Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 346 insertions, 0 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
new file mode 100644
index 000000000000..52707c5ad6ea
--- /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;
+}
+