[linux-2.6-block.git] / fs / nfs / filelayout / filelayoutdev.c

/*
 *  Device operations for the pnfs nfs4 file layout driver.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <dhildebz@umich.edu>
 *  Garth Goodson   <Garth.Goodson@netapp.com>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#include <linux/nfs_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>

#include "../internal.h"
#include "../nfs4session.h"
#include "filelayout.h"

#define NFSDBG_FACILITY		NFSDBG_PNFS_LD

static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;

void
nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
{
	struct nfs4_pnfs_ds *ds;
	int i;

	nfs4_print_deviceid(&dsaddr->id_node.deviceid);

	for (i = 0; i < dsaddr->ds_num; i++) {
		ds = dsaddr->ds_list[i];
		if (ds != NULL)
			nfs4_pnfs_ds_put(ds);
	}
	kfree(dsaddr->stripe_indices);
	kfree(dsaddr);
}

/* Decode opaque device data and return the result */
struct nfs4_file_layout_dsaddr *
nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
		gfp_t gfp_flags)
{
	int i;
	u32 cnt, num;
	u8 *indexp;
	__be32 *p;
	u8 *stripe_indices;
	u8 max_stripe_index;
	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
	struct xdr_stream stream;
	struct xdr_buf buf;
	struct page *scratch;
	struct list_head dsaddrs;
	struct nfs4_pnfs_ds_addr *da;

	/* set up xdr stream */
	scratch = alloc_page(gfp_flags);
	if (!scratch)
		goto out_err;

	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);

	/* Get the stripe count (number of stripe index) */
	p = xdr_inline_decode(&stream, 4);
	if (unlikely(!p))
		goto out_err_free_scratch;

	cnt = be32_to_cpup(p);
	dprintk("%s stripe count  %d\n", __func__, cnt);
	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
		printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
		       "supported maximum %d\n", __func__,
			cnt, NFS4_PNFS_MAX_STRIPE_CNT);
		goto out_err_free_scratch;
	}

	/* read stripe indices */
	stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags);
	if (!stripe_indices)
		goto out_err_free_scratch;

	p = xdr_inline_decode(&stream, cnt << 2);
	if (unlikely(!p))
		goto out_err_free_stripe_indices;

	indexp = &stripe_indices[0];
	max_stripe_index = 0;
	for (i = 0; i < cnt; i++) {
		*indexp = be32_to_cpup(p++);
		max_stripe_index = max(max_stripe_index, *indexp);
		indexp++;
	}

	/* Check the multipath list count */
	p = xdr_inline_decode(&stream, 4);
	if (unlikely(!p))
		goto out_err_free_stripe_indices;

	num = be32_to_cpup(p);
	dprintk("%s ds_num %u\n", __func__, num);
	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
		printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
			"supported maximum %d\n", __func__,
			num, NFS4_PNFS_MAX_MULTI_CNT);
		goto out_err_free_stripe_indices;
	}

	/* validate stripe indices are all < num */
	if (max_stripe_index >= num) {
		printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
			__func__, max_stripe_index, num);
		goto out_err_free_stripe_indices;
	}

	dsaddr = kzalloc(sizeof(*dsaddr) +
			(sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
			gfp_flags);
	if (!dsaddr)
		goto out_err_free_stripe_indices;

	dsaddr->stripe_count = cnt;
	dsaddr->stripe_indices = stripe_indices;
	stripe_indices = NULL;
	dsaddr->ds_num = num;
	nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);

	INIT_LIST_HEAD(&dsaddrs);

	for (i = 0; i < dsaddr->ds_num; i++) {
		int j;
		u32 mp_count;

		p = xdr_inline_decode(&stream, 4);
		if (unlikely(!p))
			goto out_err_free_deviceid;

		mp_count = be32_to_cpup(p); /* multipath count */
		for (j = 0; j < mp_count; j++) {
			da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
						    &stream, gfp_flags);
			if (da)
				list_add_tail(&da->da_node, &dsaddrs);
		}
		if (list_empty(&dsaddrs)) {
			dprintk("%s: no suitable DS addresses found\n",
				__func__);
			goto out_err_free_deviceid;
		}

		dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
		if (!dsaddr->ds_list[i])
			goto out_err_drain_dsaddrs;

		/* If DS was already in cache, free ds addrs */
		while (!list_empty(&dsaddrs)) {
			da = list_first_entry(&dsaddrs,
					      struct nfs4_pnfs_ds_addr,
					      da_node);
			list_del_init(&da->da_node);
			kfree(da->da_remotestr);
			kfree(da);
		}
	}

	__free_page(scratch);
	return dsaddr;

out_err_drain_dsaddrs:
	while (!list_empty(&dsaddrs)) {
		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
				      da_node);
		list_del_init(&da->da_node);
		kfree(da->da_remotestr);
		kfree(da);
	}
out_err_free_deviceid:
	nfs4_fl_free_deviceid(dsaddr);
	/* stripe_indicies was part of dsaddr */
	goto out_err_free_scratch;
out_err_free_stripe_indices:
	kfree(stripe_indices);
out_err_free_scratch:
	__free_page(scratch);
out_err:
	dprintk("%s ERROR: returning NULL\n", __func__);
	return NULL;
}

void
nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
{
	nfs4_put_deviceid_node(&dsaddr->id_node);
}

/*
 * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
 * Then: ((res + fsi) % dsaddr->stripe_count)
 */
u32
nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
{
	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
	u64 tmp;

	tmp = offset - flseg->pattern_offset;
	do_div(tmp, flseg->stripe_unit);
	tmp += flseg->first_stripe_index;
	return do_div(tmp, flseg->dsaddr->stripe_count);
}

u32
nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
{
	return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
}

struct nfs_fh *
nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
{
	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
	u32 i;

	if (flseg->stripe_type == STRIPE_SPARSE) {
		if (flseg->num_fh == 1)
			i = 0;
		else if (flseg->num_fh == 0)
			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
			return NULL;
		else
			i = nfs4_fl_calc_ds_index(lseg, j);
	} else
		i = j;
	return flseg->fh_array[i];
}

/* Upon return, either ds is connected, or ds is NULL */
struct nfs4_pnfs_ds *
nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
{
	struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
	struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];
	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
	struct nfs4_pnfs_ds *ret = ds;
	struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);

	if (ds == NULL) {
		printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
			__func__, ds_idx);
		pnfs_generic_mark_devid_invalid(devid);
		goto out;
	}
	smp_rmb();
	if (ds->ds_clp)
		goto out_test_devid;

	nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
			     dataserver_retrans, 4,
			     s->nfs_client->cl_minorversion,
			     s->nfs_client->cl_rpcclient->cl_auth->au_flavor);

out_test_devid:
	if (filelayout_test_devid_unavailable(devid))
		ret = NULL;
out:
	return ret;
}

module_param(dataserver_retrans, uint, 0644);
MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
			"retries a request before it attempts further "
			" recovery  action.");
module_param(dataserver_timeo, uint, 0644);
MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
			"NFSv4.1  client  waits for a response from a "
			" data server before it retries an NFS request.");
Commit	Line	Data
16b374ca AA	1	/*
	2	* Device operations for the pnfs nfs4 file layout driver.
	3	*
	4	* Copyright (c) 2002
	5	* The Regents of the University of Michigan
	6	* All Rights Reserved
	7	*
	8	* Dean Hildebrand <dhildebz@umich.edu>
	9	* Garth Goodson <Garth.Goodson@netapp.com>
	10	*
	11	* Permission is granted to use, copy, create derivative works, and
	12	* redistribute this software and such derivative works for any purpose,
	13	* so long as the name of the University of Michigan is not used in
	14	* any advertising or publicity pertaining to the use or distribution
	15	* of this software without specific, written prior authorization. If
	16	* the above copyright notice or any other identification of the
	17	* University of Michigan is included in any copy of any portion of
	18	* this software, then the disclaimer below must also be included.
	19	*
	20	* This software is provided as is, without representation or warranty
	21	* of any kind either express or implied, including without limitation
	22	* the implied warranties of merchantability, fitness for a particular
	23	* purpose, or noninfringement. The Regents of the University of
	24	* Michigan shall not be liable for any damages, including special,
	25	* indirect, incidental, or consequential damages, with respect to any
	26	* claim arising out of or in connection with the use of the software,
	27	* even if it has been or is hereafter advised of the possibility of
	28	* such damages.
	29	*/
	30
	31	#include <linux/nfs_fs.h>
	32	#include <linux/vmalloc.h>
98fc685a	33	#include <linux/module.h>
16b374ca	34
b5968725 TH	35	#include "../internal.h"
	36	#include "../nfs4session.h"
	37	#include "filelayout.h"
16b374ca AA	38
	39	#define NFSDBG_FACILITY NFSDBG_PNFS_LD
	40
98fc685a AA	41	static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
	42	static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
	43
1775bc34	44	void
16b374ca AA	45	nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
	46	{
	47	struct nfs4_pnfs_ds *ds;
	48	int i;
	49
a1eaecbc	50	nfs4_print_deviceid(&dsaddr->id_node.deviceid);
16b374ca AA	51
	52	for (i = 0; i < dsaddr->ds_num; i++) {
	53	ds = dsaddr->ds_list[i];
875ae069 PT	54	if (ds != NULL)
875ae069 PT	55	nfs4_pnfs_ds_put(ds);
16b374ca AA	56	}
	57	kfree(dsaddr->stripe_indices);
	58	kfree(dsaddr);
	59	}
	60
16b374ca	61	/* Decode opaque device data and return the result */
661373b1 CH	62	struct nfs4_file_layout_dsaddr *
	63	nfs4_fl_alloc_deviceid_node(struct nfs_server server, struct pnfs_device pdev,
	64	gfp_t gfp_flags)
16b374ca	65	{
35124a09	66	int i;
16b374ca AA	67	u32 cnt, num;
16b374ca AA	68	u8 *indexp;
35124a09 WAA	69	__be32 *p;
	70	u8 *stripe_indices;
	71	u8 max_stripe_index;
	72	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
	73	struct xdr_stream stream;
f7da7a12	74	struct xdr_buf buf;
35124a09	75	struct page *scratch;
14f9a607 WAA	76	struct list_head dsaddrs;
14f9a607 WAA	77	struct nfs4_pnfs_ds_addr *da;
35124a09 WAA	78
35124a09 WAA	79	/* set up xdr stream */
a75b9df9	80	scratch = alloc_page(gfp_flags);
35124a09 WAA	81	if (!scratch)
	82	goto out_err;
	83
f7da7a12	84	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
35124a09	85	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
16b374ca AA	86
16b374ca AA	87	/* Get the stripe count (number of stripe index) */
35124a09 WAA	88	p = xdr_inline_decode(&stream, 4);
	89	if (unlikely(!p))
	90	goto out_err_free_scratch;
	91
	92	cnt = be32_to_cpup(p);
16b374ca AA	93	dprintk("%s stripe count %d\n", __func__, cnt);
16b374ca AA	94	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
a030889a	95	printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
16b374ca AA	96	"supported maximum %d\n", __func__,
16b374ca AA	97	cnt, NFS4_PNFS_MAX_STRIPE_CNT);
35124a09 WAA	98	goto out_err_free_scratch;
	99	}
	100
	101	/* read stripe indices */
a75b9df9	102	stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags);
35124a09 WAA	103	if (!stripe_indices)
	104	goto out_err_free_scratch;
	105
	106	p = xdr_inline_decode(&stream, cnt << 2);
	107	if (unlikely(!p))
	108	goto out_err_free_stripe_indices;
	109
	110	indexp = &stripe_indices[0];
	111	max_stripe_index = 0;
	112	for (i = 0; i < cnt; i++) {
	113	*indexp = be32_to_cpup(p++);
	114	max_stripe_index = max(max_stripe_index, *indexp);
	115	indexp++;
16b374ca AA	116	}
	117
	118	/* Check the multipath list count */
35124a09 WAA	119	p = xdr_inline_decode(&stream, 4);
	120	if (unlikely(!p))
	121	goto out_err_free_stripe_indices;
	122
	123	num = be32_to_cpup(p);
16b374ca AA	124	dprintk("%s ds_num %u\n", __func__, num);
16b374ca AA	125	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
a030889a	126	printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
16b374ca AA	127	"supported maximum %d\n", __func__,
16b374ca AA	128	num, NFS4_PNFS_MAX_MULTI_CNT);
35124a09	129	goto out_err_free_stripe_indices;
16b374ca	130	}
35124a09 WAA	131
	132	/* validate stripe indices are all < num */
	133	if (max_stripe_index >= num) {
a030889a	134	printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
35124a09 WAA	135	__func__, max_stripe_index, num);
	136	goto out_err_free_stripe_indices;
	137	}
	138
16b374ca AA	139	dsaddr = kzalloc(sizeof(*dsaddr) +
16b374ca AA	140	(sizeof(struct nfs4_pnfs_ds ) (num - 1)),
a75b9df9	141	gfp_flags);
16b374ca	142	if (!dsaddr)
35124a09	143	goto out_err_free_stripe_indices;
16b374ca AA	144
16b374ca AA	145	dsaddr->stripe_count = cnt;
35124a09 WAA	146	dsaddr->stripe_indices = stripe_indices;
35124a09 WAA	147	stripe_indices = NULL;
16b374ca	148	dsaddr->ds_num = num;
661373b1	149	nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);
16b374ca	150
14f9a607 WAA	151	INIT_LIST_HEAD(&dsaddrs);
14f9a607 WAA	152
16b374ca AA	153	for (i = 0; i < dsaddr->ds_num; i++) {
16b374ca AA	154	int j;
35124a09 WAA	155	u32 mp_count;
	156
	157	p = xdr_inline_decode(&stream, 4);
	158	if (unlikely(!p))
	159	goto out_err_free_deviceid;
16b374ca	160
35124a09	161	mp_count = be32_to_cpup(p); /* multipath count */
35124a09	162	for (j = 0; j < mp_count; j++) {
6b7f3cf9 PT	163	da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
6b7f3cf9 PT	164	&stream, gfp_flags);
14f9a607 WAA	165	if (da)
	166	list_add_tail(&da->da_node, &dsaddrs);
	167	}
	168	if (list_empty(&dsaddrs)) {
	169	dprintk("%s: no suitable DS addresses found\n",
	170	__func__);
	171	goto out_err_free_deviceid;
	172	}
	173
	174	dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
	175	if (!dsaddr->ds_list[i])
	176	goto out_err_drain_dsaddrs;
	177
	178	/* If DS was already in cache, free ds addrs */
	179	while (!list_empty(&dsaddrs)) {
	180	da = list_first_entry(&dsaddrs,
	181	struct nfs4_pnfs_ds_addr,
	182	da_node);
	183	list_del_init(&da->da_node);
	184	kfree(da->da_remotestr);
	185	kfree(da);
16b374ca AA	186	}
16b374ca AA	187	}
35124a09 WAA	188
35124a09 WAA	189	__free_page(scratch);
16b374ca AA	190	return dsaddr;
16b374ca AA	191
14f9a607 WAA	192	out_err_drain_dsaddrs:
	193	while (!list_empty(&dsaddrs)) {
	194	da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
	195	da_node);
	196	list_del_init(&da->da_node);
	197	kfree(da->da_remotestr);
	198	kfree(da);
	199	}
35124a09	200	out_err_free_deviceid:
16b374ca	201	nfs4_fl_free_deviceid(dsaddr);
35124a09 WAA	202	/* stripe_indicies was part of dsaddr */
	203	goto out_err_free_scratch;
	204	out_err_free_stripe_indices:
	205	kfree(stripe_indices);
	206	out_err_free_scratch:
	207	__free_page(scratch);
16b374ca AA	208	out_err:
	209	dprintk("%s ERROR: returning NULL\n", __func__);
	210	return NULL;
	211	}
	212
ea8eecdd CH	213	void
ea8eecdd CH	214	nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
16b374ca	215	{
1775bc34	216	nfs4_put_deviceid_node(&dsaddr->id_node);
16b374ca	217	}
cfe7f412 FI	218
	219	/*
	220	* Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
	221	* Then: ((res + fsi) % dsaddr->stripe_count)
	222	*/
	223	u32
	224	nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
	225	{
	226	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
	227	u64 tmp;
	228
	229	tmp = offset - flseg->pattern_offset;
	230	do_div(tmp, flseg->stripe_unit);
	231	tmp += flseg->first_stripe_index;
	232	return do_div(tmp, flseg->dsaddr->stripe_count);
	233	}
	234
	235	u32
	236	nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
	237	{
	238	return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
	239	}
	240
	241	struct nfs_fh *
	242	nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
	243	{
	244	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
	245	u32 i;
	246
	247	if (flseg->stripe_type == STRIPE_SPARSE) {
	248	if (flseg->num_fh == 1)
	249	i = 0;
	250	else if (flseg->num_fh == 0)
	251	/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
	252	return NULL;
	253	else
	254	i = nfs4_fl_calc_ds_index(lseg, j);
	255	} else
	256	i = j;
	257	return flseg->fh_array[i];
	258	}
	259
7405f9e1	260	/* Upon return, either ds is connected, or ds is NULL */
cfe7f412 FI	261	struct nfs4_pnfs_ds *
	262	nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
	263	{
	264	struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
	265	struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];
554d458d	266	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
52b26a3e	267	struct nfs4_pnfs_ds *ret = ds;
7405f9e1	268	struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);
cfe7f412 FI	269
cfe7f412 FI	270	if (ds == NULL) {
a030889a	271	printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
cfe7f412	272	__func__, ds_idx);
f54bcf2e	273	pnfs_generic_mark_devid_invalid(devid);
52b26a3e	274	goto out;
cfe7f412	275	}
acd65e5b	276	smp_rmb();
c23266d5	277	if (ds->ds_clp)
52b26a3e	278	goto out_test_devid;
cfe7f412	279
7405f9e1	280	nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
30626f9c PT	281	dataserver_retrans, 4,
30626f9c PT	282	s->nfs_client->cl_minorversion,
064172f3	283	s->nfs_client->cl_rpcclient->cl_auth->au_flavor);
7405f9e1	284
52b26a3e TM	285	out_test_devid:
	286	if (filelayout_test_devid_unavailable(devid))
	287	ret = NULL;
	288	out:
	289	return ret;
cfe7f412	290	}
98fc685a AA	291
	292	module_param(dataserver_retrans, uint, 0644);
	293	MODULE_PARM_DESC(dataserver_retrans, "The number of times the NFSv4.1 client "
	294	"retries a request before it attempts further "
	295	" recovery action.");
	296	module_param(dataserver_timeo, uint, 0644);
	297	MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
	298	"NFSv4.1 client waits for a response from a "
	299	" data server before it retries an NFS request.");