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1/*
2 * Device operations for the pnfs client.
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/export.h>
32#include <linux/nfs_fs.h>
33#include "nfs4session.h"
34#include "internal.h"
35#include "pnfs.h"
36
37#include "nfs4trace.h"
38
39#define NFSDBG_FACILITY NFSDBG_PNFS
40
41/*
42 * Device ID RCU cache. A device ID is unique per server and layout type.
43 */
44#define NFS4_DEVICE_ID_HASH_BITS 5
45#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
46#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
47
48
49static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
50static DEFINE_SPINLOCK(nfs4_deviceid_lock);
51
52#ifdef NFS_DEBUG
53void
54nfs4_print_deviceid(const struct nfs4_deviceid *id)
55{
56 u32 *p = (u32 *)id;
57
58 dprintk("%s: device id= [%x%x%x%x]\n", __func__,
59 p[0], p[1], p[2], p[3]);
60}
61EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
62#endif
63
64static inline u32
65nfs4_deviceid_hash(const struct nfs4_deviceid *id)
66{
67 unsigned char *cptr = (unsigned char *)id->data;
68 unsigned int nbytes = NFS4_DEVICEID4_SIZE;
69 u32 x = 0;
70
71 while (nbytes--) {
72 x *= 37;
73 x += *cptr++;
74 }
75 return x & NFS4_DEVICE_ID_HASH_MASK;
76}
77
78static struct nfs4_deviceid_node *
79_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
80 const struct nfs_client *clp, const struct nfs4_deviceid *id,
81 long hash)
82{
83 struct nfs4_deviceid_node *d;
84
85 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
86 if (d->ld == ld && d->nfs_client == clp &&
87 !memcmp(&d->deviceid, id, sizeof(*id))) {
88 if (atomic_read(&d->ref))
89 return d;
90 else
91 continue;
92 }
93 return NULL;
94}
95
96static struct nfs4_deviceid_node *
97nfs4_get_device_info(struct nfs_server *server,
98 const struct nfs4_deviceid *dev_id,
99 const struct cred *cred, gfp_t gfp_flags)
100{
101 struct nfs4_deviceid_node *d = NULL;
102 struct pnfs_device *pdev = NULL;
103 struct page **pages = NULL;
104 u32 max_resp_sz;
105 int max_pages;
106 int rc, i;
107
108 /*
109 * Use the session max response size as the basis for setting
110 * GETDEVICEINFO's maxcount
111 */
112 max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
113 if (server->pnfs_curr_ld->max_deviceinfo_size &&
114 server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz)
115 max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size;
116 max_pages = nfs_page_array_len(0, max_resp_sz);
117 dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
118 __func__, server, max_resp_sz, max_pages);
119
120 pdev = kzalloc(sizeof(*pdev), gfp_flags);
121 if (!pdev)
122 return NULL;
123
124 pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
125 if (!pages)
126 goto out_free_pdev;
127
128 for (i = 0; i < max_pages; i++) {
129 pages[i] = alloc_page(gfp_flags);
130 if (!pages[i])
131 goto out_free_pages;
132 }
133
134 memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
135 pdev->layout_type = server->pnfs_curr_ld->id;
136 pdev->pages = pages;
137 pdev->pgbase = 0;
138 pdev->pglen = max_resp_sz;
139 pdev->mincount = 0;
140 pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
141
142 rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
143 dprintk("%s getdevice info returns %d\n", __func__, rc);
144 if (rc)
145 goto out_free_pages;
146
147 /*
148 * Found new device, need to decode it and then add it to the
149 * list of known devices for this mountpoint.
150 */
151 d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
152 gfp_flags);
153 if (d && pdev->nocache)
154 set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
155
156out_free_pages:
157 while (--i >= 0)
158 __free_page(pages[i]);
159 kfree(pages);
160out_free_pdev:
161 kfree(pdev);
162 dprintk("<-- %s d %p\n", __func__, d);
163 return d;
164}
165
166/*
167 * Lookup a deviceid in cache and get a reference count on it if found
168 *
169 * @clp nfs_client associated with deviceid
170 * @id deviceid to look up
171 */
172static struct nfs4_deviceid_node *
173__nfs4_find_get_deviceid(struct nfs_server *server,
174 const struct nfs4_deviceid *id, long hash)
175{
176 struct nfs4_deviceid_node *d;
177
178 rcu_read_lock();
179 d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
180 hash);
181 if (d != NULL && !atomic_inc_not_zero(&d->ref))
182 d = NULL;
183 rcu_read_unlock();
184 return d;
185}
186
187struct nfs4_deviceid_node *
188nfs4_find_get_deviceid(struct nfs_server *server,
189 const struct nfs4_deviceid *id, const struct cred *cred,
190 gfp_t gfp_mask)
191{
192 long hash = nfs4_deviceid_hash(id);
193 struct nfs4_deviceid_node *d, *new;
194
195 d = __nfs4_find_get_deviceid(server, id, hash);
196 if (d)
197 goto found;
198
199 new = nfs4_get_device_info(server, id, cred, gfp_mask);
200 if (!new) {
201 trace_nfs4_find_deviceid(server, id, -ENOENT);
202 return new;
203 }
204
205 spin_lock(&nfs4_deviceid_lock);
206 d = __nfs4_find_get_deviceid(server, id, hash);
207 if (d) {
208 spin_unlock(&nfs4_deviceid_lock);
209 server->pnfs_curr_ld->free_deviceid_node(new);
210 } else {
211 atomic_inc(&new->ref);
212 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
213 spin_unlock(&nfs4_deviceid_lock);
214 d = new;
215 }
216found:
217 trace_nfs4_find_deviceid(server, id, 0);
218 return d;
219}
220EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
221
222/*
223 * Remove a deviceid from cache
224 *
225 * @clp nfs_client associated with deviceid
226 * @id the deviceid to unhash
227 *
228 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
229 */
230void
231nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
232 const struct nfs_client *clp, const struct nfs4_deviceid *id)
233{
234 struct nfs4_deviceid_node *d;
235
236 spin_lock(&nfs4_deviceid_lock);
237 rcu_read_lock();
238 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
239 rcu_read_unlock();
240 if (!d) {
241 spin_unlock(&nfs4_deviceid_lock);
242 return;
243 }
244 hlist_del_init_rcu(&d->node);
245 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
246 spin_unlock(&nfs4_deviceid_lock);
247
248 /* balance the initial ref set in pnfs_insert_deviceid */
249 nfs4_put_deviceid_node(d);
250}
251EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
252
253void
254nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
255 const struct nfs4_deviceid *id)
256{
257 INIT_HLIST_NODE(&d->node);
258 INIT_HLIST_NODE(&d->tmpnode);
259 d->ld = server->pnfs_curr_ld;
260 d->nfs_client = server->nfs_client;
261 d->flags = 0;
262 d->deviceid = *id;
263 atomic_set(&d->ref, 1);
264}
265EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
266
267/*
268 * Dereference a deviceid node and delete it when its reference count drops
269 * to zero.
270 *
271 * @d deviceid node to put
272 *
273 * return true iff the node was deleted
274 * Note that since the test for d->ref == 0 is sufficient to establish
275 * that the node is no longer hashed in the global device id cache.
276 */
277bool
278nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
279{
280 if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
281 if (atomic_add_unless(&d->ref, -1, 2))
282 return false;
283 nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
284 }
285 if (!atomic_dec_and_test(&d->ref))
286 return false;
287 trace_nfs4_deviceid_free(d->nfs_client, &d->deviceid);
288 d->ld->free_deviceid_node(d);
289 return true;
290}
291EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
292
293void
294nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node)
295{
296 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
297 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
298 smp_mb__after_atomic();
299 }
300}
301EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);
302
303void
304nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
305{
306 node->timestamp_unavailable = jiffies;
307 smp_mb__before_atomic();
308 set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
309 smp_mb__after_atomic();
310}
311EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
312
313bool
314nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
315{
316 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
317 unsigned long start, end;
318
319 end = jiffies;
320 start = end - PNFS_DEVICE_RETRY_TIMEOUT;
321 if (time_in_range(node->timestamp_unavailable, start, end))
322 return true;
323 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
324 smp_mb__after_atomic();
325 }
326 return false;
327}
328EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
329
330static void
331_deviceid_purge_client(const struct nfs_client *clp, long hash)
332{
333 struct nfs4_deviceid_node *d;
334 HLIST_HEAD(tmp);
335
336 spin_lock(&nfs4_deviceid_lock);
337 rcu_read_lock();
338 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
339 if (d->nfs_client == clp && atomic_read(&d->ref)) {
340 hlist_del_init_rcu(&d->node);
341 hlist_add_head(&d->tmpnode, &tmp);
342 clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
343 }
344 rcu_read_unlock();
345 spin_unlock(&nfs4_deviceid_lock);
346
347 if (hlist_empty(&tmp))
348 return;
349
350 while (!hlist_empty(&tmp)) {
351 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
352 hlist_del(&d->tmpnode);
353 nfs4_put_deviceid_node(d);
354 }
355}
356
357void
358nfs4_deviceid_purge_client(const struct nfs_client *clp)
359{
360 long h;
361
362 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
363 return;
364 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
365 _deviceid_purge_client(clp, h);
366}
367
368/*
369 * Stop use of all deviceids associated with an nfs_client
370 */
371void
372nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
373{
374 struct nfs4_deviceid_node *d;
375 int i;
376
377 rcu_read_lock();
378 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
379 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
380 if (d->nfs_client == clp)
381 set_bit(NFS_DEVICEID_INVALID, &d->flags);
382 }
383 rcu_read_unlock();
384}
1/*
2 * Device operations for the pnfs client.
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 "pnfs.h"
32
33#define NFSDBG_FACILITY NFSDBG_PNFS
34
35/*
36 * Device ID RCU cache. A device ID is unique per server and layout type.
37 */
38#define NFS4_DEVICE_ID_HASH_BITS 5
39#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
40#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
41
42static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
43static DEFINE_SPINLOCK(nfs4_deviceid_lock);
44
45void
46nfs4_print_deviceid(const struct nfs4_deviceid *id)
47{
48 u32 *p = (u32 *)id;
49
50 dprintk("%s: device id= [%x%x%x%x]\n", __func__,
51 p[0], p[1], p[2], p[3]);
52}
53EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
54
55static inline u32
56nfs4_deviceid_hash(const struct nfs4_deviceid *id)
57{
58 unsigned char *cptr = (unsigned char *)id->data;
59 unsigned int nbytes = NFS4_DEVICEID4_SIZE;
60 u32 x = 0;
61
62 while (nbytes--) {
63 x *= 37;
64 x += *cptr++;
65 }
66 return x & NFS4_DEVICE_ID_HASH_MASK;
67}
68
69static struct nfs4_deviceid_node *
70_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
71 const struct nfs_client *clp, const struct nfs4_deviceid *id,
72 long hash)
73{
74 struct nfs4_deviceid_node *d;
75 struct hlist_node *n;
76
77 hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
78 if (d->ld == ld && d->nfs_client == clp &&
79 !memcmp(&d->deviceid, id, sizeof(*id))) {
80 if (atomic_read(&d->ref))
81 return d;
82 else
83 continue;
84 }
85 return NULL;
86}
87
88/*
89 * Lookup a deviceid in cache and get a reference count on it if found
90 *
91 * @clp nfs_client associated with deviceid
92 * @id deviceid to look up
93 */
94struct nfs4_deviceid_node *
95_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
96 const struct nfs_client *clp, const struct nfs4_deviceid *id,
97 long hash)
98{
99 struct nfs4_deviceid_node *d;
100
101 rcu_read_lock();
102 d = _lookup_deviceid(ld, clp, id, hash);
103 if (d != NULL)
104 atomic_inc(&d->ref);
105 rcu_read_unlock();
106 return d;
107}
108
109struct nfs4_deviceid_node *
110nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
111 const struct nfs_client *clp, const struct nfs4_deviceid *id)
112{
113 return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
114}
115EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
116
117/*
118 * Remove a deviceid from cache
119 *
120 * @clp nfs_client associated with deviceid
121 * @id the deviceid to unhash
122 *
123 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
124 */
125void
126nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
127 const struct nfs_client *clp, const struct nfs4_deviceid *id)
128{
129 struct nfs4_deviceid_node *d;
130
131 spin_lock(&nfs4_deviceid_lock);
132 rcu_read_lock();
133 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
134 rcu_read_unlock();
135 if (!d) {
136 spin_unlock(&nfs4_deviceid_lock);
137 return;
138 }
139 hlist_del_init_rcu(&d->node);
140 spin_unlock(&nfs4_deviceid_lock);
141 synchronize_rcu();
142
143 /* balance the initial ref set in pnfs_insert_deviceid */
144 if (atomic_dec_and_test(&d->ref))
145 d->ld->free_deviceid_node(d);
146}
147EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
148
149void
150nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
151 const struct pnfs_layoutdriver_type *ld,
152 const struct nfs_client *nfs_client,
153 const struct nfs4_deviceid *id)
154{
155 INIT_HLIST_NODE(&d->node);
156 INIT_HLIST_NODE(&d->tmpnode);
157 d->ld = ld;
158 d->nfs_client = nfs_client;
159 d->flags = 0;
160 d->deviceid = *id;
161 atomic_set(&d->ref, 1);
162}
163EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
164
165/*
166 * Uniquely initialize and insert a deviceid node into cache
167 *
168 * @new new deviceid node
169 * Note that the caller must set up the following members:
170 * new->ld
171 * new->nfs_client
172 * new->deviceid
173 *
174 * @ret the inserted node, if none found, otherwise, the found entry.
175 */
176struct nfs4_deviceid_node *
177nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
178{
179 struct nfs4_deviceid_node *d;
180 long hash;
181
182 spin_lock(&nfs4_deviceid_lock);
183 hash = nfs4_deviceid_hash(&new->deviceid);
184 d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
185 if (d) {
186 spin_unlock(&nfs4_deviceid_lock);
187 return d;
188 }
189
190 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
191 spin_unlock(&nfs4_deviceid_lock);
192 atomic_inc(&new->ref);
193
194 return new;
195}
196EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node);
197
198/*
199 * Dereference a deviceid node and delete it when its reference count drops
200 * to zero.
201 *
202 * @d deviceid node to put
203 *
204 * return true iff the node was deleted
205 * Note that since the test for d->ref == 0 is sufficient to establish
206 * that the node is no longer hashed in the global device id cache.
207 */
208bool
209nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
210{
211 if (!atomic_dec_and_test(&d->ref))
212 return false;
213 d->ld->free_deviceid_node(d);
214 return true;
215}
216EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
217
218static void
219_deviceid_purge_client(const struct nfs_client *clp, long hash)
220{
221 struct nfs4_deviceid_node *d;
222 struct hlist_node *n;
223 HLIST_HEAD(tmp);
224
225 spin_lock(&nfs4_deviceid_lock);
226 rcu_read_lock();
227 hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
228 if (d->nfs_client == clp && atomic_read(&d->ref)) {
229 hlist_del_init_rcu(&d->node);
230 hlist_add_head(&d->tmpnode, &tmp);
231 }
232 rcu_read_unlock();
233 spin_unlock(&nfs4_deviceid_lock);
234
235 if (hlist_empty(&tmp))
236 return;
237
238 synchronize_rcu();
239 while (!hlist_empty(&tmp)) {
240 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
241 hlist_del(&d->tmpnode);
242 if (atomic_dec_and_test(&d->ref))
243 d->ld->free_deviceid_node(d);
244 }
245}
246
247void
248nfs4_deviceid_purge_client(const struct nfs_client *clp)
249{
250 long h;
251
252 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
253 return;
254 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
255 _deviceid_purge_client(clp, h);
256}
257
258/*
259 * Stop use of all deviceids associated with an nfs_client
260 */
261void
262nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
263{
264 struct nfs4_deviceid_node *d;
265 struct hlist_node *n;
266 int i;
267
268 rcu_read_lock();
269 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
270 hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[i], node)
271 if (d->nfs_client == clp)
272 set_bit(NFS_DEVICEID_INVALID, &d->flags);
273 }
274 rcu_read_unlock();
275}