unimore/kernel-hacking-2024-linux-steffo
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nfsd: Protect session creation and client confirm using client_lock

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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 <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Jeff Layton 2014-07-30 08:27:07 -04:00 committed by J. Bruce Fields
parent 3dbacee6e1
commit d20c11d86d
1 changed files with 39 additions and 26 deletions
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65
fs/nfsd/nfs4state.c
View file

@ -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;