From d20c11d86d8f821a64eac7d6c8f296f06d935f4f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 30 Jul 2014 08:27:07 -0400 Subject: [PATCH] nfsd: Protect session creation and client confirm using client_lock In particular, we want to ensure that the move_to_confirmed() is protected by the nn->client_lock spin lock, so that we can use that when looking up the clientid etc. instead of relying on the client_mutex. Signed-off-by: Trond Myklebust Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 65 +++++++++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 26 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f149e30475db..52a4677f6f35 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -137,17 +137,6 @@ static __be32 mark_client_expired_locked(struct nfs4_client *clp) return nfs_ok; } -static __be32 mark_client_expired(struct nfs4_client *clp) -{ - struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); - __be32 ret; - - spin_lock(&nn->client_lock); - ret = mark_client_expired_locked(clp); - spin_unlock(&nn->client_lock); - return ret; -} - static __be32 get_client_locked(struct nfs4_client *clp) { if (is_client_expired(clp)) @@ -1437,12 +1426,10 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru new->se_cb_sec = cses->cb_sec; atomic_set(&new->se_ref, 0); idx = hash_sessionid(&new->se_sessionid); - spin_lock(&nn->client_lock); list_add(&new->se_hash, &nn->sessionid_hashtbl[idx]); spin_lock(&clp->cl_lock); list_add(&new->se_perclnt, &clp->cl_sessions); spin_unlock(&clp->cl_lock); - spin_unlock(&nn->client_lock); if (cses->flags & SESSION4_BACK_CHAN) { struct sockaddr *sa = svc_addr(rqstp); @@ -2411,6 +2398,7 @@ nfsd4_create_session(struct svc_rqst *rqstp, { struct sockaddr *sa = svc_addr(rqstp); struct nfs4_client *conf, *unconf; + struct nfs4_client *old = NULL; struct nfsd4_session *new; struct nfsd4_conn *conn; struct nfsd4_clid_slot *cs_slot = NULL; @@ -2437,6 +2425,7 @@ nfsd4_create_session(struct svc_rqst *rqstp, goto out_free_session; nfs4_lock_state(); + spin_lock(&nn->client_lock); unconf = find_unconfirmed_client(&cr_ses->clientid, true, nn); conf = find_confirmed_client(&cr_ses->clientid, true, nn); WARN_ON_ONCE(conf && unconf); @@ -2455,7 +2444,6 @@ nfsd4_create_session(struct svc_rqst *rqstp, goto out_free_conn; } } else if (unconf) { - struct nfs4_client *old; if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) || !rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) { status = nfserr_clid_inuse; @@ -2473,10 +2461,10 @@ nfsd4_create_session(struct svc_rqst *rqstp, } old = find_confirmed_client_by_name(&unconf->cl_name, nn); if (old) { - status = mark_client_expired(old); + status = mark_client_expired_locked(old); if (status) goto out_free_conn; - expire_client(old); + unhash_client_locked(old); } move_to_confirmed(unconf); conf = unconf; @@ -2492,20 +2480,29 @@ nfsd4_create_session(struct svc_rqst *rqstp, cr_ses->flags &= ~SESSION4_RDMA; init_session(rqstp, new, conf, cr_ses); - nfsd4_init_conn(rqstp, conn, new); + nfsd4_get_session_locked(new); memcpy(cr_ses->sessionid.data, new->se_sessionid.data, NFS4_MAX_SESSIONID_LEN); cs_slot->sl_seqid++; cr_ses->seqid = cs_slot->sl_seqid; - /* cache solo and embedded create sessions under the state lock */ + /* cache solo and embedded create sessions under the client_lock */ nfsd4_cache_create_session(cr_ses, cs_slot, status); + spin_unlock(&nn->client_lock); + /* init connection and backchannel */ + nfsd4_init_conn(rqstp, conn, new); + nfsd4_put_session(new); nfs4_unlock_state(); + if (old) + expire_client(old); return status; out_free_conn: + spin_unlock(&nn->client_lock); nfs4_unlock_state(); free_conn(conn); + if (old) + expire_client(old); out_free_session: __free_session(new); out_release_drc_mem: @@ -2965,6 +2962,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, struct nfsd4_setclientid_confirm *setclientid_confirm) { struct nfs4_client *conf, *unconf; + struct nfs4_client *old = NULL; nfs4_verifier confirm = setclientid_confirm->sc_confirm; clientid_t * clid = &setclientid_confirm->sc_clientid; __be32 status; @@ -2974,6 +2972,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, return nfserr_stale_clientid; nfs4_lock_state(); + spin_lock(&nn->client_lock); conf = find_confirmed_client(clid, false, nn); unconf = find_unconfirmed_client(clid, false, nn); /* @@ -2997,21 +2996,29 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, } status = nfs_ok; if (conf) { /* case 1: callback update */ + old = unconf; + unhash_client_locked(old); nfsd4_change_callback(conf, &unconf->cl_cb_conn); - nfsd4_probe_callback(conf); - expire_client(unconf); } else { /* case 3: normal case; new or rebooted client */ - conf = find_confirmed_client_by_name(&unconf->cl_name, nn); - if (conf) { - status = mark_client_expired(conf); + old = find_confirmed_client_by_name(&unconf->cl_name, nn); + if (old) { + status = mark_client_expired_locked(old); if (status) goto out; - expire_client(conf); + unhash_client_locked(old); } move_to_confirmed(unconf); - nfsd4_probe_callback(unconf); + conf = unconf; } + get_client_locked(conf); + spin_unlock(&nn->client_lock); + nfsd4_probe_callback(conf); + spin_lock(&nn->client_lock); + put_client_renew_locked(conf); out: + spin_unlock(&nn->client_lock); + if (old) + expire_client(old); nfs4_unlock_state(); return status; } @@ -5648,7 +5655,13 @@ nfs4_check_open_reclaim(clientid_t *clid, u64 nfsd_forget_client(struct nfs4_client *clp, u64 max) { - if (mark_client_expired(clp)) + __be32 ret; + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + + spin_lock(&nn->client_lock); + ret = mark_client_expired_locked(clp); + spin_unlock(&nn->client_lock); + if (ret != nfs_ok) return 0; expire_client(clp); return 1; -- 2.20.1