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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 "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}
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 "pnfs.h"
33
34#define NFSDBG_FACILITY NFSDBG_PNFS
35
36/*
37 * Device ID RCU cache. A device ID is unique per server and layout type.
38 */
39#define NFS4_DEVICE_ID_HASH_BITS 5
40#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
41#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
42
43#define PNFS_DEVICE_RETRY_TIMEOUT (120*HZ)
44
45static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
46static DEFINE_SPINLOCK(nfs4_deviceid_lock);
47
48#ifdef NFS_DEBUG
49void
50nfs4_print_deviceid(const struct nfs4_deviceid *id)
51{
52 u32 *p = (u32 *)id;
53
54 dprintk("%s: device id= [%x%x%x%x]\n", __func__,
55 p[0], p[1], p[2], p[3]);
56}
57EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
58#endif
59
60static inline u32
61nfs4_deviceid_hash(const struct nfs4_deviceid *id)
62{
63 unsigned char *cptr = (unsigned char *)id->data;
64 unsigned int nbytes = NFS4_DEVICEID4_SIZE;
65 u32 x = 0;
66
67 while (nbytes--) {
68 x *= 37;
69 x += *cptr++;
70 }
71 return x & NFS4_DEVICE_ID_HASH_MASK;
72}
73
74static struct nfs4_deviceid_node *
75_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
76 const struct nfs_client *clp, const struct nfs4_deviceid *id,
77 long hash)
78{
79 struct nfs4_deviceid_node *d;
80
81 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
82 if (d->ld == ld && d->nfs_client == clp &&
83 !memcmp(&d->deviceid, id, sizeof(*id))) {
84 if (atomic_read(&d->ref))
85 return d;
86 else
87 continue;
88 }
89 return NULL;
90}
91
92/*
93 * Lookup a deviceid in cache and get a reference count on it if found
94 *
95 * @clp nfs_client associated with deviceid
96 * @id deviceid to look up
97 */
98static struct nfs4_deviceid_node *
99_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
100 const struct nfs_client *clp, const struct nfs4_deviceid *id,
101 long hash)
102{
103 struct nfs4_deviceid_node *d;
104
105 rcu_read_lock();
106 d = _lookup_deviceid(ld, clp, id, hash);
107 if (d != NULL)
108 atomic_inc(&d->ref);
109 rcu_read_unlock();
110 return d;
111}
112
113struct nfs4_deviceid_node *
114nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
115 const struct nfs_client *clp, const struct nfs4_deviceid *id)
116{
117 return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
118}
119EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
120
121/*
122 * Remove a deviceid from cache
123 *
124 * @clp nfs_client associated with deviceid
125 * @id the deviceid to unhash
126 *
127 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
128 */
129void
130nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
131 const struct nfs_client *clp, const struct nfs4_deviceid *id)
132{
133 struct nfs4_deviceid_node *d;
134
135 spin_lock(&nfs4_deviceid_lock);
136 rcu_read_lock();
137 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
138 rcu_read_unlock();
139 if (!d) {
140 spin_unlock(&nfs4_deviceid_lock);
141 return;
142 }
143 hlist_del_init_rcu(&d->node);
144 spin_unlock(&nfs4_deviceid_lock);
145 synchronize_rcu();
146
147 /* balance the initial ref set in pnfs_insert_deviceid */
148 if (atomic_dec_and_test(&d->ref))
149 d->ld->free_deviceid_node(d);
150}
151EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
152
153void
154nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
155 const struct pnfs_layoutdriver_type *ld,
156 const struct nfs_client *nfs_client,
157 const struct nfs4_deviceid *id)
158{
159 INIT_HLIST_NODE(&d->node);
160 INIT_HLIST_NODE(&d->tmpnode);
161 d->ld = ld;
162 d->nfs_client = nfs_client;
163 d->flags = 0;
164 d->deviceid = *id;
165 atomic_set(&d->ref, 1);
166}
167EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
168
169/*
170 * Uniquely initialize and insert a deviceid node into cache
171 *
172 * @new new deviceid node
173 * Note that the caller must set up the following members:
174 * new->ld
175 * new->nfs_client
176 * new->deviceid
177 *
178 * @ret the inserted node, if none found, otherwise, the found entry.
179 */
180struct nfs4_deviceid_node *
181nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
182{
183 struct nfs4_deviceid_node *d;
184 long hash;
185
186 spin_lock(&nfs4_deviceid_lock);
187 hash = nfs4_deviceid_hash(&new->deviceid);
188 d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
189 if (d) {
190 spin_unlock(&nfs4_deviceid_lock);
191 return d;
192 }
193
194 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
195 spin_unlock(&nfs4_deviceid_lock);
196 atomic_inc(&new->ref);
197
198 return new;
199}
200EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node);
201
202/*
203 * Dereference a deviceid node and delete it when its reference count drops
204 * to zero.
205 *
206 * @d deviceid node to put
207 *
208 * return true iff the node was deleted
209 * Note that since the test for d->ref == 0 is sufficient to establish
210 * that the node is no longer hashed in the global device id cache.
211 */
212bool
213nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
214{
215 if (!atomic_dec_and_test(&d->ref))
216 return false;
217 d->ld->free_deviceid_node(d);
218 return true;
219}
220EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
221
222void
223nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
224{
225 node->timestamp_unavailable = jiffies;
226 set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
227}
228EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
229
230bool
231nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
232{
233 if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
234 unsigned long start, end;
235
236 end = jiffies;
237 start = end - PNFS_DEVICE_RETRY_TIMEOUT;
238 if (time_in_range(node->timestamp_unavailable, start, end))
239 return true;
240 clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
241 }
242 return false;
243}
244EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
245
246static void
247_deviceid_purge_client(const struct nfs_client *clp, long hash)
248{
249 struct nfs4_deviceid_node *d;
250 HLIST_HEAD(tmp);
251
252 spin_lock(&nfs4_deviceid_lock);
253 rcu_read_lock();
254 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
255 if (d->nfs_client == clp && atomic_read(&d->ref)) {
256 hlist_del_init_rcu(&d->node);
257 hlist_add_head(&d->tmpnode, &tmp);
258 }
259 rcu_read_unlock();
260 spin_unlock(&nfs4_deviceid_lock);
261
262 if (hlist_empty(&tmp))
263 return;
264
265 synchronize_rcu();
266 while (!hlist_empty(&tmp)) {
267 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
268 hlist_del(&d->tmpnode);
269 if (atomic_dec_and_test(&d->ref))
270 d->ld->free_deviceid_node(d);
271 }
272}
273
274void
275nfs4_deviceid_purge_client(const struct nfs_client *clp)
276{
277 long h;
278
279 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
280 return;
281 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
282 _deviceid_purge_client(clp, h);
283}
284
285/*
286 * Stop use of all deviceids associated with an nfs_client
287 */
288void
289nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
290{
291 struct nfs4_deviceid_node *d;
292 int i;
293
294 rcu_read_lock();
295 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
296 hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
297 if (d->nfs_client == clp)
298 set_bit(NFS_DEVICEID_INVALID, &d->flags);
299 }
300 rcu_read_unlock();
301}
302