From ec6b5d7b5064fde27aee798b81107ea3a830de85 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Fri, 3 Apr 2009 08:28:28 +0300 Subject: nfsd41: create_session operation 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 Signed-off-by: Dean Hildebrand [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 Signed-off-by: Benny Halevy [use sessionid_lock spin lock] [nfsd41: use bool inuse for slot state] Signed-off-by: Benny Halevy [nfsd41 remove sl_session from alloc_init_session] Signed-off-by: Andy Adamson Signed-off-by: Benny Halevy [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 Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 188 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 187 insertions(+), 1 deletion(-) (limited to 'fs/nfsd/nfs4state.c') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f25a7d2a9fac..463ae39df148 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -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 -- cgit v1.2.3