*/
#include <linux/types.h>
-#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/in.h>
+#include <linux/in6.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>
+#include <linux/mutex.h>
+#include <net/ipv6.h>
#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
-#define NLM_HOST_MAX 64
#define NLM_HOST_NRHASH 32
#define NLM_ADDRHASH(addr) (ntohl(addr) & (NLM_HOST_NRHASH-1))
#define NLM_HOST_REBIND (60 * HZ)
-#define NLM_HOST_EXPIRE ((nrhosts > NLM_HOST_MAX)? 300 * HZ : 120 * HZ)
-#define NLM_HOST_COLLECT ((nrhosts > NLM_HOST_MAX)? 120 * HZ : 60 * HZ)
-#define NLM_HOST_ADDR(sv) (&(sv)->s_nlmclnt->cl_xprt->addr)
+#define NLM_HOST_EXPIRE (300 * HZ)
+#define NLM_HOST_COLLECT (120 * HZ)
-static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
+static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
static unsigned long next_gc;
static int nrhosts;
-static DECLARE_MUTEX(nlm_host_sema);
+static DEFINE_MUTEX(nlm_host_mutex);
static void nlm_gc_hosts(void);
+static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
+ const char *, unsigned int, int);
+static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
+ const char *hostname,
+ unsigned int hostname_len);
-/*
- * Find an NLM server handle in the cache. If there is none, create it.
- */
-struct nlm_host *
-nlmclnt_lookup_host(struct sockaddr_in *sin, int proto, int version)
+static void nlm_clear_port(struct sockaddr *sap)
{
- return nlm_lookup_host(0, sin, proto, version);
+ switch (sap->sa_family) {
+ case AF_INET:
+ ((struct sockaddr_in *)sap)->sin_port = 0;
+ break;
+ case AF_INET6:
+ ((struct sockaddr_in6 *)sap)->sin6_port = 0;
+ break;
+ }
}
-/*
- * Find an NLM client handle in the cache. If there is none, create it.
- */
-struct nlm_host *
-nlmsvc_lookup_host(struct svc_rqst *rqstp)
+static void nlm_display_address(const struct sockaddr *sap,
+ char *buf, const size_t len)
{
- return nlm_lookup_host(1, &rqstp->rq_addr,
- rqstp->rq_prot, rqstp->rq_vers);
+ const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+ const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+
+ switch (sap->sa_family) {
+ case AF_UNSPEC:
+ snprintf(buf, len, "unspecified");
+ break;
+ case AF_INET:
+ snprintf(buf, len, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
+ break;
+ case AF_INET6:
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ snprintf(buf, len, NIPQUAD_FMT,
+ NIPQUAD(sin6->sin6_addr.s6_addr32[3]));
+ else
+ snprintf(buf, len, NIP6_FMT, NIP6(sin6->sin6_addr));
+ break;
+ default:
+ snprintf(buf, len, "unsupported address family");
+ break;
+ }
}
/*
* Common host lookup routine for server & client
*/
-struct nlm_host *
-nlm_lookup_host(int server, struct sockaddr_in *sin,
- int proto, int version)
+static struct nlm_host *nlm_lookup_host(int server,
+ const struct sockaddr_in *sin,
+ int proto, u32 version,
+ const char *hostname,
+ unsigned int hostname_len,
+ const struct sockaddr_in *ssin)
{
- struct nlm_host *host, **hp;
- u32 addr;
+ struct hlist_head *chain;
+ struct hlist_node *pos;
+ struct nlm_host *host;
+ struct nsm_handle *nsm = NULL;
int hash;
- dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
- (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
+ dprintk("lockd: nlm_lookup_host(proto=%d, vers=%u,"
+ " my role is %s, hostname=%.*s)\n",
+ proto, version, server ? "server" : "client",
+ hostname_len, hostname ? hostname : "<none>");
hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
/* Lock hash table */
- down(&nlm_host_sema);
+ mutex_lock(&nlm_host_mutex);
if (time_after_eq(jiffies, next_gc))
nlm_gc_hosts();
- for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
+ /* We may keep several nlm_host objects for a peer, because each
+ * nlm_host is identified by
+ * (address, protocol, version, server/client)
+ * We could probably simplify this a little by putting all those
+ * different NLM rpc_clients into one single nlm_host object.
+ * This would allow us to have one nlm_host per address.
+ */
+ chain = &nlm_hosts[hash];
+ hlist_for_each_entry(host, pos, chain, h_hash) {
+ if (!nlm_cmp_addr(nlm_addr(host), (struct sockaddr *)sin))
+ continue;
+
+ /* See if we have an NSM handle for this client */
+ if (!nsm)
+ nsm = host->h_nsmhandle;
+
if (host->h_proto != proto)
continue;
if (host->h_version != version)
continue;
if (host->h_server != server)
continue;
+ if (!nlm_cmp_addr(nlm_srcaddr(host), (struct sockaddr *)ssin))
+ continue;
- if (nlm_cmp_addr(&host->h_addr, sin)) {
- if (hp != nlm_hosts + hash) {
- *hp = host->h_next;
- host->h_next = nlm_hosts[hash];
- nlm_hosts[hash] = host;
- }
- nlm_get_host(host);
- up(&nlm_host_sema);
- return host;
- }
- }
-
- /* Ooops, no host found, create it */
- dprintk("lockd: creating host entry\n");
+ /* Move to head of hash chain. */
+ hlist_del(&host->h_hash);
+ hlist_add_head(&host->h_hash, chain);
- if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL)))
- goto nohost;
- memset(host, 0, sizeof(*host));
+ nlm_get_host(host);
+ dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
+ host->h_name, host->h_addrbuf);
+ goto out;
+ }
- addr = sin->sin_addr.s_addr;
- sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
+ /*
+ * The host wasn't in our hash table. If we don't
+ * have an NSM handle for it yet, create one.
+ */
+ if (nsm)
+ atomic_inc(&nsm->sm_count);
+ else {
+ host = NULL;
+ nsm = nsm_find(sin, hostname, hostname_len);
+ if (!nsm) {
+ dprintk("lockd: nlm_lookup_host failed; "
+ "no nsm handle\n");
+ goto out;
+ }
+ }
- host->h_addr = *sin;
- host->h_addr.sin_port = 0; /* ouch! */
+ host = kzalloc(sizeof(*host), GFP_KERNEL);
+ if (!host) {
+ nsm_release(nsm);
+ dprintk("lockd: nlm_lookup_host failed; no memory\n");
+ goto out;
+ }
+ host->h_name = nsm->sm_name;
+ memcpy(nlm_addr(host), sin, sizeof(*sin));
+ host->h_addrlen = sizeof(*sin);
+ nlm_clear_port(nlm_addr(host));
+ memcpy(nlm_srcaddr(host), ssin, sizeof(*ssin));
host->h_version = version;
host->h_proto = proto;
host->h_rpcclnt = NULL;
- init_MUTEX(&host->h_sema);
+ mutex_init(&host->h_mutex);
host->h_nextrebind = jiffies + NLM_HOST_REBIND;
host->h_expires = jiffies + NLM_HOST_EXPIRE;
atomic_set(&host->h_count, 1);
init_waitqueue_head(&host->h_gracewait);
+ init_rwsem(&host->h_rwsem);
host->h_state = 0; /* pseudo NSM state */
host->h_nsmstate = 0; /* real NSM state */
+ host->h_nsmhandle = nsm;
host->h_server = server;
- host->h_next = nlm_hosts[hash];
- nlm_hosts[hash] = host;
+ hlist_add_head(&host->h_hash, chain);
INIT_LIST_HEAD(&host->h_lockowners);
spin_lock_init(&host->h_lock);
+ INIT_LIST_HEAD(&host->h_granted);
+ INIT_LIST_HEAD(&host->h_reclaim);
+
+ nrhosts++;
- if (++nrhosts > NLM_HOST_MAX)
- next_gc = 0;
+ nlm_display_address((struct sockaddr *)&host->h_addr,
+ host->h_addrbuf, sizeof(host->h_addrbuf));
+ nlm_display_address((struct sockaddr *)&host->h_srcaddr,
+ host->h_srcaddrbuf, sizeof(host->h_srcaddrbuf));
-nohost:
- up(&nlm_host_sema);
+ dprintk("lockd: nlm_lookup_host created host %s\n",
+ host->h_name);
+
+out:
+ mutex_unlock(&nlm_host_mutex);
return host;
}
-struct nlm_host *
-nlm_find_client(void)
+/*
+ * Destroy a host
+ */
+static void
+nlm_destroy_host(struct nlm_host *host)
{
- /* find a nlm_host for a client for which h_killed == 0.
- * and return it
+ struct rpc_clnt *clnt;
+
+ BUG_ON(!list_empty(&host->h_lockowners));
+ BUG_ON(atomic_read(&host->h_count));
+
+ /*
+ * Release NSM handle and unmonitor host.
*/
- int hash;
- down(&nlm_host_sema);
- for (hash = 0 ; hash < NLM_HOST_NRHASH; hash++) {
- struct nlm_host *host, **hp;
- for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
- if (host->h_server &&
- host->h_killed == 0) {
- nlm_get_host(host);
- up(&nlm_host_sema);
- return host;
- }
- }
- }
- up(&nlm_host_sema);
- return NULL;
+ nsm_unmonitor(host);
+
+ clnt = host->h_rpcclnt;
+ if (clnt != NULL)
+ rpc_shutdown_client(clnt);
+ kfree(host);
+}
+
+/*
+ * Find an NLM server handle in the cache. If there is none, create it.
+ */
+struct nlm_host *nlmclnt_lookup_host(const struct sockaddr_in *sin,
+ int proto, u32 version,
+ const char *hostname,
+ unsigned int hostname_len)
+{
+ const struct sockaddr_in source = {
+ .sin_family = AF_UNSPEC,
+ };
+
+ return nlm_lookup_host(0, sin, proto, version,
+ hostname, hostname_len, &source);
+}
+
+/*
+ * Find an NLM client handle in the cache. If there is none, create it.
+ */
+struct nlm_host *
+nlmsvc_lookup_host(struct svc_rqst *rqstp,
+ const char *hostname, unsigned int hostname_len)
+{
+ const struct sockaddr_in source = {
+ .sin_family = AF_INET,
+ .sin_addr = rqstp->rq_daddr.addr,
+ };
+
+ return nlm_lookup_host(1, svc_addr_in(rqstp),
+ rqstp->rq_prot, rqstp->rq_vers,
+ hostname, hostname_len, &source);
}
-
/*
* Create the NLM RPC client for an NLM peer
*/
nlm_bind_host(struct nlm_host *host)
{
struct rpc_clnt *clnt;
- struct rpc_xprt *xprt;
- dprintk("lockd: nlm_bind_host(%08x)\n",
- (unsigned)ntohl(host->h_addr.sin_addr.s_addr));
+ dprintk("lockd: nlm_bind_host %s (%s), my addr=%s\n",
+ host->h_name, host->h_addrbuf, host->h_srcaddrbuf);
/* Lock host handle */
- down(&host->h_sema);
+ mutex_lock(&host->h_mutex);
/* If we've already created an RPC client, check whether
* RPC rebind is required
*/
if ((clnt = host->h_rpcclnt) != NULL) {
- xprt = clnt->cl_xprt;
if (time_after_eq(jiffies, host->h_nextrebind)) {
- clnt->cl_port = 0;
+ rpc_force_rebind(clnt);
host->h_nextrebind = jiffies + NLM_HOST_REBIND;
- dprintk("lockd: next rebind in %ld jiffies\n",
+ dprintk("lockd: next rebind in %lu jiffies\n",
host->h_nextrebind - jiffies);
}
} else {
- xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
- if (IS_ERR(xprt))
- goto forgetit;
-
- xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
- xprt->resvport = 1; /* NLM requires a reserved port */
-
- /* Existing NLM servers accept AUTH_UNIX only */
- clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
- host->h_version, RPC_AUTH_UNIX);
- if (IS_ERR(clnt))
- goto forgetit;
- clnt->cl_autobind = 1; /* turn on pmap queries */
-
- host->h_rpcclnt = clnt;
+ unsigned long increment = nlmsvc_timeout;
+ struct rpc_timeout timeparms = {
+ .to_initval = increment,
+ .to_increment = increment,
+ .to_maxval = increment * 6UL,
+ .to_retries = 5U,
+ };
+ struct rpc_create_args args = {
+ .protocol = host->h_proto,
+ .address = nlm_addr(host),
+ .addrsize = host->h_addrlen,
+ .saddress = nlm_srcaddr(host),
+ .timeout = &timeparms,
+ .servername = host->h_name,
+ .program = &nlm_program,
+ .version = host->h_version,
+ .authflavor = RPC_AUTH_UNIX,
+ .flags = (RPC_CLNT_CREATE_NOPING |
+ RPC_CLNT_CREATE_AUTOBIND),
+ };
+
+ /*
+ * lockd retries server side blocks automatically so we want
+ * those to be soft RPC calls. Client side calls need to be
+ * hard RPC tasks.
+ */
+ if (!host->h_server)
+ args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+
+ clnt = rpc_create(&args);
+ if (!IS_ERR(clnt))
+ host->h_rpcclnt = clnt;
+ else {
+ printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
+ clnt = NULL;
+ }
}
- up(&host->h_sema);
+ mutex_unlock(&host->h_mutex);
return clnt;
-
-forgetit:
- printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
- up(&host->h_sema);
- return NULL;
}
/*
{
dprintk("lockd: rebind host %s\n", host->h_name);
if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
- host->h_rpcclnt->cl_port = 0;
+ rpc_force_rebind(host->h_rpcclnt);
host->h_nextrebind = jiffies + NLM_HOST_REBIND;
}
}
{
if (host != NULL) {
dprintk("lockd: release host %s\n", host->h_name);
- atomic_dec(&host->h_count);
BUG_ON(atomic_read(&host->h_count) < 0);
+ if (atomic_dec_and_test(&host->h_count)) {
+ BUG_ON(!list_empty(&host->h_lockowners));
+ BUG_ON(!list_empty(&host->h_granted));
+ BUG_ON(!list_empty(&host->h_reclaim));
+ }
+ }
+}
+
+/*
+ * We were notified that the host indicated by address &sin
+ * has rebooted.
+ * Release all resources held by that peer.
+ */
+void nlm_host_rebooted(const struct sockaddr_in *sin,
+ const char *hostname,
+ unsigned int hostname_len,
+ u32 new_state)
+{
+ struct hlist_head *chain;
+ struct hlist_node *pos;
+ struct nsm_handle *nsm;
+ struct nlm_host *host;
+
+ /* Find the NSM handle for this peer */
+ nsm = __nsm_find(sin, hostname, hostname_len, 0);
+ if (nsm == NULL) {
+ dprintk("lockd: never saw rebooted peer '%.*s' before\n",
+ hostname_len, hostname);
+ return;
+ }
+
+ dprintk("lockd: nlm_host_rebooted(%.*s, %s)\n",
+ hostname_len, hostname, nsm->sm_addrbuf);
+
+ /* When reclaiming locks on this peer, make sure that
+ * we set up a new notification */
+ nsm->sm_monitored = 0;
+
+ /* Mark all hosts tied to this NSM state as having rebooted.
+ * We run the loop repeatedly, because we drop the host table
+ * lock for this.
+ * To avoid processing a host several times, we match the nsmstate.
+ */
+again: mutex_lock(&nlm_host_mutex);
+ for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+ hlist_for_each_entry(host, pos, chain, h_hash) {
+ if (host->h_nsmhandle == nsm
+ && host->h_nsmstate != new_state) {
+ host->h_nsmstate = new_state;
+ host->h_state++;
+
+ nlm_get_host(host);
+ mutex_unlock(&nlm_host_mutex);
+
+ if (host->h_server) {
+ /* We're server for this guy, just ditch
+ * all the locks he held. */
+ nlmsvc_free_host_resources(host);
+ } else {
+ /* He's the server, initiate lock recovery. */
+ nlmclnt_recovery(host);
+ }
+
+ nlm_release_host(host);
+ goto again;
+ }
+ }
}
+
+ mutex_unlock(&nlm_host_mutex);
}
/*
void
nlm_shutdown_hosts(void)
{
+ struct hlist_head *chain;
+ struct hlist_node *pos;
struct nlm_host *host;
- int i;
dprintk("lockd: shutting down host module\n");
- down(&nlm_host_sema);
+ mutex_lock(&nlm_host_mutex);
/* First, make all hosts eligible for gc */
dprintk("lockd: nuking all hosts...\n");
- for (i = 0; i < NLM_HOST_NRHASH; i++) {
- for (host = nlm_hosts[i]; host; host = host->h_next)
+ for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+ hlist_for_each_entry(host, pos, chain, h_hash) {
host->h_expires = jiffies - 1;
+ if (host->h_rpcclnt) {
+ rpc_shutdown_client(host->h_rpcclnt);
+ host->h_rpcclnt = NULL;
+ }
+ }
}
/* Then, perform a garbage collection pass */
nlm_gc_hosts();
- up(&nlm_host_sema);
+ mutex_unlock(&nlm_host_mutex);
/* complain if any hosts are left */
if (nrhosts) {
printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
dprintk("lockd: %d hosts left:\n", nrhosts);
- for (i = 0; i < NLM_HOST_NRHASH; i++) {
- for (host = nlm_hosts[i]; host; host = host->h_next) {
+ for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+ hlist_for_each_entry(host, pos, chain, h_hash) {
dprintk(" %s (cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
static void
nlm_gc_hosts(void)
{
- struct nlm_host **q, *host;
- struct rpc_clnt *clnt;
- int i;
+ struct hlist_head *chain;
+ struct hlist_node *pos, *next;
+ struct nlm_host *host;
dprintk("lockd: host garbage collection\n");
- for (i = 0; i < NLM_HOST_NRHASH; i++) {
- for (host = nlm_hosts[i]; host; host = host->h_next)
+ for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+ hlist_for_each_entry(host, pos, chain, h_hash)
host->h_inuse = 0;
}
/* Mark all hosts that hold locks, blocks or shares */
nlmsvc_mark_resources();
- for (i = 0; i < NLM_HOST_NRHASH; i++) {
- q = &nlm_hosts[i];
- while ((host = *q) != NULL) {
+ for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
+ hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
if (atomic_read(&host->h_count) || host->h_inuse
|| time_before(jiffies, host->h_expires)) {
dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
host->h_name, atomic_read(&host->h_count),
host->h_inuse, host->h_expires);
- q = &host->h_next;
continue;
}
dprintk("lockd: delete host %s\n", host->h_name);
- *q = host->h_next;
- /* Don't unmonitor hosts that have been invalidated */
- if (host->h_monitored && !host->h_killed)
- nsm_unmonitor(host);
- if ((clnt = host->h_rpcclnt) != NULL) {
- if (atomic_read(&clnt->cl_users)) {
- printk(KERN_WARNING
- "lockd: active RPC handle\n");
- clnt->cl_dead = 1;
- } else {
- rpc_destroy_client(host->h_rpcclnt);
- }
- }
- BUG_ON(!list_empty(&host->h_lockowners));
- kfree(host);
+ hlist_del_init(&host->h_hash);
+
+ nlm_destroy_host(host);
nrhosts--;
}
}
next_gc = jiffies + NLM_HOST_COLLECT;
}
+
+/*
+ * Manage NSM handles
+ */
+static LIST_HEAD(nsm_handles);
+static DEFINE_SPINLOCK(nsm_lock);
+
+static struct nsm_handle *
+__nsm_find(const struct sockaddr_in *sin,
+ const char *hostname, unsigned int hostname_len,
+ int create)
+{
+ struct nsm_handle *nsm = NULL;
+ struct nsm_handle *pos;
+
+ if (!sin)
+ return NULL;
+
+ if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+ if (printk_ratelimit()) {
+ printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+ "in NFS lock request\n",
+ hostname_len, hostname);
+ }
+ return NULL;
+ }
+
+retry:
+ spin_lock(&nsm_lock);
+ list_for_each_entry(pos, &nsm_handles, sm_link) {
+
+ if (hostname && nsm_use_hostnames) {
+ if (strlen(pos->sm_name) != hostname_len
+ || memcmp(pos->sm_name, hostname, hostname_len))
+ continue;
+ } else if (!nlm_cmp_addr(nsm_addr(pos), (struct sockaddr *)sin))
+ continue;
+ atomic_inc(&pos->sm_count);
+ kfree(nsm);
+ nsm = pos;
+ goto found;
+ }
+ if (nsm) {
+ list_add(&nsm->sm_link, &nsm_handles);
+ goto found;
+ }
+ spin_unlock(&nsm_lock);
+
+ if (!create)
+ return NULL;
+
+ nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
+ if (nsm == NULL)
+ return NULL;
+
+ memcpy(nsm_addr(nsm), sin, sizeof(*sin));
+ nsm->sm_addrlen = sizeof(*sin);
+ nsm->sm_name = (char *) (nsm + 1);
+ memcpy(nsm->sm_name, hostname, hostname_len);
+ nsm->sm_name[hostname_len] = '\0';
+ nlm_display_address((struct sockaddr *)&nsm->sm_addr,
+ nsm->sm_addrbuf, sizeof(nsm->sm_addrbuf));
+ atomic_set(&nsm->sm_count, 1);
+ goto retry;
+
+found:
+ spin_unlock(&nsm_lock);
+ return nsm;
+}
+
+static struct nsm_handle *
+nsm_find(const struct sockaddr_in *sin, const char *hostname,
+ unsigned int hostname_len)
+{
+ return __nsm_find(sin, hostname, hostname_len, 1);
+}
+
+/*
+ * Release an NSM handle
+ */
+void
+nsm_release(struct nsm_handle *nsm)
+{
+ if (!nsm)
+ return;
+ if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
+ list_del(&nsm->sm_link);
+ spin_unlock(&nsm_lock);
+ kfree(nsm);
+ }
+}