From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-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! --- fs/lockd/host.c | 346 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 346 insertions(+) create mode 100644 fs/lockd/host.c (limited to 'fs/lockd/host.c') 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 + */ + +#include +#include +#include +#include +#include +#include +#include +#include + + +#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; +} + -- cgit v1.2.3-59-g8ed1b