4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2012, 2016, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/obdclass/upcall_cache.c
34 * Supplementary groups cache.
36 #define DEBUG_SUBSYSTEM S_SEC
38 #include <libcfs/libcfs.h>
39 #include <uapi/linux/lnet/lnet-types.h>
40 #include <upcall_cache.h>
42 static struct upcall_cache_entry *alloc_entry(struct upcall_cache *cache,
43 __u64 key, void *args)
45 struct upcall_cache_entry *entry;
47 LIBCFS_ALLOC(entry, sizeof(*entry));
51 UC_CACHE_SET_NEW(entry);
52 INIT_LIST_HEAD(&entry->ue_hash);
54 atomic_set(&entry->ue_refcount, 0);
55 init_waitqueue_head(&entry->ue_waitq);
56 if (cache->uc_ops->init_entry)
57 cache->uc_ops->init_entry(entry, args);
61 /* protected by cache lock */
62 static void free_entry(struct upcall_cache *cache,
63 struct upcall_cache_entry *entry)
65 if (cache->uc_ops->free_entry)
66 cache->uc_ops->free_entry(cache, entry);
68 list_del(&entry->ue_hash);
69 CDEBUG(D_OTHER, "destroy cache entry %p for key %llu\n",
70 entry, entry->ue_key);
71 LIBCFS_FREE(entry, sizeof(*entry));
74 static inline int upcall_compare(struct upcall_cache *cache,
75 struct upcall_cache_entry *entry,
76 __u64 key, void *args)
78 if (entry->ue_key != key)
81 if (cache->uc_ops->upcall_compare)
82 return cache->uc_ops->upcall_compare(cache, entry, key, args);
87 static inline int downcall_compare(struct upcall_cache *cache,
88 struct upcall_cache_entry *entry,
89 __u64 key, void *args)
91 if (entry->ue_key != key)
94 if (cache->uc_ops->downcall_compare)
95 return cache->uc_ops->downcall_compare(cache, entry, key, args);
100 static inline void get_entry(struct upcall_cache_entry *entry)
102 atomic_inc(&entry->ue_refcount);
105 static inline void put_entry(struct upcall_cache *cache,
106 struct upcall_cache_entry *entry)
108 if (atomic_dec_and_test(&entry->ue_refcount) &&
109 (UC_CACHE_IS_INVALID(entry) || UC_CACHE_IS_EXPIRED(entry))) {
110 free_entry(cache, entry);
114 static int check_unlink_entry(struct upcall_cache *cache,
115 struct upcall_cache_entry *entry)
117 time64_t now = ktime_get_seconds();
119 if (UC_CACHE_IS_VALID(entry) && now < entry->ue_expire)
122 if (UC_CACHE_IS_ACQUIRING(entry)) {
123 if (entry->ue_acquire_expire == 0 ||
124 now < entry->ue_acquire_expire)
127 UC_CACHE_SET_EXPIRED(entry);
128 wake_up_all(&entry->ue_waitq);
129 } else if (!UC_CACHE_IS_INVALID(entry)) {
130 UC_CACHE_SET_EXPIRED(entry);
133 list_del_init(&entry->ue_hash);
134 if (!atomic_read(&entry->ue_refcount))
135 free_entry(cache, entry);
139 static inline int refresh_entry(struct upcall_cache *cache,
140 struct upcall_cache_entry *entry)
142 LASSERT(cache->uc_ops->do_upcall);
143 return cache->uc_ops->do_upcall(cache, entry);
146 struct upcall_cache_entry *upcall_cache_get_entry(struct upcall_cache *cache,
147 __u64 key, void *args)
149 struct upcall_cache_entry *entry = NULL, *new = NULL, *next;
150 struct list_head *head;
151 wait_queue_entry_t wait;
157 head = &cache->uc_hashtable[UC_CACHE_HASH_INDEX(key)];
160 spin_lock(&cache->uc_lock);
161 list_for_each_entry_safe(entry, next, head, ue_hash) {
162 /* check invalid & expired items */
163 if (check_unlink_entry(cache, entry))
165 if (upcall_compare(cache, entry, key, args) == 0) {
173 spin_unlock(&cache->uc_lock);
174 new = alloc_entry(cache, key, args);
176 CERROR("fail to alloc entry\n");
177 RETURN(ERR_PTR(-ENOMEM));
181 list_add(&new->ue_hash, head);
186 free_entry(cache, new);
189 list_move(&entry->ue_hash, head);
193 /* acquire for new one */
194 if (UC_CACHE_IS_NEW(entry)) {
195 UC_CACHE_SET_ACQUIRING(entry);
196 UC_CACHE_CLEAR_NEW(entry);
197 spin_unlock(&cache->uc_lock);
198 rc = refresh_entry(cache, entry);
199 spin_lock(&cache->uc_lock);
200 entry->ue_acquire_expire = ktime_get_seconds() +
201 cache->uc_acquire_expire;
203 UC_CACHE_CLEAR_ACQUIRING(entry);
204 UC_CACHE_SET_INVALID(entry);
205 wake_up_all(&entry->ue_waitq);
206 if (unlikely(rc == -EREMCHG)) {
207 put_entry(cache, entry);
208 GOTO(out, entry = ERR_PTR(rc));
212 /* someone (and only one) is doing upcall upon this item,
213 * wait it to complete */
214 if (UC_CACHE_IS_ACQUIRING(entry)) {
215 long expiry = (entry == new) ?
216 cfs_time_seconds(cache->uc_acquire_expire) :
217 MAX_SCHEDULE_TIMEOUT;
220 init_waitqueue_entry(&wait, current);
221 add_wait_queue(&entry->ue_waitq, &wait);
222 set_current_state(TASK_INTERRUPTIBLE);
223 spin_unlock(&cache->uc_lock);
225 left = schedule_timeout(expiry);
227 spin_lock(&cache->uc_lock);
228 remove_wait_queue(&entry->ue_waitq, &wait);
229 if (UC_CACHE_IS_ACQUIRING(entry)) {
230 /* we're interrupted or upcall failed in the middle */
231 rc = left > 0 ? -EINTR : -ETIMEDOUT;
232 CERROR("acquire for key %llu: error %d\n",
234 put_entry(cache, entry);
235 GOTO(out, entry = ERR_PTR(rc));
239 /* invalid means error, don't need to try again */
240 if (UC_CACHE_IS_INVALID(entry)) {
241 put_entry(cache, entry);
242 GOTO(out, entry = ERR_PTR(-EIDRM));
246 * We can't refresh the existing one because some
247 * memory might be shared by multiple processes.
249 if (check_unlink_entry(cache, entry)) {
250 /* if expired, try again. but if this entry is
251 * created by me but too quickly turn to expired
252 * without any error, should at least give a
253 * chance to use it once.
256 put_entry(cache, entry);
257 spin_unlock(&cache->uc_lock);
263 /* Now we know it's good */
265 spin_unlock(&cache->uc_lock);
268 EXPORT_SYMBOL(upcall_cache_get_entry);
270 void upcall_cache_put_entry(struct upcall_cache *cache,
271 struct upcall_cache_entry *entry)
280 LASSERT(atomic_read(&entry->ue_refcount) > 0);
281 spin_lock(&cache->uc_lock);
282 put_entry(cache, entry);
283 spin_unlock(&cache->uc_lock);
286 EXPORT_SYMBOL(upcall_cache_put_entry);
288 int upcall_cache_downcall(struct upcall_cache *cache, __u32 err, __u64 key,
291 struct upcall_cache_entry *entry = NULL;
292 struct list_head *head;
293 int found = 0, rc = 0;
298 head = &cache->uc_hashtable[UC_CACHE_HASH_INDEX(key)];
300 spin_lock(&cache->uc_lock);
301 list_for_each_entry(entry, head, ue_hash) {
302 if (downcall_compare(cache, entry, key, args) == 0) {
310 CDEBUG(D_OTHER, "%s: upcall for key %llu not expected\n",
311 cache->uc_name, key);
312 /* haven't found, it's possible */
313 spin_unlock(&cache->uc_lock);
318 CDEBUG(D_OTHER, "%s: upcall for key %llu returned %d\n",
319 cache->uc_name, entry->ue_key, err);
320 GOTO(out, rc = -EINVAL);
323 if (!UC_CACHE_IS_ACQUIRING(entry)) {
324 CDEBUG(D_RPCTRACE, "%s: found uptodate entry %p (key %llu)"
325 "\n", cache->uc_name, entry, entry->ue_key);
329 if (UC_CACHE_IS_INVALID(entry) || UC_CACHE_IS_EXPIRED(entry)) {
330 CERROR("%s: found a stale entry %p (key %llu) in ioctl\n",
331 cache->uc_name, entry, entry->ue_key);
332 GOTO(out, rc = -EINVAL);
335 spin_unlock(&cache->uc_lock);
336 if (cache->uc_ops->parse_downcall)
337 rc = cache->uc_ops->parse_downcall(cache, entry, args);
338 spin_lock(&cache->uc_lock);
342 entry->ue_expire = ktime_get_seconds() + cache->uc_entry_expire;
343 UC_CACHE_SET_VALID(entry);
344 CDEBUG(D_OTHER, "%s: created upcall cache entry %p for key %llu\n",
345 cache->uc_name, entry, entry->ue_key);
348 UC_CACHE_SET_INVALID(entry);
349 list_del_init(&entry->ue_hash);
351 UC_CACHE_CLEAR_ACQUIRING(entry);
352 spin_unlock(&cache->uc_lock);
353 wake_up_all(&entry->ue_waitq);
354 put_entry(cache, entry);
358 EXPORT_SYMBOL(upcall_cache_downcall);
360 void upcall_cache_flush(struct upcall_cache *cache, int force)
362 struct upcall_cache_entry *entry, *next;
366 spin_lock(&cache->uc_lock);
367 for (i = 0; i < UC_CACHE_HASH_SIZE; i++) {
368 list_for_each_entry_safe(entry, next,
369 &cache->uc_hashtable[i], ue_hash) {
370 if (!force && atomic_read(&entry->ue_refcount)) {
371 UC_CACHE_SET_EXPIRED(entry);
374 LASSERT(!atomic_read(&entry->ue_refcount));
375 free_entry(cache, entry);
378 spin_unlock(&cache->uc_lock);
381 EXPORT_SYMBOL(upcall_cache_flush);
383 void upcall_cache_flush_one(struct upcall_cache *cache, __u64 key, void *args)
385 struct list_head *head;
386 struct upcall_cache_entry *entry;
390 head = &cache->uc_hashtable[UC_CACHE_HASH_INDEX(key)];
392 spin_lock(&cache->uc_lock);
393 list_for_each_entry(entry, head, ue_hash) {
394 if (upcall_compare(cache, entry, key, args) == 0) {
401 CWARN("%s: flush entry %p: key %llu, ref %d, fl %x, "
402 "cur %lld, ex %lld/%lld\n",
403 cache->uc_name, entry, entry->ue_key,
404 atomic_read(&entry->ue_refcount), entry->ue_flags,
405 ktime_get_real_seconds(), entry->ue_acquire_expire,
407 UC_CACHE_SET_EXPIRED(entry);
408 if (!atomic_read(&entry->ue_refcount))
409 free_entry(cache, entry);
411 spin_unlock(&cache->uc_lock);
413 EXPORT_SYMBOL(upcall_cache_flush_one);
415 struct upcall_cache *upcall_cache_init(const char *name, const char *upcall,
416 struct upcall_cache_ops *ops)
418 struct upcall_cache *cache;
422 LIBCFS_ALLOC(cache, sizeof(*cache));
424 RETURN(ERR_PTR(-ENOMEM));
426 spin_lock_init(&cache->uc_lock);
427 init_rwsem(&cache->uc_upcall_rwsem);
428 for (i = 0; i < UC_CACHE_HASH_SIZE; i++)
429 INIT_LIST_HEAD(&cache->uc_hashtable[i]);
430 strlcpy(cache->uc_name, name, sizeof(cache->uc_name));
431 /* upcall pathname proc tunable */
432 strlcpy(cache->uc_upcall, upcall, sizeof(cache->uc_upcall));
433 cache->uc_entry_expire = 20 * 60;
434 cache->uc_acquire_expire = 30;
439 EXPORT_SYMBOL(upcall_cache_init);
441 void upcall_cache_cleanup(struct upcall_cache *cache)
445 upcall_cache_flush_all(cache);
446 LIBCFS_FREE(cache, sizeof(*cache));
448 EXPORT_SYMBOL(upcall_cache_cleanup);