Re: [pnfs] [RFC 25/51] nfsd41: create_session operation

[Benny Halevy <bhalevy@panasas.com>]

On Nov. 10, 2008, 22:49 +0200, Benny Halevy <bhalevy@panasas.com> wrote:
> From: Ricardo Labiaga <ricardo.labiaga@netapp.com>
> 
> Implement the create_session operation confoming to
> http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26
> 
> Look up the client id (generated by the server on exchange_id,
> given by the client on create_session).
> If neither a confirmed or unconfirmed client is found
> then the client id is stale
> If a confirmed cilent is found (i.e. we already received
> create_session for it) then compare the sequence id
> to determine if it's a replay or possibly a mis-ordered rpc.
> If the seqid is in order, update the confirmed client seqid
> and procedd with updating the session parameters.
> 
> If an unconfirmed client_id is found then verify the creds
> and seqid.  If both match move the client id to confirmed state
> and proceed with processing the create_session.
> 
> Currently, we do not support persistent sessions, and RDMA.
> 
> alloc_init_session generates a new sessionid and creates
> a session structure.
> 
> TODO: improve resource pre-allocation and negotiate session
> parameters accordingly.
> 
> Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
> Signed-off-by: Andy Adamson<andros@netapp.com>
> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
> ---
>  fs/nfsd/nfs4state.c        |  139 +++++++++++++++++++++++++++++++++++++++++-
>  fs/nfsd/nfs4xdr.c          |  147 +++++++++++++++++++++++++++++++++++++++++++-
>  include/linux/nfsd/state.h |    3 +
>  include/linux/nfsd/xdr4.h  |   21 ++++++-
>  4 files changed, 306 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index cbbb733..73bc8de 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -73,6 +73,9 @@ static u32 current_delegid = 1;
>  static u32 nfs4_init;
>  static stateid_t zerostateid;             /* bits all 0 */
>  static stateid_t onestateid;              /* bits all 1 */
> +#if defined(CONFIG_NFSD_V4_1)
> +static u64 current_sessionid = 1;
> +#endif
>  
>  #define ZERO_STATEID(stateid) (!memcmp((stateid), &zerostateid, sizeof(stateid_t)))
>  #define ONE_STATEID(stateid)  (!memcmp((stateid), &onestateid, sizeof(stateid_t)))
> @@ -352,6 +355,72 @@ dump_sessionid(const char *fn, nfs41_sessionid *sessionid)
>  	dprintk("%s: %u:%u:%u:%u\n", fn, ptr[0], ptr[1], ptr[2], ptr[3]);
>  }
>  
> +static void
> +gen_sessionid(struct nfs41_session *ses)
> +{
> +	struct nfs4_client *clp = ses->se_client;
> +	u32 *p = (u32 *)ses->se_sessionid;
> +
> +	*p++ = clp->cl_clientid.cl_boot;
> +	*p++ = clp->cl_clientid.cl_id;
> +	*p++ = (u32)boot_time;

revewiw 11-13: find something useful to put here
boot_time is already part of the clientid part.
(or reserve as 0)

> +	*p++ = current_sessionid++;
> +	BUG_ON((char *)p - (char *)ses->se_sessionid !=
> +	       sizeof(ses->se_sessionid));

remove BUG_ON

> +}
> +
> +static int
> +alloc_init_session(struct nfs4_client *clp, struct nfsd4_create_session *cses)
> +{
> +	struct nfs41_session *new;
> +	int idx, status = nfserr_resource, slotsize, i;
> +
> +	new = kzalloc(sizeof(*new), GFP_KERNEL);
> +	if (!new)
> +		goto out;
> +
> +	if (cses->fore_channel.maxreqs >= NFS41_MAX_SLOTS)
> +		cses->fore_channel.maxreqs = NFS41_MAX_SLOTS;
> +	new->se_fnumslots = cses->fore_channel.maxreqs;
> +	slotsize = new->se_fnumslots * sizeof(struct nfs41_slot);
> +
> +	new->se_slots = kzalloc(slotsize, GFP_KERNEL);
> +	if (!new->se_slots)
> +		goto out_free;
> +
> +	for (i = 0; i < new->se_fnumslots; i++) {
> +		new->se_slots[i].sl_session = new;
> +		nfs41_set_slot_state(&new->se_slots[i], NFS4_SLOT_AVAILABLE);
> +	}
> +
> +	new->se_client = clp;
> +	gen_sessionid(new);
> +	idx = hash_sessionid(&new->se_sessionid);
> +	memcpy(&clp->cl_sessionid, &new->se_sessionid, sizeof(nfs41_sessionid));
> +
> +	new->se_flags = cses->flags;
> +
> +	/* for now, accept the client values */
> +	new->se_fheaderpad_sz = cses->fore_channel.headerpadsz;
> +	new->se_fmaxreq_sz = cses->fore_channel.maxreq_sz;
> +	new->se_fmaxresp_sz = cses->fore_channel.maxresp_sz;
> +	new->se_fmaxresp_cached = cses->fore_channel.maxresp_cached;
> +	new->se_fmaxops = cses->fore_channel.maxops;

review 11-13: this is being rewritten by Andy.

> +
> +	kref_init(&new->se_ref);
> +	INIT_LIST_HEAD(&new->se_hash);
> +	INIT_LIST_HEAD(&new->se_perclnt);
> +	list_add(&new->se_hash, &sessionid_hashtbl[idx]);
> +	list_add(&new->se_perclnt, &clp->cl_sessions);
> +
> +	status = nfs_ok;
> +out:
> +	return status;
> +out_free:
> +	kfree(new);
> +	goto out;
> +}
> +
>  struct nfs41_session *
>  find_in_sessionid_hashtbl(nfs41_sessionid *sessionid)
>  {
> @@ -905,7 +974,75 @@ nfsd4_create_session(struct svc_rqst *rqstp,
>  		     struct nfsd4_compound_state *cstate,
>  		     struct nfsd4_create_session *cr_ses)
>  {
> -	return -1;	/* stub */
> +	u32 ip_addr = svc_addr_in(rqstp)->sin_addr.s_addr;
> +	struct nfs4_client *conf, *unconf;
> +	__u32   max_blocksize = svc_max_payload(rqstp);
> +	int status = 0;
> +
> +	if (STALE_CLIENTID(&cr_ses->clientid))
> +		return nfserr_stale_clientid;

review 11-13: no need to check that here since we're returning the
same error if we can't find it. Do the same for setclientid_confirm.

> +
> +	nfs4_lock_state();
> +	unconf = find_unconfirmed_client(&cr_ses->clientid);
> +	conf = find_confirmed_client(&cr_ses->clientid);
> +
> +	if (!conf && !unconf) {
> +		status = nfserr_stale_clientid;
> +		goto out;
> +	}

review 11-13: move downward as the final else lag.

> +	if (conf) {
> +		status = nfs_ok;
> +		if (conf->cl_seqid == cr_ses->seqid) {
> +			dprintk("Got a create_session replay! seqid= %d\n",
> +				conf->cl_seqid);
> +			goto out_replay;
> +		} else if (cr_ses->seqid != conf->cl_seqid + 1) {
> +			status = nfserr_seq_misordered;
> +			dprintk("Sequence misordered!\n");
> +			dprintk("Expected seqid= %d but got seqid= %d\n",
> +				conf->cl_seqid, cr_ses->seqid);
> +			goto out;
> +		}
> +		conf->cl_seqid++;
> +	} else if (unconf) {
> +		if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
> +		    (ip_addr != unconf->cl_addr)) {
> +			status = nfserr_clid_inuse;
> +			goto out;
> +		}
> +
> +		if (unconf->cl_seqid != cr_ses->seqid) {
> +			status = nfserr_seq_misordered;
> +			goto out;
> +		}
> +
> +		move_to_confirmed(unconf);
> +
> +		/*
> +		 * We do not support RDMA or persistent sessions
> +		 */
> +		cr_ses->flags &= ~SESSION4_PERSIST;
> +		cr_ses->flags &= ~SESSION4_RDMA;
> +
> +		conf = unconf;
> +	}
> +
> +	status = alloc_init_session(conf, cr_ses);
> +
> +out_replay:
> +	memcpy(cr_ses->sessionid, conf->cl_sessionid, 16);
> +	cr_ses->seqid = conf->cl_seqid;
> +	cr_ses->fore_channel.maxreq_sz = max_blocksize;
> +	cr_ses->fore_channel.maxresp_sz = max_blocksize;
> +	cr_ses->fore_channel.maxresp_cached = max_blocksize;
> +	cr_ses->back_channel.maxreq_sz = max_blocksize;
> +	cr_ses->back_channel.maxresp_sz = max_blocksize;
> +	cr_ses->back_channel.maxresp_cached = max_blocksize;
> +
> +out:
> +	nfs4_unlock_state();
> +	dprintk("%s returns %d\n", __func__, ntohl(status));
> +	return status;
>  }
>  
>  __be32
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 055f1ad..02c82d4 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -1119,7 +1119,108 @@ static __be32
>  nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
>  			    struct nfsd4_create_session *sess)
>  {
> -	return nfserr_opnotsupp;	/* stub */
> +	DECODE_HEAD;
> +
> +	u32 dummy;
> +	char *machine_name;
> +	int i;
> +	int nr_secflavs;
> +
> +	READ_BUF(16);
> +	COPYMEM(&sess->clientid, 8);
> +	READ32(sess->seqid);
> +	READ32(sess->flags);
> +
> +	/* Fore channel attrs */
> +	READ_BUF(28);
> +	READ32(sess->fore_channel.headerpadsz);
> +	READ32(sess->fore_channel.maxreq_sz);
> +	READ32(sess->fore_channel.maxresp_sz);
> +	READ32(sess->fore_channel.maxresp_cached);
> +	READ32(sess->fore_channel.maxops);
> +	READ32(sess->fore_channel.maxreqs);
> +	READ32(sess->fore_channel.nr_rdma_attrs);
> +	if (sess->fore_channel.nr_rdma_attrs == 1) {
> +		READ_BUF(4);
> +		READ32(sess->fore_channel.rdma_attrs);
> +	} else if (sess->fore_channel.nr_rdma_attrs > 1) {
> +		dprintk("Too many fore channel attr bitmaps!\n");
> +		goto xdr_error;
> +	}
> +
> +	/* Back channel attrs */
> +	READ_BUF(28);
> +	READ32(sess->back_channel.headerpadsz);
> +	READ32(sess->back_channel.maxreq_sz);
> +	READ32(sess->back_channel.maxresp_sz);
> +	READ32(sess->back_channel.maxresp_cached);
> +	READ32(sess->back_channel.maxops);
> +	READ32(sess->back_channel.maxreqs);
> +	READ32(sess->back_channel.nr_rdma_attrs);
> +	if (sess->back_channel.nr_rdma_attrs == 1) {
> +		READ_BUF(4);
> +		READ32(sess->back_channel.rdma_attrs);
> +	} else if (sess->back_channel.nr_rdma_attrs > 1) {
> +		dprintk("Too many back channel attr bitmaps!\n");
> +		goto xdr_error;
> +	}
> +
> +	READ_BUF(8);
> +	READ32(sess->callback_prog);
> +
> +	/* callback_sec_params4 */
> +	READ32(nr_secflavs);
> +	for (i = 0; i < nr_secflavs; ++i) {
> +		READ_BUF(4);
> +		READ32(dummy);
> +		switch (dummy) {
> +		case RPC_AUTH_NULL:
> +			/* Nothing to read */
> +			break;
> +		case RPC_AUTH_UNIX:
> +			READ_BUF(8);
> +			/* stamp */
> +			READ32(dummy);
> +
> +			/* machine name */
> +			READ32(dummy);
> +			READ_BUF(dummy);
> +			SAVEMEM(machine_name, dummy);
> +
> +			/* uid, gid */
> +			READ_BUF(8);
> +			READ32(sess->uid);
> +			READ32(sess->gid);
> +
> +			/* more gids */
> +			READ_BUF(4);
> +			READ32(dummy);
> +			READ_BUF(dummy * 4);
> +			for (i = 0; i < dummy; ++i)
> +				READ32(dummy);
> +			break;
> +		case RPC_AUTH_GSS:
> +			dprintk("RPC_AUTH_GSS callback secflavor "
> +				"not supported!\n");
> +			READ_BUF(8);
> +			/* gcbp_service */
> +			READ32(dummy);
> +			/* gcbp_handle_from_server */
> +			READ32(dummy);
> +			READ_BUF(dummy);
> +			p += XDR_QUADLEN(dummy);
> +			/* gcbp_handle_from_client */
> +			READ_BUF(4);
> +			READ32(dummy);
> +			READ_BUF(dummy);
> +			p += XDR_QUADLEN(dummy);
> +			break;
> +		default:
> +			dprintk("Illegal callback secflavor\n");
> +			return nfserr_inval;
> +		}
> +	}
> +	DECODE_TAIL;
>  }
>  
>  static __be32
> @@ -2839,7 +2940,49 @@ static __be32
>  nfsd4_encode_create_session(struct nfsd4_compoundres *resp, int nfserr,
>  			    struct nfsd4_create_session *sess)
>  {
> -	/* stub */
> +	ENCODE_HEAD;
> +
> +	if (nfserr)
> +		goto out;
> +
> +	RESERVE_SPACE(24);
> +	WRITEMEM(sess->sessionid, sizeof(sess->sessionid));
> +	WRITE32(sess->seqid);
> +	WRITE32(sess->flags);
> +	ADJUST_ARGS();
> +
> +	RESERVE_SPACE(28);
> +	WRITE32(sess->fore_channel.headerpadsz);
> +	WRITE32(sess->fore_channel.maxreq_sz);
> +	WRITE32(sess->fore_channel.maxresp_sz);
> +	WRITE32(sess->fore_channel.maxresp_cached);
> +	WRITE32(sess->fore_channel.maxops);
> +	WRITE32(sess->fore_channel.maxreqs);
> +	WRITE32(sess->fore_channel.nr_rdma_attrs);
> +	ADJUST_ARGS();
> +
> +	if (sess->fore_channel.nr_rdma_attrs) {
> +		RESERVE_SPACE(4);
> +		WRITE32(sess->fore_channel.rdma_attrs);
> +		ADJUST_ARGS();
> +	}
> +
> +	RESERVE_SPACE(28);
> +	WRITE32(sess->back_channel.headerpadsz);
> +	WRITE32(sess->back_channel.maxreq_sz);
> +	WRITE32(sess->back_channel.maxresp_sz);
> +	WRITE32(sess->back_channel.maxresp_cached);
> +	WRITE32(sess->back_channel.maxops);
> +	WRITE32(sess->back_channel.maxreqs);
> +	WRITE32(sess->back_channel.nr_rdma_attrs);
> +	ADJUST_ARGS();
> +
> +	if (sess->back_channel.nr_rdma_attrs) {
> +		RESERVE_SPACE(4);
> +		WRITE32(sess->back_channel.rdma_attrs);
> +		ADJUST_ARGS();
> +	}
> +out:
>  	return nfserr;
>  }
>  
> diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
> index 9bbfd88..94b5366 100644
> --- a/include/linux/nfsd/state.h
> +++ b/include/linux/nfsd/state.h
> @@ -217,6 +217,9 @@ struct nfs4_client {
>  #if defined(CONFIG_NFSD_V4_1)
>  	u32			cl_seqid;	/* seqid for create_session */
>  	u32			cl_exchange_flags;
> +	nfs41_sessionid		cl_sessionid;
> +
> +	struct svc_xprt		*cl_cb_xprt;	/* 4.1 callback transport */
>  #endif /* CONFIG_NFSD_V4_1 */
>  };
>  
> diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
> index aee8996..75d93ab 100644
> --- a/include/linux/nfsd/xdr4.h
> +++ b/include/linux/nfsd/xdr4.h
> @@ -362,8 +362,27 @@ struct nfsd4_exchange_id {
>  	u32		seqid;
>  };
>  
> +struct nfsd4_channel {
> +	u32		headerpadsz;
> +	u32		maxreq_sz;
> +	u32		maxresp_sz;
> +	u32		maxresp_cached;
> +	u32		maxops;
> +	u32		maxreqs;
> +	u32		nr_rdma_attrs;
> +	u32		rdma_attrs;
> +};
> +
>  struct nfsd4_create_session {
> -	int	foo;	/* stub */
> +	clientid_t		clientid;
> +	nfs41_sessionid		sessionid;
> +	u32			seqid;
> +	u32			flags;
> +	struct nfsd4_channel	fore_channel;
> +	struct nfsd4_channel	back_channel;
> +	u32			callback_prog;
> +	u32			uid;
> +	u32			gid;
>  };
>  
>  struct nfsd4_sequence {