Commit | Line | Data |
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a1eaecbc BH |
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 | ||
afeacc8c | 31 | #include <linux/export.h> |
a1eaecbc BH |
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 | ||
1dfed273 TM |
43 | #define PNFS_DEVICE_RETRY_TIMEOUT (120*HZ) |
44 | ||
a1eaecbc BH |
45 | static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE]; |
46 | static DEFINE_SPINLOCK(nfs4_deviceid_lock); | |
47 | ||
6f00866d | 48 | #ifdef NFS_DEBUG |
a1eaecbc BH |
49 | void |
50 | nfs4_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 | } | |
57 | EXPORT_SYMBOL_GPL(nfs4_print_deviceid); | |
6f00866d | 58 | #endif |
a1eaecbc BH |
59 | |
60 | static inline u32 | |
61 | nfs4_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 | ||
1be5683b | 74 | static struct nfs4_deviceid_node * |
35c8bb54 BH |
75 | _lookup_deviceid(const struct pnfs_layoutdriver_type *ld, |
76 | const struct nfs_client *clp, const struct nfs4_deviceid *id, | |
1be5683b ME |
77 | long hash) |
78 | { | |
79 | struct nfs4_deviceid_node *d; | |
1be5683b | 80 | |
b67bfe0d | 81 | hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) |
35c8bb54 BH |
82 | if (d->ld == ld && d->nfs_client == clp && |
83 | !memcmp(&d->deviceid, id, sizeof(*id))) { | |
1be5683b ME |
84 | if (atomic_read(&d->ref)) |
85 | return d; | |
86 | else | |
87 | continue; | |
88 | } | |
89 | return NULL; | |
90 | } | |
91 | ||
a1eaecbc BH |
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 | */ | |
17280175 | 98 | static struct nfs4_deviceid_node * |
35c8bb54 BH |
99 | _find_get_deviceid(const struct pnfs_layoutdriver_type *ld, |
100 | const struct nfs_client *clp, const struct nfs4_deviceid *id, | |
1be5683b ME |
101 | long hash) |
102 | { | |
103 | struct nfs4_deviceid_node *d; | |
104 | ||
105 | rcu_read_lock(); | |
35c8bb54 | 106 | d = _lookup_deviceid(ld, clp, id, hash); |
47cb498e TM |
107 | if (d != NULL) |
108 | atomic_inc(&d->ref); | |
1be5683b ME |
109 | rcu_read_unlock(); |
110 | return d; | |
111 | } | |
112 | ||
a1eaecbc | 113 | struct nfs4_deviceid_node * |
35c8bb54 BH |
114 | nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld, |
115 | const struct nfs_client *clp, const struct nfs4_deviceid *id) | |
1be5683b | 116 | { |
35c8bb54 | 117 | return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); |
1be5683b ME |
118 | } |
119 | EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid); | |
120 | ||
121 | /* | |
47cb498e | 122 | * Remove a deviceid from cache |
1be5683b ME |
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 | */ | |
47cb498e TM |
129 | void |
130 | nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld, | |
35c8bb54 | 131 | const struct nfs_client *clp, const struct nfs4_deviceid *id) |
a1eaecbc BH |
132 | { |
133 | struct nfs4_deviceid_node *d; | |
a1eaecbc | 134 | |
1be5683b | 135 | spin_lock(&nfs4_deviceid_lock); |
a1eaecbc | 136 | rcu_read_lock(); |
35c8bb54 | 137 | d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); |
a1eaecbc | 138 | rcu_read_unlock(); |
1be5683b ME |
139 | if (!d) { |
140 | spin_unlock(&nfs4_deviceid_lock); | |
47cb498e | 141 | return; |
1be5683b ME |
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)) | |
47cb498e | 149 | d->ld->free_deviceid_node(d); |
1be5683b ME |
150 | } |
151 | EXPORT_SYMBOL_GPL(nfs4_delete_deviceid); | |
a1eaecbc BH |
152 | |
153 | void | |
154 | nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, | |
1775bc34 | 155 | const struct pnfs_layoutdriver_type *ld, |
a1eaecbc BH |
156 | const struct nfs_client *nfs_client, |
157 | const struct nfs4_deviceid *id) | |
158 | { | |
1775bc34 | 159 | INIT_HLIST_NODE(&d->node); |
9e3bd4e2 | 160 | INIT_HLIST_NODE(&d->tmpnode); |
1775bc34 | 161 | d->ld = ld; |
a1eaecbc | 162 | d->nfs_client = nfs_client; |
c47abcf8 | 163 | d->flags = 0; |
a1eaecbc | 164 | d->deviceid = *id; |
1775bc34 | 165 | atomic_set(&d->ref, 1); |
a1eaecbc BH |
166 | } |
167 | EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node); | |
168 | ||
169 | /* | |
170 | * Uniquely initialize and insert a deviceid node into cache | |
171 | * | |
172 | * @new new deviceid node | |
1775bc34 BH |
173 | * Note that the caller must set up the following members: |
174 | * new->ld | |
175 | * new->nfs_client | |
176 | * new->deviceid | |
a1eaecbc BH |
177 | * |
178 | * @ret the inserted node, if none found, otherwise, the found entry. | |
179 | */ | |
180 | struct nfs4_deviceid_node * | |
181 | nfs4_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); | |
1be5683b | 187 | hash = nfs4_deviceid_hash(&new->deviceid); |
35c8bb54 | 188 | d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash); |
a1eaecbc BH |
189 | if (d) { |
190 | spin_unlock(&nfs4_deviceid_lock); | |
191 | return d; | |
192 | } | |
193 | ||
a1eaecbc BH |
194 | hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]); |
195 | spin_unlock(&nfs4_deviceid_lock); | |
1d92a08d | 196 | atomic_inc(&new->ref); |
a1eaecbc BH |
197 | |
198 | return new; | |
199 | } | |
200 | EXPORT_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 | * | |
47cb498e TM |
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. | |
a1eaecbc BH |
211 | */ |
212 | bool | |
213 | nfs4_put_deviceid_node(struct nfs4_deviceid_node *d) | |
214 | { | |
47cb498e | 215 | if (!atomic_dec_and_test(&d->ref)) |
a1eaecbc | 216 | return false; |
1775bc34 | 217 | d->ld->free_deviceid_node(d); |
a1eaecbc BH |
218 | return true; |
219 | } | |
220 | EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node); | |
1775bc34 | 221 | |
1dfed273 TM |
222 | void |
223 | nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node) | |
224 | { | |
225 | node->timestamp_unavailable = jiffies; | |
226 | set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags); | |
227 | } | |
228 | EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable); | |
229 | ||
230 | bool | |
231 | nfs4_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 | } | |
244 | EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable); | |
245 | ||
1775bc34 BH |
246 | static void |
247 | _deviceid_purge_client(const struct nfs_client *clp, long hash) | |
248 | { | |
249 | struct nfs4_deviceid_node *d; | |
1775bc34 BH |
250 | HLIST_HEAD(tmp); |
251 | ||
9e3bd4e2 | 252 | spin_lock(&nfs4_deviceid_lock); |
1775bc34 | 253 | rcu_read_lock(); |
b67bfe0d | 254 | hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node) |
1775bc34 BH |
255 | if (d->nfs_client == clp && atomic_read(&d->ref)) { |
256 | hlist_del_init_rcu(&d->node); | |
9e3bd4e2 | 257 | hlist_add_head(&d->tmpnode, &tmp); |
1775bc34 BH |
258 | } |
259 | rcu_read_unlock(); | |
9e3bd4e2 | 260 | spin_unlock(&nfs4_deviceid_lock); |
1775bc34 BH |
261 | |
262 | if (hlist_empty(&tmp)) | |
263 | return; | |
264 | ||
265 | synchronize_rcu(); | |
9e3bd4e2 WAA |
266 | while (!hlist_empty(&tmp)) { |
267 | d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode); | |
268 | hlist_del(&d->tmpnode); | |
1775bc34 BH |
269 | if (atomic_dec_and_test(&d->ref)) |
270 | d->ld->free_deviceid_node(d); | |
9e3bd4e2 | 271 | } |
1775bc34 BH |
272 | } |
273 | ||
274 | void | |
275 | nfs4_deviceid_purge_client(const struct nfs_client *clp) | |
276 | { | |
277 | long h; | |
278 | ||
9e3bd4e2 WAA |
279 | if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS)) |
280 | return; | |
1775bc34 BH |
281 | for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++) |
282 | _deviceid_purge_client(clp, h); | |
1775bc34 | 283 | } |
c47abcf8 AA |
284 | |
285 | /* | |
286 | * Stop use of all deviceids associated with an nfs_client | |
287 | */ | |
288 | void | |
289 | nfs4_deviceid_mark_client_invalid(struct nfs_client *clp) | |
290 | { | |
291 | struct nfs4_deviceid_node *d; | |
c47abcf8 AA |
292 | int i; |
293 | ||
294 | rcu_read_lock(); | |
295 | for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){ | |
b67bfe0d | 296 | hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node) |
c47abcf8 AA |
297 | if (d->nfs_client == clp) |
298 | set_bit(NFS_DEVICEID_INVALID, &d->flags); | |
299 | } | |
300 | rcu_read_unlock(); | |
301 | } | |
1dfed273 | 302 |