![Olaf Kirch](/assets/img/avatar_default.png)
This patch introduces the nsm_handle, which is shared by all nlm_host objects referring to the same client. With this patch applied, all nlm_hosts from the same address will share the same nsm_handle. A future patch will add sharing by name. Note: this patch changes h_name so that it is no longer guaranteed to be an IP address of the host. When the host represents an NFS server, h_name will be the name passed in the mount call. When the host represents a client, h_name will be the name presented in the lock request received from the client. A h_name is only used for printing informational messages, this change should not be significant. Signed-off-by: Olaf Kirch <okir@suse.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
495 lines
12 KiB
C
495 lines
12 KiB
C
/*
|
|
* 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>
|
|
#include <linux/mutex.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)
|
|
|
|
static struct nlm_host * nlm_hosts[NLM_HOST_NRHASH];
|
|
static unsigned long next_gc;
|
|
static int nrhosts;
|
|
static DEFINE_MUTEX(nlm_host_mutex);
|
|
|
|
|
|
static void nlm_gc_hosts(void);
|
|
static struct nsm_handle * __nsm_find(const struct sockaddr_in *,
|
|
const char *, int, int);
|
|
|
|
/*
|
|
* 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, int version,
|
|
const char *hostname, int hostname_len)
|
|
{
|
|
return nlm_lookup_host(0, sin, proto, version,
|
|
hostname, hostname_len);
|
|
}
|
|
|
|
/*
|
|
* 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, int hostname_len)
|
|
{
|
|
return nlm_lookup_host(1, &rqstp->rq_addr,
|
|
rqstp->rq_prot, rqstp->rq_vers,
|
|
hostname, hostname_len);
|
|
}
|
|
|
|
/*
|
|
* Common host lookup routine for server & client
|
|
*/
|
|
struct nlm_host *
|
|
nlm_lookup_host(int server, const struct sockaddr_in *sin,
|
|
int proto, int version,
|
|
const char *hostname,
|
|
int hostname_len)
|
|
{
|
|
struct nlm_host *host, **hp;
|
|
struct nsm_handle *nsm = NULL;
|
|
int hash;
|
|
|
|
dprintk("lockd: nlm_lookup_host(%u.%u.%u.%u, p=%d, v=%d, my role=%s, name=%.*s)\n",
|
|
NIPQUAD(sin->sin_addr.s_addr), proto, version,
|
|
server? "server" : "client",
|
|
hostname_len,
|
|
hostname? hostname : "<none>");
|
|
|
|
|
|
hash = NLM_ADDRHASH(sin->sin_addr.s_addr);
|
|
|
|
/* Lock hash table */
|
|
mutex_lock(&nlm_host_mutex);
|
|
|
|
if (time_after_eq(jiffies, next_gc))
|
|
nlm_gc_hosts();
|
|
|
|
/* 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.
|
|
*/
|
|
for (hp = &nlm_hosts[hash]; (host = *hp) != 0; hp = &host->h_next) {
|
|
if (!nlm_cmp_addr(&host->h_addr, sin))
|
|
continue;
|
|
|
|
/* See if we have an NSM handle for this client */
|
|
if (!nsm && (nsm = host->h_nsmhandle) != 0)
|
|
atomic_inc(&nsm->sm_count);
|
|
|
|
if (host->h_proto != proto)
|
|
continue;
|
|
if (host->h_version != version)
|
|
continue;
|
|
if (host->h_server != server)
|
|
continue;
|
|
|
|
{
|
|
if (hp != nlm_hosts + hash) {
|
|
*hp = host->h_next;
|
|
host->h_next = nlm_hosts[hash];
|
|
nlm_hosts[hash] = host;
|
|
}
|
|
nlm_get_host(host);
|
|
mutex_unlock(&nlm_host_mutex);
|
|
return host;
|
|
}
|
|
}
|
|
|
|
/* Sadly, the host isn't in our hash table yet. See if
|
|
* we have an NSM handle for it. If not, create one.
|
|
*/
|
|
if (!nsm && !(nsm = nsm_find(sin, hostname, hostname_len)))
|
|
goto out;
|
|
|
|
host = kzalloc(sizeof(*host), GFP_KERNEL);
|
|
if (!host) {
|
|
nsm_release(nsm);
|
|
goto out;
|
|
}
|
|
host->h_name = nsm->sm_name;
|
|
host->h_addr = *sin;
|
|
host->h_addr.sin_port = 0; /* ouch! */
|
|
host->h_version = version;
|
|
host->h_proto = proto;
|
|
host->h_rpcclnt = NULL;
|
|
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;
|
|
INIT_LIST_HEAD(&host->h_lockowners);
|
|
spin_lock_init(&host->h_lock);
|
|
INIT_LIST_HEAD(&host->h_granted);
|
|
INIT_LIST_HEAD(&host->h_reclaim);
|
|
|
|
if (++nrhosts > NLM_HOST_MAX)
|
|
next_gc = 0;
|
|
|
|
out:
|
|
mutex_unlock(&nlm_host_mutex);
|
|
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;
|
|
mutex_lock(&nlm_host_mutex);
|
|
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);
|
|
mutex_unlock(&nlm_host_mutex);
|
|
return host;
|
|
}
|
|
}
|
|
}
|
|
mutex_unlock(&nlm_host_mutex);
|
|
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;
|
|
|
|
dprintk("lockd: nlm_bind_host(%08x)\n",
|
|
(unsigned)ntohl(host->h_addr.sin_addr.s_addr));
|
|
|
|
/* Lock host handle */
|
|
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) {
|
|
if (time_after_eq(jiffies, host->h_nextrebind)) {
|
|
rpc_force_rebind(clnt);
|
|
host->h_nextrebind = jiffies + NLM_HOST_REBIND;
|
|
dprintk("lockd: next rebind in %ld jiffies\n",
|
|
host->h_nextrebind - jiffies);
|
|
}
|
|
} else {
|
|
unsigned long increment = nlmsvc_timeout * HZ;
|
|
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 = (struct sockaddr *)&host->h_addr,
|
|
.addrsize = sizeof(host->h_addr),
|
|
.timeout = &timeparms,
|
|
.servername = host->h_name,
|
|
.program = &nlm_program,
|
|
.version = host->h_version,
|
|
.authflavor = RPC_AUTH_UNIX,
|
|
.flags = (RPC_CLNT_CREATE_HARDRTRY |
|
|
RPC_CLNT_CREATE_AUTOBIND),
|
|
};
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&host->h_mutex);
|
|
return clnt;
|
|
}
|
|
|
|
/*
|
|
* 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)) {
|
|
rpc_force_rebind(host->h_rpcclnt);
|
|
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);
|
|
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 struct nlm_reboot *argp)
|
|
{
|
|
struct nlm_host *host;
|
|
int server;
|
|
|
|
/* Obtain the host pointer for this NFS server and try to
|
|
* reclaim all locks we hold on this server.
|
|
*/
|
|
server = (argp->proto & 1)? 1 : 0;
|
|
host = nlm_lookup_host(server, sin, argp->proto >> 1, argp->vers,
|
|
argp->mon, argp->len);
|
|
if (host == NULL)
|
|
return;
|
|
|
|
if (server == 0) {
|
|
/* We are client, he's the server: try to reclaim all locks. */
|
|
nlmclnt_recovery(host, argp->state);
|
|
} else {
|
|
/* He's the client, we're the server: delete all locks held by the client */
|
|
nlmsvc_free_host_resources(host);
|
|
}
|
|
nlm_release_host(host);
|
|
}
|
|
|
|
/*
|
|
* 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");
|
|
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)
|
|
host->h_expires = jiffies - 1;
|
|
}
|
|
|
|
/* Then, perform a garbage collection pass */
|
|
nlm_gc_hosts();
|
|
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) {
|
|
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;
|
|
|
|
/*
|
|
* Unmonitor unless host was invalidated (i.e. lockd restarted)
|
|
*/
|
|
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);
|
|
}
|
|
}
|
|
kfree(host);
|
|
nrhosts--;
|
|
}
|
|
}
|
|
|
|
next_gc = jiffies + NLM_HOST_COLLECT;
|
|
}
|
|
|
|
|
|
/*
|
|
* Manage NSM handles
|
|
*/
|
|
static LIST_HEAD(nsm_handles);
|
|
static DECLARE_MUTEX(nsm_sema);
|
|
|
|
static struct nsm_handle *
|
|
__nsm_find(const struct sockaddr_in *sin,
|
|
const char *hostname, int hostname_len,
|
|
int create)
|
|
{
|
|
struct nsm_handle *nsm = NULL;
|
|
struct list_head *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;
|
|
}
|
|
|
|
down(&nsm_sema);
|
|
list_for_each(pos, &nsm_handles) {
|
|
nsm = list_entry(pos, struct nsm_handle, sm_link);
|
|
|
|
if (!nlm_cmp_addr(&nsm->sm_addr, sin))
|
|
continue;
|
|
atomic_inc(&nsm->sm_count);
|
|
goto out;
|
|
}
|
|
|
|
if (!create) {
|
|
nsm = NULL;
|
|
goto out;
|
|
}
|
|
|
|
nsm = kzalloc(sizeof(*nsm) + hostname_len + 1, GFP_KERNEL);
|
|
if (nsm != NULL) {
|
|
nsm->sm_addr = *sin;
|
|
nsm->sm_name = (char *) (nsm + 1);
|
|
memcpy(nsm->sm_name, hostname, hostname_len);
|
|
nsm->sm_name[hostname_len] = '\0';
|
|
atomic_set(&nsm->sm_count, 1);
|
|
|
|
list_add(&nsm->sm_link, &nsm_handles);
|
|
}
|
|
|
|
out: up(&nsm_sema);
|
|
return nsm;
|
|
}
|
|
|
|
struct nsm_handle *
|
|
nsm_find(const struct sockaddr_in *sin, const char *hostname, 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_test(&nsm->sm_count)) {
|
|
down(&nsm_sema);
|
|
if (atomic_read(&nsm->sm_count) == 0) {
|
|
list_del(&nsm->sm_link);
|
|
kfree(nsm);
|
|
}
|
|
up(&nsm_sema);
|
|
}
|
|
}
|