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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 <linux/string_helpers.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/poll.h> | |
26 | #include <linux/seq_file.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/net.h> | |
29 | #include <linux/workqueue.h> | |
30 | #include <linux/mutex.h> | |
31 | #include <linux/pagemap.h> | |
32 | #include <asm/ioctls.h> | |
33 | #include <linux/sunrpc/types.h> | |
34 | #include <linux/sunrpc/cache.h> | |
35 | #include <linux/sunrpc/stats.h> | |
36 | #include <linux/sunrpc/rpc_pipe_fs.h> | |
37 | #include "netns.h" | |
38 | ||
39 | #define RPCDBG_FACILITY RPCDBG_CACHE | |
40 | ||
41 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item); | |
42 | static void cache_revisit_request(struct cache_head *item); | |
43 | ||
44 | static void cache_init(struct cache_head *h, struct cache_detail *detail) | |
45 | { | |
46 | time_t now = seconds_since_boot(); | |
47 | INIT_HLIST_NODE(&h->cache_list); | |
48 | h->flags = 0; | |
49 | kref_init(&h->ref); | |
50 | h->expiry_time = now + CACHE_NEW_EXPIRY; | |
51 | if (now <= detail->flush_time) | |
52 | /* ensure it isn't already expired */ | |
53 | now = detail->flush_time + 1; | |
54 | h->last_refresh = now; | |
55 | } | |
56 | ||
57 | static void cache_fresh_unlocked(struct cache_head *head, | |
58 | struct cache_detail *detail); | |
59 | ||
60 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, | |
61 | struct cache_head *key, int hash) | |
62 | { | |
63 | struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL; | |
64 | struct hlist_head *head; | |
65 | ||
66 | head = &detail->hash_table[hash]; | |
67 | ||
68 | read_lock(&detail->hash_lock); | |
69 | ||
70 | hlist_for_each_entry(tmp, head, cache_list) { | |
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, detail); | |
91 | detail->init(new, key); | |
92 | ||
93 | write_lock(&detail->hash_lock); | |
94 | ||
95 | /* check if entry appeared while we slept */ | |
96 | hlist_for_each_entry(tmp, head, cache_list) { | |
97 | if (detail->match(tmp, key)) { | |
98 | if (cache_is_expired(detail, tmp)) { | |
99 | hlist_del_init(&tmp->cache_list); | |
100 | detail->entries --; | |
101 | freeme = tmp; | |
102 | break; | |
103 | } | |
104 | cache_get(tmp); | |
105 | write_unlock(&detail->hash_lock); | |
106 | cache_put(new, detail); | |
107 | return tmp; | |
108 | } | |
109 | } | |
110 | ||
111 | hlist_add_head(&new->cache_list, head); | |
112 | detail->entries++; | |
113 | cache_get(new); | |
114 | write_unlock(&detail->hash_lock); | |
115 | ||
116 | if (freeme) { | |
117 | cache_fresh_unlocked(freeme, detail); | |
118 | cache_put(freeme, detail); | |
119 | } | |
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 | struct cache_detail *detail) | |
129 | { | |
130 | time_t now = seconds_since_boot(); | |
131 | if (now <= detail->flush_time) | |
132 | /* ensure it isn't immediately treated as expired */ | |
133 | now = detail->flush_time + 1; | |
134 | head->expiry_time = expiry; | |
135 | head->last_refresh = now; | |
136 | smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */ | |
137 | set_bit(CACHE_VALID, &head->flags); | |
138 | } | |
139 | ||
140 | static void cache_fresh_unlocked(struct cache_head *head, | |
141 | struct cache_detail *detail) | |
142 | { | |
143 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { | |
144 | cache_revisit_request(head); | |
145 | cache_dequeue(detail, head); | |
146 | } | |
147 | } | |
148 | ||
149 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, | |
150 | struct cache_head *new, struct cache_head *old, int hash) | |
151 | { | |
152 | /* The 'old' entry is to be replaced by 'new'. | |
153 | * If 'old' is not VALID, we update it directly, | |
154 | * otherwise we need to replace it | |
155 | */ | |
156 | struct cache_head *tmp; | |
157 | ||
158 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
159 | write_lock(&detail->hash_lock); | |
160 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
161 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
162 | set_bit(CACHE_NEGATIVE, &old->flags); | |
163 | else | |
164 | detail->update(old, new); | |
165 | cache_fresh_locked(old, new->expiry_time, detail); | |
166 | write_unlock(&detail->hash_lock); | |
167 | cache_fresh_unlocked(old, detail); | |
168 | return old; | |
169 | } | |
170 | write_unlock(&detail->hash_lock); | |
171 | } | |
172 | /* We need to insert a new entry */ | |
173 | tmp = detail->alloc(); | |
174 | if (!tmp) { | |
175 | cache_put(old, detail); | |
176 | return NULL; | |
177 | } | |
178 | cache_init(tmp, detail); | |
179 | detail->init(tmp, old); | |
180 | ||
181 | write_lock(&detail->hash_lock); | |
182 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
183 | set_bit(CACHE_NEGATIVE, &tmp->flags); | |
184 | else | |
185 | detail->update(tmp, new); | |
186 | hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); | |
187 | detail->entries++; | |
188 | cache_get(tmp); | |
189 | cache_fresh_locked(tmp, new->expiry_time, detail); | |
190 | cache_fresh_locked(old, 0, detail); | |
191 | write_unlock(&detail->hash_lock); | |
192 | cache_fresh_unlocked(tmp, detail); | |
193 | cache_fresh_unlocked(old, detail); | |
194 | cache_put(old, detail); | |
195 | return tmp; | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(sunrpc_cache_update); | |
198 | ||
199 | static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) | |
200 | { | |
201 | if (cd->cache_upcall) | |
202 | return cd->cache_upcall(cd, h); | |
203 | return sunrpc_cache_pipe_upcall(cd, h); | |
204 | } | |
205 | ||
206 | static inline int cache_is_valid(struct cache_head *h) | |
207 | { | |
208 | if (!test_bit(CACHE_VALID, &h->flags)) | |
209 | return -EAGAIN; | |
210 | else { | |
211 | /* entry is valid */ | |
212 | if (test_bit(CACHE_NEGATIVE, &h->flags)) | |
213 | return -ENOENT; | |
214 | else { | |
215 | /* | |
216 | * In combination with write barrier in | |
217 | * sunrpc_cache_update, ensures that anyone | |
218 | * using the cache entry after this sees the | |
219 | * updated contents: | |
220 | */ | |
221 | smp_rmb(); | |
222 | return 0; | |
223 | } | |
224 | } | |
225 | } | |
226 | ||
227 | static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h) | |
228 | { | |
229 | int rv; | |
230 | ||
231 | write_lock(&detail->hash_lock); | |
232 | rv = cache_is_valid(h); | |
233 | if (rv == -EAGAIN) { | |
234 | set_bit(CACHE_NEGATIVE, &h->flags); | |
235 | cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY, | |
236 | detail); | |
237 | rv = -ENOENT; | |
238 | } | |
239 | write_unlock(&detail->hash_lock); | |
240 | cache_fresh_unlocked(h, detail); | |
241 | return rv; | |
242 | } | |
243 | ||
244 | /* | |
245 | * This is the generic cache management routine for all | |
246 | * the authentication caches. | |
247 | * It checks the currency of a cache item and will (later) | |
248 | * initiate an upcall to fill it if needed. | |
249 | * | |
250 | * | |
251 | * Returns 0 if the cache_head can be used, or cache_puts it and returns | |
252 | * -EAGAIN if upcall is pending and request has been queued | |
253 | * -ETIMEDOUT if upcall failed or request could not be queue or | |
254 | * upcall completed but item is still invalid (implying that | |
255 | * the cache item has been replaced with a newer one). | |
256 | * -ENOENT if cache entry was negative | |
257 | */ | |
258 | int cache_check(struct cache_detail *detail, | |
259 | struct cache_head *h, struct cache_req *rqstp) | |
260 | { | |
261 | int rv; | |
262 | long refresh_age, age; | |
263 | ||
264 | /* First decide return status as best we can */ | |
265 | rv = cache_is_valid(h); | |
266 | ||
267 | /* now see if we want to start an upcall */ | |
268 | refresh_age = (h->expiry_time - h->last_refresh); | |
269 | age = seconds_since_boot() - h->last_refresh; | |
270 | ||
271 | if (rqstp == NULL) { | |
272 | if (rv == -EAGAIN) | |
273 | rv = -ENOENT; | |
274 | } else if (rv == -EAGAIN || | |
275 | (h->expiry_time != 0 && age > refresh_age/2)) { | |
276 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", | |
277 | refresh_age, age); | |
278 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { | |
279 | switch (cache_make_upcall(detail, h)) { | |
280 | case -EINVAL: | |
281 | rv = try_to_negate_entry(detail, h); | |
282 | break; | |
283 | case -EAGAIN: | |
284 | cache_fresh_unlocked(h, detail); | |
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(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 cache_clean 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 | queue_delayed_work(system_power_efficient_wq, &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 (current_detail == cd) | |
371 | current_detail = NULL; | |
372 | list_del_init(&cd->others); | |
373 | write_unlock(&cd->hash_lock); | |
374 | spin_unlock(&cache_list_lock); | |
375 | if (list_empty(&cache_list)) { | |
376 | /* module must be being unloaded so its safe to kill the worker */ | |
377 | cancel_delayed_work_sync(&cache_cleaner); | |
378 | } | |
379 | } | |
380 | EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); | |
381 | ||
382 | /* clean cache tries to find something to clean | |
383 | * and cleans it. | |
384 | * It returns 1 if it cleaned something, | |
385 | * 0 if it didn't find anything this time | |
386 | * -1 if it fell off the end of the list. | |
387 | */ | |
388 | static int cache_clean(void) | |
389 | { | |
390 | int rv = 0; | |
391 | struct list_head *next; | |
392 | ||
393 | spin_lock(&cache_list_lock); | |
394 | ||
395 | /* find a suitable table if we don't already have one */ | |
396 | while (current_detail == NULL || | |
397 | current_index >= current_detail->hash_size) { | |
398 | if (current_detail) | |
399 | next = current_detail->others.next; | |
400 | else | |
401 | next = cache_list.next; | |
402 | if (next == &cache_list) { | |
403 | current_detail = NULL; | |
404 | spin_unlock(&cache_list_lock); | |
405 | return -1; | |
406 | } | |
407 | current_detail = list_entry(next, struct cache_detail, others); | |
408 | if (current_detail->nextcheck > seconds_since_boot()) | |
409 | current_index = current_detail->hash_size; | |
410 | else { | |
411 | current_index = 0; | |
412 | current_detail->nextcheck = seconds_since_boot()+30*60; | |
413 | } | |
414 | } | |
415 | ||
416 | /* find a non-empty bucket in the table */ | |
417 | while (current_detail && | |
418 | current_index < current_detail->hash_size && | |
419 | hlist_empty(¤t_detail->hash_table[current_index])) | |
420 | current_index++; | |
421 | ||
422 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ | |
423 | ||
424 | if (current_detail && current_index < current_detail->hash_size) { | |
425 | struct cache_head *ch = NULL; | |
426 | struct cache_detail *d; | |
427 | struct hlist_head *head; | |
428 | struct hlist_node *tmp; | |
429 | ||
430 | write_lock(¤t_detail->hash_lock); | |
431 | ||
432 | /* Ok, now to clean this strand */ | |
433 | ||
434 | head = ¤t_detail->hash_table[current_index]; | |
435 | hlist_for_each_entry_safe(ch, tmp, head, cache_list) { | |
436 | if (current_detail->nextcheck > ch->expiry_time) | |
437 | current_detail->nextcheck = ch->expiry_time+1; | |
438 | if (!cache_is_expired(current_detail, ch)) | |
439 | continue; | |
440 | ||
441 | hlist_del_init(&ch->cache_list); | |
442 | current_detail->entries--; | |
443 | rv = 1; | |
444 | break; | |
445 | } | |
446 | ||
447 | write_unlock(¤t_detail->hash_lock); | |
448 | d = current_detail; | |
449 | if (!ch) | |
450 | current_index ++; | |
451 | spin_unlock(&cache_list_lock); | |
452 | if (ch) { | |
453 | set_bit(CACHE_CLEANED, &ch->flags); | |
454 | cache_fresh_unlocked(ch, d); | |
455 | cache_put(ch, d); | |
456 | } | |
457 | } else | |
458 | spin_unlock(&cache_list_lock); | |
459 | ||
460 | return rv; | |
461 | } | |
462 | ||
463 | /* | |
464 | * We want to regularly clean the cache, so we need to schedule some work ... | |
465 | */ | |
466 | static void do_cache_clean(struct work_struct *work) | |
467 | { | |
468 | int delay = 5; | |
469 | if (cache_clean() == -1) | |
470 | delay = round_jiffies_relative(30*HZ); | |
471 | ||
472 | if (list_empty(&cache_list)) | |
473 | delay = 0; | |
474 | ||
475 | if (delay) | |
476 | queue_delayed_work(system_power_efficient_wq, | |
477 | &cache_cleaner, delay); | |
478 | } | |
479 | ||
480 | ||
481 | /* | |
482 | * Clean all caches promptly. This just calls cache_clean | |
483 | * repeatedly until we are sure that every cache has had a chance to | |
484 | * be fully cleaned | |
485 | */ | |
486 | void cache_flush(void) | |
487 | { | |
488 | while (cache_clean() != -1) | |
489 | cond_resched(); | |
490 | while (cache_clean() != -1) | |
491 | cond_resched(); | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(cache_flush); | |
494 | ||
495 | void cache_purge(struct cache_detail *detail) | |
496 | { | |
497 | struct cache_head *ch = NULL; | |
498 | struct hlist_head *head = NULL; | |
499 | struct hlist_node *tmp = NULL; | |
500 | int i = 0; | |
501 | ||
502 | write_lock(&detail->hash_lock); | |
503 | if (!detail->entries) { | |
504 | write_unlock(&detail->hash_lock); | |
505 | return; | |
506 | } | |
507 | ||
508 | dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name); | |
509 | for (i = 0; i < detail->hash_size; i++) { | |
510 | head = &detail->hash_table[i]; | |
511 | hlist_for_each_entry_safe(ch, tmp, head, cache_list) { | |
512 | hlist_del_init(&ch->cache_list); | |
513 | detail->entries--; | |
514 | ||
515 | set_bit(CACHE_CLEANED, &ch->flags); | |
516 | write_unlock(&detail->hash_lock); | |
517 | cache_fresh_unlocked(ch, detail); | |
518 | cache_put(ch, detail); | |
519 | write_lock(&detail->hash_lock); | |
520 | } | |
521 | } | |
522 | write_unlock(&detail->hash_lock); | |
523 | } | |
524 | EXPORT_SYMBOL_GPL(cache_purge); | |
525 | ||
526 | ||
527 | /* | |
528 | * Deferral and Revisiting of Requests. | |
529 | * | |
530 | * If a cache lookup finds a pending entry, we | |
531 | * need to defer the request and revisit it later. | |
532 | * All deferred requests are stored in a hash table, | |
533 | * indexed by "struct cache_head *". | |
534 | * As it may be wasteful to store a whole request | |
535 | * structure, we allow the request to provide a | |
536 | * deferred form, which must contain a | |
537 | * 'struct cache_deferred_req' | |
538 | * This cache_deferred_req contains a method to allow | |
539 | * it to be revisited when cache info is available | |
540 | */ | |
541 | ||
542 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) | |
543 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) | |
544 | ||
545 | #define DFR_MAX 300 /* ??? */ | |
546 | ||
547 | static DEFINE_SPINLOCK(cache_defer_lock); | |
548 | static LIST_HEAD(cache_defer_list); | |
549 | static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; | |
550 | static int cache_defer_cnt; | |
551 | ||
552 | static void __unhash_deferred_req(struct cache_deferred_req *dreq) | |
553 | { | |
554 | hlist_del_init(&dreq->hash); | |
555 | if (!list_empty(&dreq->recent)) { | |
556 | list_del_init(&dreq->recent); | |
557 | cache_defer_cnt--; | |
558 | } | |
559 | } | |
560 | ||
561 | static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item) | |
562 | { | |
563 | int hash = DFR_HASH(item); | |
564 | ||
565 | INIT_LIST_HEAD(&dreq->recent); | |
566 | hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); | |
567 | } | |
568 | ||
569 | static void setup_deferral(struct cache_deferred_req *dreq, | |
570 | struct cache_head *item, | |
571 | int count_me) | |
572 | { | |
573 | ||
574 | dreq->item = item; | |
575 | ||
576 | spin_lock(&cache_defer_lock); | |
577 | ||
578 | __hash_deferred_req(dreq, item); | |
579 | ||
580 | if (count_me) { | |
581 | cache_defer_cnt++; | |
582 | list_add(&dreq->recent, &cache_defer_list); | |
583 | } | |
584 | ||
585 | spin_unlock(&cache_defer_lock); | |
586 | ||
587 | } | |
588 | ||
589 | struct thread_deferred_req { | |
590 | struct cache_deferred_req handle; | |
591 | struct completion completion; | |
592 | }; | |
593 | ||
594 | static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) | |
595 | { | |
596 | struct thread_deferred_req *dr = | |
597 | container_of(dreq, struct thread_deferred_req, handle); | |
598 | complete(&dr->completion); | |
599 | } | |
600 | ||
601 | static void cache_wait_req(struct cache_req *req, struct cache_head *item) | |
602 | { | |
603 | struct thread_deferred_req sleeper; | |
604 | struct cache_deferred_req *dreq = &sleeper.handle; | |
605 | ||
606 | sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); | |
607 | dreq->revisit = cache_restart_thread; | |
608 | ||
609 | setup_deferral(dreq, item, 0); | |
610 | ||
611 | if (!test_bit(CACHE_PENDING, &item->flags) || | |
612 | wait_for_completion_interruptible_timeout( | |
613 | &sleeper.completion, req->thread_wait) <= 0) { | |
614 | /* The completion wasn't completed, so we need | |
615 | * to clean up | |
616 | */ | |
617 | spin_lock(&cache_defer_lock); | |
618 | if (!hlist_unhashed(&sleeper.handle.hash)) { | |
619 | __unhash_deferred_req(&sleeper.handle); | |
620 | spin_unlock(&cache_defer_lock); | |
621 | } else { | |
622 | /* cache_revisit_request already removed | |
623 | * this from the hash table, but hasn't | |
624 | * called ->revisit yet. It will very soon | |
625 | * and we need to wait for it. | |
626 | */ | |
627 | spin_unlock(&cache_defer_lock); | |
628 | wait_for_completion(&sleeper.completion); | |
629 | } | |
630 | } | |
631 | } | |
632 | ||
633 | static void cache_limit_defers(void) | |
634 | { | |
635 | /* Make sure we haven't exceed the limit of allowed deferred | |
636 | * requests. | |
637 | */ | |
638 | struct cache_deferred_req *discard = NULL; | |
639 | ||
640 | if (cache_defer_cnt <= DFR_MAX) | |
641 | return; | |
642 | ||
643 | spin_lock(&cache_defer_lock); | |
644 | ||
645 | /* Consider removing either the first or the last */ | |
646 | if (cache_defer_cnt > DFR_MAX) { | |
647 | if (prandom_u32() & 1) | |
648 | discard = list_entry(cache_defer_list.next, | |
649 | struct cache_deferred_req, recent); | |
650 | else | |
651 | discard = list_entry(cache_defer_list.prev, | |
652 | struct cache_deferred_req, recent); | |
653 | __unhash_deferred_req(discard); | |
654 | } | |
655 | spin_unlock(&cache_defer_lock); | |
656 | if (discard) | |
657 | discard->revisit(discard, 1); | |
658 | } | |
659 | ||
660 | /* Return true if and only if a deferred request is queued. */ | |
661 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item) | |
662 | { | |
663 | struct cache_deferred_req *dreq; | |
664 | ||
665 | if (req->thread_wait) { | |
666 | cache_wait_req(req, item); | |
667 | if (!test_bit(CACHE_PENDING, &item->flags)) | |
668 | return false; | |
669 | } | |
670 | dreq = req->defer(req); | |
671 | if (dreq == NULL) | |
672 | return false; | |
673 | setup_deferral(dreq, item, 1); | |
674 | if (!test_bit(CACHE_PENDING, &item->flags)) | |
675 | /* Bit could have been cleared before we managed to | |
676 | * set up the deferral, so need to revisit just in case | |
677 | */ | |
678 | cache_revisit_request(item); | |
679 | ||
680 | cache_limit_defers(); | |
681 | return true; | |
682 | } | |
683 | ||
684 | static void cache_revisit_request(struct cache_head *item) | |
685 | { | |
686 | struct cache_deferred_req *dreq; | |
687 | struct list_head pending; | |
688 | struct hlist_node *tmp; | |
689 | int hash = DFR_HASH(item); | |
690 | ||
691 | INIT_LIST_HEAD(&pending); | |
692 | spin_lock(&cache_defer_lock); | |
693 | ||
694 | hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash) | |
695 | if (dreq->item == item) { | |
696 | __unhash_deferred_req(dreq); | |
697 | list_add(&dreq->recent, &pending); | |
698 | } | |
699 | ||
700 | spin_unlock(&cache_defer_lock); | |
701 | ||
702 | while (!list_empty(&pending)) { | |
703 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
704 | list_del_init(&dreq->recent); | |
705 | dreq->revisit(dreq, 0); | |
706 | } | |
707 | } | |
708 | ||
709 | void cache_clean_deferred(void *owner) | |
710 | { | |
711 | struct cache_deferred_req *dreq, *tmp; | |
712 | struct list_head pending; | |
713 | ||
714 | ||
715 | INIT_LIST_HEAD(&pending); | |
716 | spin_lock(&cache_defer_lock); | |
717 | ||
718 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { | |
719 | if (dreq->owner == owner) { | |
720 | __unhash_deferred_req(dreq); | |
721 | list_add(&dreq->recent, &pending); | |
722 | } | |
723 | } | |
724 | spin_unlock(&cache_defer_lock); | |
725 | ||
726 | while (!list_empty(&pending)) { | |
727 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
728 | list_del_init(&dreq->recent); | |
729 | dreq->revisit(dreq, 1); | |
730 | } | |
731 | } | |
732 | ||
733 | /* | |
734 | * communicate with user-space | |
735 | * | |
736 | * We have a magic /proc file - /proc/net/rpc/<cachename>/channel. | |
737 | * On read, you get a full request, or block. | |
738 | * On write, an update request is processed. | |
739 | * Poll works if anything to read, and always allows write. | |
740 | * | |
741 | * Implemented by linked list of requests. Each open file has | |
742 | * a ->private that also exists in this list. New requests are added | |
743 | * to the end and may wakeup and preceding readers. | |
744 | * New readers are added to the head. If, on read, an item is found with | |
745 | * CACHE_UPCALLING clear, we free it from the list. | |
746 | * | |
747 | */ | |
748 | ||
749 | static DEFINE_SPINLOCK(queue_lock); | |
750 | static DEFINE_MUTEX(queue_io_mutex); | |
751 | ||
752 | struct cache_queue { | |
753 | struct list_head list; | |
754 | int reader; /* if 0, then request */ | |
755 | }; | |
756 | struct cache_request { | |
757 | struct cache_queue q; | |
758 | struct cache_head *item; | |
759 | char * buf; | |
760 | int len; | |
761 | int readers; | |
762 | }; | |
763 | struct cache_reader { | |
764 | struct cache_queue q; | |
765 | int offset; /* if non-0, we have a refcnt on next request */ | |
766 | }; | |
767 | ||
768 | static int cache_request(struct cache_detail *detail, | |
769 | struct cache_request *crq) | |
770 | { | |
771 | char *bp = crq->buf; | |
772 | int len = PAGE_SIZE; | |
773 | ||
774 | detail->cache_request(detail, crq->item, &bp, &len); | |
775 | if (len < 0) | |
776 | return -EAGAIN; | |
777 | return PAGE_SIZE - len; | |
778 | } | |
779 | ||
780 | static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, | |
781 | loff_t *ppos, struct cache_detail *cd) | |
782 | { | |
783 | struct cache_reader *rp = filp->private_data; | |
784 | struct cache_request *rq; | |
785 | struct inode *inode = file_inode(filp); | |
786 | int err; | |
787 | ||
788 | if (count == 0) | |
789 | return 0; | |
790 | ||
791 | inode_lock(inode); /* protect against multiple concurrent | |
792 | * readers on this file */ | |
793 | again: | |
794 | spin_lock(&queue_lock); | |
795 | /* need to find next request */ | |
796 | while (rp->q.list.next != &cd->queue && | |
797 | list_entry(rp->q.list.next, struct cache_queue, list) | |
798 | ->reader) { | |
799 | struct list_head *next = rp->q.list.next; | |
800 | list_move(&rp->q.list, next); | |
801 | } | |
802 | if (rp->q.list.next == &cd->queue) { | |
803 | spin_unlock(&queue_lock); | |
804 | inode_unlock(inode); | |
805 | WARN_ON_ONCE(rp->offset); | |
806 | return 0; | |
807 | } | |
808 | rq = container_of(rp->q.list.next, struct cache_request, q.list); | |
809 | WARN_ON_ONCE(rq->q.reader); | |
810 | if (rp->offset == 0) | |
811 | rq->readers++; | |
812 | spin_unlock(&queue_lock); | |
813 | ||
814 | if (rq->len == 0) { | |
815 | err = cache_request(cd, rq); | |
816 | if (err < 0) | |
817 | goto out; | |
818 | rq->len = err; | |
819 | } | |
820 | ||
821 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
822 | err = -EAGAIN; | |
823 | spin_lock(&queue_lock); | |
824 | list_move(&rp->q.list, &rq->q.list); | |
825 | spin_unlock(&queue_lock); | |
826 | } else { | |
827 | if (rp->offset + count > rq->len) | |
828 | count = rq->len - rp->offset; | |
829 | err = -EFAULT; | |
830 | if (copy_to_user(buf, rq->buf + rp->offset, count)) | |
831 | goto out; | |
832 | rp->offset += count; | |
833 | if (rp->offset >= rq->len) { | |
834 | rp->offset = 0; | |
835 | spin_lock(&queue_lock); | |
836 | list_move(&rp->q.list, &rq->q.list); | |
837 | spin_unlock(&queue_lock); | |
838 | } | |
839 | err = 0; | |
840 | } | |
841 | out: | |
842 | if (rp->offset == 0) { | |
843 | /* need to release rq */ | |
844 | spin_lock(&queue_lock); | |
845 | rq->readers--; | |
846 | if (rq->readers == 0 && | |
847 | !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
848 | list_del(&rq->q.list); | |
849 | spin_unlock(&queue_lock); | |
850 | cache_put(rq->item, cd); | |
851 | kfree(rq->buf); | |
852 | kfree(rq); | |
853 | } else | |
854 | spin_unlock(&queue_lock); | |
855 | } | |
856 | if (err == -EAGAIN) | |
857 | goto again; | |
858 | inode_unlock(inode); | |
859 | return err ? err : count; | |
860 | } | |
861 | ||
862 | static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, | |
863 | size_t count, struct cache_detail *cd) | |
864 | { | |
865 | ssize_t ret; | |
866 | ||
867 | if (count == 0) | |
868 | return -EINVAL; | |
869 | if (copy_from_user(kaddr, buf, count)) | |
870 | return -EFAULT; | |
871 | kaddr[count] = '\0'; | |
872 | ret = cd->cache_parse(cd, kaddr, count); | |
873 | if (!ret) | |
874 | ret = count; | |
875 | return ret; | |
876 | } | |
877 | ||
878 | static ssize_t cache_slow_downcall(const char __user *buf, | |
879 | size_t count, struct cache_detail *cd) | |
880 | { | |
881 | static char write_buf[8192]; /* protected by queue_io_mutex */ | |
882 | ssize_t ret = -EINVAL; | |
883 | ||
884 | if (count >= sizeof(write_buf)) | |
885 | goto out; | |
886 | mutex_lock(&queue_io_mutex); | |
887 | ret = cache_do_downcall(write_buf, buf, count, cd); | |
888 | mutex_unlock(&queue_io_mutex); | |
889 | out: | |
890 | return ret; | |
891 | } | |
892 | ||
893 | static ssize_t cache_downcall(struct address_space *mapping, | |
894 | const char __user *buf, | |
895 | size_t count, struct cache_detail *cd) | |
896 | { | |
897 | struct page *page; | |
898 | char *kaddr; | |
899 | ssize_t ret = -ENOMEM; | |
900 | ||
901 | if (count >= PAGE_SIZE) | |
902 | goto out_slow; | |
903 | ||
904 | page = find_or_create_page(mapping, 0, GFP_KERNEL); | |
905 | if (!page) | |
906 | goto out_slow; | |
907 | ||
908 | kaddr = kmap(page); | |
909 | ret = cache_do_downcall(kaddr, buf, count, cd); | |
910 | kunmap(page); | |
911 | unlock_page(page); | |
912 | put_page(page); | |
913 | return ret; | |
914 | out_slow: | |
915 | return cache_slow_downcall(buf, count, cd); | |
916 | } | |
917 | ||
918 | static ssize_t cache_write(struct file *filp, const char __user *buf, | |
919 | size_t count, loff_t *ppos, | |
920 | struct cache_detail *cd) | |
921 | { | |
922 | struct address_space *mapping = filp->f_mapping; | |
923 | struct inode *inode = file_inode(filp); | |
924 | ssize_t ret = -EINVAL; | |
925 | ||
926 | if (!cd->cache_parse) | |
927 | goto out; | |
928 | ||
929 | inode_lock(inode); | |
930 | ret = cache_downcall(mapping, buf, count, cd); | |
931 | inode_unlock(inode); | |
932 | out: | |
933 | return ret; | |
934 | } | |
935 | ||
936 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); | |
937 | ||
938 | static unsigned int cache_poll(struct file *filp, poll_table *wait, | |
939 | struct cache_detail *cd) | |
940 | { | |
941 | unsigned int mask; | |
942 | struct cache_reader *rp = filp->private_data; | |
943 | struct cache_queue *cq; | |
944 | ||
945 | poll_wait(filp, &queue_wait, wait); | |
946 | ||
947 | /* alway allow write */ | |
948 | mask = POLLOUT | POLLWRNORM; | |
949 | ||
950 | if (!rp) | |
951 | return mask; | |
952 | ||
953 | spin_lock(&queue_lock); | |
954 | ||
955 | for (cq= &rp->q; &cq->list != &cd->queue; | |
956 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
957 | if (!cq->reader) { | |
958 | mask |= POLLIN | POLLRDNORM; | |
959 | break; | |
960 | } | |
961 | spin_unlock(&queue_lock); | |
962 | return mask; | |
963 | } | |
964 | ||
965 | static int cache_ioctl(struct inode *ino, struct file *filp, | |
966 | unsigned int cmd, unsigned long arg, | |
967 | struct cache_detail *cd) | |
968 | { | |
969 | int len = 0; | |
970 | struct cache_reader *rp = filp->private_data; | |
971 | struct cache_queue *cq; | |
972 | ||
973 | if (cmd != FIONREAD || !rp) | |
974 | return -EINVAL; | |
975 | ||
976 | spin_lock(&queue_lock); | |
977 | ||
978 | /* only find the length remaining in current request, | |
979 | * or the length of the next request | |
980 | */ | |
981 | for (cq= &rp->q; &cq->list != &cd->queue; | |
982 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
983 | if (!cq->reader) { | |
984 | struct cache_request *cr = | |
985 | container_of(cq, struct cache_request, q); | |
986 | len = cr->len - rp->offset; | |
987 | break; | |
988 | } | |
989 | spin_unlock(&queue_lock); | |
990 | ||
991 | return put_user(len, (int __user *)arg); | |
992 | } | |
993 | ||
994 | static int cache_open(struct inode *inode, struct file *filp, | |
995 | struct cache_detail *cd) | |
996 | { | |
997 | struct cache_reader *rp = NULL; | |
998 | ||
999 | if (!cd || !try_module_get(cd->owner)) | |
1000 | return -EACCES; | |
1001 | nonseekable_open(inode, filp); | |
1002 | if (filp->f_mode & FMODE_READ) { | |
1003 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); | |
1004 | if (!rp) { | |
1005 | module_put(cd->owner); | |
1006 | return -ENOMEM; | |
1007 | } | |
1008 | rp->offset = 0; | |
1009 | rp->q.reader = 1; | |
1010 | atomic_inc(&cd->readers); | |
1011 | spin_lock(&queue_lock); | |
1012 | list_add(&rp->q.list, &cd->queue); | |
1013 | spin_unlock(&queue_lock); | |
1014 | } | |
1015 | filp->private_data = rp; | |
1016 | return 0; | |
1017 | } | |
1018 | ||
1019 | static int cache_release(struct inode *inode, struct file *filp, | |
1020 | struct cache_detail *cd) | |
1021 | { | |
1022 | struct cache_reader *rp = filp->private_data; | |
1023 | ||
1024 | if (rp) { | |
1025 | spin_lock(&queue_lock); | |
1026 | if (rp->offset) { | |
1027 | struct cache_queue *cq; | |
1028 | for (cq= &rp->q; &cq->list != &cd->queue; | |
1029 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
1030 | if (!cq->reader) { | |
1031 | container_of(cq, struct cache_request, q) | |
1032 | ->readers--; | |
1033 | break; | |
1034 | } | |
1035 | rp->offset = 0; | |
1036 | } | |
1037 | list_del(&rp->q.list); | |
1038 | spin_unlock(&queue_lock); | |
1039 | ||
1040 | filp->private_data = NULL; | |
1041 | kfree(rp); | |
1042 | ||
1043 | cd->last_close = seconds_since_boot(); | |
1044 | atomic_dec(&cd->readers); | |
1045 | } | |
1046 | module_put(cd->owner); | |
1047 | return 0; | |
1048 | } | |
1049 | ||
1050 | ||
1051 | ||
1052 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) | |
1053 | { | |
1054 | struct cache_queue *cq, *tmp; | |
1055 | struct cache_request *cr; | |
1056 | struct list_head dequeued; | |
1057 | ||
1058 | INIT_LIST_HEAD(&dequeued); | |
1059 | spin_lock(&queue_lock); | |
1060 | list_for_each_entry_safe(cq, tmp, &detail->queue, list) | |
1061 | if (!cq->reader) { | |
1062 | cr = container_of(cq, struct cache_request, q); | |
1063 | if (cr->item != ch) | |
1064 | continue; | |
1065 | if (test_bit(CACHE_PENDING, &ch->flags)) | |
1066 | /* Lost a race and it is pending again */ | |
1067 | break; | |
1068 | if (cr->readers != 0) | |
1069 | continue; | |
1070 | list_move(&cr->q.list, &dequeued); | |
1071 | } | |
1072 | spin_unlock(&queue_lock); | |
1073 | while (!list_empty(&dequeued)) { | |
1074 | cr = list_entry(dequeued.next, struct cache_request, q.list); | |
1075 | list_del(&cr->q.list); | |
1076 | cache_put(cr->item, detail); | |
1077 | kfree(cr->buf); | |
1078 | kfree(cr); | |
1079 | } | |
1080 | } | |
1081 | ||
1082 | /* | |
1083 | * Support routines for text-based upcalls. | |
1084 | * Fields are separated by spaces. | |
1085 | * Fields are either mangled to quote space tab newline slosh with slosh | |
1086 | * or a hexified with a leading \x | |
1087 | * Record is terminated with newline. | |
1088 | * | |
1089 | */ | |
1090 | ||
1091 | void qword_add(char **bpp, int *lp, char *str) | |
1092 | { | |
1093 | char *bp = *bpp; | |
1094 | int len = *lp; | |
1095 | int ret; | |
1096 | ||
1097 | if (len < 0) return; | |
1098 | ||
1099 | ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t"); | |
1100 | if (ret >= len) { | |
1101 | bp += len; | |
1102 | len = -1; | |
1103 | } else { | |
1104 | bp += ret; | |
1105 | len -= ret; | |
1106 | *bp++ = ' '; | |
1107 | len--; | |
1108 | } | |
1109 | *bpp = bp; | |
1110 | *lp = len; | |
1111 | } | |
1112 | EXPORT_SYMBOL_GPL(qword_add); | |
1113 | ||
1114 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) | |
1115 | { | |
1116 | char *bp = *bpp; | |
1117 | int len = *lp; | |
1118 | ||
1119 | if (len < 0) return; | |
1120 | ||
1121 | if (len > 2) { | |
1122 | *bp++ = '\\'; | |
1123 | *bp++ = 'x'; | |
1124 | len -= 2; | |
1125 | while (blen && len >= 2) { | |
1126 | bp = hex_byte_pack(bp, *buf++); | |
1127 | len -= 2; | |
1128 | blen--; | |
1129 | } | |
1130 | } | |
1131 | if (blen || len<1) len = -1; | |
1132 | else { | |
1133 | *bp++ = ' '; | |
1134 | len--; | |
1135 | } | |
1136 | *bpp = bp; | |
1137 | *lp = len; | |
1138 | } | |
1139 | EXPORT_SYMBOL_GPL(qword_addhex); | |
1140 | ||
1141 | static void warn_no_listener(struct cache_detail *detail) | |
1142 | { | |
1143 | if (detail->last_warn != detail->last_close) { | |
1144 | detail->last_warn = detail->last_close; | |
1145 | if (detail->warn_no_listener) | |
1146 | detail->warn_no_listener(detail, detail->last_close != 0); | |
1147 | } | |
1148 | } | |
1149 | ||
1150 | static bool cache_listeners_exist(struct cache_detail *detail) | |
1151 | { | |
1152 | if (atomic_read(&detail->readers)) | |
1153 | return true; | |
1154 | if (detail->last_close == 0) | |
1155 | /* This cache was never opened */ | |
1156 | return false; | |
1157 | if (detail->last_close < seconds_since_boot() - 30) | |
1158 | /* | |
1159 | * We allow for the possibility that someone might | |
1160 | * restart a userspace daemon without restarting the | |
1161 | * server; but after 30 seconds, we give up. | |
1162 | */ | |
1163 | return false; | |
1164 | return true; | |
1165 | } | |
1166 | ||
1167 | /* | |
1168 | * register an upcall request to user-space and queue it up for read() by the | |
1169 | * upcall daemon. | |
1170 | * | |
1171 | * Each request is at most one page long. | |
1172 | */ | |
1173 | int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) | |
1174 | { | |
1175 | ||
1176 | char *buf; | |
1177 | struct cache_request *crq; | |
1178 | int ret = 0; | |
1179 | ||
1180 | if (!detail->cache_request) | |
1181 | return -EINVAL; | |
1182 | ||
1183 | if (!cache_listeners_exist(detail)) { | |
1184 | warn_no_listener(detail); | |
1185 | return -EINVAL; | |
1186 | } | |
1187 | if (test_bit(CACHE_CLEANED, &h->flags)) | |
1188 | /* Too late to make an upcall */ | |
1189 | return -EAGAIN; | |
1190 | ||
1191 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1192 | if (!buf) | |
1193 | return -EAGAIN; | |
1194 | ||
1195 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); | |
1196 | if (!crq) { | |
1197 | kfree(buf); | |
1198 | return -EAGAIN; | |
1199 | } | |
1200 | ||
1201 | crq->q.reader = 0; | |
1202 | crq->buf = buf; | |
1203 | crq->len = 0; | |
1204 | crq->readers = 0; | |
1205 | spin_lock(&queue_lock); | |
1206 | if (test_bit(CACHE_PENDING, &h->flags)) { | |
1207 | crq->item = cache_get(h); | |
1208 | list_add_tail(&crq->q.list, &detail->queue); | |
1209 | } else | |
1210 | /* Lost a race, no longer PENDING, so don't enqueue */ | |
1211 | ret = -EAGAIN; | |
1212 | spin_unlock(&queue_lock); | |
1213 | wake_up(&queue_wait); | |
1214 | if (ret == -EAGAIN) { | |
1215 | kfree(buf); | |
1216 | kfree(crq); | |
1217 | } | |
1218 | return ret; | |
1219 | } | |
1220 | EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); | |
1221 | ||
1222 | /* | |
1223 | * parse a message from user-space and pass it | |
1224 | * to an appropriate cache | |
1225 | * Messages are, like requests, separated into fields by | |
1226 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal | |
1227 | * | |
1228 | * Message is | |
1229 | * reply cachename expiry key ... content.... | |
1230 | * | |
1231 | * key and content are both parsed by cache | |
1232 | */ | |
1233 | ||
1234 | int qword_get(char **bpp, char *dest, int bufsize) | |
1235 | { | |
1236 | /* return bytes copied, or -1 on error */ | |
1237 | char *bp = *bpp; | |
1238 | int len = 0; | |
1239 | ||
1240 | while (*bp == ' ') bp++; | |
1241 | ||
1242 | if (bp[0] == '\\' && bp[1] == 'x') { | |
1243 | /* HEX STRING */ | |
1244 | bp += 2; | |
1245 | while (len < bufsize - 1) { | |
1246 | int h, l; | |
1247 | ||
1248 | h = hex_to_bin(bp[0]); | |
1249 | if (h < 0) | |
1250 | break; | |
1251 | ||
1252 | l = hex_to_bin(bp[1]); | |
1253 | if (l < 0) | |
1254 | break; | |
1255 | ||
1256 | *dest++ = (h << 4) | l; | |
1257 | bp += 2; | |
1258 | len++; | |
1259 | } | |
1260 | } else { | |
1261 | /* text with \nnn octal quoting */ | |
1262 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { | |
1263 | if (*bp == '\\' && | |
1264 | isodigit(bp[1]) && (bp[1] <= '3') && | |
1265 | isodigit(bp[2]) && | |
1266 | isodigit(bp[3])) { | |
1267 | int byte = (*++bp -'0'); | |
1268 | bp++; | |
1269 | byte = (byte << 3) | (*bp++ - '0'); | |
1270 | byte = (byte << 3) | (*bp++ - '0'); | |
1271 | *dest++ = byte; | |
1272 | len++; | |
1273 | } else { | |
1274 | *dest++ = *bp++; | |
1275 | len++; | |
1276 | } | |
1277 | } | |
1278 | } | |
1279 | ||
1280 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') | |
1281 | return -1; | |
1282 | while (*bp == ' ') bp++; | |
1283 | *bpp = bp; | |
1284 | *dest = '\0'; | |
1285 | return len; | |
1286 | } | |
1287 | EXPORT_SYMBOL_GPL(qword_get); | |
1288 | ||
1289 | ||
1290 | /* | |
1291 | * support /proc/net/rpc/$CACHENAME/content | |
1292 | * as a seqfile. | |
1293 | * We call ->cache_show passing NULL for the item to | |
1294 | * get a header, then pass each real item in the cache | |
1295 | */ | |
1296 | ||
1297 | void *cache_seq_start(struct seq_file *m, loff_t *pos) | |
1298 | __acquires(cd->hash_lock) | |
1299 | { | |
1300 | loff_t n = *pos; | |
1301 | unsigned int hash, entry; | |
1302 | struct cache_head *ch; | |
1303 | struct cache_detail *cd = m->private; | |
1304 | ||
1305 | read_lock(&cd->hash_lock); | |
1306 | if (!n--) | |
1307 | return SEQ_START_TOKEN; | |
1308 | hash = n >> 32; | |
1309 | entry = n & ((1LL<<32) - 1); | |
1310 | ||
1311 | hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list) | |
1312 | if (!entry--) | |
1313 | return ch; | |
1314 | n &= ~((1LL<<32) - 1); | |
1315 | do { | |
1316 | hash++; | |
1317 | n += 1LL<<32; | |
1318 | } while(hash < cd->hash_size && | |
1319 | hlist_empty(&cd->hash_table[hash])); | |
1320 | if (hash >= cd->hash_size) | |
1321 | return NULL; | |
1322 | *pos = n+1; | |
1323 | return hlist_entry_safe(cd->hash_table[hash].first, | |
1324 | struct cache_head, cache_list); | |
1325 | } | |
1326 | EXPORT_SYMBOL_GPL(cache_seq_start); | |
1327 | ||
1328 | void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) | |
1329 | { | |
1330 | struct cache_head *ch = p; | |
1331 | int hash = (*pos >> 32); | |
1332 | struct cache_detail *cd = m->private; | |
1333 | ||
1334 | if (p == SEQ_START_TOKEN) | |
1335 | hash = 0; | |
1336 | else if (ch->cache_list.next == NULL) { | |
1337 | hash++; | |
1338 | *pos += 1LL<<32; | |
1339 | } else { | |
1340 | ++*pos; | |
1341 | return hlist_entry_safe(ch->cache_list.next, | |
1342 | struct cache_head, cache_list); | |
1343 | } | |
1344 | *pos &= ~((1LL<<32) - 1); | |
1345 | while (hash < cd->hash_size && | |
1346 | hlist_empty(&cd->hash_table[hash])) { | |
1347 | hash++; | |
1348 | *pos += 1LL<<32; | |
1349 | } | |
1350 | if (hash >= cd->hash_size) | |
1351 | return NULL; | |
1352 | ++*pos; | |
1353 | return hlist_entry_safe(cd->hash_table[hash].first, | |
1354 | struct cache_head, cache_list); | |
1355 | } | |
1356 | EXPORT_SYMBOL_GPL(cache_seq_next); | |
1357 | ||
1358 | void cache_seq_stop(struct seq_file *m, void *p) | |
1359 | __releases(cd->hash_lock) | |
1360 | { | |
1361 | struct cache_detail *cd = m->private; | |
1362 | read_unlock(&cd->hash_lock); | |
1363 | } | |
1364 | EXPORT_SYMBOL_GPL(cache_seq_stop); | |
1365 | ||
1366 | static int c_show(struct seq_file *m, void *p) | |
1367 | { | |
1368 | struct cache_head *cp = p; | |
1369 | struct cache_detail *cd = m->private; | |
1370 | ||
1371 | if (p == SEQ_START_TOKEN) | |
1372 | return cd->cache_show(m, cd, NULL); | |
1373 | ||
1374 | ifdebug(CACHE) | |
1375 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", | |
1376 | convert_to_wallclock(cp->expiry_time), | |
1377 | kref_read(&cp->ref), cp->flags); | |
1378 | cache_get(cp); | |
1379 | if (cache_check(cd, cp, NULL)) | |
1380 | /* cache_check does a cache_put on failure */ | |
1381 | seq_printf(m, "# "); | |
1382 | else { | |
1383 | if (cache_is_expired(cd, cp)) | |
1384 | seq_printf(m, "# "); | |
1385 | cache_put(cp, cd); | |
1386 | } | |
1387 | ||
1388 | return cd->cache_show(m, cd, cp); | |
1389 | } | |
1390 | ||
1391 | static const struct seq_operations cache_content_op = { | |
1392 | .start = cache_seq_start, | |
1393 | .next = cache_seq_next, | |
1394 | .stop = cache_seq_stop, | |
1395 | .show = c_show, | |
1396 | }; | |
1397 | ||
1398 | static int content_open(struct inode *inode, struct file *file, | |
1399 | struct cache_detail *cd) | |
1400 | { | |
1401 | struct seq_file *seq; | |
1402 | int err; | |
1403 | ||
1404 | if (!cd || !try_module_get(cd->owner)) | |
1405 | return -EACCES; | |
1406 | ||
1407 | err = seq_open(file, &cache_content_op); | |
1408 | if (err) { | |
1409 | module_put(cd->owner); | |
1410 | return err; | |
1411 | } | |
1412 | ||
1413 | seq = file->private_data; | |
1414 | seq->private = cd; | |
1415 | return 0; | |
1416 | } | |
1417 | ||
1418 | static int content_release(struct inode *inode, struct file *file, | |
1419 | struct cache_detail *cd) | |
1420 | { | |
1421 | int ret = seq_release(inode, file); | |
1422 | module_put(cd->owner); | |
1423 | return ret; | |
1424 | } | |
1425 | ||
1426 | static int open_flush(struct inode *inode, struct file *file, | |
1427 | struct cache_detail *cd) | |
1428 | { | |
1429 | if (!cd || !try_module_get(cd->owner)) | |
1430 | return -EACCES; | |
1431 | return nonseekable_open(inode, file); | |
1432 | } | |
1433 | ||
1434 | static int release_flush(struct inode *inode, struct file *file, | |
1435 | struct cache_detail *cd) | |
1436 | { | |
1437 | module_put(cd->owner); | |
1438 | return 0; | |
1439 | } | |
1440 | ||
1441 | static ssize_t read_flush(struct file *file, char __user *buf, | |
1442 | size_t count, loff_t *ppos, | |
1443 | struct cache_detail *cd) | |
1444 | { | |
1445 | char tbuf[22]; | |
1446 | size_t len; | |
1447 | ||
1448 | len = snprintf(tbuf, sizeof(tbuf), "%lu\n", | |
1449 | convert_to_wallclock(cd->flush_time)); | |
1450 | return simple_read_from_buffer(buf, count, ppos, tbuf, len); | |
1451 | } | |
1452 | ||
1453 | static ssize_t write_flush(struct file *file, const char __user *buf, | |
1454 | size_t count, loff_t *ppos, | |
1455 | struct cache_detail *cd) | |
1456 | { | |
1457 | char tbuf[20]; | |
1458 | char *bp, *ep; | |
1459 | time_t then, now; | |
1460 | ||
1461 | if (*ppos || count > sizeof(tbuf)-1) | |
1462 | return -EINVAL; | |
1463 | if (copy_from_user(tbuf, buf, count)) | |
1464 | return -EFAULT; | |
1465 | tbuf[count] = 0; | |
1466 | simple_strtoul(tbuf, &ep, 0); | |
1467 | if (*ep && *ep != '\n') | |
1468 | return -EINVAL; | |
1469 | ||
1470 | bp = tbuf; | |
1471 | then = get_expiry(&bp); | |
1472 | now = seconds_since_boot(); | |
1473 | cd->nextcheck = now; | |
1474 | /* Can only set flush_time to 1 second beyond "now", or | |
1475 | * possibly 1 second beyond flushtime. This is because | |
1476 | * flush_time never goes backwards so it mustn't get too far | |
1477 | * ahead of time. | |
1478 | */ | |
1479 | if (then >= now) { | |
1480 | /* Want to flush everything, so behave like cache_purge() */ | |
1481 | if (cd->flush_time >= now) | |
1482 | now = cd->flush_time + 1; | |
1483 | then = now; | |
1484 | } | |
1485 | ||
1486 | cd->flush_time = then; | |
1487 | cache_flush(); | |
1488 | ||
1489 | *ppos += count; | |
1490 | return count; | |
1491 | } | |
1492 | ||
1493 | static ssize_t cache_read_procfs(struct file *filp, char __user *buf, | |
1494 | size_t count, loff_t *ppos) | |
1495 | { | |
1496 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1497 | ||
1498 | return cache_read(filp, buf, count, ppos, cd); | |
1499 | } | |
1500 | ||
1501 | static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, | |
1502 | size_t count, loff_t *ppos) | |
1503 | { | |
1504 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1505 | ||
1506 | return cache_write(filp, buf, count, ppos, cd); | |
1507 | } | |
1508 | ||
1509 | static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) | |
1510 | { | |
1511 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1512 | ||
1513 | return cache_poll(filp, wait, cd); | |
1514 | } | |
1515 | ||
1516 | static long cache_ioctl_procfs(struct file *filp, | |
1517 | unsigned int cmd, unsigned long arg) | |
1518 | { | |
1519 | struct inode *inode = file_inode(filp); | |
1520 | struct cache_detail *cd = PDE_DATA(inode); | |
1521 | ||
1522 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1523 | } | |
1524 | ||
1525 | static int cache_open_procfs(struct inode *inode, struct file *filp) | |
1526 | { | |
1527 | struct cache_detail *cd = PDE_DATA(inode); | |
1528 | ||
1529 | return cache_open(inode, filp, cd); | |
1530 | } | |
1531 | ||
1532 | static int cache_release_procfs(struct inode *inode, struct file *filp) | |
1533 | { | |
1534 | struct cache_detail *cd = PDE_DATA(inode); | |
1535 | ||
1536 | return cache_release(inode, filp, cd); | |
1537 | } | |
1538 | ||
1539 | static const struct file_operations cache_file_operations_procfs = { | |
1540 | .owner = THIS_MODULE, | |
1541 | .llseek = no_llseek, | |
1542 | .read = cache_read_procfs, | |
1543 | .write = cache_write_procfs, | |
1544 | .poll = cache_poll_procfs, | |
1545 | .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ | |
1546 | .open = cache_open_procfs, | |
1547 | .release = cache_release_procfs, | |
1548 | }; | |
1549 | ||
1550 | static int content_open_procfs(struct inode *inode, struct file *filp) | |
1551 | { | |
1552 | struct cache_detail *cd = PDE_DATA(inode); | |
1553 | ||
1554 | return content_open(inode, filp, cd); | |
1555 | } | |
1556 | ||
1557 | static int content_release_procfs(struct inode *inode, struct file *filp) | |
1558 | { | |
1559 | struct cache_detail *cd = PDE_DATA(inode); | |
1560 | ||
1561 | return content_release(inode, filp, cd); | |
1562 | } | |
1563 | ||
1564 | static const struct file_operations content_file_operations_procfs = { | |
1565 | .open = content_open_procfs, | |
1566 | .read = seq_read, | |
1567 | .llseek = seq_lseek, | |
1568 | .release = content_release_procfs, | |
1569 | }; | |
1570 | ||
1571 | static int open_flush_procfs(struct inode *inode, struct file *filp) | |
1572 | { | |
1573 | struct cache_detail *cd = PDE_DATA(inode); | |
1574 | ||
1575 | return open_flush(inode, filp, cd); | |
1576 | } | |
1577 | ||
1578 | static int release_flush_procfs(struct inode *inode, struct file *filp) | |
1579 | { | |
1580 | struct cache_detail *cd = PDE_DATA(inode); | |
1581 | ||
1582 | return release_flush(inode, filp, cd); | |
1583 | } | |
1584 | ||
1585 | static ssize_t read_flush_procfs(struct file *filp, char __user *buf, | |
1586 | size_t count, loff_t *ppos) | |
1587 | { | |
1588 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1589 | ||
1590 | return read_flush(filp, buf, count, ppos, cd); | |
1591 | } | |
1592 | ||
1593 | static ssize_t write_flush_procfs(struct file *filp, | |
1594 | const char __user *buf, | |
1595 | size_t count, loff_t *ppos) | |
1596 | { | |
1597 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); | |
1598 | ||
1599 | return write_flush(filp, buf, count, ppos, cd); | |
1600 | } | |
1601 | ||
1602 | static const struct file_operations cache_flush_operations_procfs = { | |
1603 | .open = open_flush_procfs, | |
1604 | .read = read_flush_procfs, | |
1605 | .write = write_flush_procfs, | |
1606 | .release = release_flush_procfs, | |
1607 | .llseek = no_llseek, | |
1608 | }; | |
1609 | ||
1610 | static void remove_cache_proc_entries(struct cache_detail *cd) | |
1611 | { | |
1612 | if (cd->procfs) { | |
1613 | proc_remove(cd->procfs); | |
1614 | cd->procfs = NULL; | |
1615 | } | |
1616 | } | |
1617 | ||
1618 | #ifdef CONFIG_PROC_FS | |
1619 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) | |
1620 | { | |
1621 | struct proc_dir_entry *p; | |
1622 | struct sunrpc_net *sn; | |
1623 | ||
1624 | sn = net_generic(net, sunrpc_net_id); | |
1625 | cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc); | |
1626 | if (cd->procfs == NULL) | |
1627 | goto out_nomem; | |
1628 | ||
1629 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, | |
1630 | cd->procfs, &cache_flush_operations_procfs, cd); | |
1631 | if (p == NULL) | |
1632 | goto out_nomem; | |
1633 | ||
1634 | if (cd->cache_request || cd->cache_parse) { | |
1635 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, | |
1636 | cd->procfs, &cache_file_operations_procfs, cd); | |
1637 | if (p == NULL) | |
1638 | goto out_nomem; | |
1639 | } | |
1640 | if (cd->cache_show) { | |
1641 | p = proc_create_data("content", S_IFREG|S_IRUSR, | |
1642 | cd->procfs, &content_file_operations_procfs, cd); | |
1643 | if (p == NULL) | |
1644 | goto out_nomem; | |
1645 | } | |
1646 | return 0; | |
1647 | out_nomem: | |
1648 | remove_cache_proc_entries(cd); | |
1649 | return -ENOMEM; | |
1650 | } | |
1651 | #else /* CONFIG_PROC_FS */ | |
1652 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) | |
1653 | { | |
1654 | return 0; | |
1655 | } | |
1656 | #endif | |
1657 | ||
1658 | void __init cache_initialize(void) | |
1659 | { | |
1660 | INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean); | |
1661 | } | |
1662 | ||
1663 | int cache_register_net(struct cache_detail *cd, struct net *net) | |
1664 | { | |
1665 | int ret; | |
1666 | ||
1667 | sunrpc_init_cache_detail(cd); | |
1668 | ret = create_cache_proc_entries(cd, net); | |
1669 | if (ret) | |
1670 | sunrpc_destroy_cache_detail(cd); | |
1671 | return ret; | |
1672 | } | |
1673 | EXPORT_SYMBOL_GPL(cache_register_net); | |
1674 | ||
1675 | void cache_unregister_net(struct cache_detail *cd, struct net *net) | |
1676 | { | |
1677 | remove_cache_proc_entries(cd); | |
1678 | sunrpc_destroy_cache_detail(cd); | |
1679 | } | |
1680 | EXPORT_SYMBOL_GPL(cache_unregister_net); | |
1681 | ||
1682 | struct cache_detail *cache_create_net(const struct cache_detail *tmpl, struct net *net) | |
1683 | { | |
1684 | struct cache_detail *cd; | |
1685 | int i; | |
1686 | ||
1687 | cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); | |
1688 | if (cd == NULL) | |
1689 | return ERR_PTR(-ENOMEM); | |
1690 | ||
1691 | cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head), | |
1692 | GFP_KERNEL); | |
1693 | if (cd->hash_table == NULL) { | |
1694 | kfree(cd); | |
1695 | return ERR_PTR(-ENOMEM); | |
1696 | } | |
1697 | ||
1698 | for (i = 0; i < cd->hash_size; i++) | |
1699 | INIT_HLIST_HEAD(&cd->hash_table[i]); | |
1700 | cd->net = net; | |
1701 | return cd; | |
1702 | } | |
1703 | EXPORT_SYMBOL_GPL(cache_create_net); | |
1704 | ||
1705 | void cache_destroy_net(struct cache_detail *cd, struct net *net) | |
1706 | { | |
1707 | kfree(cd->hash_table); | |
1708 | kfree(cd); | |
1709 | } | |
1710 | EXPORT_SYMBOL_GPL(cache_destroy_net); | |
1711 | ||
1712 | static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, | |
1713 | size_t count, loff_t *ppos) | |
1714 | { | |
1715 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1716 | ||
1717 | return cache_read(filp, buf, count, ppos, cd); | |
1718 | } | |
1719 | ||
1720 | static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, | |
1721 | size_t count, loff_t *ppos) | |
1722 | { | |
1723 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1724 | ||
1725 | return cache_write(filp, buf, count, ppos, cd); | |
1726 | } | |
1727 | ||
1728 | static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) | |
1729 | { | |
1730 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1731 | ||
1732 | return cache_poll(filp, wait, cd); | |
1733 | } | |
1734 | ||
1735 | static long cache_ioctl_pipefs(struct file *filp, | |
1736 | unsigned int cmd, unsigned long arg) | |
1737 | { | |
1738 | struct inode *inode = file_inode(filp); | |
1739 | struct cache_detail *cd = RPC_I(inode)->private; | |
1740 | ||
1741 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1742 | } | |
1743 | ||
1744 | static int cache_open_pipefs(struct inode *inode, struct file *filp) | |
1745 | { | |
1746 | struct cache_detail *cd = RPC_I(inode)->private; | |
1747 | ||
1748 | return cache_open(inode, filp, cd); | |
1749 | } | |
1750 | ||
1751 | static int cache_release_pipefs(struct inode *inode, struct file *filp) | |
1752 | { | |
1753 | struct cache_detail *cd = RPC_I(inode)->private; | |
1754 | ||
1755 | return cache_release(inode, filp, cd); | |
1756 | } | |
1757 | ||
1758 | const struct file_operations cache_file_operations_pipefs = { | |
1759 | .owner = THIS_MODULE, | |
1760 | .llseek = no_llseek, | |
1761 | .read = cache_read_pipefs, | |
1762 | .write = cache_write_pipefs, | |
1763 | .poll = cache_poll_pipefs, | |
1764 | .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ | |
1765 | .open = cache_open_pipefs, | |
1766 | .release = cache_release_pipefs, | |
1767 | }; | |
1768 | ||
1769 | static int content_open_pipefs(struct inode *inode, struct file *filp) | |
1770 | { | |
1771 | struct cache_detail *cd = RPC_I(inode)->private; | |
1772 | ||
1773 | return content_open(inode, filp, cd); | |
1774 | } | |
1775 | ||
1776 | static int content_release_pipefs(struct inode *inode, struct file *filp) | |
1777 | { | |
1778 | struct cache_detail *cd = RPC_I(inode)->private; | |
1779 | ||
1780 | return content_release(inode, filp, cd); | |
1781 | } | |
1782 | ||
1783 | const struct file_operations content_file_operations_pipefs = { | |
1784 | .open = content_open_pipefs, | |
1785 | .read = seq_read, | |
1786 | .llseek = seq_lseek, | |
1787 | .release = content_release_pipefs, | |
1788 | }; | |
1789 | ||
1790 | static int open_flush_pipefs(struct inode *inode, struct file *filp) | |
1791 | { | |
1792 | struct cache_detail *cd = RPC_I(inode)->private; | |
1793 | ||
1794 | return open_flush(inode, filp, cd); | |
1795 | } | |
1796 | ||
1797 | static int release_flush_pipefs(struct inode *inode, struct file *filp) | |
1798 | { | |
1799 | struct cache_detail *cd = RPC_I(inode)->private; | |
1800 | ||
1801 | return release_flush(inode, filp, cd); | |
1802 | } | |
1803 | ||
1804 | static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, | |
1805 | size_t count, loff_t *ppos) | |
1806 | { | |
1807 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1808 | ||
1809 | return read_flush(filp, buf, count, ppos, cd); | |
1810 | } | |
1811 | ||
1812 | static ssize_t write_flush_pipefs(struct file *filp, | |
1813 | const char __user *buf, | |
1814 | size_t count, loff_t *ppos) | |
1815 | { | |
1816 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; | |
1817 | ||
1818 | return write_flush(filp, buf, count, ppos, cd); | |
1819 | } | |
1820 | ||
1821 | const struct file_operations cache_flush_operations_pipefs = { | |
1822 | .open = open_flush_pipefs, | |
1823 | .read = read_flush_pipefs, | |
1824 | .write = write_flush_pipefs, | |
1825 | .release = release_flush_pipefs, | |
1826 | .llseek = no_llseek, | |
1827 | }; | |
1828 | ||
1829 | int sunrpc_cache_register_pipefs(struct dentry *parent, | |
1830 | const char *name, umode_t umode, | |
1831 | struct cache_detail *cd) | |
1832 | { | |
1833 | struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd); | |
1834 | if (IS_ERR(dir)) | |
1835 | return PTR_ERR(dir); | |
1836 | cd->pipefs = dir; | |
1837 | return 0; | |
1838 | } | |
1839 | EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); | |
1840 | ||
1841 | void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) | |
1842 | { | |
1843 | if (cd->pipefs) { | |
1844 | rpc_remove_cache_dir(cd->pipefs); | |
1845 | cd->pipefs = NULL; | |
1846 | } | |
1847 | } | |
1848 | EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); | |
1849 | ||
1850 | void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h) | |
1851 | { | |
1852 | write_lock(&cd->hash_lock); | |
1853 | if (!hlist_unhashed(&h->cache_list)){ | |
1854 | hlist_del_init(&h->cache_list); | |
1855 | cd->entries--; | |
1856 | write_unlock(&cd->hash_lock); | |
1857 | cache_put(h, cd); | |
1858 | } else | |
1859 | write_unlock(&cd->hash_lock); | |
1860 | } | |
1861 | EXPORT_SYMBOL_GPL(sunrpc_cache_unhash); |