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#include <linux/module.h>
34
35#include "../internal.h"
36#include "../nfs4session.h"
37#include "filelayout.h"
38
39#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
40
41static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
42static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
43
44void
45nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
46{
47	struct nfs4_pnfs_ds *ds;
48	int i;
49
50	nfs4_print_deviceid(&dsaddr->id_node.deviceid);
51
52	for (i = 0; i < dsaddr->ds_num; i++) {
53		ds = dsaddr->ds_list[i];
54		if (ds != NULL)
55			nfs4_pnfs_ds_put(ds);
56	}
57	kfree(dsaddr->stripe_indices);
58	kfree_rcu(dsaddr, id_node.rcu);
59}
60
61/* Decode opaque device data and return the result */
62struct nfs4_file_layout_dsaddr *
63nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
64		gfp_t gfp_flags)
65{
66	int i;
67	u32 cnt, num;
68	u8 *indexp;
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;
74	struct xdr_buf buf;
75	struct page *scratch;
76	struct list_head dsaddrs;
77	struct nfs4_pnfs_ds_addr *da;
78
79	/* set up xdr stream */
80	scratch = alloc_page(gfp_flags);
81	if (!scratch)
82		goto out_err;
83
84	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
85	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
86
87	/* Get the stripe count (number of stripe index) */
88	p = xdr_inline_decode(&stream, 4);
89	if (unlikely(!p))
90		goto out_err_free_scratch;
91
92	cnt = be32_to_cpup(p);
93	dprintk("%s stripe count  %d\n", __func__, cnt);
94	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
95		printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
96		       "supported maximum %d\n", __func__,
97			cnt, NFS4_PNFS_MAX_STRIPE_CNT);
98		goto out_err_free_scratch;
99	}
100
101	/* read stripe indices */
102	stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags);
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++;
116	}
117
118	/* Check the multipath list count */
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);
124	dprintk("%s ds_num %u\n", __func__, num);
125	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
126		printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
127			"supported maximum %d\n", __func__,
128			num, NFS4_PNFS_MAX_MULTI_CNT);
129		goto out_err_free_stripe_indices;
130	}
131
132	/* validate stripe indices are all < num */
133	if (max_stripe_index >= num) {
134		printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
135			__func__, max_stripe_index, num);
136		goto out_err_free_stripe_indices;
137	}
138
139	dsaddr = kzalloc(sizeof(*dsaddr) +
140			(sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
141			gfp_flags);
142	if (!dsaddr)
143		goto out_err_free_stripe_indices;
144
145	dsaddr->stripe_count = cnt;
146	dsaddr->stripe_indices = stripe_indices;
147	stripe_indices = NULL;
148	dsaddr->ds_num = num;
149	nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);
150
151	INIT_LIST_HEAD(&dsaddrs);
152
153	for (i = 0; i < dsaddr->ds_num; i++) {
154		int j;
155		u32 mp_count;
156
157		p = xdr_inline_decode(&stream, 4);
158		if (unlikely(!p))
159			goto out_err_free_deviceid;
160
161		mp_count = be32_to_cpup(p); /* multipath count */
162		for (j = 0; j < mp_count; j++) {
163			da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
164						    &stream, gfp_flags);
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);
186		}
187	}
188
189	__free_page(scratch);
190	return dsaddr;
191
192out_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	}
200out_err_free_deviceid:
201	nfs4_fl_free_deviceid(dsaddr);
202	/* stripe_indicies was part of dsaddr */
203	goto out_err_free_scratch;
204out_err_free_stripe_indices:
205	kfree(stripe_indices);
206out_err_free_scratch:
207	__free_page(scratch);
208out_err:
209	dprintk("%s ERROR: returning NULL\n", __func__);
210	return NULL;
211}
212
213void
214nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
215{
216	nfs4_put_deviceid_node(&dsaddr->id_node);
217}
218
219/*
220 * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
221 * Then: ((res + fsi) % dsaddr->stripe_count)
222 */
223u32
224nfs4_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
235u32
236nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
237{
238	return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
239}
240
241struct nfs_fh *
242nfs4_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
260/* Upon return, either ds is connected, or ds is NULL */
261struct nfs4_pnfs_ds *
262nfs4_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];
266	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
267	struct nfs4_pnfs_ds *ret = ds;
268	struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);
269
270	if (ds == NULL) {
271		printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
272			__func__, ds_idx);
273		pnfs_generic_mark_devid_invalid(devid);
274		goto out;
275	}
276	smp_rmb();
277	if (ds->ds_clp)
278		goto out_test_devid;
279
280	nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
281			     dataserver_retrans, 4,
282			     s->nfs_client->cl_minorversion,
283			     s->nfs_client->cl_rpcclient->cl_auth->au_flavor);
284
285out_test_devid:
286	if (filelayout_test_devid_unavailable(devid))
287		ret = NULL;
288out:
289	return ret;
290}
291
292module_param(dataserver_retrans, uint, 0644);
293MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
294			"retries a request before it attempts further "
295			" recovery  action.");
296module_param(dataserver_timeo, uint, 0644);
297MODULE_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.");
300