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-rw-r--r--fs/lockd/host.c346
1 files changed, 346 insertions, 0 deletions
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
new file mode 100644
index 0000000..52707c5
--- /dev/null
+++ b/fs/lockd/host.c
@@ -0,0 +1,346 @@
+/*
+ * linux/fs/lockd/host.c
+ *
+ * Management for NLM peer hosts. The nlm_host struct is shared
+ * between client and server implementation. The only reason to
+ * do so is to reduce code bloat.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/in.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/sm_inter.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)
+
+static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
+static unsigned long next_gc;
+static int nrhosts;
+static DECLARE_MUTEX(nlm_host_sema);
+
+
+static void nlm_gc_hosts(void);
+
+/*
+ * 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)
+{
+ return nlm_lookup_host(0, sin, proto, version);
+}
+
+/*
+ * Find an NLM client handle in the cache. If there is none, create it.
+ */
+struct nlm_host *
+nlmsvc_lookup_host(struct svc_rqst *rqstp)
+{
+ return nlm_lookup_host(1, &rqstp->rq_addr,
+ rqstp->rq_prot, rqstp->rq_vers);
+}
+
+/*
+ * Common host lookup routine for server & client
+ */
+struct nlm_host *
+nlm_lookup_host(int server, struct sockaddr_in *sin,
+ int proto, int version)
+{
+ struct nlm_host *host, **hp;
+ u32 addr;
+ int hash;
+
+ dprintk("lockd: nlm_lookup_host(%08x, p=%d, v=%d)\n",
+ (unsigned)(sin? ntohl(sin->sin_addr.s_addr) : 0), proto, version);
+
+ hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
+
+ /* Lock hash table */
+ down(&nlm_host_sema);
+
+ if (time_after_eq(jiffies, next_gc))
+ nlm_gc_hosts();
+
+ for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
+ if (host->h_proto != proto)
+ continue;
+ if (host->h_version != version)
+ continue;
+ if (host->h_server != server)
+ 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");
+
+ if (!(host = (struct nlm_host *) kmalloc(sizeof(*host), GFP_KERNEL)))
+ goto nohost;
+ memset(host, 0, sizeof(*host));
+
+ addr = sin->sin_addr.s_addr;
+ sprintf(host->h_name, "%u.%u.%u.%u", NIPQUAD(addr));
+
+ host->h_addr = *sin;
+ host->h_addr.sin_port = 0; /* ouch! */
+ host->h_version = version;
+ host->h_proto = proto;
+ host->h_rpcclnt = NULL;
+ init_MUTEX(&host->h_sema);
+ 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);
+ host->h_state = 0; /* pseudo NSM state */
+ host->h_nsmstate = 0; /* real NSM state */
+ host->h_server = server;
+ host->h_next = nlm_hosts[hash];
+ nlm_hosts[hash] = host;
+ INIT_LIST_HEAD(&host->h_lockowners);
+ spin_lock_init(&host->h_lock);
+
+ if (++nrhosts > NLM_HOST_MAX)
+ next_gc = 0;
+
+nohost:
+ up(&nlm_host_sema);
+ return host;
+}
+
+struct nlm_host *
+nlm_find_client(void)
+{
+ /* find a nlm_host for a client for which h_killed == 0.
+ * and return it
+ */
+ 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;
+}
+
+
+/*
+ * Create the NLM RPC client for an NLM peer
+ */
+struct rpc_clnt *
+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));
+
+ /* Lock host handle */
+ down(&host->h_sema);
+
+ /* If we've already created an RPC client, check whether
+ * RPC rebind is required
+ * Note: why keep rebinding if we're on a tcp connection?
+ */
+ if ((clnt = host->h_rpcclnt) != NULL) {
+ xprt = clnt->cl_xprt;
+ if (!xprt->stream && time_after_eq(jiffies, host->h_nextrebind)) {
+ clnt->cl_port = 0;
+ host->h_nextrebind = jiffies + NLM_HOST_REBIND;
+ dprintk("lockd: next rebind in %ld 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);
+
+ /* 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)) {
+ xprt_destroy(xprt);
+ goto forgetit;
+ }
+ clnt->cl_autobind = 1; /* turn on pmap queries */
+ xprt->nocong = 1; /* No congestion control for NLM */
+ xprt->resvport = 1; /* NLM requires a reserved port */
+
+ host->h_rpcclnt = clnt;
+ }
+
+ up(&host->h_sema);
+ return clnt;
+
+forgetit:
+ printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
+ up(&host->h_sema);
+ return NULL;
+}
+
+/*
+ * Force a portmap lookup of the remote lockd port
+ */
+void
+nlm_rebind_host(struct nlm_host *host)
+{
+ 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;
+ host->h_nextrebind = jiffies + NLM_HOST_REBIND;
+ }
+}
+
+/*
+ * Increment NLM host count
+ */
+struct nlm_host * nlm_get_host(struct nlm_host *host)
+{
+ if (host) {
+ dprintk("lockd: get host %s\n", host->h_name);
+ atomic_inc(&host->h_count);
+ host->h_expires = jiffies + NLM_HOST_EXPIRE;
+ }
+ return host;
+}
+
+/*
+ * Release NLM host after use
+ */
+void nlm_release_host(struct nlm_host *host)
+{
+ 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);
+ }
+}
+
+/*
+ * Shut down the hosts module.
+ * Note that this routine is called only at server shutdown time.
+ */
+void
+nlm_shutdown_hosts(void)
+{
+ struct nlm_host *host;
+ int i;
+
+ dprintk("lockd: shutting down host module\n");
+ down(&nlm_host_sema);
+
+ /* 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)
+ host->h_expires = jiffies - 1;
+ }
+
+ /* Then, perform a garbage collection pass */
+ nlm_gc_hosts();
+ up(&nlm_host_sema);
+
+ /* 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) {
+ dprintk(" %s (cnt %d use %d exp %ld)\n",
+ host->h_name, atomic_read(&host->h_count),
+ host->h_inuse, host->h_expires);
+ }
+ }
+ }
+}
+
+/*
+ * Garbage collect any unused NLM hosts.
+ * This GC combines reference counting for async operations with
+ * mark & sweep for resources held by remote clients.
+ */
+static void
+nlm_gc_hosts(void)
+{
+ struct nlm_host **q, *host;
+ struct rpc_clnt *clnt;
+ int i;
+
+ dprintk("lockd: host garbage collection\n");
+ for (i = 0; i < NLM_HOST_NRHASH; i++) {
+ for (host = nlm_hosts[i]; host; host = host->h_next)
+ 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) {
+ 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);
+ nrhosts--;
+ }
+ }
+
+ next_gc = jiffies + NLM_HOST_COLLECT;
+}
+
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