From 3dbacee6e127e7595f83654251cf129cbadc2c26 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 30 Jul 2014 08:27:06 -0400 Subject: [PATCH] nfsd: Protect unconfirmed client creation using client_lock ...instead of relying on the client_mutex. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 4b42cb95e315..f149e30475db 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1923,7 +1923,7 @@ add_to_unconfirmed(struct nfs4_client *clp) add_clp_to_name_tree(clp, &nn->unconf_name_tree); idhashval = clientid_hashval(clp->cl_clientid.cl_id); list_add(&clp->cl_idhash, &nn->unconf_id_hashtbl[idhashval]); - renew_client(clp); + renew_client_locked(clp); } static void @@ -1937,7 +1937,7 @@ move_to_confirmed(struct nfs4_client *clp) rb_erase(&clp->cl_namenode, &nn->unconf_name_tree); add_clp_to_name_tree(clp, &nn->conf_name_tree); set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags); - renew_client(clp); + renew_client_locked(clp); } static struct nfs4_client * @@ -1950,7 +1950,7 @@ find_client_in_id_table(struct list_head *tbl, clientid_t *clid, bool sessions) if (same_clid(&clp->cl_clientid, clid)) { if ((bool)clp->cl_minorversion != sessions) return NULL; - renew_client(clp); + renew_client_locked(clp); return clp; } } @@ -2152,7 +2152,8 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_exchange_id *exid) { - struct nfs4_client *unconf, *conf, *new; + struct nfs4_client *conf, *new; + struct nfs4_client *unconf = NULL; __be32 status; char addr_str[INET6_ADDRSTRLEN]; nfs4_verifier verf = exid->verifier; @@ -2187,6 +2188,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, /* Cases below refer to rfc 5661 section 18.35.4: */ nfs4_lock_state(); + spin_lock(&nn->client_lock); conf = find_confirmed_client_by_name(&exid->clname, nn); if (conf) { bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred); @@ -2218,7 +2220,6 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, status = nfserr_clid_inuse; goto out; } - expire_client(conf); goto out_new; } if (verfs_match) { /* case 2 */ @@ -2226,6 +2227,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, goto out_copy; } /* case 5, client reboot */ + conf = NULL; goto out_new; } @@ -2236,17 +2238,18 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, unconf = find_unconfirmed_client_by_name(&exid->clname, nn); if (unconf) /* case 4, possible retry or client restart */ - expire_client(unconf); + unhash_client_locked(unconf); /* case 1 (normal case) */ out_new: + if (conf) + unhash_client_locked(conf); new->cl_minorversion = cstate->minorversion; new->cl_mach_cred = (exid->spa_how == SP4_MACH_CRED); gen_clid(new, nn); add_to_unconfirmed(new); - conf = new; - new = NULL; + swap(new, conf); out_copy: exid->clientid.cl_boot = conf->cl_clientid.cl_boot; exid->clientid.cl_id = conf->cl_clientid.cl_id; @@ -2259,9 +2262,12 @@ out_copy: status = nfs_ok; out: + spin_unlock(&nn->client_lock); nfs4_unlock_state(); if (new) - free_client(new); + expire_client(new); + if (unconf) + expire_client(unconf); return status; } @@ -2900,7 +2906,8 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, { struct xdr_netobj clname = setclid->se_name; nfs4_verifier clverifier = setclid->se_verf; - struct nfs4_client *conf, *unconf, *new; + struct nfs4_client *conf, *new; + struct nfs4_client *unconf = NULL; __be32 status; struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); @@ -2909,6 +2916,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, return nfserr_jukebox; /* Cases below refer to rfc 3530 section 14.2.33: */ nfs4_lock_state(); + spin_lock(&nn->client_lock); conf = find_confirmed_client_by_name(&clname, nn); if (conf) { /* case 0: */ @@ -2926,7 +2934,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, } unconf = find_unconfirmed_client_by_name(&clname, nn); if (unconf) - expire_client(unconf); + unhash_client_locked(unconf); if (conf && same_verf(&conf->cl_verifier, &clverifier)) /* case 1: probable callback update */ copy_clid(new, conf); @@ -2941,9 +2949,12 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, new = NULL; status = nfs_ok; out: + spin_unlock(&nn->client_lock); nfs4_unlock_state(); if (new) free_client(new); + if (unconf) + expire_client(unconf); return status; } -- 2.20.1