blob: f0f8e1e22f6c945119ff359491dce07b79a0cf69 [file] [log] [blame]
Benny Halevya1eaecb2011-05-19 22:14:47 -04001/*
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
Marc Eshel1be56832011-05-22 19:47:09 +030069static struct nfs4_deviceid_node *
Benny Halevy35c8bb52011-05-24 18:04:02 +030070_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
71 const struct nfs_client *clp, const struct nfs4_deviceid *id,
Marc Eshel1be56832011-05-22 19:47:09 +030072 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)
Benny Halevy35c8bb52011-05-24 18:04:02 +030078 if (d->ld == ld && d->nfs_client == clp &&
79 !memcmp(&d->deviceid, id, sizeof(*id))) {
Marc Eshel1be56832011-05-22 19:47:09 +030080 if (atomic_read(&d->ref))
81 return d;
82 else
83 continue;
84 }
85 return NULL;
86}
87
Benny Halevya1eaecb2011-05-19 22:14:47 -040088/*
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 *
Benny Halevy35c8bb52011-05-24 18:04:02 +030095_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
96 const struct nfs_client *clp, const struct nfs4_deviceid *id,
Marc Eshel1be56832011-05-22 19:47:09 +030097 long hash)
Benny Halevya1eaecb2011-05-19 22:14:47 -040098{
99 struct nfs4_deviceid_node *d;
Benny Halevya1eaecb2011-05-19 22:14:47 -0400100
101 rcu_read_lock();
Benny Halevy35c8bb52011-05-24 18:04:02 +0300102 d = _lookup_deviceid(ld, clp, id, hash);
Marc Eshel1be56832011-05-22 19:47:09 +0300103 if (d && !atomic_inc_not_zero(&d->ref))
104 d = NULL;
Benny Halevya1eaecb2011-05-19 22:14:47 -0400105 rcu_read_unlock();
Marc Eshel1be56832011-05-22 19:47:09 +0300106 return d;
107}
108
109struct nfs4_deviceid_node *
Benny Halevy35c8bb52011-05-24 18:04:02 +0300110nfs4_find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
111 const struct nfs_client *clp, const struct nfs4_deviceid *id)
Marc Eshel1be56832011-05-22 19:47:09 +0300112{
Benny Halevy35c8bb52011-05-24 18:04:02 +0300113 return _find_get_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
Benny Halevya1eaecb2011-05-19 22:14:47 -0400114}
115EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
116
Marc Eshel1be56832011-05-22 19:47:09 +0300117/*
118 * Unhash and put deviceid
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 */
125struct nfs4_deviceid_node *
Benny Halevy35c8bb52011-05-24 18:04:02 +0300126nfs4_unhash_put_deviceid(const struct pnfs_layoutdriver_type *ld,
127 const struct nfs_client *clp, const struct nfs4_deviceid *id)
Marc Eshel1be56832011-05-22 19:47:09 +0300128{
129 struct nfs4_deviceid_node *d;
130
131 spin_lock(&nfs4_deviceid_lock);
132 rcu_read_lock();
Benny Halevy35c8bb52011-05-24 18:04:02 +0300133 d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
Marc Eshel1be56832011-05-22 19:47:09 +0300134 rcu_read_unlock();
135 if (!d) {
136 spin_unlock(&nfs4_deviceid_lock);
137 return NULL;
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 return d;
146
147 return NULL;
148}
149EXPORT_SYMBOL_GPL(nfs4_unhash_put_deviceid);
150
151/*
152 * Delete a deviceid from cache
153 *
154 * @clp struct nfs_client qualifying the deviceid
155 * @id deviceid to delete
156 */
157void
Benny Halevy35c8bb52011-05-24 18:04:02 +0300158nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
159 const struct nfs_client *clp, const struct nfs4_deviceid *id)
Marc Eshel1be56832011-05-22 19:47:09 +0300160{
161 struct nfs4_deviceid_node *d;
162
Benny Halevy35c8bb52011-05-24 18:04:02 +0300163 d = nfs4_unhash_put_deviceid(ld, clp, id);
Marc Eshel1be56832011-05-22 19:47:09 +0300164 if (!d)
165 return;
166 d->ld->free_deviceid_node(d);
167}
168EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
169
Benny Halevya1eaecb2011-05-19 22:14:47 -0400170void
171nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
Benny Halevy1775bc32011-05-20 13:47:33 +0200172 const struct pnfs_layoutdriver_type *ld,
Benny Halevya1eaecb2011-05-19 22:14:47 -0400173 const struct nfs_client *nfs_client,
174 const struct nfs4_deviceid *id)
175{
Benny Halevy1775bc32011-05-20 13:47:33 +0200176 INIT_HLIST_NODE(&d->node);
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400177 INIT_HLIST_NODE(&d->tmpnode);
Benny Halevy1775bc32011-05-20 13:47:33 +0200178 d->ld = ld;
Benny Halevya1eaecb2011-05-19 22:14:47 -0400179 d->nfs_client = nfs_client;
180 d->deviceid = *id;
Benny Halevy1775bc32011-05-20 13:47:33 +0200181 atomic_set(&d->ref, 1);
Benny Halevya1eaecb2011-05-19 22:14:47 -0400182}
183EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
184
185/*
186 * Uniquely initialize and insert a deviceid node into cache
187 *
188 * @new new deviceid node
Benny Halevy1775bc32011-05-20 13:47:33 +0200189 * Note that the caller must set up the following members:
190 * new->ld
191 * new->nfs_client
192 * new->deviceid
Benny Halevya1eaecb2011-05-19 22:14:47 -0400193 *
194 * @ret the inserted node, if none found, otherwise, the found entry.
195 */
196struct nfs4_deviceid_node *
197nfs4_insert_deviceid_node(struct nfs4_deviceid_node *new)
198{
199 struct nfs4_deviceid_node *d;
200 long hash;
201
202 spin_lock(&nfs4_deviceid_lock);
Marc Eshel1be56832011-05-22 19:47:09 +0300203 hash = nfs4_deviceid_hash(&new->deviceid);
Benny Halevy35c8bb52011-05-24 18:04:02 +0300204 d = _find_get_deviceid(new->ld, new->nfs_client, &new->deviceid, hash);
Benny Halevya1eaecb2011-05-19 22:14:47 -0400205 if (d) {
206 spin_unlock(&nfs4_deviceid_lock);
207 return d;
208 }
209
Benny Halevya1eaecb2011-05-19 22:14:47 -0400210 hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
211 spin_unlock(&nfs4_deviceid_lock);
Trond Myklebust1d92a082011-06-14 12:07:38 -0400212 atomic_inc(&new->ref);
Benny Halevya1eaecb2011-05-19 22:14:47 -0400213
214 return new;
215}
216EXPORT_SYMBOL_GPL(nfs4_insert_deviceid_node);
217
218/*
219 * Dereference a deviceid node and delete it when its reference count drops
220 * to zero.
221 *
222 * @d deviceid node to put
223 *
224 * @ret true iff the node was deleted
225 */
226bool
227nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
228{
229 if (!atomic_dec_and_lock(&d->ref, &nfs4_deviceid_lock))
230 return false;
231 hlist_del_init_rcu(&d->node);
232 spin_unlock(&nfs4_deviceid_lock);
233 synchronize_rcu();
Benny Halevy1775bc32011-05-20 13:47:33 +0200234 d->ld->free_deviceid_node(d);
Benny Halevya1eaecb2011-05-19 22:14:47 -0400235 return true;
236}
237EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
Benny Halevy1775bc32011-05-20 13:47:33 +0200238
239static void
240_deviceid_purge_client(const struct nfs_client *clp, long hash)
241{
242 struct nfs4_deviceid_node *d;
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400243 struct hlist_node *n;
Benny Halevy1775bc32011-05-20 13:47:33 +0200244 HLIST_HEAD(tmp);
245
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400246 spin_lock(&nfs4_deviceid_lock);
Benny Halevy1775bc32011-05-20 13:47:33 +0200247 rcu_read_lock();
248 hlist_for_each_entry_rcu(d, n, &nfs4_deviceid_cache[hash], node)
249 if (d->nfs_client == clp && atomic_read(&d->ref)) {
250 hlist_del_init_rcu(&d->node);
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400251 hlist_add_head(&d->tmpnode, &tmp);
Benny Halevy1775bc32011-05-20 13:47:33 +0200252 }
253 rcu_read_unlock();
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400254 spin_unlock(&nfs4_deviceid_lock);
Benny Halevy1775bc32011-05-20 13:47:33 +0200255
256 if (hlist_empty(&tmp))
257 return;
258
259 synchronize_rcu();
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400260 while (!hlist_empty(&tmp)) {
261 d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
262 hlist_del(&d->tmpnode);
Benny Halevy1775bc32011-05-20 13:47:33 +0200263 if (atomic_dec_and_test(&d->ref))
264 d->ld->free_deviceid_node(d);
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400265 }
Benny Halevy1775bc32011-05-20 13:47:33 +0200266}
267
268void
269nfs4_deviceid_purge_client(const struct nfs_client *clp)
270{
271 long h;
272
Weston Andros Adamson9e3bd4e2011-05-31 21:46:50 -0400273 if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
274 return;
Benny Halevy1775bc32011-05-20 13:47:33 +0200275 for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
276 _deviceid_purge_client(clp, h);
Benny Halevy1775bc32011-05-20 13:47:33 +0200277}