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Commit d20c11d8 authored by Jeff Layton's avatar Jeff Layton Committed by J. Bruce Fields
Browse files

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: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 3dbacee6

fs/nfsd/nfs4state.c

+39 −26
Original line number Diff line number Diff line
@@ -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;