[deliverable/linux.git] / fs / nfs / nfs4filelayoutdev.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 "internal.h"
#include "nfs4filelayout.h"

#define NFSDBG_FACILITY		NFSDBG_PNFS_LD

/*
 * Data server cache
 *
 * Data servers can be mapped to different device ids.
 * nfs4_pnfs_ds reference counting
 *   - set to 1 on allocation
 *   - incremented when a device id maps a data server already in the cache.
 *   - decremented when deviceid is removed from the cache.
 */
DEFINE_SPINLOCK(nfs4_ds_cache_lock);
static LIST_HEAD(nfs4_data_server_cache);

/* Debug routines */
void
print_ds(struct nfs4_pnfs_ds *ds)
{
	if (ds == NULL) {
		printk("%s NULL device\n", __func__);
		return;
	}
	printk("        ip_addr %x port %hu\n"
		"        ref count %d\n"
		"        client %p\n"
		"        cl_exchange_flags %x\n",
		ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
		atomic_read(&ds->ds_count), ds->ds_clp,
		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
}

void
print_ds_list(struct nfs4_file_layout_dsaddr *dsaddr)
{
	int i;

	ifdebug(FACILITY) {
		printk("%s dsaddr->ds_num %d\n", __func__,
		       dsaddr->ds_num);
		for (i = 0; i < dsaddr->ds_num; i++)
			print_ds(dsaddr->ds_list[i]);
	}
}

void print_deviceid(struct nfs4_deviceid *id)
{
	u32 *p = (u32 *)id;

	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
		p[0], p[1], p[2], p[3]);
}

/* nfs4_ds_cache_lock is held */
static struct nfs4_pnfs_ds *
_data_server_lookup_locked(u32 ip_addr, u32 port)
{
	struct nfs4_pnfs_ds *ds;

	dprintk("_data_server_lookup: ip_addr=%x port=%hu\n",
			ntohl(ip_addr), ntohs(port));

	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
		if (ds->ds_ip_addr == ip_addr &&
		    ds->ds_port == port) {
			return ds;
		}
	}
	return NULL;
}

static void
destroy_ds(struct nfs4_pnfs_ds *ds)
{
	dprintk("--> %s\n", __func__);
	ifdebug(FACILITY)
		print_ds(ds);

	if (ds->ds_clp)
		nfs_put_client(ds->ds_clp);
	kfree(ds);
}

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

	print_deviceid(&dsaddr->deviceid.de_id);

	for (i = 0; i < dsaddr->ds_num; i++) {
		ds = dsaddr->ds_list[i];
		if (ds != NULL) {
			if (atomic_dec_and_lock(&ds->ds_count,
						&nfs4_ds_cache_lock)) {
				list_del_init(&ds->ds_node);
				spin_unlock(&nfs4_ds_cache_lock);
				destroy_ds(ds);
			}
		}
	}
	kfree(dsaddr->stripe_indices);
	kfree(dsaddr);
}

void
nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *device)
{
	struct nfs4_file_layout_dsaddr *dsaddr =
		container_of(device, struct nfs4_file_layout_dsaddr, deviceid);

	nfs4_fl_free_deviceid(dsaddr);
}

static struct nfs4_pnfs_ds *
nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port)
{
	struct nfs4_pnfs_ds *tmp_ds, *ds;

	ds = kzalloc(sizeof(*tmp_ds), GFP_KERNEL);
	if (!ds)
		goto out;

	spin_lock(&nfs4_ds_cache_lock);
	tmp_ds = _data_server_lookup_locked(ip_addr, port);
	if (tmp_ds == NULL) {
		ds->ds_ip_addr = ip_addr;
		ds->ds_port = port;
		atomic_set(&ds->ds_count, 1);
		INIT_LIST_HEAD(&ds->ds_node);
		ds->ds_clp = NULL;
		list_add(&ds->ds_node, &nfs4_data_server_cache);
		dprintk("%s add new data server ip 0x%x\n", __func__,
			ds->ds_ip_addr);
	} else {
		kfree(ds);
		atomic_inc(&tmp_ds->ds_count);
		dprintk("%s data server found ip 0x%x, inc'ed ds_count to %d\n",
			__func__, tmp_ds->ds_ip_addr,
			atomic_read(&tmp_ds->ds_count));
		ds = tmp_ds;
	}
	spin_unlock(&nfs4_ds_cache_lock);
out:
	return ds;
}

/*
 * Currently only support ipv4, and one multi-path address.
 */
static struct nfs4_pnfs_ds *
decode_and_add_ds(__be32 **pp, struct inode *inode)
{
	struct nfs4_pnfs_ds *ds = NULL;
	char *buf;
	const char *ipend, *pstr;
	u32 ip_addr, port;
	int nlen, rlen, i;
	int tmp[2];
	__be32 *r_netid, *r_addr, *p = *pp;

	/* r_netid */
	nlen = be32_to_cpup(p++);
	r_netid = p;
	p += XDR_QUADLEN(nlen);

	/* r_addr */
	rlen = be32_to_cpup(p++);
	r_addr = p;
	p += XDR_QUADLEN(rlen);
	*pp = p;

	/* Check that netid is "tcp" */
	if (nlen != 3 ||  memcmp((char *)r_netid, "tcp", 3)) {
		dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
		goto out_err;
	}

	/* ipv6 length plus port is legal */
	if (rlen > INET6_ADDRSTRLEN + 8) {
		dprintk("%s: Invalid address, length %d\n", __func__,
			rlen);
		goto out_err;
	}
	buf = kmalloc(rlen + 1, GFP_KERNEL);
	buf[rlen] = '\0';
	memcpy(buf, r_addr, rlen);

	/* replace the port dots with dashes for the in4_pton() delimiter*/
	for (i = 0; i < 2; i++) {
		char *res = strrchr(buf, '.');
		if (!res) {
			dprintk("%s: Failed finding expected dots in port\n",
				__func__);
			goto out_free;
		}
		*res = '-';
	}

	/* Currently only support ipv4 address */
	if (in4_pton(buf, rlen, (u8 *)&ip_addr, '-', &ipend) == 0) {
		dprintk("%s: Only ipv4 addresses supported\n", __func__);
		goto out_free;
	}

	/* port */
	pstr = ipend;
	sscanf(pstr, "-%d-%d", &tmp[0], &tmp[1]);
	port = htons((tmp[0] << 8) | (tmp[1]));

	ds = nfs4_pnfs_ds_add(inode, ip_addr, port);
	dprintk("%s: Decoded address and port %s\n", __func__, buf);
out_free:
	kfree(buf);
out_err:
	return ds;
}

/* Decode opaque device data and return the result */
static struct nfs4_file_layout_dsaddr*
decode_device(struct inode *ino, struct pnfs_device *pdev)
{
	int i, dummy;
	u32 cnt, num;
	u8 *indexp;
	__be32 *p = (__be32 *)pdev->area, *indicesp;
	struct nfs4_file_layout_dsaddr *dsaddr;

	/* Get the stripe count (number of stripe index) */
	cnt = be32_to_cpup(p++);
	dprintk("%s stripe count  %d\n", __func__, cnt);
	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
		printk(KERN_WARNING "%s: stripe count %d greater than "
		       "supported maximum %d\n", __func__,
			cnt, NFS4_PNFS_MAX_STRIPE_CNT);
		goto out_err;
	}

	/* Check the multipath list count */
	indicesp = p;
	p += XDR_QUADLEN(cnt << 2);
	num = be32_to_cpup(p++);
	dprintk("%s ds_num %u\n", __func__, num);
	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
		printk(KERN_WARNING "%s: multipath count %d greater than "
			"supported maximum %d\n", __func__,
			num, NFS4_PNFS_MAX_MULTI_CNT);
		goto out_err;
	}
	dsaddr = kzalloc(sizeof(*dsaddr) +
			(sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
			GFP_KERNEL);
	if (!dsaddr)
		goto out_err;

	dsaddr->stripe_indices = kzalloc(sizeof(u8) * cnt, GFP_KERNEL);
	if (!dsaddr->stripe_indices)
		goto out_err_free;

	dsaddr->stripe_count = cnt;
	dsaddr->ds_num = num;

	memcpy(&dsaddr->deviceid.de_id, &pdev->dev_id, sizeof(pdev->dev_id));

	/* Go back an read stripe indices */
	p = indicesp;
	indexp = &dsaddr->stripe_indices[0];
	for (i = 0; i < dsaddr->stripe_count; i++) {
		*indexp = be32_to_cpup(p++);
		if (*indexp >= num)
			goto out_err_free;
		indexp++;
	}
	/* Skip already read multipath list count */
	p++;

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

		dummy = be32_to_cpup(p++); /* multipath count */
		if (dummy > 1) {
			printk(KERN_WARNING
			       "%s: Multipath count %d not supported, "
			       "skipping all greater than 1\n", __func__,
				dummy);
		}
		for (j = 0; j < dummy; j++) {
			if (j == 0) {
				dsaddr->ds_list[i] = decode_and_add_ds(&p, ino);
				if (dsaddr->ds_list[i] == NULL)
					goto out_err_free;
			} else {
				u32 len;
				/* skip extra multipath */
				len = be32_to_cpup(p++);
				p += XDR_QUADLEN(len);
				len = be32_to_cpup(p++);
				p += XDR_QUADLEN(len);
				continue;
			}
		}
	}
	return dsaddr;

out_err_free:
	nfs4_fl_free_deviceid(dsaddr);
out_err:
	dprintk("%s ERROR: returning NULL\n", __func__);
	return NULL;
}

/*
 * Decode the opaque device specified in 'dev'
 * and add it to the list of available devices.
 * If the deviceid is already cached, nfs4_add_deviceid will return
 * a pointer to the cached struct and throw away the new.
 */
static struct nfs4_file_layout_dsaddr*
decode_and_add_device(struct inode *inode, struct pnfs_device *dev)
{
	struct nfs4_file_layout_dsaddr *dsaddr;
	struct pnfs_deviceid_node *d;

	dsaddr = decode_device(inode, dev);
	if (!dsaddr) {
		printk(KERN_WARNING "%s: Could not decode or add device\n",
			__func__);
		return NULL;
	}

	d = pnfs_add_deviceid(NFS_SERVER(inode)->nfs_client->cl_devid_cache,
			      &dsaddr->deviceid);

	return container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
}

/*
 * Retrieve the information for dev_id, add it to the list
 * of available devices, and return it.
 */
struct nfs4_file_layout_dsaddr *
get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id)
{
	struct pnfs_device *pdev = NULL;
	u32 max_resp_sz;
	int max_pages;
	struct page **pages = NULL;
	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
	int rc, i;
	struct nfs_server *server = NFS_SERVER(inode);

	/*
	 * Use the session max response size as the basis for setting
	 * GETDEVICEINFO's maxcount
	 */
	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
	max_pages = max_resp_sz >> PAGE_SHIFT;
	dprintk("%s inode %p max_resp_sz %u max_pages %d\n",
		__func__, inode, max_resp_sz, max_pages);

	pdev = kzalloc(sizeof(struct pnfs_device), GFP_KERNEL);
	if (pdev == NULL)
		return NULL;

	pages = kzalloc(max_pages * sizeof(struct page *), GFP_KERNEL);
	if (pages == NULL) {
		kfree(pdev);
		return NULL;
	}
	for (i = 0; i < max_pages; i++) {
		pages[i] = alloc_page(GFP_KERNEL);
		if (!pages[i])
			goto out_free;
	}

	/* set pdev->area */
	pdev->area = vmap(pages, max_pages, VM_MAP, PAGE_KERNEL);
	if (!pdev->area)
		goto out_free;

	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
	pdev->layout_type = LAYOUT_NFSV4_1_FILES;
	pdev->pages = pages;
	pdev->pgbase = 0;
	pdev->pglen = PAGE_SIZE * max_pages;
	pdev->mincount = 0;

	rc = nfs4_proc_getdeviceinfo(server, pdev);
	dprintk("%s getdevice info returns %d\n", __func__, rc);
	if (rc)
		goto out_free;

	/*
	 * Found new device, need to decode it and then add it to the
	 * list of known devices for this mountpoint.
	 */
	dsaddr = decode_and_add_device(inode, pdev);
out_free:
	if (pdev->area != NULL)
		vunmap(pdev->area);
	for (i = 0; i < max_pages; i++)
		__free_page(pages[i]);
	kfree(pages);
	kfree(pdev);
	dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
	return dsaddr;
}

struct nfs4_file_layout_dsaddr *
nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct nfs4_deviceid *id)
{
	struct pnfs_deviceid_node *d;

	d = pnfs_find_get_deviceid(clp->cl_devid_cache, id);
	return (d == NULL) ? NULL :
		container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
}
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>
	33
	34	#include "internal.h"
	35	#include "nfs4filelayout.h"
	36
	37	#define NFSDBG_FACILITY NFSDBG_PNFS_LD
	38
	39	/*
	40	* Data server cache
	41	*
	42	* Data servers can be mapped to different device ids.
	43	* nfs4_pnfs_ds reference counting
	44	* - set to 1 on allocation
	45	* - incremented when a device id maps a data server already in the cache.
	46	* - decremented when deviceid is removed from the cache.
	47	*/
	48	DEFINE_SPINLOCK(nfs4_ds_cache_lock);
	49	static LIST_HEAD(nfs4_data_server_cache);
	50
	51	/* Debug routines */
	52	void
	53	print_ds(struct nfs4_pnfs_ds *ds)
	54	{
	55	if (ds == NULL) {
	56	printk("%s NULL device\n", __func__);
	57	return;
	58	}
	59	printk(" ip_addr %x port %hu\n"
	60	" ref count %d\n"
	61	" client %p\n"
	62	" cl_exchange_flags %x\n",
	63	ntohl(ds->ds_ip_addr), ntohs(ds->ds_port),
	64	atomic_read(&ds->ds_count), ds->ds_clp,
65	ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
66	}
67
68	void
69	print_ds_list(struct nfs4_file_layout_dsaddr *dsaddr)
70	{
71	int i;
72
73	ifdebug(FACILITY) {
74	printk("%s dsaddr->ds_num %d\n", __func__,
75	dsaddr->ds_num);
76	for (i = 0; i < dsaddr->ds_num; i++)
77	print_ds(dsaddr->ds_list[i]);
78	}
79	}
80
81	void print_deviceid(struct nfs4_deviceid *id)
82	{
83	u32 p = (u32 )id;
84
85	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
86	p[0], p[1], p[2], p[3]);
87	}
88
89	/* nfs4_ds_cache_lock is held */
90	static struct nfs4_pnfs_ds *
91	_data_server_lookup_locked(u32 ip_addr, u32 port)
92	{
93	struct nfs4_pnfs_ds *ds;
94
95	dprintk("_data_server_lookup: ip_addr=%x port=%hu\n",
96	ntohl(ip_addr), ntohs(port));
97
98	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) {
99	if (ds->ds_ip_addr == ip_addr &&
100	ds->ds_port == port) {
101	return ds;
102	}
103	}
104	return NULL;
105	}
106
107	static void
108	destroy_ds(struct nfs4_pnfs_ds *ds)
109	{
110	dprintk("--> %s\n", __func__);
111	ifdebug(FACILITY)
112	print_ds(ds);
113
114	if (ds->ds_clp)
115	nfs_put_client(ds->ds_clp);
116	kfree(ds);
117	}
118
119	static void
120	nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
121	{
122	struct nfs4_pnfs_ds *ds;
123	int i;
124
125	print_deviceid(&dsaddr->deviceid.de_id);
126
127	for (i = 0; i < dsaddr->ds_num; i++) {
128	ds = dsaddr->ds_list[i];
129	if (ds != NULL) {
130	if (atomic_dec_and_lock(&ds->ds_count,
131	&nfs4_ds_cache_lock)) {
132	list_del_init(&ds->ds_node);
133	spin_unlock(&nfs4_ds_cache_lock);
134	destroy_ds(ds);
135	}
136	}
137	}
138	kfree(dsaddr->stripe_indices);
139	kfree(dsaddr);
140	}
141
142	void
143	nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *device)
144	{
145	struct nfs4_file_layout_dsaddr *dsaddr =
146	container_of(device, struct nfs4_file_layout_dsaddr, deviceid);
147
148	nfs4_fl_free_deviceid(dsaddr);
149	}
150
151	static struct nfs4_pnfs_ds *
152	nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port)
153	{
154	struct nfs4_pnfs_ds tmp_ds, ds;
155
156	ds = kzalloc(sizeof(*tmp_ds), GFP_KERNEL);
157	if (!ds)
158	goto out;
159
160	spin_lock(&nfs4_ds_cache_lock);
161	tmp_ds = _data_server_lookup_locked(ip_addr, port);
162	if (tmp_ds == NULL) {
163	ds->ds_ip_addr = ip_addr;
164	ds->ds_port = port;
165	atomic_set(&ds->ds_count, 1);
166	INIT_LIST_HEAD(&ds->ds_node);
167	ds->ds_clp = NULL;
168	list_add(&ds->ds_node, &nfs4_data_server_cache);
169	dprintk("%s add new data server ip 0x%x\n", __func__,
170	ds->ds_ip_addr);
171	} else {
172	kfree(ds);
173	atomic_inc(&tmp_ds->ds_count);
174	dprintk("%s data server found ip 0x%x, inc'ed ds_count to %d\n",
175	__func__, tmp_ds->ds_ip_addr,
176	atomic_read(&tmp_ds->ds_count));
177	ds = tmp_ds;
178	}
179	spin_unlock(&nfs4_ds_cache_lock);
180	out:
181	return ds;
182	}
183
184	/*
185	* Currently only support ipv4, and one multi-path address.
186	*/
187	static struct nfs4_pnfs_ds *
188	decode_and_add_ds(__be32 *pp, struct inode inode)
189	{
190	struct nfs4_pnfs_ds *ds = NULL;
191	char *buf;
192	const char ipend, pstr;
193	u32 ip_addr, port;
194	int nlen, rlen, i;
195	int tmp[2];
196	__be32 r_netid, r_addr, p = pp;
197
198	/* r_netid */
199	nlen = be32_to_cpup(p++);
200	r_netid = p;
201	p += XDR_QUADLEN(nlen);
202
203	/* r_addr */
204	rlen = be32_to_cpup(p++);
205	r_addr = p;
206	p += XDR_QUADLEN(rlen);
207	*pp = p;
208
209	/* Check that netid is "tcp" */
210	if (nlen != 3 \|\| memcmp((char *)r_netid, "tcp", 3)) {
211	dprintk("%s: ERROR: non ipv4 TCP r_netid\n", __func__);
212	goto out_err;
213	}
214
215	/* ipv6 length plus port is legal */
216	if (rlen > INET6_ADDRSTRLEN + 8) {
ad3d2eed	217	dprintk("%s: Invalid address, length %d\n", __func__,
16b374ca AA	218	rlen);
	219	goto out_err;
	220	}
	221	buf = kmalloc(rlen + 1, GFP_KERNEL);
	222	buf[rlen] = '\0';
	223	memcpy(buf, r_addr, rlen);
	224
	225	/* replace the port dots with dashes for the in4_pton() delimiter*/
	226	for (i = 0; i < 2; i++) {
	227	char *res = strrchr(buf, '.');
ad3d2eed JJ	228	if (!res) {
	229	dprintk("%s: Failed finding expected dots in port\n",
	230	__func__);
	231	goto out_free;
	232	}
16b374ca AA	233	*res = '-';
	234	}
	235
	236	/* Currently only support ipv4 address */
	237	if (in4_pton(buf, rlen, (u8 *)&ip_addr, '-', &ipend) == 0) {
	238	dprintk("%s: Only ipv4 addresses supported\n", __func__);
	239	goto out_free;
	240	}
	241
	242	/* port */
	243	pstr = ipend;
	244	sscanf(pstr, "-%d-%d", &tmp[0], &tmp[1]);
	245	port = htons((tmp[0] << 8) \| (tmp[1]));
	246
	247	ds = nfs4_pnfs_ds_add(inode, ip_addr, port);
ad3d2eed	248	dprintk("%s: Decoded address and port %s\n", __func__, buf);
16b374ca AA	249	out_free:
	250	kfree(buf);
	251	out_err:
	252	return ds;
	253	}
	254
	255	/* Decode opaque device data and return the result */
	256	static struct nfs4_file_layout_dsaddr*
	257	decode_device(struct inode ino, struct pnfs_device pdev)
	258	{
	259	int i, dummy;
	260	u32 cnt, num;
	261	u8 *indexp;
	262	__be32 p = (__be32 )pdev->area, *indicesp;
	263	struct nfs4_file_layout_dsaddr *dsaddr;
	264
	265	/* Get the stripe count (number of stripe index) */
	266	cnt = be32_to_cpup(p++);
	267	dprintk("%s stripe count %d\n", __func__, cnt);
	268	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
	269	printk(KERN_WARNING "%s: stripe count %d greater than "
	270	"supported maximum %d\n", __func__,
	271	cnt, NFS4_PNFS_MAX_STRIPE_CNT);
	272	goto out_err;
	273	}
	274
	275	/* Check the multipath list count */
	276	indicesp = p;
	277	p += XDR_QUADLEN(cnt << 2);
	278	num = be32_to_cpup(p++);
	279	dprintk("%s ds_num %u\n", __func__, num);
	280	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
	281	printk(KERN_WARNING "%s: multipath count %d greater than "
	282	"supported maximum %d\n", __func__,
	283	num, NFS4_PNFS_MAX_MULTI_CNT);
	284	goto out_err;
	285	}
	286	dsaddr = kzalloc(sizeof(*dsaddr) +
	287	(sizeof(struct nfs4_pnfs_ds ) (num - 1)),
	288	GFP_KERNEL);
	289	if (!dsaddr)
	290	goto out_err;
	291
	292	dsaddr->stripe_indices = kzalloc(sizeof(u8) * cnt, GFP_KERNEL);
	293	if (!dsaddr->stripe_indices)
	294	goto out_err_free;
	295
	296	dsaddr->stripe_count = cnt;
	297	dsaddr->ds_num = num;
	298
	299	memcpy(&dsaddr->deviceid.de_id, &pdev->dev_id, sizeof(pdev->dev_id));
	300
	301	/* Go back an read stripe indices */
	302	p = indicesp;
	303	indexp = &dsaddr->stripe_indices[0];
	304	for (i = 0; i < dsaddr->stripe_count; i++) {
	305	*indexp = be32_to_cpup(p++);
	306	if (*indexp >= num)
	307	goto out_err_free;
	308	indexp++;
	309	}
	310	/* Skip already read multipath list count */
	311	p++;
	312
313	for (i = 0; i < dsaddr->ds_num; i++) {
314	int j;
315
316	dummy = be32_to_cpup(p++); /* multipath count */
317	if (dummy > 1) {
318	printk(KERN_WARNING
319	"%s: Multipath count %d not supported, "
320	"skipping all greater than 1\n", __func__,
321	dummy);
322	}
323	for (j = 0; j < dummy; j++) {
324	if (j == 0) {
325	dsaddr->ds_list[i] = decode_and_add_ds(&p, ino);
326	if (dsaddr->ds_list[i] == NULL)
327	goto out_err_free;
328	} else {
329	u32 len;
330	/* skip extra multipath */
331	len = be32_to_cpup(p++);
332	p += XDR_QUADLEN(len);
333	len = be32_to_cpup(p++);
334	p += XDR_QUADLEN(len);
335	continue;
336	}
337	}
338	}
339	return dsaddr;
340
341	out_err_free:
342	nfs4_fl_free_deviceid(dsaddr);
343	out_err:
344	dprintk("%s ERROR: returning NULL\n", __func__);
345	return NULL;
346	}
347
348	/*
349	* Decode the opaque device specified in 'dev'
350	* and add it to the list of available devices.
351	* If the deviceid is already cached, nfs4_add_deviceid will return
352	* a pointer to the cached struct and throw away the new.
353	*/
354	static struct nfs4_file_layout_dsaddr*
355	decode_and_add_device(struct inode inode, struct pnfs_device dev)
356	{
357	struct nfs4_file_layout_dsaddr *dsaddr;
358	struct pnfs_deviceid_node *d;
359
360	dsaddr = decode_device(inode, dev);
361	if (!dsaddr) {
362	printk(KERN_WARNING "%s: Could not decode or add device\n",
363	__func__);
364	return NULL;
365	}
366
367	d = pnfs_add_deviceid(NFS_SERVER(inode)->nfs_client->cl_devid_cache,
368	&dsaddr->deviceid);
369
370	return container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
371	}
372
373	/*
374	* Retrieve the information for dev_id, add it to the list
375	* of available devices, and return it.
376	*/
377	struct nfs4_file_layout_dsaddr *
378	get_device_info(struct inode inode, struct nfs4_deviceid dev_id)
379	{
380	struct pnfs_device *pdev = NULL;
381	u32 max_resp_sz;
382	int max_pages;
383	struct page **pages = NULL;
384	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
385	int rc, i;
386	struct nfs_server *server = NFS_SERVER(inode);
387
388	/*
389	* Use the session max response size as the basis for setting
390	* GETDEVICEINFO's maxcount
391	*/
392	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
393	max_pages = max_resp_sz >> PAGE_SHIFT;
394	dprintk("%s inode %p max_resp_sz %u max_pages %d\n",
395	__func__, inode, max_resp_sz, max_pages);
396
397	pdev = kzalloc(sizeof(struct pnfs_device), GFP_KERNEL);
398	if (pdev == NULL)
399	return NULL;
400
401	pages = kzalloc(max_pages * sizeof(struct page *), GFP_KERNEL);
402	if (pages == NULL) {
403	kfree(pdev);
404	return NULL;
405	}
406	for (i = 0; i < max_pages; i++) {
407	pages[i] = alloc_page(GFP_KERNEL);
408	if (!pages[i])
409	goto out_free;
410	}
411
412	/* set pdev->area */
413	pdev->area = vmap(pages, max_pages, VM_MAP, PAGE_KERNEL);
414	if (!pdev->area)
415	goto out_free;
416
417	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
418	pdev->layout_type = LAYOUT_NFSV4_1_FILES;
419	pdev->pages = pages;
420	pdev->pgbase = 0;
421	pdev->pglen = PAGE_SIZE * max_pages;
422	pdev->mincount = 0;
423
424	rc = nfs4_proc_getdeviceinfo(server, pdev);
425	dprintk("%s getdevice info returns %d\n", __func__, rc);
426	if (rc)
427	goto out_free;
428
429	/*
430	* Found new device, need to decode it and then add it to the
431	* list of known devices for this mountpoint.
432	*/
433	dsaddr = decode_and_add_device(inode, pdev);
434	out_free:
435	if (pdev->area != NULL)
436	vunmap(pdev->area);
437	for (i = 0; i < max_pages; i++)
438	__free_page(pages[i]);
439	kfree(pages);
440	kfree(pdev);
441	dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
442	return dsaddr;
443	}
444
445	struct nfs4_file_layout_dsaddr *
446	nfs4_fl_find_get_deviceid(struct nfs_client clp, struct nfs4_deviceid id)
447	{
448	struct pnfs_deviceid_node *d;
449
450	d = pnfs_find_get_deviceid(clp->cl_devid_cache, id);
451	return (d == NULL) ? NULL :
452	container_of(d, struct nfs4_file_layout_dsaddr, deviceid);
453	}