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Commit eb16e907 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

lockd: Start PF_INET6 listener only if IPv6 support is available 



Apparently a lot of people need to disable IPv6 completely on their
distributor-built systems, which have CONFIG_IPV6_MODULE enabled at
build time.

They do this by blacklisting the ipv6.ko module.  This causes the
creation of the lockd service listener to fail if CONFIG_IPV6_MODULE
is set, but the module cannot be loaded.

Now that the kernel's PF_INET6 RPC listeners are completely separate
from PF_INET listeners, we can always start PF_INET.  Then lockd can
try to start PF_INET6, but it isn't required to be available.

Note this has the added benefit that NLM callbacks from AF_INET6
servers will never come from AF_INET remotes.  We no longer have to
worry about matching mapped IPv4 addresses to AF_INET when comparing
addresses.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 93559828

fs/lockd/clntlock.c

+1 −50
Original line number Diff line number Diff line
@@ -139,55 +139,6 @@ int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout) 
	return 0;

}



#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

static const struct in6_addr *nlmclnt_map_v4addr(const struct sockaddr *sap,

						 struct in6_addr *addr_mapped)

{

	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;



	switch (sap->sa_family) {

	case AF_INET6:

		return &((const struct sockaddr_in6 *)sap)->sin6_addr;

	case AF_INET:

		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, addr_mapped);

		return addr_mapped;

	}



	return NULL;

}



/*

 * If lockd is using a PF_INET6 listener, all incoming requests appear

 * to come from AF_INET6 remotes.  The address of AF_INET remotes are

 * mapped to AF_INET6 automatically by the network layer.  In case the

 * user passed an AF_INET server address at mount time, ensure both

 * addresses are AF_INET6 before comparing them.

 */

static int nlmclnt_cmp_addr(const struct nlm_host *host,

			    const struct sockaddr *sap)

{

	const struct in6_addr *addr1;

	const struct in6_addr *addr2;

	struct in6_addr addr1_mapped;

	struct in6_addr addr2_mapped;



	addr1 = nlmclnt_map_v4addr(nlm_addr(host), &addr1_mapped);

	if (likely(addr1 != NULL)) {

		addr2 = nlmclnt_map_v4addr(sap, &addr2_mapped);

		if (likely(addr2 != NULL))

			return ipv6_addr_equal(addr1, addr2);

	}



	return 0;

}

#else	/* !(CONFIG_IPV6 || CONFIG_IPV6_MODULE) */

static int nlmclnt_cmp_addr(const struct nlm_host *host,

			    const struct sockaddr *sap)

{

	return nlm_cmp_addr(nlm_addr(host), sap);

}

#endif	/* !(CONFIG_IPV6 || CONFIG_IPV6_MODULE) */



/*

 * The server lockd has called us back to tell us the lock was granted

 */
@@ -215,7 +166,7 @@ __be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock) 
		 */

		if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)

			continue;

		if (!nlmclnt_cmp_addr(block->b_host, addr))

		if (!nlm_cmp_addr(nlm_addr(block->b_host), addr))

			continue;

		if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)

			continue;

fs/lockd/svc.c

+21 −9
Original line number Diff line number Diff line
@@ -193,20 +193,30 @@ lockd(void *vrqstp) 
	return 0;

}



static int create_lockd_listener(struct svc_serv *serv, char *name,

				 unsigned short port)

static int create_lockd_listener(struct svc_serv *serv, const char *name,

				 const int family, const unsigned short port)

{

	struct svc_xprt *xprt;



	xprt = svc_find_xprt(serv, name, 0, 0);

	xprt = svc_find_xprt(serv, name, family, 0);

	if (xprt == NULL)

		return svc_create_xprt(serv, name, PF_INET,

					port, SVC_SOCK_DEFAULTS);



		return svc_create_xprt(serv, name, family, port,

						SVC_SOCK_DEFAULTS);

	svc_xprt_put(xprt);

	return 0;

}



static int create_lockd_family(struct svc_serv *serv, const int family)

{

	int err;



	err = create_lockd_listener(serv, "udp", family, nlm_udpport);

	if (err < 0)

		return err;



	return create_lockd_listener(serv, "tcp", family, nlm_tcpport);

}



/*

 * Ensure there are active UDP and TCP listeners for lockd.

 *
@@ -222,13 +232,15 @@ static int make_socks(struct svc_serv *serv) 
	static int warned;

	int err;



	err = create_lockd_listener(serv, "udp", nlm_udpport);

	err = create_lockd_family(serv, PF_INET);

	if (err < 0)

		goto out_err;



	err = create_lockd_listener(serv, "tcp", nlm_tcpport);

	if (err < 0)

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

	err = create_lockd_family(serv, PF_INET6);

	if (err < 0 && err != -EAFNOSUPPORT)

		goto out_err;

#endif	/* CONFIG_IPV6 || CONFIG_IPV6_MODULE */



	warned = 0;

	return 0;