[net-next-2.6.git] / fs / nfsd / 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/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);

struct nfsd_list {
	struct list_head 	list;
	struct task_struct	*task;
};
static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);

#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		(sizeof(nfsd_acl_version)/sizeof(nfsd_acl_version[0]))
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		= "nfsd",
	.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		(sizeof(nfsd_version)/sizeof(nfsd_version[0]))
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 */

};

/*
 * 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, found_one, i;
	struct list_head *victim;
	
	lock_kernel();
	dprintk("nfsd: creating service: vers 0x%x\n",
		nfsd_versbits);
	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_start();
	if (error<0)
		goto out;
	if (!nfsd_serv) {
		/*
		 * Use the nfsd_ctlbits to define which
		 * versions that will be advertised.
		 * If nfsd_ctlbits doesn't list any version,
		 * export them all.
		 */
		found_one = 0;

		for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
			if (NFSCTL_VERISSET(nfsd_versbits, i)) {
				nfsd_program.pg_vers[i] = nfsd_version[i];
				found_one = 1;
			} else
				nfsd_program.pg_vers[i] = NULL;
		}

		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)
		found_one = 0;

		for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
			if (NFSCTL_VERISSET(nfsd_versbits, i)) {
				nfsd_acl_program.pg_vers[i] =
					nfsd_acl_version[i];
				found_one = 1;
			} else
				nfsd_acl_program.pg_vers[i] = NULL;
		}

		if (!found_one) {
			for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
				nfsd_acl_program.pg_vers[i] =
					nfsd_acl_version[i];
		}
#endif

		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(&current->pending.signal, signo) &&
			    !sigismember(&current->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 */
	unlock_kernel();
	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;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfsd/nfssvc.c
	3	*
	4	* Central processing for nfsd.
	5	*
	6	* Authors: Olaf Kirch (okir@monad.swb.de)
	7	*
	8	* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
	9	*/
	10
	11	#include <linux/config.h>
	12	#include <linux/module.h>
	13
	14	#include <linux/time.h>
	15	#include <linux/errno.h>
	16	#include <linux/nfs.h>
	17	#include <linux/in.h>
	18	#include <linux/uio.h>
	19	#include <linux/unistd.h>
	20	#include <linux/slab.h>
	21	#include <linux/smp.h>
	22	#include <linux/smp_lock.h>
	23	#include <linux/fs_struct.h>
	24
	25	#include <linux/sunrpc/types.h>
	26	#include <linux/sunrpc/stats.h>
	27	#include <linux/sunrpc/svc.h>
	28	#include <linux/sunrpc/svcsock.h>
	29	#include <linux/sunrpc/cache.h>
	30	#include <linux/nfsd/nfsd.h>
	31	#include <linux/nfsd/stats.h>
	32	#include <linux/nfsd/cache.h>
70c3b76c	33	#include <linux/nfsd/syscall.h>
1da177e4	34	#include <linux/lockd/bind.h>
a257cdd0	35	#include <linux/nfsacl.h>
1da177e4 LT	36
	37	#define NFSDDBG_FACILITY NFSDDBG_SVC
	38
	39	/* these signals will be delivered to an nfsd thread
	40	* when handling a request
	41	*/
	42	#define ALLOWED_SIGS (sigmask(SIGKILL))
	43	/* these signals will be delivered to an nfsd thread
	44	* when not handling a request. i.e. when waiting
	45	*/
	46	#define SHUTDOWN_SIGS (sigmask(SIGKILL) \| sigmask(SIGHUP) \| sigmask(SIGINT) \| sigmask(SIGQUIT))
	47	/* if the last thread dies with SIGHUP, then the exports table is
	48	* left unchanged ( like 2.4-{0-9} ). Any other signal will clear
	49	* the exports table (like 2.2).
	50	*/
	51	#define SIG_NOCLEAN SIGHUP
	52
	53	extern struct svc_program nfsd_program;
	54	static void nfsd(struct svc_rqst *rqstp);
	55	struct timeval nfssvc_boot;
70c3b76c	56	struct svc_serv *nfsd_serv;
1da177e4 LT	57	static atomic_t nfsd_busy;
	58	static unsigned long nfsd_last_call;
	59	static DEFINE_SPINLOCK(nfsd_call_lock);
	60
	61	struct nfsd_list {
	62	struct list_head list;
	63	struct task_struct *task;
	64	};
	65	static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
	66
3fb803a9 AG	67	#if defined(CONFIG_NFSD_V2_ACL) \|\| defined(CONFIG_NFSD_V3_ACL)
	68	static struct svc_stat nfsd_acl_svcstats;
	69	static struct svc_version * nfsd_acl_version[] = {
	70	[2] = &nfsd_acl_version2,
	71	[3] = &nfsd_acl_version3,
	72	};
	73
	74	#define NFSD_ACL_MINVERS 2
	75	#define NFSD_ACL_NRVERS (sizeof(nfsd_acl_version)/sizeof(nfsd_acl_version[0]))
	76	static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
	77
	78	static struct svc_program nfsd_acl_program = {
	79	.pg_prog = NFS_ACL_PROGRAM,
	80	.pg_nvers = NFSD_ACL_NRVERS,
	81	.pg_vers = nfsd_acl_versions,
	82	.pg_name = "nfsd",
	83	.pg_class = "nfsd",
	84	.pg_stats = &nfsd_acl_svcstats,
	85	.pg_authenticate = &svc_set_client,
	86	};
	87
	88	static struct svc_stat nfsd_acl_svcstats = {
	89	.program = &nfsd_acl_program,
	90	};
	91	#endif /* defined(CONFIG_NFSD_V2_ACL) \|\| defined(CONFIG_NFSD_V3_ACL) */
	92
70c3b76c N	93	static struct svc_version * nfsd_version[] = {
	94	[2] = &nfsd_version2,
	95	#if defined(CONFIG_NFSD_V3)
	96	[3] = &nfsd_version3,
	97	#endif
	98	#if defined(CONFIG_NFSD_V4)
	99	[4] = &nfsd_version4,
	100	#endif
	101	};
	102
	103	#define NFSD_MINVERS 2
	104	#define NFSD_NRVERS (sizeof(nfsd_version)/sizeof(nfsd_version[0]))
	105	static struct svc_version *nfsd_versions[NFSD_NRVERS];
	106
	107	struct svc_program nfsd_program = {
3fb803a9 AG	108	#if defined(CONFIG_NFSD_V2_ACL) \|\| defined(CONFIG_NFSD_V3_ACL)
	109	.pg_next = &nfsd_acl_program,
	110	#endif
70c3b76c N	111	.pg_prog = NFS_PROGRAM, /* program number */
	112	.pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
	113	.pg_vers = nfsd_versions, /* version table */
	114	.pg_name = "nfsd", /* program name */
	115	.pg_class = "nfsd", /* authentication class */
	116	.pg_stats = &nfsd_svcstats, /* version table */
	117	.pg_authenticate = &svc_set_client, /* export authentication */
	118
	119	};
	120
1da177e4 LT	121	/*
	122	* Maximum number of nfsd processes
	123	*/
	124	#define NFSD_MAXSERVS 8192
	125
	126	int nfsd_nrthreads(void)
	127	{
	128	if (nfsd_serv == NULL)
	129	return 0;
	130	else
	131	return nfsd_serv->sv_nrthreads;
	132	}
	133
	134	int
	135	nfsd_svc(unsigned short port, int nrservs)
	136	{
	137	int error;
70c3b76c	138	int none_left, found_one, i;
1da177e4 LT	139	struct list_head *victim;
	140
	141	lock_kernel();
70c3b76c N	142	dprintk("nfsd: creating service: vers 0x%x\n",
70c3b76c N	143	nfsd_versbits);
1da177e4 LT	144	error = -EINVAL;
	145	if (nrservs <= 0)
	146	nrservs = 0;
	147	if (nrservs > NFSD_MAXSERVS)
	148	nrservs = NFSD_MAXSERVS;
	149
	150	/* Readahead param cache - will no-op if it already exists */
	151	error = nfsd_racache_init(2*nrservs);
	152	if (error<0)
	153	goto out;
76a3550e	154	error = nfs4_state_start();
1da177e4 LT	155	if (error<0)
	156	goto out;
	157	if (!nfsd_serv) {
70c3b76c N	158	/*
	159	* Use the nfsd_ctlbits to define which
	160	* versions that will be advertised.
	161	* If nfsd_ctlbits doesn't list any version,
	162	* export them all.
	163	*/
	164	found_one = 0;
	165
	166	for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
	167	if (NFSCTL_VERISSET(nfsd_versbits, i)) {
	168	nfsd_program.pg_vers[i] = nfsd_version[i];
	169	found_one = 1;
	170	} else
	171	nfsd_program.pg_vers[i] = NULL;
	172	}
	173
	174	if (!found_one) {
	175	for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
	176	nfsd_program.pg_vers[i] = nfsd_version[i];
	177	}
	178
3fb803a9 AG	179
	180	#if defined(CONFIG_NFSD_V2_ACL) \|\| defined(CONFIG_NFSD_V3_ACL)
	181	found_one = 0;
	182
	183	for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
	184	if (NFSCTL_VERISSET(nfsd_versbits, i)) {
	185	nfsd_acl_program.pg_vers[i] =
	186	nfsd_acl_version[i];
	187	found_one = 1;
	188	} else
	189	nfsd_acl_program.pg_vers[i] = NULL;
	190	}
	191
	192	if (!found_one) {
	193	for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
	194	nfsd_acl_program.pg_vers[i] =
	195	nfsd_acl_version[i];
	196	}
	197	#endif
	198
1da177e4 LT	199	atomic_set(&nfsd_busy, 0);
	200	error = -ENOMEM;
	201	nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE);
	202	if (nfsd_serv == NULL)
	203	goto out;
	204	error = svc_makesock(nfsd_serv, IPPROTO_UDP, port);
	205	if (error < 0)
	206	goto failure;
	207
	208	#ifdef CONFIG_NFSD_TCP
	209	error = svc_makesock(nfsd_serv, IPPROTO_TCP, port);
	210	if (error < 0)
	211	goto failure;
	212	#endif
	213	do_gettimeofday(&nfssvc_boot); /* record boot time */
	214	} else
	215	nfsd_serv->sv_nrthreads++;
	216	nrservs -= (nfsd_serv->sv_nrthreads-1);
	217	while (nrservs > 0) {
	218	nrservs--;
	219	__module_get(THIS_MODULE);
	220	error = svc_create_thread(nfsd, nfsd_serv);
	221	if (error < 0) {
	222	module_put(THIS_MODULE);
	223	break;
	224	}
	225	}
	226	victim = nfsd_list.next;
	227	while (nrservs < 0 && victim != &nfsd_list) {
	228	struct nfsd_list *nl =
	229	list_entry(victim,struct nfsd_list, list);
	230	victim = victim->next;
	231	send_sig(SIG_NOCLEAN, nl->task, 1);
	232	nrservs++;
	233	}
	234	failure:
	235	none_left = (nfsd_serv->sv_nrthreads == 1);
	236	svc_destroy(nfsd_serv); /* Release server */
	237	if (none_left) {
	238	nfsd_serv = NULL;
	239	nfsd_racache_shutdown();
	240	nfs4_state_shutdown();
	241	}
	242	out:
	243	unlock_kernel();
	244	return error;
	245	}
	246
	247	static inline void
	248	update_thread_usage(int busy_threads)
	249	{
	250	unsigned long prev_call;
	251	unsigned long diff;
	252	int decile;
	253
	254	spin_lock(&nfsd_call_lock);
	255	prev_call = nfsd_last_call;
	256	nfsd_last_call = jiffies;
	257	decile = busy_threads*10/nfsdstats.th_cnt;
	258	if (decile>0 && decile <= 10) {
	259	diff = nfsd_last_call - prev_call;
	260	if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
	261	nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
	262	if (decile == 10)
263	nfsdstats.th_fullcnt++;
264	}
265	spin_unlock(&nfsd_call_lock);
266	}
267
268	/*
269	* This is the NFS server kernel thread
270	*/
271	static void
272	nfsd(struct svc_rqst *rqstp)
273	{
274	struct svc_serv *serv = rqstp->rq_server;
275	struct fs_struct *fsp;
276	int err;
277	struct nfsd_list me;
278	sigset_t shutdown_mask, allowed_mask;
279
280	/* Lock module and set up kernel thread */
281	lock_kernel();
282	daemonize("nfsd");
283
284	/* After daemonize() this kernel thread shares current->fs
285	* with the init process. We need to create files with a
286	* umask of 0 instead of init's umask. */
287	fsp = copy_fs_struct(current->fs);
288	if (!fsp) {
289	printk("Unable to start nfsd thread: out of memory\n");
290	goto out;
291	}
292	exit_fs(current);
293	current->fs = fsp;
294	current->fs->umask = 0;
295
296	siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
297	siginitsetinv(&allowed_mask, ALLOWED_SIGS);
298
299	nfsdstats.th_cnt++;
300
301	lockd_up(); /* start lockd */
302
303	me.task = current;
304	list_add(&me.list, &nfsd_list);
305
306	unlock_kernel();
307
308	/*
309	* We want less throttling in balance_dirty_pages() so that nfs to
310	* localhost doesn't cause nfsd to lock up due to all the client's
311	* dirty pages.
312	*/
313	current->flags \|= PF_LESS_THROTTLE;
314
315	/*
316	* The main request loop
317	*/
318	for (;;) {
319	/* Block all but the shutdown signals */
320	sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
321
322	/*
323	* Find a socket with data available and call its
324	* recvfrom routine.
325	*/
326	while ((err = svc_recv(serv, rqstp,
327	6060HZ)) == -EAGAIN)
328	;
329	if (err < 0)
330	break;
331	update_thread_usage(atomic_read(&nfsd_busy));
332	atomic_inc(&nfsd_busy);
333
334	/* Lock the export hash tables for reading. */
335	exp_readlock();
336
337	/* Process request with signals blocked. */
338	sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
339
340	svc_process(serv, rqstp);
341
342	/* Unlock export hash tables */
343	exp_readunlock();
344	update_thread_usage(atomic_read(&nfsd_busy));
345	atomic_dec(&nfsd_busy);
346	}
347
348	if (err != -EINTR) {
349	printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
350	} else {
351	unsigned int signo;
352
353	for (signo = 1; signo <= _NSIG; signo++)
354	if (sigismember(&current->pending.signal, signo) &&
355	!sigismember(&current->blocked, signo))
356	break;
357	err = signo;
358	}
9e416052 N	359	/* Clear signals before calling lockd_down() and svc_exit_thread() */
9e416052 N	360	flush_signals(current);
1da177e4 LT	361
	362	lock_kernel();
	363
	364	/* Release lockd */
	365	lockd_down();
	366
	367	/* Check if this is last thread */
	368	if (serv->sv_nrthreads==1) {
	369
	370	printk(KERN_WARNING "nfsd: last server has exited\n");
	371	if (err != SIG_NOCLEAN) {
	372	printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
	373	nfsd_export_flush();
	374	}
	375	nfsd_serv = NULL;
	376	nfsd_racache_shutdown(); /* release read-ahead cache */
	377	nfs4_state_shutdown();
	378	}
	379	list_del(&me.list);
	380	nfsdstats.th_cnt --;
	381
	382	out:
	383	/* Release the thread */
	384	svc_exit_thread(rqstp);
	385
	386	/* Release module */
c4f92dba	387	unlock_kernel();
1da177e4 LT	388	module_put_and_exit(0);
	389	}
	390
	391	int
	392	nfsd_dispatch(struct svc_rqst rqstp, u32 statp)
	393	{
	394	struct svc_procedure *proc;
	395	kxdrproc_t xdr;
	396	u32 nfserr;
	397	u32 *nfserrp;
	398
	399	dprintk("nfsd_dispatch: vers %d proc %d\n",
	400	rqstp->rq_vers, rqstp->rq_proc);
	401	proc = rqstp->rq_procinfo;
	402
	403	/* Check whether we have this call in the cache. */
	404	switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
	405	case RC_INTR:
	406	case RC_DROPIT:
	407	return 0;
	408	case RC_REPLY:
	409	return 1;
	410	case RC_DOIT:;
	411	/* do it */
	412	}
	413
	414	/* Decode arguments */
	415	xdr = proc->pc_decode;
	416	if (xdr && !xdr(rqstp, (u32*)rqstp->rq_arg.head[0].iov_base,
	417	rqstp->rq_argp)) {
	418	dprintk("nfsd: failed to decode arguments!\n");
	419	nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
	420	*statp = rpc_garbage_args;
	421	return 1;
	422	}
	423
	424	/* need to grab the location to store the status, as
	425	* nfsv4 does some encoding while processing
	426	*/
	427	nfserrp = rqstp->rq_res.head[0].iov_base
	428	+ rqstp->rq_res.head[0].iov_len;
	429	rqstp->rq_res.head[0].iov_len += sizeof(u32);
	430
	431	/* Now call the procedure handler, and encode NFS status. */
	432	nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
	433	if (nfserr == nfserr_jukebox && rqstp->rq_vers == 2)
	434	nfserr = nfserr_dropit;
	435	if (nfserr == nfserr_dropit) {
	436	dprintk("nfsd: Dropping request due to malloc failure!\n");
	437	nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
	438	return 0;
	439	}
	440
	441	if (rqstp->rq_proc != 0)
	442	*nfserrp++ = nfserr;
	443
	444	/* Encode result.
	445	* For NFSv2, additional info is never returned in case of an error.
	446	*/
	447	if (!(nfserr && rqstp->rq_vers == 2)) {
	448	xdr = proc->pc_encode;
	449	if (xdr && !xdr(rqstp, nfserrp,
	450	rqstp->rq_resp)) {
	451	/* Failed to encode result. Release cache entry */
452	dprintk("nfsd: failed to encode result!\n");
453	nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
454	*statp = rpc_system_err;
455	return 1;
456	}
457	}
458
459	/* Store reply in cache. */
460	nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
461	return 1;
462	}