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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 | ||
43 | static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE]; | |
44 | static DEFINE_SPINLOCK(nfs4_deviceid_lock); | |
45 | ||
6f00866d | 46 | #ifdef NFS_DEBUG |
a1eaecbc BH |
47 | void |
48 | nfs4_print_deviceid(const struct nfs4_deviceid *id) | |
49 | { | |
50 | u32 *p = (u32 *)id; | |
51 | ||
52 | dprintk("%s: device id= [%x%x%x%x]\n", __func__, | |
53 | p[0], p[1], p[2], p[3]); | |
54 | } | |
55 | EXPORT_SYMBOL_GPL(nfs4_print_deviceid); | |
6f00866d | 56 | #endif |
a1eaecbc BH |
57 | |
58 | static inline u32 | |
59 | nfs4_deviceid_hash(const struct nfs4_deviceid *id) | |
60 | { | |
61 | unsigned char *cptr = (unsigned char *)id->data; | |
62 | unsigned int nbytes = NFS4_DEVICEID4_SIZE; | |
63 | u32 x = 0; | |
64 | ||
65 | while (nbytes--) { | |
66 | x *= 37; | |
67 | x += *cptr++; | |
68 | } | |
69 | return x & NFS4_DEVICE_ID_HASH_MASK; | |
70 | } | |
71 | ||
1be5683b | 72 | static struct nfs4_deviceid_node * |
35c8bb54 BH |
73 | _lookup_deviceid(const struct pnfs_layoutdriver_type *ld, |
74 | const struct nfs_client *clp, const struct nfs4_deviceid *id, | |
1be5683b ME |
75 | long hash) |
76 | { | |
77 | struct nfs4_deviceid_node *d; | |
78 | struct hlist_node *n; | |
79 | ||
80 | hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node) | |
35c8bb54 BH |
81 | if (d->ld == ld && d->nfs_client == clp && |
82 | !memcmp(&d->deviceid, id, sizeof(*id))) { | |
1be5683b ME |
83 | if (atomic_read(&d->ref)) |
84 | return d; | |
85 | else | |
86 | continue; | |
87 | } | |
88 | return NULL; | |
89 | } | |
90 | ||
a1eaecbc BH |
91 | /* |
92 | * Lookup a deviceid in cache and get a reference count on it if found | |
93 | * | |
94 | * @clp nfs_client associated with deviceid | |
95 | * @id deviceid to look up | |
96 | */ | |
17280175 | 97 | static struct nfs4_deviceid_node * |
35c8bb54 BH |
98 | _find_get_deviceid(const struct pnfs_layoutdriver_type *ld, |
99 | const struct nfs_client *clp, const struct nfs4_deviceid *id, | |
1be5683b ME |
100 | long hash) |
101 | { | |
102 | struct nfs4_deviceid_node *d; | |
103 | ||
104 | rcu_read_lock(); | |
35c8bb54 | 105 | d = _lookup_deviceid(ld, clp, id, hash); |
47cb498e TM |
106 | if (d != NULL) |
107 | atomic_inc(&d->ref); | |
1be5683b ME |
108 | rcu_read_unlock(); |
109 | return d; | |
110 | } | |
111 | ||
a1eaecbc | 112 | struct nfs4_deviceid_node * |
35c8bb54 BH |
113 | nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld, |
114 | const struct nfs_client *clp, const struct nfs4_deviceid *id) | |
1be5683b | 115 | { |
35c8bb54 | 116 | return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); |
1be5683b ME |
117 | } |
118 | EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid); | |
119 | ||
120 | /* | |
47cb498e | 121 | * Remove a deviceid from cache |
1be5683b ME |
122 | * |
123 | * @clp nfs_client associated with deviceid | |
124 | * @id the deviceid to unhash | |
125 | * | |
126 | * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise. | |
127 | */ | |
47cb498e TM |
128 | void |
129 | nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld, | |
35c8bb54 | 130 | const struct nfs_client *clp, const struct nfs4_deviceid *id) |
a1eaecbc BH |
131 | { |
132 | struct nfs4_deviceid_node *d; | |
a1eaecbc | 133 | |
1be5683b | 134 | spin_lock(&nfs4_deviceid_lock); |
a1eaecbc | 135 | rcu_read_lock(); |
35c8bb54 | 136 | d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id)); |
a1eaecbc | 137 | rcu_read_unlock(); |
1be5683b ME |
138 | if (!d) { |
139 | spin_unlock(&nfs4_deviceid_lock); | |
47cb498e | 140 | return; |
1be5683b ME |
141 | } |
142 | hlist_del_init_rcu(&d->node); | |
143 | spin_unlock(&nfs4_deviceid_lock); | |
144 | synchronize_rcu(); | |
145 | ||
146 | /* balance the initial ref set in pnfs_insert_deviceid */ | |
147 | if (atomic_dec_and_test(&d->ref)) | |
47cb498e | 148 | d->ld->free_deviceid_node(d); |
1be5683b ME |
149 | } |
150 | EXPORT_SYMBOL_GPL(nfs4_delete_deviceid); | |
a1eaecbc BH |
151 | |
152 | void | |
153 | nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, | |
1775bc34 | 154 | const struct pnfs_layoutdriver_type *ld, |
a1eaecbc BH |
155 | const struct nfs_client *nfs_client, |
156 | const struct nfs4_deviceid *id) | |
157 | { | |
1775bc34 | 158 | INIT_HLIST_NODE(&d->node); |
9e3bd4e2 | 159 | INIT_HLIST_NODE(&d->tmpnode); |
1775bc34 | 160 | d->ld = ld; |
a1eaecbc | 161 | d->nfs_client = nfs_client; |
c47abcf8 | 162 | d->flags = 0; |
a1eaecbc | 163 | d->deviceid = *id; |
1775bc34 | 164 | atomic_set(&d->ref, 1); |
a1eaecbc BH |
165 | } |
166 | EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node); | |
167 | ||
168 | /* | |
169 | * Uniquely initialize and insert a deviceid node into cache | |
170 | * | |
171 | * @new new deviceid node | |
1775bc34 BH |
172 | * Note that the caller must set up the following members: |
173 | * new->ld | |
174 | * new->nfs_client | |
175 | * new->deviceid | |
a1eaecbc BH |
176 | * |
177 | * @ret the inserted node, if none found, otherwise, the found entry. | |
178 | */ | |
179 | struct nfs4_deviceid_node * | |
180 | nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new) | |
181 | { | |
182 | struct nfs4_deviceid_node *d; | |
183 | long hash; | |
184 | ||
185 | spin_lock(&nfs4_deviceid_lock); | |
1be5683b | 186 | hash = nfs4_deviceid_hash(&new->deviceid); |
35c8bb54 | 187 | d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash); |
a1eaecbc BH |
188 | if (d) { |
189 | spin_unlock(&nfs4_deviceid_lock); | |
190 | return d; | |
191 | } | |
192 | ||
a1eaecbc BH |
193 | hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]); |
194 | spin_unlock(&nfs4_deviceid_lock); | |
1d92a08d | 195 | atomic_inc(&new->ref); |
a1eaecbc BH |
196 | |
197 | return new; | |
198 | } | |
199 | EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node); | |
200 | ||
201 | /* | |
202 | * Dereference a deviceid node and delete it when its reference count drops | |
203 | * to zero. | |
204 | * | |
205 | * @d deviceid node to put | |
206 | * | |
47cb498e TM |
207 | * return true iff the node was deleted |
208 | * Note that since the test for d->ref == 0 is sufficient to establish | |
209 | * that the node is no longer hashed in the global device id cache. | |
a1eaecbc BH |
210 | */ |
211 | bool | |
212 | nfs4_put_deviceid_node(struct nfs4_deviceid_node *d) | |
213 | { | |
47cb498e | 214 | if (!atomic_dec_and_test(&d->ref)) |
a1eaecbc | 215 | return false; |
1775bc34 | 216 | d->ld->free_deviceid_node(d); |
a1eaecbc BH |
217 | return true; |
218 | } | |
219 | EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node); | |
1775bc34 BH |
220 | |
221 | static void | |
222 | _deviceid_purge_client(const struct nfs_client *clp, long hash) | |
223 | { | |
224 | struct nfs4_deviceid_node *d; | |
9e3bd4e2 | 225 | struct hlist_node *n; |
1775bc34 BH |
226 | HLIST_HEAD(tmp); |
227 | ||
9e3bd4e2 | 228 | spin_lock(&nfs4_deviceid_lock); |
1775bc34 BH |
229 | rcu_read_lock(); |
230 | hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node) | |
231 | if (d->nfs_client == clp && atomic_read(&d->ref)) { | |
232 | hlist_del_init_rcu(&d->node); | |
9e3bd4e2 | 233 | hlist_add_head(&d->tmpnode, &tmp); |
1775bc34 BH |
234 | } |
235 | rcu_read_unlock(); | |
9e3bd4e2 | 236 | spin_unlock(&nfs4_deviceid_lock); |
1775bc34 BH |
237 | |
238 | if (hlist_empty(&tmp)) | |
239 | return; | |
240 | ||
241 | synchronize_rcu(); | |
9e3bd4e2 WAA |
242 | while (!hlist_empty(&tmp)) { |
243 | d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode); | |
244 | hlist_del(&d->tmpnode); | |
1775bc34 BH |
245 | if (atomic_dec_and_test(&d->ref)) |
246 | d->ld->free_deviceid_node(d); | |
9e3bd4e2 | 247 | } |
1775bc34 BH |
248 | } |
249 | ||
250 | void | |
251 | nfs4_deviceid_purge_client(const struct nfs_client *clp) | |
252 | { | |
253 | long h; | |
254 | ||
9e3bd4e2 WAA |
255 | if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS)) |
256 | return; | |
1775bc34 BH |
257 | for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++) |
258 | _deviceid_purge_client(clp, h); | |
1775bc34 | 259 | } |
c47abcf8 AA |
260 | |
261 | /* | |
262 | * Stop use of all deviceids associated with an nfs_client | |
263 | */ | |
264 | void | |
265 | nfs4_deviceid_mark_client_invalid(struct nfs_client *clp) | |
266 | { | |
267 | struct nfs4_deviceid_node *d; | |
268 | struct hlist_node *n; | |
269 | int i; | |
270 | ||
271 | rcu_read_lock(); | |
272 | for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){ | |
273 | hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[i], node) | |
274 | if (d->nfs_client == clp) | |
275 | set_bit(NFS_DEVICEID_INVALID, &d->flags); | |
276 | } | |
277 | rcu_read_unlock(); | |
278 | } |