqid + 1) {
> >> status = nfserr_seq_misordered;
> >> dprintk("Sequence misordered!\n");
> >> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> >> index 1dfec1d..238612e 100644
> >> --- a/fs/nfsd/nfs4xdr.c
> >> +++ b/fs/nfsd/nfs4xdr.c
> >> @@ -3064,6 +3064,23 @@ nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
> >> slot->sl_datalen = (char *)resp->p - (char *)p;
> >> }
> >>
> >> +__be32
> >> +nfsd4_replay_create_session(struct nfsd4_compoundres *resp,
> >> + struct nfsd4_clid_slot *slot)
> >> +{
> >> + __be32 *p;
> >> +
> >> + RESERVE_SPACE(8);
> >> + WRITE32(OP_CREATE_SESSION);
> >> + *p++ = slot->sl_status; /* already in network byte order */
> >> + ADJUST_ARGS();
> >> +
> >> + memcpy(resp->p, slot->sl_data, slot->sl_datalen);
> >> + p += XDR_QUADLEN(slot->sl_datalen);
> >> + ADJUST_ARGS();
> >> + return slot->sl_status;
> >> +}
> >> +
> >> static __be32
> >> nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int nfserr,
> >> struct nfsd4_destroy_session *destroy_session)
> >> diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
> >> index 2b49d67..9cd6399 100644
> >> --- a/include/linux/nfsd/nfsd.h
> >> +++ b/include/linux/nfsd/nfsd.h
> >> @@ -301,6 +301,8 @@ void nfsd_lockd_shutdown(void);
> >> #define nfserr_replay_me cpu_to_be32(11001)
> >> /* nfs41 replay detected */
> >> #define nfserr_replay_cache cpu_to_be32(11002)
> >> +/* nfs41 clientid cache replay detected */
> >> +#define nfserr_replay_clientid_cache cpu_to_be32(11003)
> >>
> >> /* Check for dir entries '.' and '..' */
> >> #define isdotent(n, l) (l < 3 && n[0] == '.' && (l == 1 || n[1] == '.'))
> >> diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
> >> index 21e0b73..ac00985 100644
> >> --- a/include/linux/nfsd/xdr4.h
> >> +++ b/include/linux/nfsd/xdr4.h
> >> @@ -519,6 +519,8 @@ extern __be32 nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
> >> struct nfsd4_sequence *seq);
> >> extern void nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
> >> struct nfsd4_clid_slot *slot, int nfserr);
> >> +extern __be32 nfsd4_replay_create_session(struct nfsd4_compoundres *resp,
> >> + struct nfsd4_clid_slot *slot);
> >> extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
> >> struct nfsd4_compound_state *,
> >> struct nfsd4_exchange_id *);
> >> --
> >> 1.5.4.3
> >>
> > _______________________________________________
> > pNFS mailing list
> > [email protected]
> > http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs
> >


2009-05-18 14:42:22

by Andy Adamson

[permalink] [raw]
Subject: Re: [pnfs] [PATCH 07/31] nfsd41: replay solo and embedded create session

On Mon, May 18, 2009 at 10:23 AM, J. Bruce Fields <[email protected]> wrote:
> On Mon, May 18, 2009 at 10:02:25AM -0400, William A. (Andy) Adamson wrote:
>> On Fri, May 15, 2009 at 7:08 PM, J. Bruce Fields <[email protected]> wrote:
>> > On Tue, Apr 28, 2009 at 12:59:41PM -0400, [email protected] wrote:
>> >> From: Andy Adamson <[email protected]>
>> >>
>> >> CREATE_SESSION can be preceeded by a SEQUENCE operation (an embedded
>> >> CREATE_SESSION) and the create session single slot cache must be maintained.
>> >> Always replay a create session from nfsd4_replay_create_session(). Leave
>> >> nfsd4_store_cache_entry() for session (sequence operation) replays.
>> >>
>> >> Set cstate->status to a new internal error, nfserr_replay_clientid_cache, and
>> >> change the logic in nfsd4_proc_compound so that CREATE_SESSION replays replace
>> >> encode_operation.
>> >> The new internal error is needed to differentiate between an embedded
>> >> CREATE_SESSION replay and a SEQUENCE replay.
>> >
>> > And making the clientid_cache cache just the unencoded
>> > nfsd4_create_session would avoid the need for this special case, since
>> > it would look to nfsd4_proc_compound() like any other create_session.
>>
>> I believe we will still need the new internal case.
>> When the sequence operation replay case gets hit in
>> nfsd4_proc_compound, the entire reply has been constructed from the
>> cache, so the sequence operation replay exits nfsd4_proc_compound
>> processing.
>>
>> In the create session replay case, only the create session operation
>> will be reconstructed from the cache, and it might be an embedded
>> create session (part of another sessions sequence compound) and so the
>> rest of the operations in that compound would need to be processed.
>> So, the create session replay does not exit nfsd4_proc_compound
>> processing.
>
> Right--and in that respect it's just like any other (non-replay) case.
>
> So you'd still need the sequence case, but you wouldn't need the
> replay_clientid_cache case, which would be encoded normally--the only
> "replay" would be done inside create_session's proc function, which
> would restore the saved values to the struct nfsd4_create_session.

Got it.

-->Andy

>
> Where possible, I'm happier keeping special cases inside the individual
> op functions rather than in nfsd_proc_compound.
>
> --b.
>
>>
>> -->Andy
>> >
>> > --b.
>> >
>> >>
>> >> Signed-off-by: Andy Adamson <[email protected]>
>> >> ---
>> >> fs/nfsd/nfs4proc.c | 9 +++++++--
>> >> fs/nfsd/nfs4state.c | 5 +++++
>> >> fs/nfsd/nfs4xdr.c | 17 +++++++++++++++++
>> >> include/linux/nfsd/nfsd.h | 2 ++
>> >> include/linux/nfsd/xdr4.h | 2 ++
>> >> 5 files changed, 33 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
>> >> index b2883e9..32d5866 100644
>> >> --- a/fs/nfsd/nfs4proc.c
>> >> +++ b/fs/nfsd/nfs4proc.c
>> >> @@ -996,7 +996,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
>> >> BUG_ON(op->status == nfs_ok);
>> >>
>> >> encode_op:
>> >> - /* Only from SEQUENCE or CREATE_SESSION */
>> >> + /* Only from SEQUENCE */
>> >> if (resp->cstate.status == nfserr_replay_cache) {
>> >> dprintk("%s NFS4.1 replay from cache\n", __func__);
>> >> if (nfsd4_not_cached(resp))
>> >> @@ -1005,7 +1005,12 @@ encode_op:
>> >> status = op->status;
>> >> goto out;
>> >> }
>> >> - if (op->status == nfserr_replay_me) {
>> >> + /* Only from CREATE_SESSION */
>> >> + if (resp->cstate.status == nfserr_replay_clientid_cache) {
>> >> + dprintk("%s NFS4.1 replay from clientid cache\n",
>> >> + __func__);
>> >> + status = op->status;
>> >> + } else if (op->status == nfserr_replay_me) {
>> >> op->replay = &cstate->replay_owner->so_replay;
>> >> nfsd4_encode_replay(resp, op);
>> >> status = op->status = op->replay->rp_status;
>> >> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> >> index de7cc51..e216169 100644
>> >> --- a/fs/nfsd/nfs4state.c
>> >> +++ b/fs/nfsd/nfs4state.c
>> >> @@ -1350,6 +1350,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
>> >> struct nfsd4_create_session *cr_ses)
>> >> {
>> >> u32 ip_addr = svc_addr_in(rqstp)->sin_addr.s_addr;
>> >> + struct nfsd4_compoundres *resp = rqstp->rq_resp;
>> >> struct nfs4_client *conf, *unconf;
>> >> struct nfsd4_clid_slot *slot = NULL;
>> >> int status = 0;
>> >> @@ -1364,6 +1365,10 @@ nfsd4_create_session(struct svc_rqst *rqstp,
>> >> if (status == nfserr_replay_cache) {
>> >> dprintk("Got a create_session replay! seqid= %d\n",
>> >> slot->sl_seqid);
>> >> + cstate->status = nfserr_replay_clientid_cache;
>> >> + /* Return the cached reply status */
>> >> + status = nfsd4_replay_create_session(resp, slot);
>> >> + goto out;
>> >> } else if (cr_ses->seqid != conf->cl_slot.sl_seqid + 1) {
>> >> status = nfserr_seq_misordered;
>> >> dprintk("Sequence misordered!\n");
>> >> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
>> >> index 1dfec1d..238612e 100644
>> >> --- a/fs/nfsd/nfs4xdr.c
>> >> +++ b/fs/nfsd/nfs4xdr.c
>> >> @@ -3064,6 +3064,23 @@ nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
>> >> slot->sl_datalen = (char *)resp->p - (char *)p;
>> >> }
>> >>
>> >> +__be32
>> >> +nfsd4_replay_create_session(struct nfsd4_compoundres *resp,
>> >> + struct nfsd4_clid_slot *slot)
>> >> +{
>> >> + __be32 *p;
>> >> +
>> >> + RESERVE_SPACE(8);
>> >> + WRITE32(OP_CREATE_SESSION);
>> >> + *p++ = slot->sl_status; /* already in network byte order */
>> >> + ADJUST_ARGS();
>> >> +
>> >> + memcpy(resp->p, slot->sl_data, slot->sl_datalen);
>> >> + p += XDR_QUADLEN(slot->sl_datalen);
>> >> + ADJUST_ARGS();
>> >> + return slot->sl_status;
>> >> +}
>> >> +
>> >> static __be32
>> >> nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int nfserr,
>> >> struct nfsd4_destroy_session *destroy_session)
>> >> diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
>> >> index 2b49d67..9cd6399 100644
>> >> --- a/include/linux/nfsd/nfsd.h
>> >> +++ b/include/linux/nfsd/nfsd.h
>> >> @@ -301,6 +301,8 @@ void nfsd_lockd_shutdown(void);
>> >> #define nfserr_replay_me cpu_to_be32(11001)
>> >> /* nfs41 replay detected */
>> >> #define nfserr_replay_cache cpu_to_be32(11002)
>> >> +/* nfs41 clientid cache replay detected */
>> >> +#define nfserr_replay_clientid_cache cpu_to_be32(11003)
>> >>
>> >> /* Check for dir entries '.' and '..' */
>> >> #define isdotent(n, l) (l < 3 && n[0] == '.' && (l == 1 || n[1] == '.'))
>> >> diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
>> >> index 21e0b73..ac00985 100644
>> >> --- a/include/linux/nfsd/xdr4.h
>> >> +++ b/include/linux/nfsd/xdr4.h
>> >> @@ -519,6 +519,8 @@ extern __be32 nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
>> >> struct nfsd4_sequence *seq);
>> >> extern void nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
>> >> struct nfsd4_clid_slot *slot, int nfserr);
>> >> +extern __be32 nfsd4_replay_create_session(struct nfsd4_compoundres *resp,
>> >> + struct nfsd4_clid_slot *slot);
>> >> extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
>> >> struct nfsd4_compound_state *,
>> >> struct nfsd4_exchange_id *);
>> >> --
>> >> 1.5.4.3
>> >>
>> > _______________________________________________
>> > pNFS mailing list
>> > [email protected]
>> > http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs
>> >
>