git: 088ba4356a11 - main - nfsd: Fix CreateSession for an established ClientID
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Date: Wed, 13 Jul 2022 23:30:25 UTC
The branch main has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=088ba4356a114416b1d68bf5ae3b3e0accf6d0df commit 088ba4356a114416b1d68bf5ae3b3e0accf6d0df Author: Rick Macklem <rmacklem@FreeBSD.org> AuthorDate: 2022-07-13 23:28:56 +0000 Commit: Rick Macklem <rmacklem@FreeBSD.org> CommitDate: 2022-07-13 23:28:56 +0000 nfsd: Fix CreateSession for an established ClientID I mis-read the RFC w.r.t. handling of the sequenceid when a CreateSession is done after the initial one that confirms the ClientID. Fortunately this does not affect most extant NFSv4.1/4.2 clients, since they only acquire a single session for TCP for a ClientID (Solaris might be an exception?). This patch fixes the server to handle this case, where the RFC requires the sequenceid be incremented for each CreateSession and is required to reply to a retried CreateSession with a cached reply. It adds a field to nfsclient called lc_prevsess, which caches the sessionid, which is the only field in a CreateSession reply that will change for a retry, to implement this reply cache. The recent commits up to d4a11b3e3bdd that mark session slots bad when "intr" and/or "soft" mounts are used by the client needs this server patch. Without this patch, the client will do a full recovery, including a new ClientID, losing all byte range locks. However, prior to the recent client commits, the client would hang when all session slots were bad, so even without this patch it is not a regression. PR: 260011 MFC after: 2 weeks --- sys/fs/nfs/nfsrvstate.h | 1 + sys/fs/nfsserver/nfs_nfsdstate.c | 63 ++++++++++++++++++++++++++-------------- 2 files changed, 43 insertions(+), 21 deletions(-) diff --git a/sys/fs/nfs/nfsrvstate.h b/sys/fs/nfs/nfsrvstate.h index 9eebeece9727..4c171e8b3f50 100644 --- a/sys/fs/nfs/nfsrvstate.h +++ b/sys/fs/nfs/nfsrvstate.h @@ -99,6 +99,7 @@ struct nfsclient { struct nfsstatehead lc_deleg; /* Delegations */ struct nfsstatehead lc_olddeleg; /* and old delegations */ struct nfssessionhead lc_session; /* List of NFSv4.1 sessions */ + uint64_t lc_prevsess; /* CreateSession cache */ time_t lc_expiry; /* Expiry time (sec) */ time_t lc_delegtime; /* Old deleg expiry (sec) */ nfsquad_t lc_clientid; /* 64 bit clientid */ diff --git a/sys/fs/nfsserver/nfs_nfsdstate.c b/sys/fs/nfsserver/nfs_nfsdstate.c index eafb7c958396..aac845e68af7 100644 --- a/sys/fs/nfsserver/nfs_nfsdstate.c +++ b/sys/fs/nfsserver/nfs_nfsdstate.c @@ -336,10 +336,10 @@ nfsrv_setclient(struct nfsrv_descript *nd, struct nfsclient **new_clpp, * Add it after assigning a client id to it. */ new_clp->lc_flags |= LCL_NEEDSCONFIRM; - if ((nd->nd_flag & ND_NFSV41) != 0) - new_clp->lc_confirm.lval[0] = confirmp->lval[0] = - ++confirm_index; - else + if ((nd->nd_flag & ND_NFSV41) != 0) { + confirmp->lval[0] = ++confirm_index; + new_clp->lc_confirm.lval[0] = confirmp->lval[0] - 1; + } else confirmp->qval = new_clp->lc_confirm.qval = ++confirm_index; clientidp->lval[0] = new_clp->lc_clientid.lval[0] = @@ -348,6 +348,7 @@ nfsrv_setclient(struct nfsrv_descript *nd, struct nfsclient **new_clpp, nfsrv_nextclientindex(); new_clp->lc_stateindex = 0; new_clp->lc_statemaxindex = 0; + new_clp->lc_prevsess = 0; new_clp->lc_cbref = 0; new_clp->lc_expiry = nfsrv_leaseexpiry(); LIST_INIT(&new_clp->lc_open); @@ -449,10 +450,10 @@ nfsrv_setclient(struct nfsrv_descript *nd, struct nfsclient **new_clpp, } new_clp->lc_flags |= LCL_NEEDSCONFIRM; - if ((nd->nd_flag & ND_NFSV41) != 0) - new_clp->lc_confirm.lval[0] = confirmp->lval[0] = - ++confirm_index; - else + if ((nd->nd_flag & ND_NFSV41) != 0) { + confirmp->lval[0] = ++confirm_index; + new_clp->lc_confirm.lval[0] = confirmp->lval[0] - 1; + } else confirmp->qval = new_clp->lc_confirm.qval = ++confirm_index; clientidp->lval[0] = new_clp->lc_clientid.lval[0] = @@ -461,6 +462,7 @@ nfsrv_setclient(struct nfsrv_descript *nd, struct nfsclient **new_clpp, nfsrv_nextclientindex(); new_clp->lc_stateindex = 0; new_clp->lc_statemaxindex = 0; + new_clp->lc_prevsess = 0; new_clp->lc_cbref = 0; new_clp->lc_expiry = nfsrv_leaseexpiry(); @@ -596,6 +598,7 @@ nfsrv_getclient(nfsquad_t clientid, int opflags, struct nfsclient **clpp, struct nfssessionhash *shp; struct nfsdsession *sep; uint64_t sessid[2]; + bool sess_replay; static uint64_t next_sess = 0; if (clpp) @@ -676,13 +679,29 @@ nfsrv_getclient(nfsquad_t clientid, int opflags, struct nfsclient **clpp, * Perform any operations specified by the opflags. */ if (opflags & CLOPS_CONFIRM) { - if ((nd->nd_flag & ND_NFSV41) != 0 && - clp->lc_confirm.lval[0] != confirm.lval[0]) + sess_replay = false; + if ((nd->nd_flag & ND_NFSV41) != 0) { + /* + * For the case where lc_confirm.lval[0] == confirm.lval[0], + * use the new session, but with the previous sessionid. + * This is not exactly what the RFC describes, but should + * result in the same reply as the previous CreateSession. + */ + if (clp->lc_confirm.lval[0] + 1 == confirm.lval[0]) { + clp->lc_confirm.lval[0] = confirm.lval[0]; + clp->lc_prevsess = sessid[0]; + } else if (clp->lc_confirm.lval[0] == confirm.lval[0]) { + if (clp->lc_prevsess == 0) + error = NFSERR_SEQMISORDERED; + else + sessid[0] = clp->lc_prevsess; + sess_replay = true; + } else error = NFSERR_SEQMISORDERED; - else if ((nd->nd_flag & ND_NFSV41) == 0 && + } else if ((nd->nd_flag & ND_NFSV41) == 0 && clp->lc_confirm.qval != confirm.qval) error = NFSERR_STALECLIENTID; - else if (nfsrv_notsamecredname(nd, clp)) + if (error == 0 && nfsrv_notsamecredname(nd, clp)) error = NFSERR_CLIDINUSE; if (!error) { @@ -716,7 +735,7 @@ nfsrv_getclient(nfsquad_t clientid, int opflags, struct nfsclient **clpp, if (nsep != NULL) { /* Hold a reference on the xprt for a backchannel. */ if ((nsep->sess_crflags & NFSV4CRSESS_CONNBACKCHAN) - != 0) { + != 0 && !sess_replay) { if (clp->lc_req.nr_client == NULL) clp->lc_req.nr_client = (struct __rpc_client *) clnt_bck_create(nd->nd_xprt->xp_socket, @@ -735,14 +754,16 @@ nfsrv_getclient(nfsquad_t clientid, int opflags, struct nfsclient **clpp, NFSX_V4SESSIONID); NFSBCOPY(sessid, nsep->sess_cbsess.nfsess_sessionid, NFSX_V4SESSIONID); - shp = NFSSESSIONHASH(nsep->sess_sessionid); - NFSLOCKSTATE(); - NFSLOCKSESSION(shp); - LIST_INSERT_HEAD(&shp->list, nsep, sess_hash); - LIST_INSERT_HEAD(&clp->lc_session, nsep, sess_list); - nsep->sess_clp = clp; - NFSUNLOCKSESSION(shp); - NFSUNLOCKSTATE(); + if (!sess_replay) { + shp = NFSSESSIONHASH(nsep->sess_sessionid); + NFSLOCKSTATE(); + NFSLOCKSESSION(shp); + LIST_INSERT_HEAD(&shp->list, nsep, sess_hash); + LIST_INSERT_HEAD(&clp->lc_session, nsep, sess_list); + nsep->sess_clp = clp; + NFSUNLOCKSESSION(shp); + NFSUNLOCKSTATE(); + } } } } else if (clp->lc_flags & LCL_NEEDSCONFIRM) {