kernel-ark/fs/nfsd/nfssvc.c
J. Bruce Fields e8ff2a8453 knfsd: move nfsv4 slab creation/destruction to module init/exit
We have some slabs that the nfs4 server uses to store state objects.
We're currently creating and destroying those slabs whenever the server
is brought up or down.  That seems excessive; may as well just do that
in module initialization and exit.

Also add some minor header cleanup.  (Thanks to Andrew Morton for that
and a compile fix.)

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by:  Neil Brown <neilb@suse.de>
2007-10-09 18:31:56 -04:00

575 lines
13 KiB
C

/*
* linux/fs/nfsd/nfssvc.c
*
* Central processing for nfsd.
*
* Authors: Olaf Kirch (okir@monad.swb.de)
*
* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/nfs.h>
#include <linux/in.h>
#include <linux/uio.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/freezer.h>
#include <linux/fs_struct.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/cache.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/stats.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/syscall.h>
#include <linux/lockd/bind.h>
#include <linux/nfsacl.h>
#define NFSDDBG_FACILITY NFSDDBG_SVC
/* these signals will be delivered to an nfsd thread
* when handling a request
*/
#define ALLOWED_SIGS (sigmask(SIGKILL))
/* these signals will be delivered to an nfsd thread
* when not handling a request. i.e. when waiting
*/
#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT))
/* if the last thread dies with SIGHUP, then the exports table is
* left unchanged ( like 2.4-{0-9} ). Any other signal will clear
* the exports table (like 2.2).
*/
#define SIG_NOCLEAN SIGHUP
extern struct svc_program nfsd_program;
static void nfsd(struct svc_rqst *rqstp);
struct timeval nfssvc_boot;
struct svc_serv *nfsd_serv;
static atomic_t nfsd_busy;
static unsigned long nfsd_last_call;
static DEFINE_SPINLOCK(nfsd_call_lock);
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static struct svc_stat nfsd_acl_svcstats;
static struct svc_version * nfsd_acl_version[] = {
[2] = &nfsd_acl_version2,
[3] = &nfsd_acl_version3,
};
#define NFSD_ACL_MINVERS 2
#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
static struct svc_program nfsd_acl_program = {
.pg_prog = NFS_ACL_PROGRAM,
.pg_nvers = NFSD_ACL_NRVERS,
.pg_vers = nfsd_acl_versions,
.pg_name = "nfsacl",
.pg_class = "nfsd",
.pg_stats = &nfsd_acl_svcstats,
.pg_authenticate = &svc_set_client,
};
static struct svc_stat nfsd_acl_svcstats = {
.program = &nfsd_acl_program,
};
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
static struct svc_version * nfsd_version[] = {
[2] = &nfsd_version2,
#if defined(CONFIG_NFSD_V3)
[3] = &nfsd_version3,
#endif
#if defined(CONFIG_NFSD_V4)
[4] = &nfsd_version4,
#endif
};
#define NFSD_MINVERS 2
#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
static struct svc_version *nfsd_versions[NFSD_NRVERS];
struct svc_program nfsd_program = {
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
.pg_next = &nfsd_acl_program,
#endif
.pg_prog = NFS_PROGRAM, /* program number */
.pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
.pg_vers = nfsd_versions, /* version table */
.pg_name = "nfsd", /* program name */
.pg_class = "nfsd", /* authentication class */
.pg_stats = &nfsd_svcstats, /* version table */
.pg_authenticate = &svc_set_client, /* export authentication */
};
int nfsd_vers(int vers, enum vers_op change)
{
if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
return -1;
switch(change) {
case NFSD_SET:
nfsd_versions[vers] = nfsd_version[vers];
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
if (vers < NFSD_ACL_NRVERS)
nfsd_acl_versions[vers] = nfsd_acl_version[vers];
#endif
break;
case NFSD_CLEAR:
nfsd_versions[vers] = NULL;
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
if (vers < NFSD_ACL_NRVERS)
nfsd_acl_versions[vers] = NULL;
#endif
break;
case NFSD_TEST:
return nfsd_versions[vers] != NULL;
case NFSD_AVAIL:
return nfsd_version[vers] != NULL;
}
return 0;
}
/*
* Maximum number of nfsd processes
*/
#define NFSD_MAXSERVS 8192
int nfsd_nrthreads(void)
{
if (nfsd_serv == NULL)
return 0;
else
return nfsd_serv->sv_nrthreads;
}
static int killsig; /* signal that was used to kill last nfsd */
static void nfsd_last_thread(struct svc_serv *serv)
{
/* When last nfsd thread exits we need to do some clean-up */
struct svc_sock *svsk;
list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
lockd_down();
nfsd_serv = NULL;
nfsd_racache_shutdown();
nfs4_state_shutdown();
printk(KERN_WARNING "nfsd: last server has exited\n");
if (killsig != SIG_NOCLEAN) {
printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
nfsd_export_flush();
}
}
void nfsd_reset_versions(void)
{
int found_one = 0;
int i;
for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
if (nfsd_program.pg_vers[i])
found_one = 1;
}
if (!found_one) {
for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
nfsd_program.pg_vers[i] = nfsd_version[i];
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
nfsd_acl_program.pg_vers[i] =
nfsd_acl_version[i];
#endif
}
}
int nfsd_create_serv(void)
{
int err = 0;
lock_kernel();
if (nfsd_serv) {
svc_get(nfsd_serv);
unlock_kernel();
return 0;
}
if (nfsd_max_blksize == 0) {
/* choose a suitable default */
struct sysinfo i;
si_meminfo(&i);
/* Aim for 1/4096 of memory per thread
* This gives 1MB on 4Gig machines
* But only uses 32K on 128M machines.
* Bottom out at 8K on 32M and smaller.
* Of course, this is only a default.
*/
nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
i.totalram <<= PAGE_SHIFT - 12;
while (nfsd_max_blksize > i.totalram &&
nfsd_max_blksize >= 8*1024*2)
nfsd_max_blksize /= 2;
}
atomic_set(&nfsd_busy, 0);
nfsd_serv = svc_create_pooled(&nfsd_program,
nfsd_max_blksize,
nfsd_last_thread,
nfsd, SIG_NOCLEAN, THIS_MODULE);
if (nfsd_serv == NULL)
err = -ENOMEM;
unlock_kernel();
do_gettimeofday(&nfssvc_boot); /* record boot time */
return err;
}
static int nfsd_init_socks(int port)
{
int error;
if (!list_empty(&nfsd_serv->sv_permsocks))
return 0;
error = lockd_up(IPPROTO_UDP);
if (error >= 0) {
error = svc_makesock(nfsd_serv, IPPROTO_UDP, port,
SVC_SOCK_DEFAULTS);
if (error < 0)
lockd_down();
}
if (error < 0)
return error;
#ifdef CONFIG_NFSD_TCP
error = lockd_up(IPPROTO_TCP);
if (error >= 0) {
error = svc_makesock(nfsd_serv, IPPROTO_TCP, port,
SVC_SOCK_DEFAULTS);
if (error < 0)
lockd_down();
}
if (error < 0)
return error;
#endif
return 0;
}
int nfsd_nrpools(void)
{
if (nfsd_serv == NULL)
return 0;
else
return nfsd_serv->sv_nrpools;
}
int nfsd_get_nrthreads(int n, int *nthreads)
{
int i = 0;
if (nfsd_serv != NULL) {
for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
}
return 0;
}
int nfsd_set_nrthreads(int n, int *nthreads)
{
int i = 0;
int tot = 0;
int err = 0;
if (nfsd_serv == NULL || n <= 0)
return 0;
if (n > nfsd_serv->sv_nrpools)
n = nfsd_serv->sv_nrpools;
/* enforce a global maximum number of threads */
tot = 0;
for (i = 0; i < n; i++) {
if (nthreads[i] > NFSD_MAXSERVS)
nthreads[i] = NFSD_MAXSERVS;
tot += nthreads[i];
}
if (tot > NFSD_MAXSERVS) {
/* total too large: scale down requested numbers */
for (i = 0; i < n && tot > 0; i++) {
int new = nthreads[i] * NFSD_MAXSERVS / tot;
tot -= (nthreads[i] - new);
nthreads[i] = new;
}
for (i = 0; i < n && tot > 0; i++) {
nthreads[i]--;
tot--;
}
}
/*
* There must always be a thread in pool 0; the admin
* can't shut down NFS completely using pool_threads.
*/
if (nthreads[0] == 0)
nthreads[0] = 1;
/* apply the new numbers */
lock_kernel();
svc_get(nfsd_serv);
for (i = 0; i < n; i++) {
err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
nthreads[i]);
if (err)
break;
}
svc_destroy(nfsd_serv);
unlock_kernel();
return err;
}
int
nfsd_svc(unsigned short port, int nrservs)
{
int error;
lock_kernel();
dprintk("nfsd: creating service\n");
error = -EINVAL;
if (nrservs <= 0)
nrservs = 0;
if (nrservs > NFSD_MAXSERVS)
nrservs = NFSD_MAXSERVS;
/* Readahead param cache - will no-op if it already exists */
error = nfsd_racache_init(2*nrservs);
if (error<0)
goto out;
nfs4_state_start();
nfsd_reset_versions();
error = nfsd_create_serv();
if (error)
goto out;
error = nfsd_init_socks(port);
if (error)
goto failure;
error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
failure:
svc_destroy(nfsd_serv); /* Release server */
out:
unlock_kernel();
return error;
}
static inline void
update_thread_usage(int busy_threads)
{
unsigned long prev_call;
unsigned long diff;
int decile;
spin_lock(&nfsd_call_lock);
prev_call = nfsd_last_call;
nfsd_last_call = jiffies;
decile = busy_threads*10/nfsdstats.th_cnt;
if (decile>0 && decile <= 10) {
diff = nfsd_last_call - prev_call;
if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
if (decile == 10)
nfsdstats.th_fullcnt++;
}
spin_unlock(&nfsd_call_lock);
}
/*
* This is the NFS server kernel thread
*/
static void
nfsd(struct svc_rqst *rqstp)
{
struct fs_struct *fsp;
int err;
sigset_t shutdown_mask, allowed_mask;
/* Lock module and set up kernel thread */
lock_kernel();
daemonize("nfsd");
/* After daemonize() this kernel thread shares current->fs
* with the init process. We need to create files with a
* umask of 0 instead of init's umask. */
fsp = copy_fs_struct(current->fs);
if (!fsp) {
printk("Unable to start nfsd thread: out of memory\n");
goto out;
}
exit_fs(current);
current->fs = fsp;
current->fs->umask = 0;
siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
siginitsetinv(&allowed_mask, ALLOWED_SIGS);
nfsdstats.th_cnt++;
rqstp->rq_task = current;
unlock_kernel();
/*
* We want less throttling in balance_dirty_pages() so that nfs to
* localhost doesn't cause nfsd to lock up due to all the client's
* dirty pages.
*/
current->flags |= PF_LESS_THROTTLE;
set_freezable();
/*
* The main request loop
*/
for (;;) {
/* Block all but the shutdown signals */
sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
/*
* Find a socket with data available and call its
* recvfrom routine.
*/
while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
;
if (err < 0)
break;
update_thread_usage(atomic_read(&nfsd_busy));
atomic_inc(&nfsd_busy);
/* Lock the export hash tables for reading. */
exp_readlock();
/* Process request with signals blocked. */
sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
svc_process(rqstp);
/* Unlock export hash tables */
exp_readunlock();
update_thread_usage(atomic_read(&nfsd_busy));
atomic_dec(&nfsd_busy);
}
if (err != -EINTR) {
printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
} else {
unsigned int signo;
for (signo = 1; signo <= _NSIG; signo++)
if (sigismember(&current->pending.signal, signo) &&
!sigismember(&current->blocked, signo))
break;
killsig = signo;
}
/* Clear signals before calling svc_exit_thread() */
flush_signals(current);
lock_kernel();
nfsdstats.th_cnt --;
out:
/* Release the thread */
svc_exit_thread(rqstp);
/* Release module */
unlock_kernel();
module_put_and_exit(0);
}
static __be32 map_new_errors(u32 vers, __be32 nfserr)
{
if (nfserr == nfserr_jukebox && vers == 2)
return nfserr_dropit;
if (nfserr == nfserr_wrongsec && vers < 4)
return nfserr_acces;
return nfserr;
}
int
nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
{
struct svc_procedure *proc;
kxdrproc_t xdr;
__be32 nfserr;
__be32 *nfserrp;
dprintk("nfsd_dispatch: vers %d proc %d\n",
rqstp->rq_vers, rqstp->rq_proc);
proc = rqstp->rq_procinfo;
/* Check whether we have this call in the cache. */
switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
case RC_INTR:
case RC_DROPIT:
return 0;
case RC_REPLY:
return 1;
case RC_DOIT:;
/* do it */
}
/* Decode arguments */
xdr = proc->pc_decode;
if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
rqstp->rq_argp)) {
dprintk("nfsd: failed to decode arguments!\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
*statp = rpc_garbage_args;
return 1;
}
/* need to grab the location to store the status, as
* nfsv4 does some encoding while processing
*/
nfserrp = rqstp->rq_res.head[0].iov_base
+ rqstp->rq_res.head[0].iov_len;
rqstp->rq_res.head[0].iov_len += sizeof(__be32);
/* Now call the procedure handler, and encode NFS status. */
nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
nfserr = map_new_errors(rqstp->rq_vers, nfserr);
if (nfserr == nfserr_dropit) {
dprintk("nfsd: Dropping request; may be revisited later\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
return 0;
}
if (rqstp->rq_proc != 0)
*nfserrp++ = nfserr;
/* Encode result.
* For NFSv2, additional info is never returned in case of an error.
*/
if (!(nfserr && rqstp->rq_vers == 2)) {
xdr = proc->pc_encode;
if (xdr && !xdr(rqstp, nfserrp,
rqstp->rq_resp)) {
/* Failed to encode result. Release cache entry */
dprintk("nfsd: failed to encode result!\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
*statp = rpc_system_err;
return 1;
}
}
/* Store reply in cache. */
nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
return 1;
}