[PATCH 005 of 9] knfsd: Be more selective in which sockets lockd listens on.

NeilBrown
2006-07-25T01:57:39Z

Currently lockd listens on UDP always, and TCP if CONFIG_NFSD_TCP
is set.

However as lockd performs services of the client as well, this is a
problem. If CONFIG_NfSD_TCP is not set, and a tcp mount is used, the
server will not be able to call back to lockd.

So:
- add an option to lockd_up saying which protocol is needed
- Always open sockets for which an explicit port was given, otherwise
only open a socket of the type required
- Change nfsd to do one lockd_up per socket rather than one per thread.

This
- removes the dependancy on CONFIG_NFSD_TCP
- means that lockd may open sockets other than at startup
- means that lockd will *not* listen on UDP if the only
mounts are TCP mount (and nfsd hasn't started).

The latter is the only one that concerns me at all - I don't know if
this might be a problem with some servers.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./fs/lockd/clntlock.c | 2 -
./fs/lockd/svc.c | 47 ++++++++++++++++++++++++++++++++++++-------
./fs/nfs/super.c | 6 +++--
./fs/nfsd/nfssvc.c | 16 +++++++++-----
./include/linux/lockd/bind.h | 2 -
5 files changed, 56 insertions(+), 17 deletions(-)

diff .prev/fs/lockd/clntlock.c ./fs/lockd/clntlock.c
--- .prev/fs/lockd/clntlock.c 2006-07-24 15:15:04.000000000 +1000
+++ ./fs/lockd/clntlock.c 2006-07-24 15:15:04.000000000 +1000
@@ -202,7 +202,7 @@ reclaimer(void *ptr)
/* This one ensures that our parent doesn't terminate while the
* reclaim is in progress */
lock_kernel();
- lockd_up();
+ lockd_up(0);

nlmclnt_prepare_reclaim(host);
/* First, reclaim all locks that have been marked. */

diff .prev/fs/lockd/svc.c ./fs/lockd/svc.c
--- .prev/fs/lockd/svc.c 2006-07-24 15:13:40.000000000 +1000
+++ ./fs/lockd/svc.c 2006-07-24 15:15:04.000000000 +1000
@@ -31,6 +31,7 @@
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
+#include <net/ip.h>
#include <linux/lockd/lockd.h>
#include <linux/nfs.h>

@@ -46,6 +47,7 @@ EXPORT_SYMBOL(nlmsvc_ops);
static DEFINE_MUTEX(nlmsvc_mutex);
static unsigned int nlmsvc_users;
static pid_t nlmsvc_pid;
+static struct svc_serv *nlmsvc_serv;
int nlmsvc_grace_period;
unsigned long nlmsvc_timeout;

@@ -112,6 +114,7 @@ lockd(struct svc_rqst *rqstp)
* Let our maker know we're running.
*/
nlmsvc_pid = current->pid;
+ nlmsvc_serv = serv;
complete(&lockd_start_done);

daemonize("lockd");
@@ -189,6 +192,7 @@ lockd(struct svc_rqst *rqstp)
nlmsvc_invalidate_all();
nlm_shutdown_hosts();
nlmsvc_pid = 0;
+ nlmsvc_serv = NULL;
} else
printk(KERN_DEBUG
"lockd: new process, skipping host shutdown\n");
@@ -205,11 +209,42 @@ lockd(struct svc_rqst *rqstp)
module_put_and_exit(0);
}

+
+static int find_socket(struct svc_serv *serv, int proto)
+{
+ struct svc_sock *svsk;
+ int found = 0;
+ list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
+ if (svsk->sk_sk->sk_protocol == proto) {
+ found = 1;
+ break;
+ }
+ return found;
+}
+
+static int make_socks(struct svc_serv *serv, int proto)
+{
+ /* Make any sockets that are needed but not present.
+ * If nlm_udpport or nlm_tcpport were set as module
+ * options, make those sockets unconditionally
+ */
+ int err = 0;
+ if (proto == IPPROTO_UDP || nlm_udpport)
+ if (!find_socket(serv, IPPROTO_UDP))
+ err = svc_makesock(serv, IPPROTO_UDP, nlm_udpport);
+ if (err)
+ return err;
+ if (proto == IPPROTO_TCP || nlm_tcpport)
+ if (!find_socket(serv, IPPROTO_TCP))
+ err= svc_makesock(serv, IPPROTO_TCP, nlm_tcpport);
+ return err;
+}
+
/*
* Bring up the lockd process if it's not already up.
*/
int
-lockd_up(void)
+lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
{
static int warned;
struct svc_serv * serv;
@@ -224,8 +259,10 @@ lockd_up(void)
/*
* Check whether we're already up and running.
*/
- if (nlmsvc_pid)
+ if (nlmsvc_pid) {
+ error = make_socks(nlmsvc_serv, proto);
goto out;
+ }

/*
* Sanity check: if there's no pid,
@@ -242,11 +279,7 @@ lockd_up(void)
goto out;
}

- if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0
-#ifdef CONFIG_NFSD_TCP
- || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
-#endif
- ) {
+ if ((error = make_socks(serv, proto)) < 0) {
if (warned++ == 0)
printk(KERN_WARNING
"lockd_up: makesock failed, error=%d\n", error);

diff .prev/fs/nfs/super.c ./fs/nfs/super.c
--- .prev/fs/nfs/super.c 2006-07-24 15:15:04.000000000 +1000
+++ ./fs/nfs/super.c 2006-07-24 15:15:04.000000000 +1000
@@ -869,7 +869,8 @@ nfs_fill_super(struct super_block *sb, s

/* Start lockd here, before we might error out */
if (!(server->flags & NFS_MOUNT_NONLM))
- lockd_up();
+ lockd_up((server->flags & NFS_MOUNT_TCP)
+ ? IPPROTO_TCP : IPPROTO_UDP);

server->namelen = data->namlen;
server->hostname = kmalloc(strlen(data->hostname) + 1, GFP_KERNEL);
@@ -1112,7 +1113,8 @@ static struct super_block *nfs_clone_sb(
nfs_copy_fh(&server->fh, data->fh);
sb = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
if (!IS_ERR(sb) && sb->s_root == NULL && !(server->flags & NFS_MOUNT_NONLM))
- lockd_up();
+ lockd_up((server->flags & NFS_MOUNT_TCP)
+ ? IPPROTO_TCP : IPPROTO_UDP);
return sb;
}

diff .prev/fs/nfsd/nfssvc.c ./fs/nfsd/nfssvc.c
--- .prev/fs/nfsd/nfssvc.c 2006-07-24 15:14:31.000000000 +1000
+++ ./fs/nfsd/nfssvc.c 2006-07-24 15:15:04.000000000 +1000
@@ -134,6 +134,9 @@ static int killsig = 0; /* signal that w
static void nfsd_last_thread(struct svc_serv *serv)
{
/* When last nfsd thread exits we need to do some clean-up */
+ struct svc_sock *svsk;
+ list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
+ lockd_down();
nfsd_serv = NULL;
nfsd_racache_shutdown();
nfs4_state_shutdown();
@@ -218,11 +221,16 @@ nfsd_svc(unsigned short port, int nrserv
error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
if (error < 0)
goto failure;
-
+ error = lockd_up(IPPROTO_UDP);
+ if (error < 0)
+ goto failure;
#ifdef CONFIG_NFSD_TCP
error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
if (error < 0)
goto failure;
+ error = lockd_up(IPPROTO_TCP);
+ if (error < 0)
+ goto failure;
#endif
do_gettimeofday(&nfssvc_boot); /* record boot time */
} else
@@ -306,8 +314,6 @@ nfsd(struct svc_rqst *rqstp)

nfsdstats.th_cnt++;

- lockd_up(); /* start lockd */
-
me.task = current;
list_add(&me.list, &nfsd_list);

@@ -364,13 +370,11 @@ nfsd(struct svc_rqst *rqstp)
break;
killsig = signo;
}
- /* Clear signals before calling lockd_down() and svc_exit_thread() */
+ /* Clear signals before calling svc_exit_thread() */
flush_signals(current);

lock_kernel();

- /* Release lockd */
- lockd_down();
list_del(&me.list);
nfsdstats.th_cnt --;

diff .prev/include/linux/lockd/bind.h ./include/linux/lockd/bind.h
--- .prev/include/linux/lockd/bind.h 2006-07-24 15:15:04.000000000 +1000
+++ ./include/linux/lockd/bind.h 2006-07-24 15:15:04.000000000 +1000
@@ -30,7 +30,7 @@ extern struct nlmsvc_binding * nlmsvc_op
* Functions exported by the lockd module
*/
extern int nlmclnt_proc(struct inode *, int, struct file_lock *);
-extern int lockd_up(void);
+extern int lockd_up(int proto);
extern void lockd_down(void);

#endif /* LINUX_LOCKD_BIND_H */