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![Jeff Layton](/assets/img/avatar_default.png)
lockd needs these sort of routines, as does the NFSv4 callback code. Move lockd's routines into common code and rename them so that they can be used by others. Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
569 lines
15 KiB
C
569 lines
15 KiB
C
/*
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* linux/fs/lockd/host.c
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*
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* Management for NLM peer hosts. The nlm_host struct is shared
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* between client and server implementation. The only reason to
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* do so is to reduce code bloat.
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*
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* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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*/
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/lockd/lockd.h>
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#include <linux/mutex.h>
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#include <net/ipv6.h>
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#define NLMDBG_FACILITY NLMDBG_HOSTCACHE
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#define NLM_HOST_NRHASH 32
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#define NLM_HOST_REBIND (60 * HZ)
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#define NLM_HOST_EXPIRE (300 * HZ)
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#define NLM_HOST_COLLECT (120 * HZ)
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static struct hlist_head nlm_hosts[NLM_HOST_NRHASH];
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static unsigned long next_gc;
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static int nrhosts;
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static DEFINE_MUTEX(nlm_host_mutex);
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static void nlm_gc_hosts(void);
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struct nlm_lookup_host_info {
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const int server; /* search for server|client */
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const struct sockaddr *sap; /* address to search for */
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const size_t salen; /* it's length */
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const unsigned short protocol; /* transport to search for*/
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const u32 version; /* NLM version to search for */
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const char *hostname; /* remote's hostname */
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const size_t hostname_len; /* it's length */
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const struct sockaddr *src_sap; /* our address (optional) */
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const size_t src_len; /* it's length */
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const int noresvport; /* use non-priv port */
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};
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/*
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* Hash function must work well on big- and little-endian platforms
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*/
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static unsigned int __nlm_hash32(const __be32 n)
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{
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unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);
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return hash ^ (hash >> 8);
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}
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static unsigned int __nlm_hash_addr4(const struct sockaddr *sap)
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{
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const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
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return __nlm_hash32(sin->sin_addr.s_addr);
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}
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static unsigned int __nlm_hash_addr6(const struct sockaddr *sap)
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{
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const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
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const struct in6_addr addr = sin6->sin6_addr;
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return __nlm_hash32(addr.s6_addr32[0]) ^
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__nlm_hash32(addr.s6_addr32[1]) ^
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__nlm_hash32(addr.s6_addr32[2]) ^
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__nlm_hash32(addr.s6_addr32[3]);
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}
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static unsigned int nlm_hash_address(const struct sockaddr *sap)
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{
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unsigned int hash;
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switch (sap->sa_family) {
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case AF_INET:
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hash = __nlm_hash_addr4(sap);
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break;
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case AF_INET6:
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hash = __nlm_hash_addr6(sap);
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break;
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default:
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hash = 0;
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}
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return hash & (NLM_HOST_NRHASH - 1);
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}
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/*
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* Common host lookup routine for server & client
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*/
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static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
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{
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struct hlist_head *chain;
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struct hlist_node *pos;
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struct nlm_host *host;
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struct nsm_handle *nsm = NULL;
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mutex_lock(&nlm_host_mutex);
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if (time_after_eq(jiffies, next_gc))
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nlm_gc_hosts();
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/* We may keep several nlm_host objects for a peer, because each
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* nlm_host is identified by
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* (address, protocol, version, server/client)
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* We could probably simplify this a little by putting all those
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* different NLM rpc_clients into one single nlm_host object.
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* This would allow us to have one nlm_host per address.
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*/
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chain = &nlm_hosts[nlm_hash_address(ni->sap)];
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hlist_for_each_entry(host, pos, chain, h_hash) {
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if (!rpc_cmp_addr(nlm_addr(host), ni->sap))
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continue;
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/* See if we have an NSM handle for this client */
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if (!nsm)
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nsm = host->h_nsmhandle;
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if (host->h_proto != ni->protocol)
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continue;
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if (host->h_version != ni->version)
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continue;
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if (host->h_server != ni->server)
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continue;
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if (ni->server &&
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!rpc_cmp_addr(nlm_srcaddr(host), ni->src_sap))
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continue;
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/* Move to head of hash chain. */
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hlist_del(&host->h_hash);
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hlist_add_head(&host->h_hash, chain);
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nlm_get_host(host);
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dprintk("lockd: nlm_lookup_host found host %s (%s)\n",
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host->h_name, host->h_addrbuf);
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goto out;
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}
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/*
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* The host wasn't in our hash table. If we don't
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* have an NSM handle for it yet, create one.
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*/
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if (nsm)
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atomic_inc(&nsm->sm_count);
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else {
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host = NULL;
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nsm = nsm_get_handle(ni->sap, ni->salen,
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ni->hostname, ni->hostname_len);
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if (!nsm) {
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dprintk("lockd: nlm_lookup_host failed; "
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"no nsm handle\n");
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goto out;
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}
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}
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host = kzalloc(sizeof(*host), GFP_KERNEL);
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if (!host) {
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nsm_release(nsm);
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dprintk("lockd: nlm_lookup_host failed; no memory\n");
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goto out;
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}
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host->h_name = nsm->sm_name;
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host->h_addrbuf = nsm->sm_addrbuf;
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memcpy(nlm_addr(host), ni->sap, ni->salen);
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host->h_addrlen = ni->salen;
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rpc_set_port(nlm_addr(host), 0);
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memcpy(nlm_srcaddr(host), ni->src_sap, ni->src_len);
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host->h_version = ni->version;
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host->h_proto = ni->protocol;
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host->h_rpcclnt = NULL;
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mutex_init(&host->h_mutex);
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host->h_nextrebind = jiffies + NLM_HOST_REBIND;
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host->h_expires = jiffies + NLM_HOST_EXPIRE;
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atomic_set(&host->h_count, 1);
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init_waitqueue_head(&host->h_gracewait);
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init_rwsem(&host->h_rwsem);
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host->h_state = 0; /* pseudo NSM state */
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host->h_nsmstate = 0; /* real NSM state */
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host->h_nsmhandle = nsm;
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host->h_server = ni->server;
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host->h_noresvport = ni->noresvport;
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hlist_add_head(&host->h_hash, chain);
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INIT_LIST_HEAD(&host->h_lockowners);
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spin_lock_init(&host->h_lock);
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INIT_LIST_HEAD(&host->h_granted);
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INIT_LIST_HEAD(&host->h_reclaim);
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nrhosts++;
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dprintk("lockd: nlm_lookup_host created host %s\n",
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host->h_name);
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out:
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mutex_unlock(&nlm_host_mutex);
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return host;
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}
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/*
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* Destroy a host
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*/
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static void
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nlm_destroy_host(struct nlm_host *host)
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{
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struct rpc_clnt *clnt;
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BUG_ON(!list_empty(&host->h_lockowners));
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BUG_ON(atomic_read(&host->h_count));
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nsm_unmonitor(host);
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nsm_release(host->h_nsmhandle);
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clnt = host->h_rpcclnt;
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if (clnt != NULL)
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rpc_shutdown_client(clnt);
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kfree(host);
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}
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/**
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* nlmclnt_lookup_host - Find an NLM host handle matching a remote server
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* @sap: network address of server
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* @salen: length of server address
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* @protocol: transport protocol to use
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* @version: NLM protocol version
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* @hostname: '\0'-terminated hostname of server
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* @noresvport: 1 if non-privileged port should be used
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*
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* Returns an nlm_host structure that matches the passed-in
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* [server address, transport protocol, NLM version, server hostname].
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* If one doesn't already exist in the host cache, a new handle is
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* created and returned.
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*/
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struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
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const size_t salen,
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const unsigned short protocol,
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const u32 version,
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const char *hostname,
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int noresvport)
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{
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const struct sockaddr source = {
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.sa_family = AF_UNSPEC,
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};
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struct nlm_lookup_host_info ni = {
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.server = 0,
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.sap = sap,
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.salen = salen,
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.protocol = protocol,
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.version = version,
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.hostname = hostname,
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.hostname_len = strlen(hostname),
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.src_sap = &source,
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.src_len = sizeof(source),
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.noresvport = noresvport,
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};
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dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
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(hostname ? hostname : "<none>"), version,
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(protocol == IPPROTO_UDP ? "udp" : "tcp"));
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return nlm_lookup_host(&ni);
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}
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/**
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* nlmsvc_lookup_host - Find an NLM host handle matching a remote client
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* @rqstp: incoming NLM request
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* @hostname: name of client host
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* @hostname_len: length of client hostname
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*
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* Returns an nlm_host structure that matches the [client address,
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* transport protocol, NLM version, client hostname] of the passed-in
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* NLM request. If one doesn't already exist in the host cache, a
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* new handle is created and returned.
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*
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* Before possibly creating a new nlm_host, construct a sockaddr
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* for a specific source address in case the local system has
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* multiple network addresses. The family of the address in
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* rq_daddr is guaranteed to be the same as the family of the
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* address in rq_addr, so it's safe to use the same family for
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* the source address.
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*/
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struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
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const char *hostname,
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const size_t hostname_len)
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{
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struct sockaddr_in sin = {
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.sin_family = AF_INET,
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};
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struct sockaddr_in6 sin6 = {
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.sin6_family = AF_INET6,
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};
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struct nlm_lookup_host_info ni = {
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.server = 1,
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.sap = svc_addr(rqstp),
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.salen = rqstp->rq_addrlen,
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.protocol = rqstp->rq_prot,
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.version = rqstp->rq_vers,
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.hostname = hostname,
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.hostname_len = hostname_len,
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.src_len = rqstp->rq_addrlen,
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};
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dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
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(int)hostname_len, hostname, rqstp->rq_vers,
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(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
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switch (ni.sap->sa_family) {
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case AF_INET:
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sin.sin_addr.s_addr = rqstp->rq_daddr.addr.s_addr;
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ni.src_sap = (struct sockaddr *)&sin;
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break;
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case AF_INET6:
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ipv6_addr_copy(&sin6.sin6_addr, &rqstp->rq_daddr.addr6);
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ni.src_sap = (struct sockaddr *)&sin6;
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break;
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default:
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return NULL;
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}
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return nlm_lookup_host(&ni);
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}
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/*
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* Create the NLM RPC client for an NLM peer
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*/
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struct rpc_clnt *
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nlm_bind_host(struct nlm_host *host)
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{
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struct rpc_clnt *clnt;
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dprintk("lockd: nlm_bind_host %s (%s)\n",
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host->h_name, host->h_addrbuf);
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/* Lock host handle */
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mutex_lock(&host->h_mutex);
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/* If we've already created an RPC client, check whether
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* RPC rebind is required
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*/
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if ((clnt = host->h_rpcclnt) != NULL) {
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if (time_after_eq(jiffies, host->h_nextrebind)) {
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rpc_force_rebind(clnt);
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host->h_nextrebind = jiffies + NLM_HOST_REBIND;
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dprintk("lockd: next rebind in %lu jiffies\n",
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host->h_nextrebind - jiffies);
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}
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} else {
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unsigned long increment = nlmsvc_timeout;
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struct rpc_timeout timeparms = {
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.to_initval = increment,
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.to_increment = increment,
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.to_maxval = increment * 6UL,
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.to_retries = 5U,
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};
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struct rpc_create_args args = {
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.protocol = host->h_proto,
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.address = nlm_addr(host),
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.addrsize = host->h_addrlen,
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.saddress = nlm_srcaddr(host),
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.timeout = &timeparms,
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.servername = host->h_name,
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.program = &nlm_program,
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.version = host->h_version,
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.authflavor = RPC_AUTH_UNIX,
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.flags = (RPC_CLNT_CREATE_NOPING |
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RPC_CLNT_CREATE_AUTOBIND),
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};
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/*
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* lockd retries server side blocks automatically so we want
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* those to be soft RPC calls. Client side calls need to be
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* hard RPC tasks.
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*/
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if (!host->h_server)
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args.flags |= RPC_CLNT_CREATE_HARDRTRY;
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if (host->h_noresvport)
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args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
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clnt = rpc_create(&args);
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if (!IS_ERR(clnt))
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host->h_rpcclnt = clnt;
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else {
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printk("lockd: couldn't create RPC handle for %s\n", host->h_name);
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clnt = NULL;
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}
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}
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mutex_unlock(&host->h_mutex);
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return clnt;
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}
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|
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/*
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* Force a portmap lookup of the remote lockd port
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*/
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void
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nlm_rebind_host(struct nlm_host *host)
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{
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dprintk("lockd: rebind host %s\n", host->h_name);
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if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {
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rpc_force_rebind(host->h_rpcclnt);
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host->h_nextrebind = jiffies + NLM_HOST_REBIND;
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}
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}
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|
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/*
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* Increment NLM host count
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*/
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struct nlm_host * nlm_get_host(struct nlm_host *host)
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{
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if (host) {
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dprintk("lockd: get host %s\n", host->h_name);
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atomic_inc(&host->h_count);
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host->h_expires = jiffies + NLM_HOST_EXPIRE;
|
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}
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return host;
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}
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|
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/*
|
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* Release NLM host after use
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*/
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void nlm_release_host(struct nlm_host *host)
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{
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if (host != NULL) {
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dprintk("lockd: release host %s\n", host->h_name);
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BUG_ON(atomic_read(&host->h_count) < 0);
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if (atomic_dec_and_test(&host->h_count)) {
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BUG_ON(!list_empty(&host->h_lockowners));
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BUG_ON(!list_empty(&host->h_granted));
|
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BUG_ON(!list_empty(&host->h_reclaim));
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}
|
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}
|
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}
|
|
|
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/**
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* nlm_host_rebooted - Release all resources held by rebooted host
|
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* @info: pointer to decoded results of NLM_SM_NOTIFY call
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*
|
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* We were notified that the specified host has rebooted. Release
|
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* all resources held by that peer.
|
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*/
|
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void nlm_host_rebooted(const struct nlm_reboot *info)
|
|
{
|
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struct hlist_head *chain;
|
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struct hlist_node *pos;
|
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struct nsm_handle *nsm;
|
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struct nlm_host *host;
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|
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nsm = nsm_reboot_lookup(info);
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if (unlikely(nsm == NULL))
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return;
|
|
|
|
/* Mark all hosts tied to this NSM state as having rebooted.
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|
* 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.
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|
*/
|
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again: mutex_lock(&nlm_host_mutex);
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for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
|
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hlist_for_each_entry(host, pos, chain, h_hash) {
|
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if (host->h_nsmhandle == nsm
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&& host->h_nsmstate != info->state) {
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host->h_nsmstate = info->state;
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host->h_state++;
|
|
|
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nlm_get_host(host);
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mutex_unlock(&nlm_host_mutex);
|
|
|
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if (host->h_server) {
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/* We're server for this guy, just ditch
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* all the locks he held. */
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nlmsvc_free_host_resources(host);
|
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} else {
|
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/* He's the server, initiate lock recovery. */
|
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nlmclnt_recovery(host);
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}
|
|
|
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nlm_release_host(host);
|
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goto again;
|
|
}
|
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}
|
|
}
|
|
|
|
mutex_unlock(&nlm_host_mutex);
|
|
}
|
|
|
|
/*
|
|
* Shut down the hosts module.
|
|
* Note that this routine is called only at server shutdown time.
|
|
*/
|
|
void
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nlm_shutdown_hosts(void)
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{
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struct hlist_head *chain;
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struct hlist_node *pos;
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struct nlm_host *host;
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dprintk("lockd: shutting down host module\n");
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mutex_lock(&nlm_host_mutex);
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/* First, make all hosts eligible for gc */
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dprintk("lockd: nuking all hosts...\n");
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for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
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hlist_for_each_entry(host, pos, chain, h_hash) {
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host->h_expires = jiffies - 1;
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if (host->h_rpcclnt) {
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rpc_shutdown_client(host->h_rpcclnt);
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host->h_rpcclnt = NULL;
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}
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}
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}
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/* Then, perform a garbage collection pass */
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nlm_gc_hosts();
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mutex_unlock(&nlm_host_mutex);
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/* complain if any hosts are left */
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if (nrhosts) {
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printk(KERN_WARNING "lockd: couldn't shutdown host module!\n");
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dprintk("lockd: %d hosts left:\n", nrhosts);
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for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
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hlist_for_each_entry(host, pos, chain, h_hash) {
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dprintk(" %s (cnt %d use %d exp %ld)\n",
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host->h_name, atomic_read(&host->h_count),
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host->h_inuse, host->h_expires);
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}
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}
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}
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}
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/*
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* Garbage collect any unused NLM hosts.
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* This GC combines reference counting for async operations with
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* mark & sweep for resources held by remote clients.
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*/
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static void
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nlm_gc_hosts(void)
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{
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struct hlist_head *chain;
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struct hlist_node *pos, *next;
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struct nlm_host *host;
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dprintk("lockd: host garbage collection\n");
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for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
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hlist_for_each_entry(host, pos, chain, h_hash)
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host->h_inuse = 0;
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}
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/* Mark all hosts that hold locks, blocks or shares */
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nlmsvc_mark_resources();
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for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
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hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
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if (atomic_read(&host->h_count) || host->h_inuse
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|| time_before(jiffies, host->h_expires)) {
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dprintk("nlm_gc_hosts skipping %s (cnt %d use %d exp %ld)\n",
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host->h_name, atomic_read(&host->h_count),
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host->h_inuse, host->h_expires);
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continue;
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}
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dprintk("lockd: delete host %s\n", host->h_name);
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hlist_del_init(&host->h_hash);
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nlm_destroy_host(host);
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nrhosts--;
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}
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}
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next_gc = jiffies + NLM_HOST_COLLECT;
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}
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