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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
43static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
44static DEFINE_SPINLOCK(nfs4_deviceid_lock);
45
46#ifdef NFS_DEBUG
47void
48nfs4_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}
55EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
56#endif
57
58static inline u32
59nfs4_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
72static struct nfs4_deviceid_node *
73_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
74 const struct nfs_client *clp, const struct nfs4_deviceid *id,
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)
81 if (d->ld == ld && d->nfs_client == clp &&
82 !memcmp(&d->deviceid, id, sizeof(*id))) {
83 if (atomic_read(&d->ref))
84 return d;
85 else
86 continue;
87 }
88 return NULL;
89}
90
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 */
97static struct nfs4_deviceid_node *
98_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
99 const struct nfs_client *clp, const struct nfs4_deviceid *id,
100 long hash)
101{
102 struct nfs4_deviceid_node *d;
103
104 rcu_read_lock();
105 d = _lookup_deviceid(ld, clp, id, hash);
106 if (d != NULL)
107 atomic_inc(&d->ref);
108 rcu_read_unlock();
109 return d;
110}
111
112struct nfs4_deviceid_node *
113nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
114 const struct nfs_client *clp, const struct nfs4_deviceid *id)
115{
116 return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
117}
118EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
119
120/*
121 * Remove a deviceid from cache
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 */
128void
129nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
130 const struct nfs_client *clp, const struct nfs4_deviceid *id)
131{
132 struct nfs4_deviceid_node *d;
133
134 spin_lock(&nfs4_deviceid_lock);
135 rcu_read_lock();
136 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
137 rcu_read_unlock();
138 if (!d) {
139 spin_unlock(&nfs4_deviceid_lock);
140 return;
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))
148 d->ld->free_deviceid_node(d);
149}
150EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
151
152void
153nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
154 const struct pnfs_layoutdriver_type *ld,
155 const struct nfs_client *nfs_client,
156 const struct nfs4_deviceid *id)
157{
158 INIT_HLIST_NODE(&d->node);
159 INIT_HLIST_NODE(&d->tmpnode);
160 d->ld = ld;
161 d->nfs_client = nfs_client;
162 d->flags = 0;
163 d->deviceid = *id;
164 atomic_set(&d->ref, 1);
165}
166EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
167
168/*
169 * Uniquely initialize and insert a deviceid node into cache
170 *
171 * @new new deviceid node
172 * Note that the caller must set up the following members:
173 * new->ld
174 * new->nfs_client
175 * new->deviceid
176 *
177 * @ret the inserted node, if none found, otherwise, the found entry.
178 */
179struct nfs4_deviceid_node *
180nfs4_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);
186 hash = nfs4_deviceid_hash(&new->deviceid);
187 d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
188 if (d) {
189 spin_unlock(&nfs4_deviceid_lock);
190 return d;
191 }
192
193 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
194 spin_unlock(&nfs4_deviceid_lock);
195 atomic_inc(&new->ref);
196
197 return new;
198}
199EXPORT_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 *
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.
210 */
211bool
212nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
213{
214 if (!atomic_dec_and_test(&d->ref))
215 return false;
216 d->ld->free_deviceid_node(d);
217 return true;
218}
219EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
220
221static void
222_deviceid_purge_client(const struct nfs_client *clp, long hash)
223{
224 struct nfs4_deviceid_node *d;
225 struct hlist_node *n;
226 HLIST_HEAD(tmp);
227
228 spin_lock(&nfs4_deviceid_lock);
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);
233 hlist_add_head(&d->tmpnode, &tmp);
234 }
235 rcu_read_unlock();
236 spin_unlock(&nfs4_deviceid_lock);
237
238 if (hlist_empty(&tmp))
239 return;
240
241 synchronize_rcu();
242 while (!hlist_empty(&tmp)) {
243 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
244 hlist_del(&d->tmpnode);
245 if (atomic_dec_and_test(&d->ref))
246 d->ld->free_deviceid_node(d);
247 }
248}
249
250void
251nfs4_deviceid_purge_client(const struct nfs_client *clp)
252{
253 long h;
254
255 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
256 return;
257 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
258 _deviceid_purge_client(clp, h);
259}
260
261/*
262 * Stop use of all deviceids associated with an nfs_client
263 */
264void
265nfs4_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}