swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 9ee1c939d1cb936b1f98e8d81aeffab57bae46ab authored by Linus Torvalds on 17 June 2005, 19:48:29 UTC
Linux 2.6.12
Linux 2.6.12
Tip revision: 9ee1c93
nfssvc.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/config.h>
#include <linux/module.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/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/lockd/bind.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;
static struct svc_serv *nfsd_serv;
static atomic_t nfsd_busy;
static unsigned long nfsd_last_call;
static DEFINE_SPINLOCK(nfsd_call_lock);
struct nfsd_list {
struct list_head list;
struct task_struct *task;
};
static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
/*
* 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;
}
int
nfsd_svc(unsigned short port, int nrservs)
{
int error;
int none_left;
struct list_head *victim;
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;
error = nfs4_state_init();
if (error<0)
goto out;
if (!nfsd_serv) {
atomic_set(&nfsd_busy, 0);
error = -ENOMEM;
nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE);
if (nfsd_serv == NULL)
goto out;
error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
if (error < 0)
goto failure;
#ifdef CONFIG_NFSD_TCP
error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
if (error < 0)
goto failure;
#endif
do_gettimeofday(&nfssvc_boot); /* record boot time */
} else
nfsd_serv->sv_nrthreads++;
nrservs -= (nfsd_serv->sv_nrthreads-1);
while (nrservs > 0) {
nrservs--;
__module_get(THIS_MODULE);
error = svc_create_thread(nfsd, nfsd_serv);
if (error < 0) {
module_put(THIS_MODULE);
break;
}
}
victim = nfsd_list.next;
while (nrservs < 0 && victim != &nfsd_list) {
struct nfsd_list *nl =
list_entry(victim,struct nfsd_list, list);
victim = victim->next;
send_sig(SIG_NOCLEAN, nl->task, 1);
nrservs++;
}
failure:
none_left = (nfsd_serv->sv_nrthreads == 1);
svc_destroy(nfsd_serv); /* Release server */
if (none_left) {
nfsd_serv = NULL;
nfsd_racache_shutdown();
nfs4_state_shutdown();
}
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 svc_serv *serv = rqstp->rq_server;
struct fs_struct *fsp;
int err;
struct nfsd_list me;
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++;
lockd_up(); /* start lockd */
me.task = current;
list_add(&me.list, &nfsd_list);
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;
/*
* 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(serv, 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(serv, 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(¤t->pending.signal, signo) &&
!sigismember(¤t->blocked, signo))
break;
err = signo;
}
/* Clear signals before calling lockd_down() and svc_exit_thread() */
flush_signals(current);
lock_kernel();
/* Release lockd */
lockd_down();
/* Check if this is last thread */
if (serv->sv_nrthreads==1) {
printk(KERN_WARNING "nfsd: last server has exited\n");
if (err != SIG_NOCLEAN) {
printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
nfsd_export_flush();
}
nfsd_serv = NULL;
nfsd_racache_shutdown(); /* release read-ahead cache */
nfs4_state_shutdown();
}
list_del(&me.list);
nfsdstats.th_cnt --;
out:
/* Release the thread */
svc_exit_thread(rqstp);
/* Release module */
module_put_and_exit(0);
}
int
nfsd_dispatch(struct svc_rqst *rqstp, u32 *statp)
{
struct svc_procedure *proc;
kxdrproc_t xdr;
u32 nfserr;
u32 *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, (u32*)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(u32);
/* Now call the procedure handler, and encode NFS status. */
nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
nfserr = nfserr_dropit;
if (nfserr == nfserr_dropit) {
dprintk("nfsd: Dropping request due to malloc failure!\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;
}
extern struct svc_version nfsd_version2, nfsd_version3, nfsd_version4;
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_NRVERS (sizeof(nfsd_version)/sizeof(nfsd_version[0]))
struct svc_program nfsd_program = {
.pg_prog = NFS_PROGRAM, /* program number */
.pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
.pg_vers = nfsd_version, /* 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 */
};