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#include "../nfs4trace.h"
39
40#define NFSDBG_FACILITY NFSDBG_PNFS_LD
41
42static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
43static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
44
45void
46nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
47{
48 struct nfs4_pnfs_ds *ds;
49 int i;
50
51 nfs4_print_deviceid(dev_id: &dsaddr->id_node.deviceid);
52
53 for (i = 0; i < dsaddr->ds_num; i++) {
54 ds = dsaddr->ds_list[i];
55 if (ds != NULL)
56 nfs4_pnfs_ds_put(ds);
57 }
58 kfree(objp: dsaddr->stripe_indices);
59 kfree_rcu(dsaddr, id_node.rcu);
60}
61
62/* Decode opaque device data and return the result */
63struct nfs4_file_layout_dsaddr *
64nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
65 gfp_t gfp_flags)
66{
67 int i;
68 u32 cnt, num;
69 u8 *indexp;
70 __be32 *p;
71 u8 *stripe_indices;
72 u8 max_stripe_index;
73 struct nfs4_file_layout_dsaddr *dsaddr = NULL;
74 struct xdr_stream stream;
75 struct xdr_buf buf;
76 struct page *scratch;
77 struct list_head dsaddrs;
78 struct nfs4_pnfs_ds_addr *da;
79
80 /* set up xdr stream */
81 scratch = alloc_page(gfp_flags);
82 if (!scratch)
83 goto out_err;
84
85 xdr_init_decode_pages(xdr: &stream, buf: &buf, pages: pdev->pages, len: pdev->pglen);
86 xdr_set_scratch_page(xdr: &stream, page: scratch);
87
88 /* Get the stripe count (number of stripe index) */
89 p = xdr_inline_decode(xdr: &stream, nbytes: 4);
90 if (unlikely(!p))
91 goto out_err_free_scratch;
92
93 cnt = be32_to_cpup(p);
94 dprintk("%s stripe count %d\n", __func__, cnt);
95 if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
96 printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
97 "supported maximum %d\n", __func__,
98 cnt, NFS4_PNFS_MAX_STRIPE_CNT);
99 goto out_err_free_scratch;
100 }
101
102 /* read stripe indices */
103 stripe_indices = kcalloc(n: cnt, size: sizeof(u8), flags: gfp_flags);
104 if (!stripe_indices)
105 goto out_err_free_scratch;
106
107 p = xdr_inline_decode(xdr: &stream, nbytes: cnt << 2);
108 if (unlikely(!p))
109 goto out_err_free_stripe_indices;
110
111 indexp = &stripe_indices[0];
112 max_stripe_index = 0;
113 for (i = 0; i < cnt; i++) {
114 *indexp = be32_to_cpup(p: p++);
115 max_stripe_index = max(max_stripe_index, *indexp);
116 indexp++;
117 }
118
119 /* Check the multipath list count */
120 p = xdr_inline_decode(xdr: &stream, nbytes: 4);
121 if (unlikely(!p))
122 goto out_err_free_stripe_indices;
123
124 num = be32_to_cpup(p);
125 dprintk("%s ds_num %u\n", __func__, num);
126 if (num > NFS4_PNFS_MAX_MULTI_CNT) {
127 printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
128 "supported maximum %d\n", __func__,
129 num, NFS4_PNFS_MAX_MULTI_CNT);
130 goto out_err_free_stripe_indices;
131 }
132
133 /* validate stripe indices are all < num */
134 if (max_stripe_index >= num) {
135 printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
136 __func__, max_stripe_index, num);
137 goto out_err_free_stripe_indices;
138 }
139
140 dsaddr = kzalloc(struct_size(dsaddr, ds_list, num), flags: gfp_flags);
141 if (!dsaddr)
142 goto out_err_free_stripe_indices;
143
144 dsaddr->stripe_count = cnt;
145 dsaddr->stripe_indices = stripe_indices;
146 stripe_indices = NULL;
147 dsaddr->ds_num = num;
148 nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);
149
150 INIT_LIST_HEAD(list: &dsaddrs);
151
152 for (i = 0; i < dsaddr->ds_num; i++) {
153 int j;
154 u32 mp_count;
155
156 p = xdr_inline_decode(xdr: &stream, nbytes: 4);
157 if (unlikely(!p))
158 goto out_err_free_deviceid;
159
160 mp_count = be32_to_cpup(p); /* multipath count */
161 for (j = 0; j < mp_count; j++) {
162 da = nfs4_decode_mp_ds_addr(net: server->nfs_client->cl_net,
163 xdr: &stream, gfp_flags);
164 if (da)
165 list_add_tail(new: &da->da_node, head: &dsaddrs);
166 }
167 if (list_empty(head: &dsaddrs)) {
168 dprintk("%s: no suitable DS addresses found\n",
169 __func__);
170 goto out_err_free_deviceid;
171 }
172
173 dsaddr->ds_list[i] = nfs4_pnfs_ds_add(dsaddrs: &dsaddrs, gfp_flags);
174 if (!dsaddr->ds_list[i])
175 goto out_err_drain_dsaddrs;
176 trace_fl_getdevinfo(server, deviceid: &pdev->dev_id, ds_remotestr: dsaddr->ds_list[i]->ds_remotestr);
177
178 /* If DS was already in cache, free ds addrs */
179 while (!list_empty(head: &dsaddrs)) {
180 da = list_first_entry(&dsaddrs,
181 struct nfs4_pnfs_ds_addr,
182 da_node);
183 list_del_init(entry: &da->da_node);
184 kfree(objp: da->da_remotestr);
185 kfree(objp: da);
186 }
187 }
188
189 __free_page(scratch);
190 return dsaddr;
191
192out_err_drain_dsaddrs:
193 while (!list_empty(head: &dsaddrs)) {
194 da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
195 da_node);
196 list_del_init(entry: &da->da_node);
197 kfree(objp: da->da_remotestr);
198 kfree(objp: 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(objp: 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(inode: lseg->pls_layout->plh_inode);
269 int status;
270
271 if (ds == NULL) {
272 printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
273 __func__, ds_idx);
274 pnfs_generic_mark_devid_invalid(node: devid);
275 goto out;
276 }
277 smp_rmb();
278 if (ds->ds_clp)
279 goto out_test_devid;
280
281 status = nfs4_pnfs_ds_connect(mds_srv: s, ds, devid, timeo: dataserver_timeo,
282 retrans: dataserver_retrans, version: 4,
283 minor_version: s->nfs_client->cl_minorversion);
284 if (status) {
285 nfs4_mark_deviceid_unavailable(node: devid);
286 ret = NULL;
287 goto out;
288 }
289
290out_test_devid:
291 if (ret->ds_clp == NULL ||
292 filelayout_test_devid_unavailable(node: devid))
293 ret = NULL;
294out:
295 return ret;
296}
297
298module_param(dataserver_retrans, uint, 0644);
299MODULE_PARM_DESC(dataserver_retrans, "The number of times the NFSv4.1 client "
300 "retries a request before it attempts further "
301 " recovery action.");
302module_param(dataserver_timeo, uint, 0644);
303MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
304 "NFSv4.1 client waits for a response from a "
305 " data server before it retries an NFS request.");
306

source code of linux/fs/nfs/filelayout/filelayoutdev.c