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1 | /* | |
2 | * net/sunrpc/cache.c | |
3 | * | |
4 | * Generic code for various authentication-related caches | |
5 | * used by sunrpc clients and servers. | |
6 | * | |
7 | * Copyright (C) 2002 Neil Brown <neilb@cse.unsw.edu.au> | |
8 | * | |
9 | * Released under terms in GPL version 2. See COPYING. | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <linux/types.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/file.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/signal.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/kmod.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/ctype.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <linux/poll.h> | |
25 | #include <linux/seq_file.h> | |
26 | #include <linux/proc_fs.h> | |
27 | #include <linux/net.h> | |
28 | #include <linux/workqueue.h> | |
29 | #include <linux/mutex.h> | |
30 | #include <linux/pagemap.h> | |
31 | #include <asm/ioctls.h> | |
32 | #include <linux/sunrpc/types.h> | |
33 | #include <linux/sunrpc/cache.h> | |
34 | #include <linux/sunrpc/stats.h> | |
35 | #include <linux/sunrpc/rpc_pipe_fs.h> | |
36 | #include "netns.h" | |
37 | ||
38 | #define RPCDBG_FACILITY RPCDBG_CACHE | |
39 | ||
40 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item); | |
41 | static void cache_revisit_request(struct cache_head *item); | |
42 | ||
43 | static void cache_init(struct cache_head *h) | |
44 | { | |
45 | time_t now = seconds_since_boot(); | |
46 | h->next = NULL; | |
47 | h->flags = 0; | |
48 | kref_init(&h->ref); | |
49 | h->expiry_time = now + CACHE_NEW_EXPIRY; | |
50 | h->last_refresh = now; | |
51 | } | |
52 | ||
53 | static inline int cache_is_expired(struct cache_detail *detail, struct cache_head *h) | |
54 | { | |
55 | return (h->expiry_time < seconds_since_boot()) || | |
56 | (detail->flush_time > h->last_refresh); | |
57 | } | |
58 | ||
59 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, | |
60 | struct cache_head *key, int hash) | |
61 | { | |
62 | struct cache_head **head, **hp; | |
63 | struct cache_head *new = NULL, *freeme = NULL; | |
64 | ||
65 | head = &detail->hash_table[hash]; | |
66 | ||
67 | read_lock(&detail->hash_lock); | |
68 | ||
69 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
70 | struct cache_head *tmp = *hp; | |
71 | if (detail->match(tmp, key)) { | |
72 | if (cache_is_expired(detail, tmp)) | |
73 | /* This entry is expired, we will discard it. */ | |
74 | break; | |
75 | cache_get(tmp); | |
76 | read_unlock(&detail->hash_lock); | |
77 | return tmp; | |
78 | } | |
79 | } | |
80 | read_unlock(&detail->hash_lock); | |
81 | /* Didn't find anything, insert an empty entry */ | |
82 | ||
83 | new = detail->alloc(); | |
84 | if (!new) | |
85 | return NULL; | |
86 | /* must fully initialise 'new', else | |
87 | * we might get lose if we need to | |
88 | * cache_put it soon. | |
89 | */ | |
90 | cache_init(new); | |
91 | detail->init(new, key); | |
92 | ||
93 | write_lock(&detail->hash_lock); | |
94 | ||
95 | /* check if entry appeared while we slept */ | |
96 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
97 | struct cache_head *tmp = *hp; | |
98 | if (detail->match(tmp, key)) { | |
99 | if (cache_is_expired(detail, tmp)) { | |
100 | *hp = tmp->next; | |
101 | tmp->next = NULL; | |
102 | detail->entries --; | |
103 | freeme = tmp; | |
104 | break; | |
105 | } | |
106 | cache_get(tmp); | |
107 | write_unlock(&detail->hash_lock); | |
108 | cache_put(new, detail); | |
109 | return tmp; | |
110 | } | |
111 | } | |
112 | new->next = *head; | |
113 | *head = new; | |
114 | detail->entries++; | |
115 | cache_get(new); | |
116 | write_unlock(&detail->hash_lock); | |
117 | ||
118 | if (freeme) | |
119 | cache_put(freeme, detail); | |
120 | return new; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); | |
123 | ||
124 | ||
125 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); | |
126 | ||
127 | static void cache_fresh_locked(struct cache_head *head, time_t expiry) | |
128 | { | |
129 | head->expiry_time = expiry; | |
130 | head->last_refresh = seconds_since_boot(); | |
131 | smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */ | |
132 | set_bit(CACHE_VALID, &head->flags); | |
133 | } | |
134 | ||
135 | static void cache_fresh_unlocked(struct cache_head *head, | |
136 | struct cache_detail *detail) | |
137 | { | |
138 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { | |
139 | cache_revisit_request(head); | |
140 | cache_dequeue(detail, head); | |
141 | } | |
142 | } | |
143 | ||
144 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, | |
145 | struct cache_head *new, struct cache_head *old, int hash) | |
146 | { | |
147 | /* The 'old' entry is to be replaced by 'new'. | |
148 | * If 'old' is not VALID, we update it directly, | |
149 | * otherwise we need to replace it | |
150 | */ | |
151 | struct cache_head **head; | |
152 | struct cache_head *tmp; | |
153 | ||
154 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
155 | write_lock(&detail->hash_lock); | |
156 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
157 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
158 | set_bit(CACHE_NEGATIVE, &old->flags); | |
159 | else | |
160 | detail->update(old, new); | |
161 | cache_fresh_locked(old, new->expiry_time); | |
162 | write_unlock(&detail->hash_lock); | |
163 | cache_fresh_unlocked(old, detail); | |
164 | return old; | |
165 | } | |
166 | write_unlock(&detail->hash_lock); | |
167 | } | |
168 | /* We need to insert a new entry */ | |
169 | tmp = detail->alloc(); | |
170 | if (!tmp) { | |
171 | cache_put(old, detail); | |
172 | return NULL; | |
173 | } | |
174 | cache_init(tmp); | |
175 | detail->init(tmp, old); | |
176 | head = &detail->hash_table[hash]; | |
177 | ||
178 | write_lock(&detail->hash_lock); | |
179 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
180 | set_bit(CACHE_NEGATIVE, &tmp->flags); | |
181 | else | |
182 | detail->update(tmp, new); | |
183 | tmp->next = *head; | |
184 | *head = tmp; | |
185 | detail->entries++; | |
186 | cache_get(tmp); | |
187 | cache_fresh_locked(tmp, new->expiry_time); | |
188 | cache_fresh_locked(old, 0); | |
189 | write_unlock(&detail->hash_lock); | |
190 | cache_fresh_unlocked(tmp, detail); | |
191 | cache_fresh_unlocked(old, detail); | |
192 | cache_put(old, detail); | |
193 | return tmp; | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(sunrpc_cache_update); | |
196 | ||
197 | static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) | |
198 | { | |
199 | if (cd->cache_upcall) | |
200 | return cd->cache_upcall(cd, h); | |
201 | return sunrpc_cache_pipe_upcall(cd, h); | |
202 | } | |
203 | ||
204 | static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h) | |
205 | { | |
206 | if (!test_bit(CACHE_VALID, &h->flags)) | |
207 | return -EAGAIN; | |
208 | else { | |
209 | /* entry is valid */ | |
210 | if (test_bit(CACHE_NEGATIVE, &h->flags)) | |
211 | return -ENOENT; | |
212 | else { | |
213 | /* | |
214 | * In combination with write barrier in | |
215 | * sunrpc_cache_update, ensures that anyone | |
216 | * using the cache entry after this sees the | |
217 | * updated contents: | |
218 | */ | |
219 | smp_rmb(); | |
220 | return 0; | |
221 | } | |
222 | } | |
223 | } | |
224 | ||
225 | static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h) | |
226 | { | |
227 | int rv; | |
228 | ||
229 | write_lock(&detail->hash_lock); | |
230 | rv = cache_is_valid(detail, h); | |
231 | if (rv != -EAGAIN) { | |
232 | write_unlock(&detail->hash_lock); | |
233 | return rv; | |
234 | } | |
235 | set_bit(CACHE_NEGATIVE, &h->flags); | |
236 | cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY); | |
237 | write_unlock(&detail->hash_lock); | |
238 | cache_fresh_unlocked(h, detail); | |
239 | return -ENOENT; | |
240 | } | |
241 | ||
242 | /* | |
243 | * This is the generic cache management routine for all | |
244 | * the authentication caches. | |
245 | * It checks the currency of a cache item and will (later) | |
246 | * initiate an upcall to fill it if needed. | |
247 | * | |
248 | * | |
249 | * Returns 0 if the cache_head can be used, or cache_puts it and returns | |
250 | * -EAGAIN if upcall is pending and request has been queued | |
251 | * -ETIMEDOUT if upcall failed or request could not be queue or | |
252 | * upcall completed but item is still invalid (implying that | |
253 | * the cache item has been replaced with a newer one). | |
254 | * -ENOENT if cache entry was negative | |
255 | */ | |
256 | int cache_check(struct cache_detail *detail, | |
257 | struct cache_head *h, struct cache_req *rqstp) | |
258 | { | |
259 | int rv; | |
260 | long refresh_age, age; | |
261 | ||
262 | /* First decide return status as best we can */ | |
263 | rv = cache_is_valid(detail, h); | |
264 | ||
265 | /* now see if we want to start an upcall */ | |
266 | refresh_age = (h->expiry_time - h->last_refresh); | |
267 | age = seconds_since_boot() - h->last_refresh; | |
268 | ||
269 | if (rqstp == NULL) { | |
270 | if (rv == -EAGAIN) | |
271 | rv = -ENOENT; | |
272 | } else if (rv == -EAGAIN || age > refresh_age/2) { | |
273 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", | |
274 | refresh_age, age); | |
275 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { | |
276 | switch (cache_make_upcall(detail, h)) { | |
277 | case -EINVAL: | |
278 | clear_bit(CACHE_PENDING, &h->flags); | |
279 | cache_revisit_request(h); | |
280 | rv = try_to_negate_entry(detail, h); | |
281 | break; | |
282 | case -EAGAIN: | |
283 | clear_bit(CACHE_PENDING, &h->flags); | |
284 | cache_revisit_request(h); | |
285 | break; | |
286 | } | |
287 | } | |
288 | } | |
289 | ||
290 | if (rv == -EAGAIN) { | |
291 | if (!cache_defer_req(rqstp, h)) { | |
292 | /* | |
293 | * Request was not deferred; handle it as best | |
294 | * we can ourselves: | |
295 | */ | |
296 | rv = cache_is_valid(detail, h); | |
297 | if (rv == -EAGAIN) | |
298 | rv = -ETIMEDOUT; | |
299 | } | |
300 | } | |
301 | if (rv) | |
302 | cache_put(h, detail); | |
303 | return rv; | |
304 | } | |
305 | EXPORT_SYMBOL_GPL(cache_check); | |
306 | ||
307 | /* | |
308 | * caches need to be periodically cleaned. | |
309 | * For this we maintain a list of cache_detail and | |
310 | * a current pointer into that list and into the table | |
311 | * for that entry. | |
312 | * | |
313 | * Each time clean_cache is called it finds the next non-empty entry | |
314 | * in the current table and walks the list in that entry | |
315 | * looking for entries that can be removed. | |
316 | * | |
317 | * An entry gets removed if: | |
318 | * - The expiry is before current time | |
319 | * - The last_refresh time is before the flush_time for that cache | |
320 | * | |
321 | * later we might drop old entries with non-NEVER expiry if that table | |
322 | * is getting 'full' for some definition of 'full' | |
323 | * | |
324 | * The question of "how often to scan a table" is an interesting one | |
325 | * and is answered in part by the use of the "nextcheck" field in the | |
326 | * cache_detail. | |
327 | * When a scan of a table begins, the nextcheck field is set to a time | |
328 | * that is well into the future. | |
329 | * While scanning, if an expiry time is found that is earlier than the | |
330 | * current nextcheck time, nextcheck is set to that expiry time. | |
331 | * If the flush_time is ever set to a time earlier than the nextcheck | |
332 | * time, the nextcheck time is then set to that flush_time. | |
333 | * | |
334 | * A table is then only scanned if the current time is at least | |
335 | * the nextcheck time. | |
336 | * | |
337 | */ | |
338 | ||
339 | static LIST_HEAD(cache_list); | |
340 | static DEFINE_SPINLOCK(cache_list_lock); | |
341 | static struct cache_detail *current_detail; | |
342 | static int current_index; | |
343 | ||
344 | static void do_cache_clean(struct work_struct *work); | |
345 | static struct delayed_work cache_cleaner; | |
346 | ||
347 | void sunrpc_init_cache_detail(struct cache_detail *cd) | |
348 | { | |
349 | rwlock_init(&cd->hash_lock); | |
350 | INIT_LIST_HEAD(&cd->queue); | |
351 | spin_lock(&cache_list_lock); | |
352 | cd->nextcheck = 0; | |
353 | cd->entries = 0; | |
354 | atomic_set(&cd->readers, 0); | |
355 | cd->last_close = 0; | |
356 | cd->last_warn = -1; | |
357 | list_add(&cd->others, &cache_list); | |
358 | spin_unlock(&cache_list_lock); | |
359 | ||
360 | /* start the cleaning process */ | |
361 | schedule_delayed_work(&cache_cleaner, 0); | |
362 | } | |
363 | EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail); | |
364 | ||
365 | void sunrpc_destroy_cache_detail(struct cache_detail *cd) | |
366 | { | |
367 | cache_purge(cd); | |
368 | spin_lock(&cache_list_lock); | |
369 | write_lock(&cd->hash_lock); | |
370 | if (cd->entries || atomic_read(&cd->inuse)) { | |
371 | write_unlock(&cd->hash_lock); | |
372 | spin_unlock(&cache_list_lock); | |
373 | goto out; | |
374 | } | |
375 | if (current_detail == cd) | |
376 | current_detail = NULL; | |
377 | list_del_init(&cd->others); | |
378 | write_unlock(&cd->hash_lock); | |
379 | spin_unlock(&cache_list_lock); | |
380 | if (list_empty(&cache_list)) { | |
381 | /* module must be being unloaded so its safe to kill the worker */ | |
382 | cancel_delayed_work_sync(&cache_cleaner); | |
383 | } | |
384 | return; | |
385 | out: | |
386 | printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); | |
387 | } | |
388 | EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); | |
389 | ||
390 | /* clean cache tries to find something to clean | |
391 | * and cleans it. | |
392 | * It returns 1 if it cleaned something, | |
393 | * 0 if it didn't find anything this time | |
394 | * -1 if it fell off the end of the list. | |
395 | */ | |
396 | static int cache_clean(void) | |
397 | { | |
398 | int rv = 0; | |
399 | struct list_head *next; | |
400 | ||
401 | spin_lock(&cache_list_lock); | |
402 | ||
403 | /* find a suitable table if we don't already have one */ | |
404 | while (current_detail == NULL || | |
405 | current_index >= current_detail->hash_size) { | |
406 | if (current_detail) | |
407 | next = current_detail->others.next; | |
408 | else | |
409 | next = cache_list.next; | |
410 | if (next == &cache_list) { | |
411 | current_detail = NULL; | |
412 | spin_unlock(&cache_list_lock); | |
413 | return -1; | |
414 | } | |
415 | current_detail = list_entry(next, struct cache_detail, others); | |
416 | if (current_detail->nextcheck > seconds_since_boot()) | |
417 | current_index = current_detail->hash_size; | |
418 | else { | |
419 | current_index = 0; | |
420 | current_detail->nextcheck = seconds_since_boot()+30*60; | |
421 | } | |
422 | } | |
423 | ||
424 | /* find a non-empty bucket in the table */ | |
425 | while (current_detail && | |
426 | current_index < current_detail->hash_size && | |
427 | current_detail->hash_table[current_index] == NULL) | |
428 | current_index++; | |
429 | ||
430 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ | |
431 | ||
432 | if (current_detail && current_index < current_detail->hash_size) { | |
433 | struct cache_head *ch, **cp; | |
434 | struct cache_detail *d; | |
435 | ||
436 | write_lock(¤t_detail->hash_lock); | |
437 | ||
438 | /* Ok, now to clean this strand */ | |
439 | ||
440 | cp = & current_detail->hash_table[current_index]; | |
441 | for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) { | |
442 | if (current_detail->nextcheck > ch->expiry_time) | |
443 | current_detail->nextcheck = ch->expiry_time+1; | |
444 | if (!cache_is_expired(current_detail, ch)) | |
445 | continue; | |
446 | ||
447 | *cp = ch->next; | |
448 | ch->next = NULL; | |
449 | current_detail->entries--; | |
450 | rv = 1; | |
451 | break; | |
452 | } | |
453 | ||
454 | write_unlock(¤t_detail->hash_lock); | |
455 | d = current_detail; | |
456 | if (!ch) | |
457 | current_index ++; | |
458 | spin_unlock(&cache_list_lock); | |
459 | if (ch) { | |
460 | if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) | |
461 | cache_dequeue(current_detail, ch); | |
462 | cache_revisit_request(ch); | |
463 | cache_put(ch, d); | |
464 | } | |
465 | } else | |
466 | spin_unlock(&cache_list_lock); | |
467 | ||
468 | return rv; | |
469 | } | |
470 | ||
471 | /* | |
472 | * We want to regularly clean the cache, so we need to schedule some work ... | |
473 | */ | |
474 | static void do_cache_clean(struct work_struct *work) | |
475 | { | |
476 | int delay = 5; | |
477 | if (cache_clean() == -1) | |
478 | delay = round_jiffies_relative(30*HZ); | |
479 | ||
480 | if (list_empty(&cache_list)) | |
481 | delay = 0; | |
482 | ||
483 | if (delay) | |
484 | schedule_delayed_work(&cache_cleaner, delay); | |
485 | } | |
486 | ||
487 | ||
488 | /* | |
489 | * Clean all caches promptly. This just calls cache_clean | |
490 | * repeatedly until we are sure that every cache has had a chance to | |
491 | * be fully cleaned | |
492 | */ | |
493 | void cache_flush(void) | |
494 | { | |
495 | while (cache_clean() != -1) | |
496 | cond_resched(); | |
497 | while (cache_clean() != -1) | |
498 | cond_resched(); | |
499 | } | |
500 | EXPORT_SYMBOL_GPL(cache_flush); | |
501 | ||
502 | void cache_purge(struct cache_detail *detail) | |
503 | { | |
504 | detail->flush_time = LONG_MAX; | |
505 | detail->nextcheck = seconds_since_boot(); | |
506 | cache_flush(); | |
507 | detail->flush_time = 1; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(cache_purge); | |
510 | ||
511 | ||
512 | /* | |
513 | * Deferral and Revisiting of Requests. | |
514 | * | |
515 | * If a cache lookup finds a pending entry, we | |
516 | * need to defer the request and revisit it later. | |
517 | * All deferred requests are stored in a hash table, | |
518 | * indexed by "struct cache_head *". | |
519 | * As it may be wasteful to store a whole request | |
520 | * structure, we allow the request to provide a | |
521 | * deferred form, which must contain a | |
522 | * 'struct cache_deferred_req' | |
523 | * This cache_deferred_req contains a method to allow | |
524 | * it to be revisited when cache info is available | |
525 | */ | |
526 | ||
527 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) | |
528 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) | |
529 | ||
530 | #define DFR_MAX 300 /* ??? */ | |
531 | ||
532 | static DEFINE_SPINLOCK(cache_defer_lock); | |
533 | static LIST_HEAD(cache_defer_list); | |
534 | static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; | |
535 | static int cache_defer_cnt; | |
536 | ||
537 | static void __unhash_deferred_req(struct cache_deferred_req *dreq) | |
538 | { | |
539 | hlist_del_init(&dreq->hash); | |
540 | if (!list_empty(&dreq->recent)) { | |
541 | list_del_init(&dreq->recent); | |
542 | cache_defer_cnt--; | |
543 | } | |
544 | } | |
545 | ||
546 | static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item) | |
547 | { | |
548 | int hash = DFR_HASH(item); | |
549 | ||
550 | INIT_LIST_HEAD(&dreq->recent); | |
551 | hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); | |
552 | } | |
553 | ||
554 | static void setup_deferral(struct cache_deferred_req *dreq, | |
555 | struct cache_head *item, | |
556 | int count_me) | |
557 | { | |
558 | ||
559 | dreq->item = item; | |
560 | ||
561 | spin_lock(&cache_defer_lock); | |
562 | ||
563 | __hash_deferred_req(dreq, item); | |
564 | ||
565 | if (count_me) { | |
566 | cache_defer_cnt++; | |
567 | list_add(&dreq->recent, &cache_defer_list); | |
568 | } | |
569 | ||
570 | spin_unlock(&cache_defer_lock); | |
571 | ||
572 | } | |
573 | ||
574 | struct thread_deferred_req { | |
575 | struct cache_deferred_req handle; | |
576 | struct completion completion; | |
577 | }; | |
578 | ||
579 | static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) | |
580 | { | |
581 | struct thread_deferred_req *dr = | |
582 | container_of(dreq, struct thread_deferred_req, handle); | |
583 | complete(&dr->completion); | |
584 | } | |
585 | ||
586 | static void cache_wait_req(struct cache_req *req, struct cache_head *item) | |
587 | { | |
588 | struct thread_deferred_req sleeper; | |
589 | struct cache_deferred_req *dreq = &sleeper.handle; | |
590 | ||
591 | sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); | |
592 | dreq->revisit = cache_restart_thread; | |
593 | ||
594 | setup_deferral(dreq, item, 0); | |
595 | ||
596 | if (!test_bit(CACHE_PENDING, &item->flags) || | |
597 | wait_for_completion_interruptible_timeout( | |
598 | &sleeper.completion, req->thread_wait) <= 0) { | |
599 | /* The completion wasn't completed, so we need | |
600 | * to clean up | |
601 | */ | |
602 | spin_lock(&cache_defer_lock); | |
603 | if (!hlist_unhashed(&sleeper.handle.hash)) { | |
604 | __unhash_deferred_req(&sleeper.handle); | |
605 | spin_unlock(&cache_defer_lock); | |
606 | } else { | |
607 | /* cache_revisit_request already removed | |
608 | * this from the hash table, but hasn't | |
609 | * called ->revisit yet. It will very soon | |
610 | * and we need to wait for it. | |
611 | */ | |
612 | spin_unlock(&cache_defer_lock); | |
613 | wait_for_completion(&sleeper.completion); | |
614 | } | |
615 | } | |
616 | } | |
617 | ||
618 | static void cache_limit_defers(void) | |
619 | { | |
620 | /* Make sure we haven't exceed the limit of allowed deferred | |
621 | * requests. | |
622 | */ | |
623 | struct cache_deferred_req *discard = NULL; | |
624 | ||
625 | if (cache_defer_cnt <= DFR_MAX) | |
626 | return; | |
627 | ||
628 | spin_lock(&cache_defer_lock); | |
629 | ||
630 | /* Consider removing either the first or the last */ | |
631 | if (cache_defer_cnt > DFR_MAX) { | |
632 | if (net_random() & 1) | |
633 | discard = list_entry(cache_defer_list.next, | |
634 | struct cache_deferred_req, recent); | |
635 | else | |
636 | discard = list_entry(cache_defer_list.prev, | |
637 | struct cache_deferred_req, recent); | |
638 | __unhash_deferred_req(discard); | |
639 | } | |
640 | spin_unlock(&cache_defer_lock); | |
641 | if (discard) | |
642 | discard->revisit(discard, 1); | |
643 | } | |
644 | ||
645 | /* Return true if and only if a deferred request is queued. */ | |
646 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item) | |
647 | { | |
648 | struct cache_deferred_req *dreq; | |
649 | ||
650 | if (req->thread_wait) { | |
651 | cache_wait_req(req, item); | |
652 | if (!test_bit(CACHE_PENDING, &item->flags)) | |
653 | return false; | |
654 | } | |
655 | dreq = req->defer(req); | |
656 | if (dreq == NULL) | |
657 | return false; | |
658 | setup_deferral(dreq, item, 1); | |
659 | if (!test_bit(CACHE_PENDING, &item->flags)) | |
660 | /* Bit could have been cleared before we managed to | |
661 | * set up the deferral, so need to revisit just in case | |
662 | */ | |
663 | cache_revisit_request(item); | |
664 | ||
665 | cache_limit_defers(); | |
666 | return true; | |
667 | } | |
668 | ||
669 | static void cache_revisit_request(struct cache_head *item) | |
670 | { | |
671 | struct cache_deferred_req *dreq; | |
672 | struct list_head pending; | |
673 | struct hlist_node *tmp; | |
674 | int hash = DFR_HASH(item); | |
675 | ||
676 | INIT_LIST_HEAD(&pending); | |
677 | spin_lock(&cache_defer_lock); | |
678 | ||
679 | hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash) | |
680 | if (dreq->item == item) { | |
681 | __unhash_deferred_req(dreq); | |
682 | list_add(&dreq->recent, &pending); | |
683 | } | |
684 | ||
685 | spin_unlock(&cache_defer_lock); | |
686 | ||
687 | while (!list_empty(&pending)) { | |
688 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
689 | list_del_init(&dreq->recent); | |
690 | dreq->revisit(dreq, 0); | |
691 | } | |
692 | } | |
693 | ||
694 | void cache_clean_deferred(void *owner) | |
695 | { | |
696 | struct cache_deferred_req *dreq, *tmp; | |
697 | struct list_head pending; | |
698 | ||
699 | ||
700 | INIT_LIST_HEAD(&pending); | |
701 | spin_lock(&cache_defer_lock); | |
702 | ||
703 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { | |
704 | if (dreq->owner == owner) { | |
705 | __unhash_deferred_req(dreq); | |
706 | list_add(&dreq->recent, &pending); | |
707 | } | |
708 | } | |
709 | spin_unlock(&cache_defer_lock); | |
710 | ||
711 | while (!list_empty(&pending)) { | |
712 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
713 | list_del_init(&dreq->recent); | |
714 | dreq->revisit(dreq, 1); | |
715 | } | |
716 | } | |
717 | ||
718 | /* | |
719 | * communicate with user-space | |
720 | * | |
721 | * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. | |
722 | * On read, you get a full request, or block. | |
723 | * On write, an update request is processed. | |
724 | * Poll works if anything to read, and always allows write. | |
725 | * | |
726 | * Implemented by linked list of requests. Each open file has | |
727 | * a ->private that also exists in this list. New requests are added | |
728 | * to the end and may wakeup and preceding readers. | |
729 | * New readers are added to the head. If, on read, an item is found with | |
730 | * CACHE_UPCALLING clear, we free it from the list. | |
731 | * | |
732 | */ | |
733 | ||
734 | static DEFINE_SPINLOCK(queue_lock); | |
735 | static DEFINE_MUTEX(queue_io_mutex); | |
736 | ||
737 | struct cache_queue { | |
738 | struct list_head list; | |
739 | int reader; /* if 0, then request */ | |
740 | }; | |
741 | struct cache_request { | |
742 | struct cache_queue q; | |
743 | struct cache_head *item; | |
744 | char * buf; | |
745 | int len; | |
746 | int readers; | |
747 | }; | |
748 | struct cache_reader { | |
749 | struct cache_queue q; | |
750 | int offset; /* if non-0, we have a refcnt on next request */ | |
751 | }; | |
752 | ||
753 | static int cache_request(struct cache_detail *detail, | |
754 | struct cache_request *crq) | |
755 | { | |
756 | char *bp = crq->buf; | |
757 | int len = PAGE_SIZE; | |
758 | ||
759 | detail->cache_request(detail, crq->item, &bp, &len); | |
760 | if (len < 0) | |
761 | return -EAGAIN; | |
762 | return PAGE_SIZE - len; | |
763 | } | |
764 | ||
765 | static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, | |
766 | loff_t *ppos, struct cache_detail *cd) | |
767 | { | |
768 | struct cache_reader *rp = filp->private_data; | |
769 | struct cache_request *rq; | |
770 | struct inode *inode = file_inode(filp); | |
771 | int err; | |
772 | ||
773 | if (count == 0) | |
774 | return 0; | |
775 | ||
776 | mutex_lock(&inode->i_mutex); /* protect against multiple concurrent | |
777 | * readers on this file */ | |
778 | again: | |
779 | spin_lock(&queue_lock); | |
780 | /* need to find next request */ | |
781 | while (rp->q.list.next != &cd->queue && | |
782 | list_entry(rp->q.list.next, struct cache_queue, list) | |
783 | ->reader) { | |
784 | struct list_head *next = rp->q.list.next; | |
785 | list_move(&rp->q.list, next); | |
786 | } | |
787 | if (rp->q.list.next == &cd->queue) { | |
788 | spin_unlock(&queue_lock); | |
789 | mutex_unlock(&inode->i_mutex); | |
790 | WARN_ON_ONCE(rp->offset); | |
791 | return 0; | |
792 | } | |
793 | rq = container_of(rp->q.list.next, struct cache_request, q.list); | |
794 | WARN_ON_ONCE(rq->q.reader); | |
795 | if (rp->offset == 0) | |
796 | rq->readers++; | |
797 | spin_unlock(&queue_lock); | |
798 | ||
799 | if (rq->len == 0) { | |
800 | err = cache_request(cd, rq); | |
801 | if (err < 0) | |
802 | goto out; | |
803 | rq->len = err; | |
804 | } | |
805 | ||
806 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
807 | err = -EAGAIN; | |
808 | spin_lock(&queue_lock); | |
809 | list_move(&rp->q.list, &rq->q.list); | |
810 | spin_unlock(&queue_lock); | |
811 | } else { | |
812 | if (rp->offset + count > rq->len) | |
813 | count = rq->len - rp->offset; | |
814 | err = -EFAULT; | |
815 | if (copy_to_user(buf, rq->buf + rp->offset, count)) | |
816 | goto out; | |
817 | rp->offset += count; | |
818 | if (rp->offset >= rq->len) { | |
819 | rp->offset = 0; | |
820 | spin_lock(&queue_lock); | |
821 | list_move(&rp->q.list, &rq->q.list); | |
822 | spin_unlock(&queue_lock); | |
823 | } | |
824 | err = 0; | |
825 | } | |
826 | out: | |
827 | if (rp->offset == 0) { | |
828 | /* need to release rq */ | |
829 | spin_lock(&queue_lock); | |
830 | rq->readers--; | |
831 | if (rq->readers == 0 && | |
832 | !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
833 | list_del(&rq->q.list); | |
834 | spin_unlock(&queue_lock); | |
835 | cache_put(rq->item, cd); | |
836 | kfree(rq->buf); | |
837 | kfree(rq); | |
838 | } else | |
839 | spin_unlock(&queue_lock); | |
840 | } | |
841 | if (err == -EAGAIN) | |
842 | goto again; | |
843 | mutex_unlock(&inode->i_mutex); | |
844 | return err ? err : count; | |
845 | } | |
846 | ||
847 | static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, | |
848 | size_t count, struct cache_detail *cd) | |
849 | { | |
850 | ssize_t ret; | |
851 | ||
852 | if (count == 0) | |
853 | return -EINVAL; | |
854 | if (copy_from_user(kaddr, buf, count)) | |
855 | return -EFAULT; | |
856 | kaddr[count] = '\0'; | |
857 | ret = cd->cache_parse(cd, kaddr, count); | |
858 | if (!ret) | |
859 | ret = count; | |
860 | return ret; | |
861 | } | |
862 | ||
863 | static ssize_t cache_slow_downcall(const char __user *buf, | |
864 | size_t count, struct cache_detail *cd) | |
865 | { | |
866 | static char write_buf[8192]; /* protected by queue_io_mutex */ | |
867 | ssize_t ret = -EINVAL; | |
868 | ||
869 | if (count >= sizeof(write_buf)) | |
870 | goto out; | |
871 | mutex_lock(&queue_io_mutex); | |
872 | ret = cache_do_downcall(write_buf, buf, count, cd); | |
873 | mutex_unlock(&queue_io_mutex); | |
874 | out: | |
875 | return ret; | |
876 | } | |
877 | ||
878 | static ssize_t cache_downcall(struct address_space *mapping, | |
879 | const char __user *buf, | |
880 | size_t count, struct cache_detail *cd) | |
881 | { | |
882 | struct page *page; | |
883 | char *kaddr; | |
884 | ssize_t ret = -ENOMEM; | |
885 | ||
886 | if (count >= PAGE_CACHE_SIZE) | |
887 | goto out_slow; | |
888 | ||
889 | page = find_or_create_page(mapping, 0, GFP_KERNEL); | |
890 | if (!page) | |
891 | goto out_slow; | |
892 | ||
893 | kaddr = kmap(page); | |
894 | ret = cache_do_downcall(kaddr, buf, count, cd); | |
895 | kunmap(page); | |
896 | unlock_page(page); | |
897 | page_cache_release(page); | |
898 | return ret; | |
899 | out_slow: | |
900 | return cache_slow_downcall(buf, count, cd); | |
901 | } | |
902 | ||
903 | static ssize_t cache_write(struct file *filp, const char __user *buf, | |
904 | size_t count, loff_t *ppos, | |
905 | struct cache_detail *cd) | |
906 | { | |
907 | struct address_space *mapping = filp->f_mapping; | |
908 | struct inode *inode = file_inode(filp); | |
909 | ssize_t ret = -EINVAL; | |
910 | ||
911 | if (!cd->cache_parse) | |
912 | goto out; | |
913 | ||
914 | mutex_lock(&inode->i_mutex); | |
915 | ret = cache_downcall(mapping, buf, count, cd); | |
916 | mutex_unlock(&inode->i_mutex); | |
917 | out: | |
918 | return ret; | |
919 | } | |
920 | ||
921 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); | |
922 | ||
923 | static unsigned int cache_poll(struct file *filp, poll_table *wait, | |
924 | struct cache_detail *cd) | |
925 | { | |
926 | unsigned int mask; | |
927 | struct cache_reader *rp = filp->private_data; | |
928 | struct cache_queue *cq; | |
929 | ||
930 | poll_wait(filp, &queue_wait, wait); | |
931 | ||
932 | /* alway allow write */ | |
933 | mask = POLL_OUT | POLLWRNORM; | |
934 | ||
935 | if (!rp) | |
936 | return mask; | |
937 | ||
938 | spin_lock(&queue_lock); | |
939 | ||
940 | for (cq= &rp->q; &cq->list != &cd->queue; | |
941 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
942 | if (!cq->reader) { | |
943 | mask |= POLLIN | POLLRDNORM; | |
944 | break; | |
945 | } | |
946 | spin_unlock(&queue_lock); | |
947 | return mask; | |
948 | } | |
949 | ||
950 | static int cache_ioctl(struct inode *ino, struct file *filp, | |
951 | unsigned int cmd, unsigned long arg, | |
952 | struct cache_detail *cd) | |
953 | { | |
954 | int len = 0; | |
955 | struct cache_reader *rp = filp->private_data; | |
956 | struct cache_queue *cq; | |
957 | ||
958 | if (cmd != FIONREAD || !rp) | |
959 | return -EINVAL; | |
960 | ||
961 | spin_lock(&queue_lock); | |
962 | ||
963 | /* only find the length remaining in current request, | |
964 | * or the length of the next request | |
965 | */ | |
966 | for (cq= &rp->q; &cq->list != &cd->queue; | |
967 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
968 | if (!cq->reader) { | |
969 | struct cache_request *cr = | |
970 | container_of(cq, struct cache_request, q); | |
971 | len = cr->len - rp->offset; | |
972 | break; | |
973 | } | |
974 | spin_unlock(&queue_lock); | |
975 | ||
976 | return put_user(len, (int __user *)arg); | |
977 | } | |
978 | ||
979 | static int cache_open(struct inode *inode, struct file *filp, | |
980 | struct cache_detail *cd) | |
981 | { | |
982 | struct cache_reader *rp = NULL; | |
983 | ||
984 | if (!cd || !try_module_get(cd->owner)) | |
985 | return -EACCES; | |
986 | nonseekable_open(inode, filp); | |
987 | if (filp->f_mode & FMODE_READ) { | |
988 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); | |
989 | if (!rp) | |
990 | return -ENOMEM; | |
991 | rp->offset = 0; | |
992 | rp->q.reader = 1; | |
993 | atomic_inc(&cd->readers); | |
994 | spin_lock(&queue_lock); | |
995 | list_add(&rp->q.list, &cd->queue); | |
996 | spin_unlock(&queue_lock); | |
997 | } | |
998 | filp->private_data = rp; | |
999 | return 0; | |
1000 | } | |
1001 | ||
1002 | static int cache_release(struct inode *inode, struct file *filp, | |
1003 | struct cache_detail *cd) | |
1004 | { | |
1005 | struct cache_reader *rp = filp->private_data; | |
1006 | ||
1007 | if (rp) { | |
1008 | spin_lock(&queue_lock); | |
1009 | if (rp->offset) { | |
1010 | struct cache_queue *cq; | |
1011 | for (cq= &rp->q; &cq->list != &cd->queue; | |
1012 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
1013 | if (!cq->reader) { | |
1014 | container_of(cq, struct cache_request, q) | |
1015 | ->readers--; | |
1016 | break; | |
1017 | } | |
1018 | rp->offset = 0; | |
1019 | } | |
1020 | list_del(&rp->q.list); | |
1021 | spin_unlock(&queue_lock); | |
1022 | ||
1023 | filp->private_data = NULL; | |
1024 | kfree(rp); | |
1025 | ||
1026 | cd->last_close = seconds_since_boot(); | |
1027 | atomic_dec(&cd->readers); | |
1028 | } | |
1029 | module_put(cd->owner); | |
1030 | return 0; | |
1031 | } | |
1032 | ||
1033 | ||
1034 | ||
1035 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) | |
1036 | { | |
1037 | struct cache_queue *cq; | |
1038 | spin_lock(&queue_lock); | |
1039 | list_for_each_entry(cq, &detail->queue, list) | |
1040 | if (!cq->reader) { | |
1041 | struct cache_request *cr = container_of(cq, struct cache_request, q); | |
1042 | if (cr->item != ch) | |
1043 | continue; | |
1044 | if (cr->readers != 0) | |
1045 | continue; | |
1046 | list_del(&cr->q.list); | |
1047 | spin_unlock(&queue_lock); | |
1048 | cache_put(cr->item, detail); | |
1049 | kfree(cr->buf); | |
1050 | kfree(cr); | |
1051 | return; | |
1052 | } | |
1053 | spin_unlock(&queue_lock); | |
1054 | } | |
1055 | ||
1056 | /* | |
1057 | * Support routines for text-based upcalls. | |
1058 | * Fields are separated by spaces. | |
1059 | * Fields are either mangled to quote space tab newline slosh with slosh | |
1060 | * or a hexified with a leading \x | |
1061 | * Record is terminated with newline. | |
1062 | * | |
1063 | */ | |
1064 | ||
1065 | void qword_add(char **bpp, int *lp, char *str) | |
1066 | { | |
1067 | char *bp = *bpp; | |
1068 | int len = *lp; | |
1069 | char c; | |
1070 | ||
1071 | if (len < 0) return; | |
1072 | ||
1073 | while ((c=*str++) && len) | |
1074 | switch(c) { | |
1075 | case ' ': | |
1076 | case '\t': | |
1077 | case '\n': | |
1078 | case '\\': | |
1079 | if (len >= 4) { | |
1080 | *bp++ = '\\'; | |
1081 | *bp++ = '0' + ((c & 0300)>>6); | |
1082 | *bp++ = '0' + ((c & 0070)>>3); | |
1083 | *bp++ = '0' + ((c & 0007)>>0); | |
1084 | } | |
1085 | len -= 4; | |
1086 | break; | |
1087 | default: | |
1088 | *bp++ = c; | |
1089 | len--; | |
1090 | } | |
1091 | if (c || len <1) len = -1; | |
1092 | else { | |
1093 | *bp++ = ' '; | |
1094 | len--; | |
1095 | } | |
1096 | *bpp = bp; | |
1097 | *lp = len; | |
1098 | } | |
1099 | EXPORT_SYMBOL_GPL(qword_add); | |
1100 | ||
1101 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) | |
1102 | { | |
1103 | char *bp = *bpp; | |
1104 | int len = *lp; | |
1105 | ||
1106 | if (len < 0) return; | |
1107 | ||
1108 | if (len > 2) { | |
1109 | *bp++ = '\\'; | |
1110 | *bp++ = 'x'; | |
1111 | len -= 2; | |
1112 | while (blen && len >= 2) { | |
1113 | unsigned char c = *buf++; | |
1114 | *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); | |
1115 | *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); | |
1116 | len -= 2; | |
1117 | blen--; | |
1118 | } | |
1119 | } | |
1120 | if (blen || len<1) len = -1; | |
1121 | else { | |
1122 | *bp++ = ' '; | |
1123 | len--; | |
1124 | } | |
1125 | *bpp = bp; | |
1126 | *lp = len; | |
1127 | } | |
1128 | EXPORT_SYMBOL_GPL(qword_addhex); | |
1129 | ||
1130 | static void warn_no_listener(struct cache_detail *detail) | |
1131 | { | |
1132 | if (detail->last_warn != detail->last_close) { | |
1133 | detail->last_warn = detail->last_close; | |
1134 | if (detail->warn_no_listener) | |
1135 | detail->warn_no_listener(detail, detail->last_close != 0); | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | static bool cache_listeners_exist(struct cache_detail *detail) | |
1140 | { | |
1141 | if (atomic_read(&detail->readers)) | |
1142 | return true; | |
1143 | if (detail->last_close == 0) | |
1144 | /* This cache was never opened */ | |
1145 | return false; | |
1146 | if (detail->last_close < seconds_since_boot() - 30) | |
1147 | /* | |
1148 | * We allow for the possibility that someone might | |
1149 | * restart a userspace daemon without restarting the | |
1150 | * server; but after 30 seconds, we give up. | |
1151 | */ | |
1152 | return false; | |
1153 | return true; | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * register an upcall request to user-space and queue it up for read() by the | |
1158 | * upcall daemon. | |
1159 | * | |
1160 | * Each request is at most one page long. | |
1161 | */ | |
1162 | int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) | |
1163 | { | |
1164 | ||
1165 | char *buf; | |
1166 | struct cache_request *crq; | |
1167 | ||
1168 | if (!detail->cache_request) | |
1169 | return -EINVAL; | |
1170 | ||
1171 | if (!cache_listeners_exist(detail)) { | |
1172 | warn_no_listener(detail); | |
1173 | return -EINVAL; | |
1174 | } | |
1175 | ||
1176 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1177 | if (!buf) | |
1178 | return -EAGAIN; | |
1179 | ||
1180 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); | |
1181 | if (!crq) { | |
1182 | kfree(buf); | |
1183 | return -EAGAIN; | |
1184 | } | |
1185 | ||
1186 | crq->q.reader = 0; | |
1187 | crq->item = cache_get(h); | |
1188 | crq->buf = buf; | |
1189 | crq->len = 0; | |
1190 | crq->readers = 0; | |
1191 | spin_lock(&queue_lock); | |
1192 | list_add_tail(&crq->q.list, &detail->queue); | |
1193 | spin_unlock(&queue_lock); | |
1194 | wake_up(&queue_wait); | |
1195 | return 0; | |
1196 | } | |
1197 | EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); | |
1198 | ||
1199 | /* | |
1200 | * parse a message from user-space and pass it | |
1201 | * to an appropriate cache | |
1202 | * Messages are, like requests, separated into fields by | |
1203 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal | |
1204 | * | |
1205 | * Message is | |
1206 | * reply cachename expiry key ... content.... | |
1207 | * | |
1208 | * key and content are both parsed by cache | |
1209 | */ | |
1210 | ||
1211 | #define isodigit(c) (isdigit(c) && c <= '7') | |
1212 | int qword_get(char **bpp, char *dest, int bufsize) | |
1213 | { | |
1214 | /* return bytes copied, or -1 on error */ | |
1215 | char *bp = *bpp; | |
1216 | int len = 0; | |
1217 | ||
1218 | while (*bp == ' ') bp++; | |
1219 | ||
1220 | if (bp[0] == '\\' && bp[1] == 'x') { | |
1221 | /* HEX STRING */ | |
1222 | bp += 2; | |
1223 | while (len < bufsize) { | |
1224 | int h, l; | |
1225 | ||
1226 | h = hex_to_bin(bp[0]); | |
1227 | if (h < 0) | |
1228 | break; | |
1229 | ||
1230 | l = hex_to_bin(bp[1]); | |
1231 | if (l < 0) | |
1232 | break; | |
1233 | ||
1234 | *dest++ = (h << 4) | l; | |
1235 | bp += 2; | |
1236 | len++; | |
1237 | } | |
1238 | } else { | |
1239 | /* text with \nnn octal quoting */ | |
1240 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { | |
1241 | if (*bp == '\\' && | |
1242 | isodigit(bp[1]) && (bp[1] <= '3') && | |
1243 | isodigit(bp[2]) && | |
1244 | isodigit(bp[3])) { | |
1245 | int byte = (*++bp -'0'); | |
1246 | bp++; | |
1247 | byte = (byte << 3) | (*bp++ - '0'); | |
1248 | byte = (byte << 3) | (*bp++ - '0'); | |
1249 | *dest++ = byte; | |
1250 | len++; | |
1251 | } else { | |
1252 | *dest++ = *bp++; | |
1253 | len++; | |
1254 | } | |
1255 | } | |
1256 | } | |
1257 | ||
1258 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') | |
1259 | return -1; | |
1260 | while (*bp == ' ') bp++; | |
1261 | *bpp = bp; | |
1262 | *dest = '\0'; | |
1263 | return len; | |
1264 | } | |
1265 | EXPORT_SYMBOL_GPL(qword_get); | |
1266 | ||
1267 | ||
1268 | /* | |
1269 | * support /proc/sunrpc/cache/$CACHENAME/content | |
1270 | * as a seqfile. | |
1271 | * We call ->cache_show passing NULL for the item to | |
1272 | * get a header, then pass each real item in the cache | |
1273 | */ | |
1274 | ||
1275 | struct handle { | |
1276 | struct cache_detail *cd; | |
1277 | }; | |
1278 | ||
1279 | static void *c_start(struct seq_file *m, loff_t *pos) | |
1280 | __acquires(cd->hash_lock) | |
1281 | { | |
1282 | loff_t n = *pos; | |
1283 | unsigned int hash, entry; | |
1284 | struct cache_head *ch; | |
1285 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1286 | ||
1287 | ||
1288 | read_lock(&cd->hash_lock); | |
1289 | if (!n--) | |
1290 | return SEQ_START_TOKEN; | |
1291 | hash = n >> 32; | |
1292 | entry = n & ((1LL<<32) - 1); | |
1293 | ||
1294 | for (ch=cd->hash_table[hash]; ch; ch=ch->next) | |
1295 | if (!entry--) | |
1296 | return ch; | |
1297 | n &= ~((1LL<<32) - 1); | |
1298 | do { | |
1299 | hash++; | |
1300 | n += 1LL<<32; | |
1301 | } while(hash < cd->hash_size && | |
1302 | cd->hash_table[hash]==NULL); | |
1303 | if (hash >= cd->hash_size) | |
1304 | return NULL; | |
1305 | *pos = n+1; | |
1306 | return cd->hash_table[hash]; | |
1307 | } | |
1308 | ||
1309 | static void *c_next(struct seq_file *m, void *p, loff_t *pos) | |
1310 | { | |
1311 | struct cache_head *ch = p; | |
1312 | int hash = (*pos >> 32); | |
1313 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1314 | ||
1315 | if (p == SEQ_START_TOKEN) | |
1316 | hash = 0; | |
1317 | else if (ch->next == NULL) { | |
1318 | hash++; | |
1319 | *pos += 1LL<<32; | |
1320 | } else { | |
1321 | ++*pos; | |
1322 | return ch->next; | |
1323 | } | |
1324 | *pos &= ~((1LL<<32) - 1); | |
1325 | while (hash < cd->hash_size && | |
1326 | cd->hash_table[hash] == NULL) { | |
1327 | hash++; | |
1328 | *pos += 1LL<<32; | |
1329 | } | |
1330 | if (hash >= cd->hash_size) | |
1331 | return NULL; | |
1332 | ++*pos; | |
1333 | return cd->hash_table[hash]; | |
1334 | } | |
1335 | ||
1336 | static void c_stop(struct seq_file *m, void *p) | |
1337 | __releases(cd->hash_lock) | |
1338 | { | |
1339 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1340 | read_unlock(&cd->hash_lock); | |
1341 | } | |
1342 | ||
1343 | static int c_show(struct seq_file *m, void *p) | |
1344 | { | |
1345 | struct cache_head *cp = p; | |
1346 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1347 | ||
1348 | if (p == SEQ_START_TOKEN) | |
1349 | return cd->cache_show(m, cd, NULL); | |
1350 | ||
1351 | ifdebug(CACHE) | |
1352 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", | |
1353 | convert_to_wallclock(cp->expiry_time), | |
1354 | atomic_read(&cp->ref.refcount), cp->flags); | |
1355 | cache_get(cp); | |
1356 | if (cache_check(cd, cp, NULL)) | |
1357 | /* cache_check does a cache_put on failure */ | |
1358 | seq_printf(m, "# "); | |
1359 | else { | |
1360 | if (cache_is_expired(cd, cp)) | |
1361 | seq_printf(m, "# "); | |
1362 | cache_put(cp, cd); | |
1363 | } | |
1364 | ||
1365 | return cd->cache_show(m, cd, cp); | |
1366 | } | |
1367 | ||
1368 | static const struct seq_operations cache_content_op = { | |
1369 | .start = c_start, | |
1370 | .next = c_next, | |
1371 | .stop = c_stop, | |
1372 | .show = c_show, | |
1373 | }; | |
1374 | ||
1375 | static int content_open(struct inode *inode, struct file *file, | |
1376 | struct cache_detail *cd) | |
1377 | { | |
1378 | struct handle *han; | |
1379 | ||
1380 | if (!cd || !try_module_get(cd->owner)) | |
1381 | return -EACCES; | |
1382 | han = __seq_open_private(file, &cache_content_op, sizeof(*han)); | |
1383 | if (han == NULL) { | |
1384 | module_put(cd->owner); | |
1385 | return -ENOMEM; | |
1386 | } | |
1387 | ||
1388 | han->cd = cd; | |
1389 | return 0; | |
1390 | } | |
1391 | ||
1392 | static int content_release(struct inode *inode, struct file *file, | |
1393 | struct cache_detail *cd) | |
1394 | { | |
1395 | int ret = seq_release_private(inode, file); | |
1396 | module_put(cd->owner); | |
1397 | return ret; | |
1398 | } | |
1399 | ||
1400 | static int open_flush(struct inode *inode, struct file *file, | |
1401 | struct cache_detail *cd) | |
1402 | { | |
1403 | if (!cd || !try_module_get(cd->owner)) | |
1404 | return -EACCES; | |
1405 | return nonseekable_open(inode, file); | |
1406 | } | |
1407 | ||
1408 | static int release_flush(struct inode *inode, struct file *file, | |
1409 | struct cache_detail *cd) | |
1410 | { | |
1411 | module_put(cd->owner); | |
1412 | return 0; | |
1413 | } | |
1414 | ||
1415 | static ssize_t read_flush(struct file *file, char __user *buf, | |
1416 | size_t count, loff_t *ppos, | |
1417 | struct cache_detail *cd) | |
1418 | { | |
1419 | char tbuf[22]; | |
1420 | unsigned long p = *ppos; | |
1421 | size_t len; | |
1422 | ||
1423 | snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time)); | |
1424 | len = strlen(tbuf); | |
1425 | if (p >= len) | |
1426 | return 0; | |
1427 | len -= p; | |
1428 | if (len > count) | |
1429 | len = count; | |
1430 | if (copy_to_user(buf, (void*)(tbuf+p), len)) | |
1431 | return -EFAULT; | |
1432 | *ppos += len; | |
1433 | return len; | |
1434 | } | |
1435 | ||
1436 | static ssize_t write_flush(struct file *file, const char __user *buf, | |
1437 | size_t count, loff_t *ppos, | |
1438 | struct cache_detail *cd) | |
1439 | { | |
1440 | char tbuf[20]; | |
1441 | char *bp, *ep; | |
1442 | ||
1443 | if (*ppos || count > sizeof(tbuf)-1) | |
1444 | return -EINVAL; | |
1445 | if (copy_from_user(tbuf, buf, count)) | |
1446 | return -EFAULT; | |
1447 | tbuf[count] = 0; | |
1448 | simple_strtoul(tbuf, &ep, 0); | |
1449 | if (*ep && *ep != '\n') | |
1450 | return -EINVAL; | |
1451 | ||
1452 | bp = tbuf; | |
1453 | cd->flush_time = get_expiry(&bp); | |
1454 | cd->nextcheck = seconds_since_boot(); | |
1455 | cache_flush(); | |
1456 | ||
1457 | *ppos += count; | |
1458 | return count; | |
1459 | } | |
1460 | ||
1461 | static ssize_t cache_read_procfs(struct file *filp, char __user *buf, | |
1462 | size_t count, loff_t *ppos) | |
1463 | { | |
1464 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1465 | ||
1466 | return cache_read(filp, buf, count, ppos, cd); | |
1467 | } | |
1468 | ||
1469 | static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, | |
1470 | size_t count, loff_t *ppos) | |
1471 | { | |
1472 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1473 | ||
1474 | return cache_write(filp, buf, count, ppos, cd); | |
1475 | } | |
1476 | ||
1477 | static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) | |
1478 | { | |
1479 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1480 | ||
1481 | return cache_poll(filp, wait, cd); | |
1482 | } | |
1483 | ||
1484 | static long cache_ioctl_procfs(struct file *filp, | |
1485 | unsigned int cmd, unsigned long arg) | |
1486 | { | |
1487 | struct inode *inode = file_inode(filp); | |
1488 | struct cache_detail *cd = PDE_DATA(inode); | |
1489 | ||
1490 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1491 | } | |
1492 | ||
1493 | static int cache_open_procfs(struct inode *inode, struct file *filp) | |
1494 | { | |
1495 | struct cache_detail *cd = PDE_DATA(inode); | |
1496 | ||
1497 | return cache_open(inode, filp, cd); | |
1498 | } | |
1499 | ||
1500 | static int cache_release_procfs(struct inode *inode, struct file *filp) | |
1501 | { | |
1502 | struct cache_detail *cd = PDE_DATA(inode); | |
1503 | ||
1504 | return cache_release(inode, filp, cd); | |
1505 | } | |
1506 | ||
1507 | static const struct file_operations cache_file_operations_procfs = { | |
1508 | .owner = THIS_MODULE, | |
1509 | .llseek = no_llseek, | |
1510 | .read = cache_read_procfs, | |
1511 | .write = cache_write_procfs, | |
1512 | .poll = cache_poll_procfs, | |
1513 | .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ | |
1514 | .open = cache_open_procfs, | |
1515 | .release = cache_release_procfs, | |
1516 | }; | |
1517 | ||
1518 | static int content_open_procfs(struct inode *inode, struct file *filp) | |
1519 | { | |
1520 | struct cache_detail *cd = PDE_DATA(inode); | |
1521 | ||
1522 | return content_open(inode, filp, cd); | |
1523 | } | |
1524 | ||
1525 | static int content_release_procfs(struct inode *inode, struct file *filp) | |
1526 | { | |
1527 | struct cache_detail *cd = PDE_DATA(inode); | |
1528 | ||
1529 | return content_release(inode, filp, cd); | |
1530 | } | |
1531 | ||
1532 | static const struct file_operations content_file_operations_procfs = { | |
1533 | .open = content_open_procfs, | |
1534 | .read = seq_read, | |
1535 | .llseek = seq_lseek, | |
1536 | .release = content_release_procfs, | |
1537 | }; | |
1538 | ||
1539 | static int open_flush_procfs(struct inode *inode, struct file *filp) | |
1540 | { | |
1541 | struct cache_detail *cd = PDE_DATA(inode); | |
1542 | ||
1543 | return open_flush(inode, filp, cd); | |
1544 | } | |
1545 | ||
1546 | static int release_flush_procfs(struct inode *inode, struct file *filp) | |
1547 | { | |
1548 | struct cache_detail *cd = PDE_DATA(inode); | |
1549 | ||
1550 | return release_flush(inode, filp, cd); | |
1551 | } | |
1552 | ||
1553 | static ssize_t read_flush_procfs(struct file *filp, char __user *buf, | |
1554 | size_t count, loff_t *ppos) | |
1555 | { | |
1556 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1557 | ||
1558 | return read_flush(filp, buf, count, ppos, cd); | |
1559 | } | |
1560 | ||
1561 | static ssize_t write_flush_procfs(struct file *filp, | |
1562 | const char __user *buf, | |
1563 | size_t count, loff_t *ppos) | |
1564 | { | |
1565 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1566 | ||
1567 | return write_flush(filp, buf, count, ppos, cd); | |
1568 | } | |
1569 | ||
1570 | static const struct file_operations cache_flush_operations_procfs = { | |
1571 | .open = open_flush_procfs, | |
1572 | .read = read_flush_procfs, | |
1573 | .write = write_flush_procfs, | |
1574 | .release = release_flush_procfs, | |
1575 | .llseek = no_llseek, | |
1576 | }; | |
1577 | ||
1578 | static void remove_cache_proc_entries(struct cache_detail *cd, struct net *net) | |
1579 | { | |
1580 | struct sunrpc_net *sn; | |
1581 | ||
1582 | if (cd->u.procfs.proc_ent == NULL) | |
1583 | return; | |
1584 | if (cd->u.procfs.flush_ent) | |
1585 | remove_proc_entry("flush", cd->u.procfs.proc_ent); | |
1586 | if (cd->u.procfs.channel_ent) | |
1587 | remove_proc_entry("channel", cd->u.procfs.proc_ent); | |
1588 | if (cd->u.procfs.content_ent) | |
1589 | remove_proc_entry("content", cd->u.procfs.proc_ent); | |
1590 | cd->u.procfs.proc_ent = NULL; | |
1591 | sn = net_generic(net, sunrpc_net_id); | |
1592 | remove_proc_entry(cd->name, sn->proc_net_rpc); | |
1593 | } | |
1594 | ||
1595 | #ifdef CONFIG_PROC_FS | |
1596 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) | |
1597 | { | |
1598 | struct proc_dir_entry *p; | |
1599 | struct sunrpc_net *sn; | |
1600 | ||
1601 | sn = net_generic(net, sunrpc_net_id); | |
1602 | cd->u.procfs.proc_ent = proc_mkdir(cd->name, sn->proc_net_rpc); | |
1603 | if (cd->u.procfs.proc_ent == NULL) | |
1604 | goto out_nomem; | |
1605 | cd->u.procfs.channel_ent = NULL; | |
1606 | cd->u.procfs.content_ent = NULL; | |
1607 | ||
1608 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, | |
1609 | cd->u.procfs.proc_ent, | |
1610 | &cache_flush_operations_procfs, cd); | |
1611 | cd->u.procfs.flush_ent = p; | |
1612 | if (p == NULL) | |
1613 | goto out_nomem; | |
1614 | ||
1615 | if (cd->cache_request || cd->cache_parse) { | |
1616 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, | |
1617 | cd->u.procfs.proc_ent, | |
1618 | &cache_file_operations_procfs, cd); | |
1619 | cd->u.procfs.channel_ent = p; | |
1620 | if (p == NULL) | |
1621 | goto out_nomem; | |
1622 | } | |
1623 | if (cd->cache_show) { | |
1624 | p = proc_create_data("content", S_IFREG|S_IRUSR, | |
1625 | cd->u.procfs.proc_ent, | |
1626 | &content_file_operations_procfs, cd); | |
1627 | cd->u.procfs.content_ent = p; | |
1628 | if (p == NULL) | |
1629 | goto out_nomem; | |
1630 | } | |
1631 | return 0; | |
1632 | out_nomem: | |
1633 | remove_cache_proc_entries(cd, net); | |
1634 | return -ENOMEM; | |
1635 | } | |
1636 | #else /* CONFIG_PROC_FS */ | |
1637 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) | |
1638 | { | |
1639 | return 0; | |
1640 | } | |
1641 | #endif | |
1642 | ||
1643 | void __init cache_initialize(void) | |
1644 | { | |
1645 | INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean); | |
1646 | } | |
1647 | ||
1648 | int cache_register_net(struct cache_detail *cd, struct net *net) | |
1649 | { | |
1650 | int ret; | |
1651 | ||
1652 | sunrpc_init_cache_detail(cd); | |
1653 | ret = create_cache_proc_entries(cd, net); | |
1654 | if (ret) | |
1655 | sunrpc_destroy_cache_detail(cd); | |
1656 | return ret; | |
1657 | } | |
1658 | EXPORT_SYMBOL_GPL(cache_register_net); | |
1659 | ||
1660 | void cache_unregister_net(struct cache_detail *cd, struct net *net) | |
1661 | { | |
1662 | remove_cache_proc_entries(cd, net); | |
1663 | sunrpc_destroy_cache_detail(cd); | |
1664 | } | |
1665 | EXPORT_SYMBOL_GPL(cache_unregister_net); | |
1666 | ||
1667 | struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) | |
1668 | { | |
1669 | struct cache_detail *cd; | |
1670 | ||
1671 | cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); | |
1672 | if (cd == NULL) | |
1673 | return ERR_PTR(-ENOMEM); | |
1674 | ||
1675 | cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *), | |
1676 | GFP_KERNEL); | |
1677 | if (cd->hash_table == NULL) { | |
1678 | kfree(cd); | |
1679 | return ERR_PTR(-ENOMEM); | |
1680 | } | |
1681 | cd->net = net; | |
1682 | return cd; | |
1683 | } | |
1684 | EXPORT_SYMBOL_GPL(cache_create_net); | |
1685 | ||
1686 | void cache_destroy_net(struct cache_detail *cd, struct net *net) | |
1687 | { | |
1688 | kfree(cd->hash_table); | |
1689 | kfree(cd); | |
1690 | } | |
1691 | EXPORT_SYMBOL_GPL(cache_destroy_net); | |
1692 | ||
1693 | static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, | |
1694 | size_t count, loff_t *ppos) | |
1695 | { | |
1696 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1697 | ||
1698 | return cache_read(filp, buf, count, ppos, cd); | |
1699 | } | |
1700 | ||
1701 | static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, | |
1702 | size_t count, loff_t *ppos) | |
1703 | { | |
1704 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1705 | ||
1706 | return cache_write(filp, buf, count, ppos, cd); | |
1707 | } | |
1708 | ||
1709 | static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) | |
1710 | { | |
1711 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1712 | ||
1713 | return cache_poll(filp, wait, cd); | |
1714 | } | |
1715 | ||
1716 | static long cache_ioctl_pipefs(struct file *filp, | |
1717 | unsigned int cmd, unsigned long arg) | |
1718 | { | |
1719 | struct inode *inode = file_inode(filp); | |
1720 | struct cache_detail *cd = RPC_I(inode)->private; | |
1721 | ||
1722 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1723 | } | |
1724 | ||
1725 | static int cache_open_pipefs(struct inode *inode, struct file *filp) | |
1726 | { | |
1727 | struct cache_detail *cd = RPC_I(inode)->private; | |
1728 | ||
1729 | return cache_open(inode, filp, cd); | |
1730 | } | |
1731 | ||
1732 | static int cache_release_pipefs(struct inode *inode, struct file *filp) | |
1733 | { | |
1734 | struct cache_detail *cd = RPC_I(inode)->private; | |
1735 | ||
1736 | return cache_release(inode, filp, cd); | |
1737 | } | |
1738 | ||
1739 | const struct file_operations cache_file_operations_pipefs = { | |
1740 | .owner = THIS_MODULE, | |
1741 | .llseek = no_llseek, | |
1742 | .read = cache_read_pipefs, | |
1743 | .write = cache_write_pipefs, | |
1744 | .poll = cache_poll_pipefs, | |
1745 | .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ | |
1746 | .open = cache_open_pipefs, | |
1747 | .release = cache_release_pipefs, | |
1748 | }; | |
1749 | ||
1750 | static int content_open_pipefs(struct inode *inode, struct file *filp) | |
1751 | { | |
1752 | struct cache_detail *cd = RPC_I(inode)->private; | |
1753 | ||
1754 | return content_open(inode, filp, cd); | |
1755 | } | |
1756 | ||
1757 | static int content_release_pipefs(struct inode *inode, struct file *filp) | |
1758 | { | |
1759 | struct cache_detail *cd = RPC_I(inode)->private; | |
1760 | ||
1761 | return content_release(inode, filp, cd); | |
1762 | } | |
1763 | ||
1764 | const struct file_operations content_file_operations_pipefs = { | |
1765 | .open = content_open_pipefs, | |
1766 | .read = seq_read, | |
1767 | .llseek = seq_lseek, | |
1768 | .release = content_release_pipefs, | |
1769 | }; | |
1770 | ||
1771 | static int open_flush_pipefs(struct inode *inode, struct file *filp) | |
1772 | { | |
1773 | struct cache_detail *cd = RPC_I(inode)->private; | |
1774 | ||
1775 | return open_flush(inode, filp, cd); | |
1776 | } | |
1777 | ||
1778 | static int release_flush_pipefs(struct inode *inode, struct file *filp) | |
1779 | { | |
1780 | struct cache_detail *cd = RPC_I(inode)->private; | |
1781 | ||
1782 | return release_flush(inode, filp, cd); | |
1783 | } | |
1784 | ||
1785 | static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, | |
1786 | size_t count, loff_t *ppos) | |
1787 | { | |
1788 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1789 | ||
1790 | return read_flush(filp, buf, count, ppos, cd); | |
1791 | } | |
1792 | ||
1793 | static ssize_t write_flush_pipefs(struct file *filp, | |
1794 | const char __user *buf, | |
1795 | size_t count, loff_t *ppos) | |
1796 | { | |
1797 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1798 | ||
1799 | return write_flush(filp, buf, count, ppos, cd); | |
1800 | } | |
1801 | ||
1802 | const struct file_operations cache_flush_operations_pipefs = { | |
1803 | .open = open_flush_pipefs, | |
1804 | .read = read_flush_pipefs, | |
1805 | .write = write_flush_pipefs, | |
1806 | .release = release_flush_pipefs, | |
1807 | .llseek = no_llseek, | |
1808 | }; | |
1809 | ||
1810 | int sunrpc_cache_register_pipefs(struct dentry *parent, | |
1811 | const char *name, umode_t umode, | |
1812 | struct cache_detail *cd) | |
1813 | { | |
1814 | struct qstr q; | |
1815 | struct dentry *dir; | |
1816 | int ret = 0; | |
1817 | ||
1818 | q.name = name; | |
1819 | q.len = strlen(name); | |
1820 | q.hash = full_name_hash(q.name, q.len); | |
1821 | dir = rpc_create_cache_dir(parent, &q, umode, cd); | |
1822 | if (!IS_ERR(dir)) | |
1823 | cd->u.pipefs.dir = dir; | |
1824 | else | |
1825 | ret = PTR_ERR(dir); | |
1826 | return ret; | |
1827 | } | |
1828 | EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); | |
1829 | ||
1830 | void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) | |
1831 | { | |
1832 | rpc_remove_cache_dir(cd->u.pipefs.dir); | |
1833 | cd->u.pipefs.dir = NULL; | |
1834 | } | |
1835 | EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); | |
1836 |