kernel-ark/fs/lockd/host.c
Tim Schmielau cd354f1ae7 [PATCH] remove many unneeded #includes of sched.h
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:54 -08:00

523 lines
13 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/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 hlist_head 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);
static struct nsm_handle * nsm_find(const struct sockaddr_in *sin,
const char *hostname,
int hostname_len);
/*
* Common host lookup routine for server & client
*/
static struct nlm_host *
nlm_lookup_host(int server, const struct sockaddr_in *sin,
int proto, int version,
const char *hostname,
int hostname_len)
{
struct hlist_head *chain;
struct hlist_node *pos;
struct nlm_host *host;
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.
*/
chain = &nlm_hosts[hash];
hlist_for_each_entry(host, pos, chain, h_hash) {
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;
if (host->h_proto != proto)
continue;
if (host->h_version != version)
continue;
if (host->h_server != server)
continue;
/* Move to head of hash chain. */
hlist_del(&host->h_hash);
hlist_add_head(&host->h_hash, chain);
nlm_get_host(host);
goto out;
}
if (nsm)
atomic_inc(&nsm->sm_count);
host = NULL;
/* 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;
hlist_add_head(&host->h_hash, chain);
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;
}
/*
* Destroy a host
*/
static void
nlm_destroy_host(struct nlm_host *host)
{
struct rpc_clnt *clnt;
BUG_ON(!list_empty(&host->h_lockowners));
BUG_ON(atomic_read(&host->h_count));
/*
* Release NSM handle and unmonitor host.
*/
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);
}
/*
* 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, svc_addr_in(rqstp),
rqstp->rq_prot, rqstp->rq_vers,
hostname, hostname_len);
}
/*
* 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 char *hostname, int hostname_len,
u32 new_state)
{
struct hlist_head *chain;
struct hlist_node *pos;
struct nsm_handle *nsm;
struct nlm_host *host;
dprintk("lockd: nlm_host_rebooted(%s, %u.%u.%u.%u)\n",
hostname, NIPQUAD(sin->sin_addr));
/* Find the NSM handle for this peer */
if (!(nsm = __nsm_find(sin, hostname, hostname_len, 0)))
return;
/* When reclaiming locks on this peer, make sure that
* we set up a new notification */
nsm->sm_monitored = 0;
/* Mark all hosts tied to this NSM state as having rebooted.
* 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.
*/
again: mutex_lock(&nlm_host_mutex);
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash) {
if (host->h_nsmhandle == nsm
&& host->h_nsmstate != new_state) {
host->h_nsmstate = new_state;
host->h_state++;
nlm_get_host(host);
mutex_unlock(&nlm_host_mutex);
if (host->h_server) {
/* We're server for this guy, just ditch
* all the locks he held. */
nlmsvc_free_host_resources(host);
} else {
/* He's the server, initiate lock recovery. */
nlmclnt_recovery(host);
}
nlm_release_host(host);
goto again;
}
}
}
mutex_unlock(&nlm_host_mutex);
}
/*
* Shut down the hosts module.
* Note that this routine is called only at server shutdown time.
*/
void
nlm_shutdown_hosts(void)
{
struct hlist_head *chain;
struct hlist_node *pos;
struct nlm_host *host;
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 (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash)
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 (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash) {
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 hlist_head *chain;
struct hlist_node *pos, *next;
struct nlm_host *host;
dprintk("lockd: host garbage collection\n");
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry(host, pos, chain, h_hash)
host->h_inuse = 0;
}
/* Mark all hosts that hold locks, blocks or shares */
nlmsvc_mark_resources();
for (chain = nlm_hosts; chain < nlm_hosts + NLM_HOST_NRHASH; ++chain) {
hlist_for_each_entry_safe(host, pos, next, chain, h_hash) {
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);
continue;
}
dprintk("lockd: delete host %s\n", host->h_name);
hlist_del_init(&host->h_hash);
nlm_destroy_host(host);
nrhosts--;
}
}
next_gc = jiffies + NLM_HOST_COLLECT;
}
/*
* Manage NSM handles
*/
static LIST_HEAD(nsm_handles);
static DEFINE_MUTEX(nsm_mutex);
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;
}
mutex_lock(&nsm_mutex);
list_for_each(pos, &nsm_handles) {
nsm = list_entry(pos, struct nsm_handle, sm_link);
if (hostname && nsm_use_hostnames) {
if (strlen(nsm->sm_name) != hostname_len
|| memcmp(nsm->sm_name, hostname, hostname_len))
continue;
} else 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:
mutex_unlock(&nsm_mutex);
return nsm;
}
static 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)) {
mutex_lock(&nsm_mutex);
if (atomic_read(&nsm->sm_count) == 0) {
list_del(&nsm->sm_link);
kfree(nsm);
}
mutex_unlock(&nsm_mutex);
}
}