nfsd41: create_session operation
authorAndy Adamson <andros@netapp.com>
Fri, 3 Apr 2009 05:28:28 +0000 (08:28 +0300)
committerJ. Bruce Fields <bfields@citi.umich.edu>
Sat, 4 Apr 2009 00:41:18 +0000 (17:41 -0700)
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.

NFSD_PAGES_PER_SLOT is used for the max response cached calculation, and for
the counting of DRC pages using the hard limits set in struct srv_serv.

A note on NFSD_PAGES_PER_SLOT:

Other patches in this series allow for NFSD_PAGES_PER_SLOT + 1 pages to be
cached in a DRC slot when the response size is less than NFSD_PAGES_PER_SLOT *
PAGE_SIZE but xdr_buf pages are used. e.g. a READDIR operation will encode a
small amount of data in the xdr_buf head, and then the READDIR in the xdr_buf
pages.  So, the hard limit calculation use of pages by a session is
underestimated by the number of cached operations using the xdr_buf pages.

Yet another patch caches no pages for the solo sequence operation, or any
compound where cache_this is False.  So the hard limit calculation use of
pages by a session is overestimated by the number of these operations in the
cache.

TODO: improve resource pre-allocation and negotiate session
parameters accordingly.  Respect and possibly adjust
backchannel attributes.

Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
[nfsd41: remove headerpadsz from channel attributes]
Our client and server only support a headerpadsz of 0.
[nfsd41: use DRC limits in fore channel init]
[nfsd41: do not change CREATE_SESSION back channel attrs]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[use sessionid_lock spin lock]
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from alloc_init_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[simplify nfsd4_encode_create_session error handling]
[nfsd41: fix comment style in init_forechannel_attrs]
[nfsd41: allocate struct nfsd4_session and slot table in one piece]
[nfsd41: no need to INIT_LIST_HEAD in alloc_init_session just prior to list_add]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/nfsd/nfs4state.c
fs/nfsd/nfs4xdr.c
include/linux/nfsd/state.h
include/linux/nfsd/xdr4.h

index f25a7d2..463ae39 100644 (file)
@@ -68,6 +68,7 @@ static u32 current_delegid = 1;
 static u32 nfs4_init;
 static stateid_t zerostateid;             /* bits all 0 */
 static stateid_t onestateid;              /* bits all 1 */
+static u64 current_sessionid = 1;
 
 #define ZERO_STATEID(stateid) (!memcmp((stateid), &zerostateid, sizeof(stateid_t)))
 #define ONE_STATEID(stateid)  (!memcmp((stateid), &onestateid, sizeof(stateid_t)))
@@ -401,6 +402,131 @@ dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
        dprintk("%s: %u:%u:%u:%u\n", fn, ptr[0], ptr[1], ptr[2], ptr[3]);
 }
 
+static void
+gen_sessionid(struct nfsd4_session *ses)
+{
+       struct nfs4_client *clp = ses->se_client;
+       struct nfsd4_sessionid *sid;
+
+       sid = (struct nfsd4_sessionid *)ses->se_sessionid.data;
+       sid->clientid = clp->cl_clientid;
+       sid->sequence = current_sessionid++;
+       sid->reserved = 0;
+}
+
+/*
+ * Give the client the number of slots it requests bound by
+ * NFSD_MAX_SLOTS_PER_SESSION and by sv_drc_max_pages.
+ *
+ * If we run out of pages (sv_drc_pages_used == sv_drc_max_pages) we
+ * should (up to a point) re-negotiate active sessions and reduce their
+ * slot usage to make rooom for new connections. For now we just fail the
+ * create session.
+ */
+static int set_forechannel_maxreqs(struct nfsd4_channel_attrs *fchan)
+{
+       int status = 0, np = fchan->maxreqs * NFSD_PAGES_PER_SLOT;
+
+       spin_lock(&nfsd_serv->sv_lock);
+       if (np + nfsd_serv->sv_drc_pages_used > nfsd_serv->sv_drc_max_pages)
+               np = nfsd_serv->sv_drc_max_pages - nfsd_serv->sv_drc_pages_used;
+       nfsd_serv->sv_drc_pages_used += np;
+       spin_unlock(&nfsd_serv->sv_lock);
+
+       if (np <= 0) {
+               status = nfserr_resource;
+               fchan->maxreqs = 0;
+       } else
+               fchan->maxreqs = np / NFSD_PAGES_PER_SLOT;
+
+       return status;
+}
+
+/*
+ * fchan holds the client values on input, and the server values on output
+ */
+static int init_forechannel_attrs(struct svc_rqst *rqstp,
+                                   struct nfsd4_session *session,
+                                   struct nfsd4_channel_attrs *fchan)
+{
+       int status = 0;
+       __u32   maxcount = svc_max_payload(rqstp);
+
+       /* headerpadsz set to zero in encode routine */
+
+       /* Use the client's max request and max response size if possible */
+       if (fchan->maxreq_sz > maxcount)
+               fchan->maxreq_sz = maxcount;
+       session->se_fmaxreq_sz = fchan->maxreq_sz;
+
+       if (fchan->maxresp_sz > maxcount)
+               fchan->maxresp_sz = maxcount;
+       session->se_fmaxresp_sz = fchan->maxresp_sz;
+
+       /* Set the max response cached size our default which is
+        * a multiple of PAGE_SIZE and small */
+       session->se_fmaxresp_cached = NFSD_PAGES_PER_SLOT * PAGE_SIZE;
+       fchan->maxresp_cached = session->se_fmaxresp_cached;
+
+       /* Use the client's maxops if possible */
+       if (fchan->maxops > NFSD_MAX_OPS_PER_COMPOUND)
+               fchan->maxops = NFSD_MAX_OPS_PER_COMPOUND;
+       session->se_fmaxops = fchan->maxops;
+
+       /* try to use the client requested number of slots */
+       if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
+               fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;
+
+       /* FIXME: Error means no more DRC pages so the server should
+        * recover pages from existing sessions. For now fail session
+        * creation.
+        */
+       status = set_forechannel_maxreqs(fchan);
+
+       session->se_fnumslots = fchan->maxreqs;
+       return status;
+}
+
+static int
+alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp,
+                  struct nfsd4_create_session *cses)
+{
+       struct nfsd4_session *new, tmp;
+       int idx, status = nfserr_resource, slotsize;
+
+       memset(&tmp, 0, sizeof(tmp));
+
+       /* FIXME: For now, we just accept the client back channel attributes. */
+       status = init_forechannel_attrs(rqstp, &tmp, &cses->fore_channel);
+       if (status)
+               goto out;
+
+       /* allocate struct nfsd4_session and slot table in one piece */
+       slotsize = tmp.se_fnumslots * sizeof(struct nfsd4_slot);
+       new = kzalloc(sizeof(*new) + slotsize, GFP_KERNEL);
+       if (!new)
+               goto out;
+
+       memcpy(new, &tmp, sizeof(*new));
+
+       new->se_client = clp;
+       gen_sessionid(new);
+       idx = hash_sessionid(&new->se_sessionid);
+       memcpy(clp->cl_sessionid.data, new->se_sessionid.data,
+              NFS4_MAX_SESSIONID_LEN);
+
+       new->se_flags = cses->flags;
+       kref_init(&new->se_ref);
+       spin_lock(&sessionid_lock);
+       list_add(&new->se_hash, &sessionid_hashtbl[idx]);
+       list_add(&new->se_perclnt, &clp->cl_sessions);
+       spin_unlock(&sessionid_lock);
+
+       status = nfs_ok;
+out:
+       return status;
+}
+
 /* caller must hold sessionid_lock */
 static struct nfsd4_session *
 find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid)
@@ -1182,7 +1308,67 @@ 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;
+       int status = 0;
+
+       nfs4_lock_state();
+       unconf = find_unconfirmed_client(&cr_ses->clientid);
+       conf = find_confirmed_client(&cr_ses->clientid);
+
+       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;
+       } else {
+               status = nfserr_stale_clientid;
+               goto out;
+       }
+
+       status = alloc_init_session(rqstp, conf, cr_ses);
+       if (status)
+               goto out;
+
+out_replay:
+       memcpy(cr_ses->sessionid.data, conf->cl_sessionid.data,
+              NFS4_MAX_SESSIONID_LEN);
+       cr_ses->seqid = conf->cl_seqid;
+
+out:
+       nfs4_unlock_state();
+       dprintk("%s returns %d\n", __func__, ntohl(status));
+       return status;
 }
 
 __be32
index 09415bc..671f9b9 100644 (file)
@@ -1099,7 +1099,108 @@ 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(dummy); /* headerpadsz is always 0 */
+       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(dummy); /* headerpadsz is always 0 */
+       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
@@ -2821,8 +2922,49 @@ static __be32
 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, int nfserr,
                            struct nfsd4_create_session *sess)
 {
-       /* stub */
-       return nfserr;
+       ENCODE_HEAD;
+
+       if (nfserr)
+               return nfserr;
+
+       RESERVE_SPACE(24);
+       WRITEMEM(sess->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+       WRITE32(sess->seqid);
+       WRITE32(sess->flags);
+       ADJUST_ARGS();
+
+       RESERVE_SPACE(28);
+       WRITE32(0); /* 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(0); /* 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();
+       }
+       return 0;
 }
 
 static __be32
index f1edb1d..692edf4 100644 (file)
@@ -99,8 +99,12 @@ struct nfs4_callback {
        struct rpc_clnt *       cb_client;
 };
 
+/* Maximum number of slots per session. 128 is useful for long haul TCP */
+#define NFSD_MAX_SLOTS_PER_SESSION     128
 /* Maximum number of pages per slot cache entry */
 #define NFSD_PAGES_PER_SLOT    1
+/* Maximum number of operations per session compound */
+#define NFSD_MAX_OPS_PER_COMPOUND      16
 
 struct nfsd4_cache_entry {
        __be32          ce_status;
@@ -129,7 +133,7 @@ struct nfsd4_session {
        u32                     se_fmaxresp_cached;
        u32                     se_fmaxops;
        u32                     se_fnumslots;
-       struct nfsd4_slot       *se_slots;      /* forward channel slots */
+       struct nfsd4_slot       se_slots[];     /* forward channel slots */
 };
 
 static inline void
@@ -188,6 +192,7 @@ struct nfs4_client {
        struct list_head        cl_sessions;
        u32                     cl_seqid;       /* seqid for create_session */
        u32                     cl_exchange_flags;
+       struct nfs4_sessionid   cl_sessionid;
 };
 
 /* struct nfs4_client_reset
index 69cb467..9468829 100644 (file)
@@ -359,8 +359,27 @@ struct nfsd4_exchange_id {
        int             spa_how;
 };
 
+struct nfsd4_channel_attrs {
+       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;
+       struct nfs4_sessionid   sessionid;
+       u32                     seqid;
+       u32                     flags;
+       struct nfsd4_channel_attrs fore_channel;
+       struct nfsd4_channel_attrs back_channel;
+       u32                     callback_prog;
+       u32                     uid;
+       u32                     gid;
 };
 
 struct nfsd4_sequence {