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Commit eed2965a authored by Greg Banks's avatar Greg Banks Committed by Linus Torvalds
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[PATCH] knfsd: allow admin to set nthreads per node 



Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool.  The
format is a list of space-separated integers, one per pool.

Signed-off-by: default avatarGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bfd24160

fs/nfsd/nfsctl.c

+70 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ enum { 
	NFSD_List,

	NFSD_Fh,

	NFSD_Threads,

	NFSD_Pool_Threads,

	NFSD_Versions,

	NFSD_Ports,

	/*
@@ -78,6 +79,7 @@ static ssize_t write_getfd(struct file *file, char *buf, size_t size); 
static ssize_t write_getfs(struct file *file, char *buf, size_t size);

static ssize_t write_filehandle(struct file *file, char *buf, size_t size);

static ssize_t write_threads(struct file *file, char *buf, size_t size);

static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);

static ssize_t write_versions(struct file *file, char *buf, size_t size);

static ssize_t write_ports(struct file *file, char *buf, size_t size);

#ifdef CONFIG_NFSD_V4
@@ -95,6 +97,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = { 
	[NFSD_Getfs] = write_getfs,

	[NFSD_Fh] = write_filehandle,

	[NFSD_Threads] = write_threads,

	[NFSD_Pool_Threads] = write_pool_threads,

	[NFSD_Versions] = write_versions,

	[NFSD_Ports] = write_ports,

#ifdef CONFIG_NFSD_V4
@@ -363,6 +366,72 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size) 
	return strlen(buf);

}



extern int nfsd_nrpools(void);

extern int nfsd_get_nrthreads(int n, int *);

extern int nfsd_set_nrthreads(int n, int *);



static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)

{

	/* if size > 0, look for an array of number of threads per node

	 * and apply them  then write out number of threads per node as reply

	 */

	char *mesg = buf;

	int i;

	int rv;

	int len;

    	int npools = nfsd_nrpools();

	int *nthreads;



	if (npools == 0) {

		/*

		 * NFS is shut down.  The admin can start it by

		 * writing to the threads file but NOT the pool_threads

		 * file, sorry.  Report zero threads.

		 */

		strcpy(buf, "0\n");

		return strlen(buf);

	}



	nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);

	if (nthreads == NULL)

		return -ENOMEM;



	if (size > 0) {

		for (i = 0; i < npools; i++) {

			rv = get_int(&mesg, &nthreads[i]);

			if (rv == -ENOENT)

				break;		/* fewer numbers than pools */

			if (rv)

				goto out_free;	/* syntax error */

			rv = -EINVAL;

			if (nthreads[i] < 0)

				goto out_free;

		}

		rv = nfsd_set_nrthreads(i, nthreads);

		if (rv)

			goto out_free;

	}



	rv = nfsd_get_nrthreads(npools, nthreads);

	if (rv)

		goto out_free;



	mesg = buf;

	size = SIMPLE_TRANSACTION_LIMIT;

	for (i = 0; i < npools && size > 0; i++) {

		snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));

		len = strlen(mesg);

		size -= len;

		mesg += len;

	}



	return (mesg-buf);



out_free:

	kfree(nthreads);

	return rv;

}



static ssize_t write_versions(struct file *file, char *buf, size_t size)

{

	/*
@@ -544,6 +613,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) 
		[NFSD_List] = {"exports", &exports_operations, S_IRUGO},

		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},

#ifdef CONFIG_NFSD_V4

fs/nfsd/nfssvc.c

+74 −0
Original line number Diff line number Diff line
@@ -238,6 +238,80 @@ static int nfsd_init_socks(int port) 
	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)

{