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Commit | Line | Data |
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1da177e4 LT |
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> | |
4a3e2f71 | 29 | #include <linux/mutex.h> |
da77005f | 30 | #include <linux/pagemap.h> |
1da177e4 LT |
31 | #include <asm/ioctls.h> |
32 | #include <linux/sunrpc/types.h> | |
33 | #include <linux/sunrpc/cache.h> | |
34 | #include <linux/sunrpc/stats.h> | |
8854e82d | 35 | #include <linux/sunrpc/rpc_pipe_fs.h> |
1da177e4 LT |
36 | |
37 | #define RPCDBG_FACILITY RPCDBG_CACHE | |
38 | ||
e0bb89ef | 39 | static int cache_defer_req(struct cache_req *req, struct cache_head *item); |
1da177e4 LT |
40 | static void cache_revisit_request(struct cache_head *item); |
41 | ||
74cae61a | 42 | static void cache_init(struct cache_head *h) |
1da177e4 LT |
43 | { |
44 | time_t now = get_seconds(); | |
45 | h->next = NULL; | |
46 | h->flags = 0; | |
baab935f | 47 | kref_init(&h->ref); |
1da177e4 LT |
48 | h->expiry_time = now + CACHE_NEW_EXPIRY; |
49 | h->last_refresh = now; | |
50 | } | |
51 | ||
15a5f6bd N |
52 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, |
53 | struct cache_head *key, int hash) | |
54 | { | |
55 | struct cache_head **head, **hp; | |
56 | struct cache_head *new = NULL; | |
57 | ||
58 | head = &detail->hash_table[hash]; | |
59 | ||
60 | read_lock(&detail->hash_lock); | |
61 | ||
62 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
63 | struct cache_head *tmp = *hp; | |
64 | if (detail->match(tmp, key)) { | |
65 | cache_get(tmp); | |
66 | read_unlock(&detail->hash_lock); | |
67 | return tmp; | |
68 | } | |
69 | } | |
70 | read_unlock(&detail->hash_lock); | |
71 | /* Didn't find anything, insert an empty entry */ | |
72 | ||
73 | new = detail->alloc(); | |
74 | if (!new) | |
75 | return NULL; | |
2f34931f NB |
76 | /* must fully initialise 'new', else |
77 | * we might get lose if we need to | |
78 | * cache_put it soon. | |
79 | */ | |
15a5f6bd | 80 | cache_init(new); |
2f34931f | 81 | detail->init(new, key); |
15a5f6bd N |
82 | |
83 | write_lock(&detail->hash_lock); | |
84 | ||
85 | /* check if entry appeared while we slept */ | |
86 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
87 | struct cache_head *tmp = *hp; | |
88 | if (detail->match(tmp, key)) { | |
89 | cache_get(tmp); | |
90 | write_unlock(&detail->hash_lock); | |
baab935f | 91 | cache_put(new, detail); |
15a5f6bd N |
92 | return tmp; |
93 | } | |
94 | } | |
15a5f6bd N |
95 | new->next = *head; |
96 | *head = new; | |
97 | detail->entries++; | |
98 | cache_get(new); | |
99 | write_unlock(&detail->hash_lock); | |
100 | ||
101 | return new; | |
102 | } | |
24c3767e | 103 | EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); |
15a5f6bd | 104 | |
ebd0cb1a | 105 | |
f866a819 | 106 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); |
ebd0cb1a | 107 | |
908329f2 | 108 | static void cache_fresh_locked(struct cache_head *head, time_t expiry) |
ebd0cb1a N |
109 | { |
110 | head->expiry_time = expiry; | |
111 | head->last_refresh = get_seconds(); | |
908329f2 | 112 | set_bit(CACHE_VALID, &head->flags); |
ebd0cb1a N |
113 | } |
114 | ||
115 | static void cache_fresh_unlocked(struct cache_head *head, | |
908329f2 | 116 | struct cache_detail *detail) |
ebd0cb1a | 117 | { |
ebd0cb1a N |
118 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { |
119 | cache_revisit_request(head); | |
f866a819 | 120 | cache_dequeue(detail, head); |
ebd0cb1a N |
121 | } |
122 | } | |
123 | ||
15a5f6bd N |
124 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, |
125 | struct cache_head *new, struct cache_head *old, int hash) | |
126 | { | |
127 | /* The 'old' entry is to be replaced by 'new'. | |
128 | * If 'old' is not VALID, we update it directly, | |
129 | * otherwise we need to replace it | |
130 | */ | |
131 | struct cache_head **head; | |
132 | struct cache_head *tmp; | |
133 | ||
134 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
135 | write_lock(&detail->hash_lock); | |
136 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
137 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
138 | set_bit(CACHE_NEGATIVE, &old->flags); | |
139 | else | |
140 | detail->update(old, new); | |
908329f2 | 141 | cache_fresh_locked(old, new->expiry_time); |
15a5f6bd | 142 | write_unlock(&detail->hash_lock); |
908329f2 | 143 | cache_fresh_unlocked(old, detail); |
15a5f6bd N |
144 | return old; |
145 | } | |
146 | write_unlock(&detail->hash_lock); | |
147 | } | |
148 | /* We need to insert a new entry */ | |
149 | tmp = detail->alloc(); | |
150 | if (!tmp) { | |
baab935f | 151 | cache_put(old, detail); |
15a5f6bd N |
152 | return NULL; |
153 | } | |
154 | cache_init(tmp); | |
155 | detail->init(tmp, old); | |
156 | head = &detail->hash_table[hash]; | |
157 | ||
158 | write_lock(&detail->hash_lock); | |
159 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
160 | set_bit(CACHE_NEGATIVE, &tmp->flags); | |
161 | else | |
162 | detail->update(tmp, new); | |
163 | tmp->next = *head; | |
164 | *head = tmp; | |
f2d39586 | 165 | detail->entries++; |
15a5f6bd | 166 | cache_get(tmp); |
908329f2 | 167 | cache_fresh_locked(tmp, new->expiry_time); |
ebd0cb1a | 168 | cache_fresh_locked(old, 0); |
15a5f6bd | 169 | write_unlock(&detail->hash_lock); |
908329f2 N |
170 | cache_fresh_unlocked(tmp, detail); |
171 | cache_fresh_unlocked(old, detail); | |
baab935f | 172 | cache_put(old, detail); |
15a5f6bd N |
173 | return tmp; |
174 | } | |
24c3767e | 175 | EXPORT_SYMBOL_GPL(sunrpc_cache_update); |
1da177e4 | 176 | |
bc74b4f5 TM |
177 | static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) |
178 | { | |
179 | if (!cd->cache_upcall) | |
180 | return -EINVAL; | |
181 | return cd->cache_upcall(cd, h); | |
182 | } | |
989a19b9 N |
183 | |
184 | static inline int cache_is_valid(struct cache_detail *detail, struct cache_head *h) | |
185 | { | |
186 | if (!test_bit(CACHE_VALID, &h->flags) || | |
187 | h->expiry_time < get_seconds()) | |
188 | return -EAGAIN; | |
189 | else if (detail->flush_time > h->last_refresh) | |
190 | return -EAGAIN; | |
191 | else { | |
192 | /* entry is valid */ | |
193 | if (test_bit(CACHE_NEGATIVE, &h->flags)) | |
194 | return -ENOENT; | |
195 | else | |
196 | return 0; | |
197 | } | |
198 | } | |
e9dc1221 | 199 | |
1da177e4 LT |
200 | /* |
201 | * This is the generic cache management routine for all | |
202 | * the authentication caches. | |
203 | * It checks the currency of a cache item and will (later) | |
204 | * initiate an upcall to fill it if needed. | |
205 | * | |
206 | * | |
207 | * Returns 0 if the cache_head can be used, or cache_puts it and returns | |
989a19b9 N |
208 | * -EAGAIN if upcall is pending and request has been queued |
209 | * -ETIMEDOUT if upcall failed or request could not be queue or | |
210 | * upcall completed but item is still invalid (implying that | |
211 | * the cache item has been replaced with a newer one). | |
1da177e4 LT |
212 | * -ENOENT if cache entry was negative |
213 | */ | |
214 | int cache_check(struct cache_detail *detail, | |
215 | struct cache_head *h, struct cache_req *rqstp) | |
216 | { | |
217 | int rv; | |
218 | long refresh_age, age; | |
219 | ||
220 | /* First decide return status as best we can */ | |
989a19b9 | 221 | rv = cache_is_valid(detail, h); |
1da177e4 LT |
222 | |
223 | /* now see if we want to start an upcall */ | |
224 | refresh_age = (h->expiry_time - h->last_refresh); | |
225 | age = get_seconds() - h->last_refresh; | |
226 | ||
227 | if (rqstp == NULL) { | |
228 | if (rv == -EAGAIN) | |
229 | rv = -ENOENT; | |
230 | } else if (rv == -EAGAIN || age > refresh_age/2) { | |
46121cf7 CL |
231 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", |
232 | refresh_age, age); | |
1da177e4 LT |
233 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
234 | switch (cache_make_upcall(detail, h)) { | |
235 | case -EINVAL: | |
236 | clear_bit(CACHE_PENDING, &h->flags); | |
5c4d2639 | 237 | cache_revisit_request(h); |
1da177e4 LT |
238 | if (rv == -EAGAIN) { |
239 | set_bit(CACHE_NEGATIVE, &h->flags); | |
908329f2 N |
240 | cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY); |
241 | cache_fresh_unlocked(h, detail); | |
1da177e4 LT |
242 | rv = -ENOENT; |
243 | } | |
244 | break; | |
245 | ||
246 | case -EAGAIN: | |
247 | clear_bit(CACHE_PENDING, &h->flags); | |
248 | cache_revisit_request(h); | |
249 | break; | |
250 | } | |
251 | } | |
252 | } | |
253 | ||
989a19b9 | 254 | if (rv == -EAGAIN) { |
9e4c6379 | 255 | if (cache_defer_req(rqstp, h) < 0) { |
989a19b9 N |
256 | /* Request is not deferred */ |
257 | rv = cache_is_valid(detail, h); | |
258 | if (rv == -EAGAIN) | |
259 | rv = -ETIMEDOUT; | |
260 | } | |
261 | } | |
4013edea | 262 | if (rv) |
baab935f | 263 | cache_put(h, detail); |
1da177e4 LT |
264 | return rv; |
265 | } | |
24c3767e | 266 | EXPORT_SYMBOL_GPL(cache_check); |
1da177e4 | 267 | |
1da177e4 LT |
268 | /* |
269 | * caches need to be periodically cleaned. | |
270 | * For this we maintain a list of cache_detail and | |
271 | * a current pointer into that list and into the table | |
272 | * for that entry. | |
273 | * | |
274 | * Each time clean_cache is called it finds the next non-empty entry | |
275 | * in the current table and walks the list in that entry | |
276 | * looking for entries that can be removed. | |
277 | * | |
278 | * An entry gets removed if: | |
279 | * - The expiry is before current time | |
280 | * - The last_refresh time is before the flush_time for that cache | |
281 | * | |
282 | * later we might drop old entries with non-NEVER expiry if that table | |
283 | * is getting 'full' for some definition of 'full' | |
284 | * | |
285 | * The question of "how often to scan a table" is an interesting one | |
286 | * and is answered in part by the use of the "nextcheck" field in the | |
287 | * cache_detail. | |
288 | * When a scan of a table begins, the nextcheck field is set to a time | |
289 | * that is well into the future. | |
290 | * While scanning, if an expiry time is found that is earlier than the | |
291 | * current nextcheck time, nextcheck is set to that expiry time. | |
292 | * If the flush_time is ever set to a time earlier than the nextcheck | |
293 | * time, the nextcheck time is then set to that flush_time. | |
294 | * | |
295 | * A table is then only scanned if the current time is at least | |
296 | * the nextcheck time. | |
cca5172a | 297 | * |
1da177e4 LT |
298 | */ |
299 | ||
300 | static LIST_HEAD(cache_list); | |
301 | static DEFINE_SPINLOCK(cache_list_lock); | |
302 | static struct cache_detail *current_detail; | |
303 | static int current_index; | |
304 | ||
65f27f38 DH |
305 | static void do_cache_clean(struct work_struct *work); |
306 | static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean); | |
1da177e4 | 307 | |
5b7a1b9f | 308 | static void sunrpc_init_cache_detail(struct cache_detail *cd) |
ffe9386b | 309 | { |
1da177e4 LT |
310 | rwlock_init(&cd->hash_lock); |
311 | INIT_LIST_HEAD(&cd->queue); | |
312 | spin_lock(&cache_list_lock); | |
313 | cd->nextcheck = 0; | |
314 | cd->entries = 0; | |
315 | atomic_set(&cd->readers, 0); | |
316 | cd->last_close = 0; | |
317 | cd->last_warn = -1; | |
318 | list_add(&cd->others, &cache_list); | |
319 | spin_unlock(&cache_list_lock); | |
320 | ||
321 | /* start the cleaning process */ | |
52bad64d | 322 | schedule_delayed_work(&cache_cleaner, 0); |
1da177e4 LT |
323 | } |
324 | ||
5b7a1b9f | 325 | static void sunrpc_destroy_cache_detail(struct cache_detail *cd) |
1da177e4 LT |
326 | { |
327 | cache_purge(cd); | |
328 | spin_lock(&cache_list_lock); | |
329 | write_lock(&cd->hash_lock); | |
330 | if (cd->entries || atomic_read(&cd->inuse)) { | |
331 | write_unlock(&cd->hash_lock); | |
332 | spin_unlock(&cache_list_lock); | |
df95a9d4 | 333 | goto out; |
1da177e4 LT |
334 | } |
335 | if (current_detail == cd) | |
336 | current_detail = NULL; | |
337 | list_del_init(&cd->others); | |
338 | write_unlock(&cd->hash_lock); | |
339 | spin_unlock(&cache_list_lock); | |
1da177e4 LT |
340 | if (list_empty(&cache_list)) { |
341 | /* module must be being unloaded so its safe to kill the worker */ | |
4011cd97 | 342 | cancel_delayed_work_sync(&cache_cleaner); |
1da177e4 | 343 | } |
df95a9d4 BF |
344 | return; |
345 | out: | |
346 | printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); | |
1da177e4 LT |
347 | } |
348 | ||
349 | /* clean cache tries to find something to clean | |
350 | * and cleans it. | |
351 | * It returns 1 if it cleaned something, | |
352 | * 0 if it didn't find anything this time | |
353 | * -1 if it fell off the end of the list. | |
354 | */ | |
355 | static int cache_clean(void) | |
356 | { | |
357 | int rv = 0; | |
358 | struct list_head *next; | |
359 | ||
360 | spin_lock(&cache_list_lock); | |
361 | ||
362 | /* find a suitable table if we don't already have one */ | |
363 | while (current_detail == NULL || | |
364 | current_index >= current_detail->hash_size) { | |
365 | if (current_detail) | |
366 | next = current_detail->others.next; | |
367 | else | |
368 | next = cache_list.next; | |
369 | if (next == &cache_list) { | |
370 | current_detail = NULL; | |
371 | spin_unlock(&cache_list_lock); | |
372 | return -1; | |
373 | } | |
374 | current_detail = list_entry(next, struct cache_detail, others); | |
375 | if (current_detail->nextcheck > get_seconds()) | |
376 | current_index = current_detail->hash_size; | |
377 | else { | |
378 | current_index = 0; | |
379 | current_detail->nextcheck = get_seconds()+30*60; | |
380 | } | |
381 | } | |
382 | ||
383 | /* find a non-empty bucket in the table */ | |
384 | while (current_detail && | |
385 | current_index < current_detail->hash_size && | |
386 | current_detail->hash_table[current_index] == NULL) | |
387 | current_index++; | |
388 | ||
389 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ | |
cca5172a | 390 | |
1da177e4 LT |
391 | if (current_detail && current_index < current_detail->hash_size) { |
392 | struct cache_head *ch, **cp; | |
393 | struct cache_detail *d; | |
cca5172a | 394 | |
1da177e4 LT |
395 | write_lock(¤t_detail->hash_lock); |
396 | ||
397 | /* Ok, now to clean this strand */ | |
cca5172a | 398 | |
1da177e4 LT |
399 | cp = & current_detail->hash_table[current_index]; |
400 | ch = *cp; | |
401 | for (; ch; cp= & ch->next, ch= *cp) { | |
402 | if (current_detail->nextcheck > ch->expiry_time) | |
403 | current_detail->nextcheck = ch->expiry_time+1; | |
f64f9e71 JP |
404 | if (ch->expiry_time >= get_seconds() && |
405 | ch->last_refresh >= current_detail->flush_time) | |
1da177e4 LT |
406 | continue; |
407 | if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) | |
f866a819 | 408 | cache_dequeue(current_detail, ch); |
1da177e4 | 409 | |
baab935f | 410 | if (atomic_read(&ch->ref.refcount) == 1) |
1da177e4 LT |
411 | break; |
412 | } | |
413 | if (ch) { | |
414 | *cp = ch->next; | |
415 | ch->next = NULL; | |
416 | current_detail->entries--; | |
417 | rv = 1; | |
418 | } | |
419 | write_unlock(¤t_detail->hash_lock); | |
420 | d = current_detail; | |
421 | if (!ch) | |
422 | current_index ++; | |
423 | spin_unlock(&cache_list_lock); | |
5c4d2639 N |
424 | if (ch) { |
425 | cache_revisit_request(ch); | |
baab935f | 426 | cache_put(ch, d); |
5c4d2639 | 427 | } |
1da177e4 LT |
428 | } else |
429 | spin_unlock(&cache_list_lock); | |
430 | ||
431 | return rv; | |
432 | } | |
433 | ||
434 | /* | |
435 | * We want to regularly clean the cache, so we need to schedule some work ... | |
436 | */ | |
65f27f38 | 437 | static void do_cache_clean(struct work_struct *work) |
1da177e4 LT |
438 | { |
439 | int delay = 5; | |
440 | if (cache_clean() == -1) | |
6aad89c8 | 441 | delay = round_jiffies_relative(30*HZ); |
1da177e4 LT |
442 | |
443 | if (list_empty(&cache_list)) | |
444 | delay = 0; | |
445 | ||
446 | if (delay) | |
447 | schedule_delayed_work(&cache_cleaner, delay); | |
448 | } | |
449 | ||
450 | ||
cca5172a | 451 | /* |
1da177e4 | 452 | * Clean all caches promptly. This just calls cache_clean |
cca5172a | 453 | * repeatedly until we are sure that every cache has had a chance to |
1da177e4 LT |
454 | * be fully cleaned |
455 | */ | |
456 | void cache_flush(void) | |
457 | { | |
458 | while (cache_clean() != -1) | |
459 | cond_resched(); | |
460 | while (cache_clean() != -1) | |
461 | cond_resched(); | |
462 | } | |
24c3767e | 463 | EXPORT_SYMBOL_GPL(cache_flush); |
1da177e4 LT |
464 | |
465 | void cache_purge(struct cache_detail *detail) | |
466 | { | |
467 | detail->flush_time = LONG_MAX; | |
468 | detail->nextcheck = get_seconds(); | |
469 | cache_flush(); | |
470 | detail->flush_time = 1; | |
471 | } | |
24c3767e | 472 | EXPORT_SYMBOL_GPL(cache_purge); |
1da177e4 LT |
473 | |
474 | ||
475 | /* | |
476 | * Deferral and Revisiting of Requests. | |
477 | * | |
478 | * If a cache lookup finds a pending entry, we | |
479 | * need to defer the request and revisit it later. | |
480 | * All deferred requests are stored in a hash table, | |
481 | * indexed by "struct cache_head *". | |
482 | * As it may be wasteful to store a whole request | |
cca5172a | 483 | * structure, we allow the request to provide a |
1da177e4 LT |
484 | * deferred form, which must contain a |
485 | * 'struct cache_deferred_req' | |
486 | * This cache_deferred_req contains a method to allow | |
487 | * it to be revisited when cache info is available | |
488 | */ | |
489 | ||
490 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) | |
491 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) | |
492 | ||
493 | #define DFR_MAX 300 /* ??? */ | |
494 | ||
495 | static DEFINE_SPINLOCK(cache_defer_lock); | |
496 | static LIST_HEAD(cache_defer_list); | |
497 | static struct list_head cache_defer_hash[DFR_HASHSIZE]; | |
498 | static int cache_defer_cnt; | |
499 | ||
e0bb89ef | 500 | static int cache_defer_req(struct cache_req *req, struct cache_head *item) |
1da177e4 | 501 | { |
cd68c374 | 502 | struct cache_deferred_req *dreq, *discard; |
1da177e4 LT |
503 | int hash = DFR_HASH(item); |
504 | ||
01f3bd1f BF |
505 | if (cache_defer_cnt >= DFR_MAX) { |
506 | /* too much in the cache, randomly drop this one, | |
507 | * or continue and drop the oldest below | |
508 | */ | |
509 | if (net_random()&1) | |
9e4c6379 | 510 | return -ENOMEM; |
01f3bd1f | 511 | } |
1da177e4 LT |
512 | dreq = req->defer(req); |
513 | if (dreq == NULL) | |
9e4c6379 | 514 | return -ENOMEM; |
1da177e4 LT |
515 | |
516 | dreq->item = item; | |
1da177e4 LT |
517 | |
518 | spin_lock(&cache_defer_lock); | |
519 | ||
520 | list_add(&dreq->recent, &cache_defer_list); | |
521 | ||
522 | if (cache_defer_hash[hash].next == NULL) | |
523 | INIT_LIST_HEAD(&cache_defer_hash[hash]); | |
524 | list_add(&dreq->hash, &cache_defer_hash[hash]); | |
525 | ||
526 | /* it is in, now maybe clean up */ | |
cd68c374 | 527 | discard = NULL; |
1da177e4 | 528 | if (++cache_defer_cnt > DFR_MAX) { |
cd68c374 N |
529 | discard = list_entry(cache_defer_list.prev, |
530 | struct cache_deferred_req, recent); | |
531 | list_del_init(&discard->recent); | |
532 | list_del_init(&discard->hash); | |
1da177e4 LT |
533 | cache_defer_cnt--; |
534 | } | |
535 | spin_unlock(&cache_defer_lock); | |
536 | ||
cd68c374 | 537 | if (discard) |
1da177e4 | 538 | /* there was one too many */ |
cd68c374 N |
539 | discard->revisit(discard, 1); |
540 | ||
4013edea | 541 | if (!test_bit(CACHE_PENDING, &item->flags)) { |
1da177e4 LT |
542 | /* must have just been validated... */ |
543 | cache_revisit_request(item); | |
9e4c6379 | 544 | return -EAGAIN; |
1da177e4 | 545 | } |
9e4c6379 | 546 | return 0; |
1da177e4 LT |
547 | } |
548 | ||
549 | static void cache_revisit_request(struct cache_head *item) | |
550 | { | |
551 | struct cache_deferred_req *dreq; | |
552 | struct list_head pending; | |
553 | ||
554 | struct list_head *lp; | |
555 | int hash = DFR_HASH(item); | |
556 | ||
557 | INIT_LIST_HEAD(&pending); | |
558 | spin_lock(&cache_defer_lock); | |
cca5172a | 559 | |
1da177e4 LT |
560 | lp = cache_defer_hash[hash].next; |
561 | if (lp) { | |
562 | while (lp != &cache_defer_hash[hash]) { | |
563 | dreq = list_entry(lp, struct cache_deferred_req, hash); | |
564 | lp = lp->next; | |
565 | if (dreq->item == item) { | |
67e7328f | 566 | list_del_init(&dreq->hash); |
1da177e4 LT |
567 | list_move(&dreq->recent, &pending); |
568 | cache_defer_cnt--; | |
569 | } | |
570 | } | |
571 | } | |
572 | spin_unlock(&cache_defer_lock); | |
573 | ||
574 | while (!list_empty(&pending)) { | |
575 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
576 | list_del_init(&dreq->recent); | |
577 | dreq->revisit(dreq, 0); | |
578 | } | |
579 | } | |
580 | ||
581 | void cache_clean_deferred(void *owner) | |
582 | { | |
583 | struct cache_deferred_req *dreq, *tmp; | |
584 | struct list_head pending; | |
585 | ||
586 | ||
587 | INIT_LIST_HEAD(&pending); | |
588 | spin_lock(&cache_defer_lock); | |
cca5172a | 589 | |
1da177e4 LT |
590 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { |
591 | if (dreq->owner == owner) { | |
67e7328f | 592 | list_del_init(&dreq->hash); |
1da177e4 LT |
593 | list_move(&dreq->recent, &pending); |
594 | cache_defer_cnt--; | |
595 | } | |
596 | } | |
597 | spin_unlock(&cache_defer_lock); | |
598 | ||
599 | while (!list_empty(&pending)) { | |
600 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
601 | list_del_init(&dreq->recent); | |
602 | dreq->revisit(dreq, 1); | |
603 | } | |
604 | } | |
605 | ||
606 | /* | |
607 | * communicate with user-space | |
608 | * | |
a490c681 BF |
609 | * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. |
610 | * On read, you get a full request, or block. | |
611 | * On write, an update request is processed. | |
612 | * Poll works if anything to read, and always allows write. | |
1da177e4 | 613 | * |
cca5172a | 614 | * Implemented by linked list of requests. Each open file has |
a490c681 | 615 | * a ->private that also exists in this list. New requests are added |
1da177e4 LT |
616 | * to the end and may wakeup and preceding readers. |
617 | * New readers are added to the head. If, on read, an item is found with | |
618 | * CACHE_UPCALLING clear, we free it from the list. | |
619 | * | |
620 | */ | |
621 | ||
622 | static DEFINE_SPINLOCK(queue_lock); | |
4a3e2f71 | 623 | static DEFINE_MUTEX(queue_io_mutex); |
1da177e4 LT |
624 | |
625 | struct cache_queue { | |
626 | struct list_head list; | |
627 | int reader; /* if 0, then request */ | |
628 | }; | |
629 | struct cache_request { | |
630 | struct cache_queue q; | |
631 | struct cache_head *item; | |
632 | char * buf; | |
633 | int len; | |
634 | int readers; | |
635 | }; | |
636 | struct cache_reader { | |
637 | struct cache_queue q; | |
638 | int offset; /* if non-0, we have a refcnt on next request */ | |
639 | }; | |
640 | ||
173912a6 TM |
641 | static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, |
642 | loff_t *ppos, struct cache_detail *cd) | |
1da177e4 LT |
643 | { |
644 | struct cache_reader *rp = filp->private_data; | |
645 | struct cache_request *rq; | |
da77005f | 646 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
647 | int err; |
648 | ||
649 | if (count == 0) | |
650 | return 0; | |
651 | ||
da77005f | 652 | mutex_lock(&inode->i_mutex); /* protect against multiple concurrent |
1da177e4 LT |
653 | * readers on this file */ |
654 | again: | |
655 | spin_lock(&queue_lock); | |
656 | /* need to find next request */ | |
657 | while (rp->q.list.next != &cd->queue && | |
658 | list_entry(rp->q.list.next, struct cache_queue, list) | |
659 | ->reader) { | |
660 | struct list_head *next = rp->q.list.next; | |
661 | list_move(&rp->q.list, next); | |
662 | } | |
663 | if (rp->q.list.next == &cd->queue) { | |
664 | spin_unlock(&queue_lock); | |
da77005f | 665 | mutex_unlock(&inode->i_mutex); |
09a62660 | 666 | BUG_ON(rp->offset); |
1da177e4 LT |
667 | return 0; |
668 | } | |
669 | rq = container_of(rp->q.list.next, struct cache_request, q.list); | |
09a62660 | 670 | BUG_ON(rq->q.reader); |
1da177e4 LT |
671 | if (rp->offset == 0) |
672 | rq->readers++; | |
673 | spin_unlock(&queue_lock); | |
674 | ||
675 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
676 | err = -EAGAIN; | |
677 | spin_lock(&queue_lock); | |
678 | list_move(&rp->q.list, &rq->q.list); | |
679 | spin_unlock(&queue_lock); | |
680 | } else { | |
681 | if (rp->offset + count > rq->len) | |
682 | count = rq->len - rp->offset; | |
683 | err = -EFAULT; | |
684 | if (copy_to_user(buf, rq->buf + rp->offset, count)) | |
685 | goto out; | |
686 | rp->offset += count; | |
687 | if (rp->offset >= rq->len) { | |
688 | rp->offset = 0; | |
689 | spin_lock(&queue_lock); | |
690 | list_move(&rp->q.list, &rq->q.list); | |
691 | spin_unlock(&queue_lock); | |
692 | } | |
693 | err = 0; | |
694 | } | |
695 | out: | |
696 | if (rp->offset == 0) { | |
697 | /* need to release rq */ | |
698 | spin_lock(&queue_lock); | |
699 | rq->readers--; | |
700 | if (rq->readers == 0 && | |
701 | !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
702 | list_del(&rq->q.list); | |
703 | spin_unlock(&queue_lock); | |
baab935f | 704 | cache_put(rq->item, cd); |
1da177e4 LT |
705 | kfree(rq->buf); |
706 | kfree(rq); | |
707 | } else | |
708 | spin_unlock(&queue_lock); | |
709 | } | |
710 | if (err == -EAGAIN) | |
711 | goto again; | |
da77005f | 712 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
713 | return err ? err : count; |
714 | } | |
715 | ||
da77005f TM |
716 | static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, |
717 | size_t count, struct cache_detail *cd) | |
718 | { | |
719 | ssize_t ret; | |
1da177e4 | 720 | |
da77005f TM |
721 | if (copy_from_user(kaddr, buf, count)) |
722 | return -EFAULT; | |
723 | kaddr[count] = '\0'; | |
724 | ret = cd->cache_parse(cd, kaddr, count); | |
725 | if (!ret) | |
726 | ret = count; | |
727 | return ret; | |
728 | } | |
729 | ||
730 | static ssize_t cache_slow_downcall(const char __user *buf, | |
731 | size_t count, struct cache_detail *cd) | |
1da177e4 | 732 | { |
da77005f TM |
733 | static char write_buf[8192]; /* protected by queue_io_mutex */ |
734 | ssize_t ret = -EINVAL; | |
1da177e4 | 735 | |
1da177e4 | 736 | if (count >= sizeof(write_buf)) |
da77005f | 737 | goto out; |
4a3e2f71 | 738 | mutex_lock(&queue_io_mutex); |
da77005f TM |
739 | ret = cache_do_downcall(write_buf, buf, count, cd); |
740 | mutex_unlock(&queue_io_mutex); | |
741 | out: | |
742 | return ret; | |
743 | } | |
1da177e4 | 744 | |
da77005f TM |
745 | static ssize_t cache_downcall(struct address_space *mapping, |
746 | const char __user *buf, | |
747 | size_t count, struct cache_detail *cd) | |
748 | { | |
749 | struct page *page; | |
750 | char *kaddr; | |
751 | ssize_t ret = -ENOMEM; | |
752 | ||
753 | if (count >= PAGE_CACHE_SIZE) | |
754 | goto out_slow; | |
755 | ||
756 | page = find_or_create_page(mapping, 0, GFP_KERNEL); | |
757 | if (!page) | |
758 | goto out_slow; | |
759 | ||
760 | kaddr = kmap(page); | |
761 | ret = cache_do_downcall(kaddr, buf, count, cd); | |
762 | kunmap(page); | |
763 | unlock_page(page); | |
764 | page_cache_release(page); | |
765 | return ret; | |
766 | out_slow: | |
767 | return cache_slow_downcall(buf, count, cd); | |
768 | } | |
1da177e4 | 769 | |
173912a6 TM |
770 | static ssize_t cache_write(struct file *filp, const char __user *buf, |
771 | size_t count, loff_t *ppos, | |
772 | struct cache_detail *cd) | |
da77005f TM |
773 | { |
774 | struct address_space *mapping = filp->f_mapping; | |
775 | struct inode *inode = filp->f_path.dentry->d_inode; | |
da77005f TM |
776 | ssize_t ret = -EINVAL; |
777 | ||
778 | if (!cd->cache_parse) | |
779 | goto out; | |
780 | ||
781 | mutex_lock(&inode->i_mutex); | |
782 | ret = cache_downcall(mapping, buf, count, cd); | |
783 | mutex_unlock(&inode->i_mutex); | |
784 | out: | |
785 | return ret; | |
1da177e4 LT |
786 | } |
787 | ||
788 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); | |
789 | ||
173912a6 TM |
790 | static unsigned int cache_poll(struct file *filp, poll_table *wait, |
791 | struct cache_detail *cd) | |
1da177e4 LT |
792 | { |
793 | unsigned int mask; | |
794 | struct cache_reader *rp = filp->private_data; | |
795 | struct cache_queue *cq; | |
1da177e4 LT |
796 | |
797 | poll_wait(filp, &queue_wait, wait); | |
798 | ||
799 | /* alway allow write */ | |
800 | mask = POLL_OUT | POLLWRNORM; | |
801 | ||
802 | if (!rp) | |
803 | return mask; | |
804 | ||
805 | spin_lock(&queue_lock); | |
806 | ||
807 | for (cq= &rp->q; &cq->list != &cd->queue; | |
808 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
809 | if (!cq->reader) { | |
810 | mask |= POLLIN | POLLRDNORM; | |
811 | break; | |
812 | } | |
813 | spin_unlock(&queue_lock); | |
814 | return mask; | |
815 | } | |
816 | ||
173912a6 TM |
817 | static int cache_ioctl(struct inode *ino, struct file *filp, |
818 | unsigned int cmd, unsigned long arg, | |
819 | struct cache_detail *cd) | |
1da177e4 LT |
820 | { |
821 | int len = 0; | |
822 | struct cache_reader *rp = filp->private_data; | |
823 | struct cache_queue *cq; | |
1da177e4 LT |
824 | |
825 | if (cmd != FIONREAD || !rp) | |
826 | return -EINVAL; | |
827 | ||
828 | spin_lock(&queue_lock); | |
829 | ||
830 | /* only find the length remaining in current request, | |
831 | * or the length of the next request | |
832 | */ | |
833 | for (cq= &rp->q; &cq->list != &cd->queue; | |
834 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
835 | if (!cq->reader) { | |
836 | struct cache_request *cr = | |
837 | container_of(cq, struct cache_request, q); | |
838 | len = cr->len - rp->offset; | |
839 | break; | |
840 | } | |
841 | spin_unlock(&queue_lock); | |
842 | ||
843 | return put_user(len, (int __user *)arg); | |
844 | } | |
845 | ||
173912a6 TM |
846 | static int cache_open(struct inode *inode, struct file *filp, |
847 | struct cache_detail *cd) | |
1da177e4 LT |
848 | { |
849 | struct cache_reader *rp = NULL; | |
850 | ||
f7e86ab9 TM |
851 | if (!cd || !try_module_get(cd->owner)) |
852 | return -EACCES; | |
1da177e4 LT |
853 | nonseekable_open(inode, filp); |
854 | if (filp->f_mode & FMODE_READ) { | |
1da177e4 LT |
855 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); |
856 | if (!rp) | |
857 | return -ENOMEM; | |
858 | rp->offset = 0; | |
859 | rp->q.reader = 1; | |
860 | atomic_inc(&cd->readers); | |
861 | spin_lock(&queue_lock); | |
862 | list_add(&rp->q.list, &cd->queue); | |
863 | spin_unlock(&queue_lock); | |
864 | } | |
865 | filp->private_data = rp; | |
866 | return 0; | |
867 | } | |
868 | ||
173912a6 TM |
869 | static int cache_release(struct inode *inode, struct file *filp, |
870 | struct cache_detail *cd) | |
1da177e4 LT |
871 | { |
872 | struct cache_reader *rp = filp->private_data; | |
1da177e4 LT |
873 | |
874 | if (rp) { | |
875 | spin_lock(&queue_lock); | |
876 | if (rp->offset) { | |
877 | struct cache_queue *cq; | |
878 | for (cq= &rp->q; &cq->list != &cd->queue; | |
879 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
880 | if (!cq->reader) { | |
881 | container_of(cq, struct cache_request, q) | |
882 | ->readers--; | |
883 | break; | |
884 | } | |
885 | rp->offset = 0; | |
886 | } | |
887 | list_del(&rp->q.list); | |
888 | spin_unlock(&queue_lock); | |
889 | ||
890 | filp->private_data = NULL; | |
891 | kfree(rp); | |
892 | ||
893 | cd->last_close = get_seconds(); | |
894 | atomic_dec(&cd->readers); | |
895 | } | |
f7e86ab9 | 896 | module_put(cd->owner); |
1da177e4 LT |
897 | return 0; |
898 | } | |
899 | ||
900 | ||
901 | ||
f866a819 | 902 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) |
1da177e4 LT |
903 | { |
904 | struct cache_queue *cq; | |
905 | spin_lock(&queue_lock); | |
906 | list_for_each_entry(cq, &detail->queue, list) | |
907 | if (!cq->reader) { | |
908 | struct cache_request *cr = container_of(cq, struct cache_request, q); | |
909 | if (cr->item != ch) | |
910 | continue; | |
911 | if (cr->readers != 0) | |
4013edea | 912 | continue; |
1da177e4 LT |
913 | list_del(&cr->q.list); |
914 | spin_unlock(&queue_lock); | |
baab935f | 915 | cache_put(cr->item, detail); |
1da177e4 LT |
916 | kfree(cr->buf); |
917 | kfree(cr); | |
918 | return; | |
919 | } | |
920 | spin_unlock(&queue_lock); | |
921 | } | |
922 | ||
923 | /* | |
924 | * Support routines for text-based upcalls. | |
925 | * Fields are separated by spaces. | |
926 | * Fields are either mangled to quote space tab newline slosh with slosh | |
927 | * or a hexified with a leading \x | |
928 | * Record is terminated with newline. | |
929 | * | |
930 | */ | |
931 | ||
932 | void qword_add(char **bpp, int *lp, char *str) | |
933 | { | |
934 | char *bp = *bpp; | |
935 | int len = *lp; | |
936 | char c; | |
937 | ||
938 | if (len < 0) return; | |
939 | ||
940 | while ((c=*str++) && len) | |
941 | switch(c) { | |
942 | case ' ': | |
943 | case '\t': | |
944 | case '\n': | |
945 | case '\\': | |
946 | if (len >= 4) { | |
947 | *bp++ = '\\'; | |
948 | *bp++ = '0' + ((c & 0300)>>6); | |
949 | *bp++ = '0' + ((c & 0070)>>3); | |
950 | *bp++ = '0' + ((c & 0007)>>0); | |
951 | } | |
952 | len -= 4; | |
953 | break; | |
954 | default: | |
955 | *bp++ = c; | |
956 | len--; | |
957 | } | |
958 | if (c || len <1) len = -1; | |
959 | else { | |
960 | *bp++ = ' '; | |
961 | len--; | |
962 | } | |
963 | *bpp = bp; | |
964 | *lp = len; | |
965 | } | |
24c3767e | 966 | EXPORT_SYMBOL_GPL(qword_add); |
1da177e4 LT |
967 | |
968 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) | |
969 | { | |
970 | char *bp = *bpp; | |
971 | int len = *lp; | |
972 | ||
973 | if (len < 0) return; | |
974 | ||
975 | if (len > 2) { | |
976 | *bp++ = '\\'; | |
977 | *bp++ = 'x'; | |
978 | len -= 2; | |
979 | while (blen && len >= 2) { | |
980 | unsigned char c = *buf++; | |
981 | *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); | |
982 | *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); | |
983 | len -= 2; | |
984 | blen--; | |
985 | } | |
986 | } | |
987 | if (blen || len<1) len = -1; | |
988 | else { | |
989 | *bp++ = ' '; | |
990 | len--; | |
991 | } | |
992 | *bpp = bp; | |
993 | *lp = len; | |
994 | } | |
24c3767e | 995 | EXPORT_SYMBOL_GPL(qword_addhex); |
1da177e4 LT |
996 | |
997 | static void warn_no_listener(struct cache_detail *detail) | |
998 | { | |
999 | if (detail->last_warn != detail->last_close) { | |
1000 | detail->last_warn = detail->last_close; | |
1001 | if (detail->warn_no_listener) | |
2da8ca26 | 1002 | detail->warn_no_listener(detail, detail->last_close != 0); |
1da177e4 LT |
1003 | } |
1004 | } | |
1005 | ||
1006 | /* | |
bc74b4f5 TM |
1007 | * register an upcall request to user-space and queue it up for read() by the |
1008 | * upcall daemon. | |
1009 | * | |
1da177e4 LT |
1010 | * Each request is at most one page long. |
1011 | */ | |
bc74b4f5 TM |
1012 | int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, |
1013 | void (*cache_request)(struct cache_detail *, | |
1014 | struct cache_head *, | |
1015 | char **, | |
1016 | int *)) | |
1da177e4 LT |
1017 | { |
1018 | ||
1019 | char *buf; | |
1020 | struct cache_request *crq; | |
1021 | char *bp; | |
1022 | int len; | |
1023 | ||
1da177e4 LT |
1024 | if (atomic_read(&detail->readers) == 0 && |
1025 | detail->last_close < get_seconds() - 30) { | |
1026 | warn_no_listener(detail); | |
1027 | return -EINVAL; | |
1028 | } | |
1029 | ||
1030 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1031 | if (!buf) | |
1032 | return -EAGAIN; | |
1033 | ||
1034 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); | |
1035 | if (!crq) { | |
1036 | kfree(buf); | |
1037 | return -EAGAIN; | |
1038 | } | |
1039 | ||
1040 | bp = buf; len = PAGE_SIZE; | |
1041 | ||
bc74b4f5 | 1042 | cache_request(detail, h, &bp, &len); |
1da177e4 LT |
1043 | |
1044 | if (len < 0) { | |
1045 | kfree(buf); | |
1046 | kfree(crq); | |
1047 | return -EAGAIN; | |
1048 | } | |
1049 | crq->q.reader = 0; | |
1050 | crq->item = cache_get(h); | |
1051 | crq->buf = buf; | |
1052 | crq->len = PAGE_SIZE - len; | |
1053 | crq->readers = 0; | |
1054 | spin_lock(&queue_lock); | |
1055 | list_add_tail(&crq->q.list, &detail->queue); | |
1056 | spin_unlock(&queue_lock); | |
1057 | wake_up(&queue_wait); | |
1058 | return 0; | |
1059 | } | |
bc74b4f5 | 1060 | EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); |
1da177e4 LT |
1061 | |
1062 | /* | |
1063 | * parse a message from user-space and pass it | |
1064 | * to an appropriate cache | |
1065 | * Messages are, like requests, separated into fields by | |
1066 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal | |
1067 | * | |
cca5172a | 1068 | * Message is |
1da177e4 LT |
1069 | * reply cachename expiry key ... content.... |
1070 | * | |
cca5172a | 1071 | * key and content are both parsed by cache |
1da177e4 LT |
1072 | */ |
1073 | ||
1074 | #define isodigit(c) (isdigit(c) && c <= '7') | |
1075 | int qword_get(char **bpp, char *dest, int bufsize) | |
1076 | { | |
1077 | /* return bytes copied, or -1 on error */ | |
1078 | char *bp = *bpp; | |
1079 | int len = 0; | |
1080 | ||
1081 | while (*bp == ' ') bp++; | |
1082 | ||
1083 | if (bp[0] == '\\' && bp[1] == 'x') { | |
1084 | /* HEX STRING */ | |
1085 | bp += 2; | |
1086 | while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { | |
1087 | int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; | |
1088 | bp++; | |
1089 | byte <<= 4; | |
1090 | byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; | |
1091 | *dest++ = byte; | |
1092 | bp++; | |
1093 | len++; | |
1094 | } | |
1095 | } else { | |
1096 | /* text with \nnn octal quoting */ | |
1097 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { | |
1098 | if (*bp == '\\' && | |
1099 | isodigit(bp[1]) && (bp[1] <= '3') && | |
1100 | isodigit(bp[2]) && | |
1101 | isodigit(bp[3])) { | |
1102 | int byte = (*++bp -'0'); | |
1103 | bp++; | |
1104 | byte = (byte << 3) | (*bp++ - '0'); | |
1105 | byte = (byte << 3) | (*bp++ - '0'); | |
1106 | *dest++ = byte; | |
1107 | len++; | |
1108 | } else { | |
1109 | *dest++ = *bp++; | |
1110 | len++; | |
1111 | } | |
1112 | } | |
1113 | } | |
1114 | ||
1115 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') | |
1116 | return -1; | |
1117 | while (*bp == ' ') bp++; | |
1118 | *bpp = bp; | |
1119 | *dest = '\0'; | |
1120 | return len; | |
1121 | } | |
24c3767e | 1122 | EXPORT_SYMBOL_GPL(qword_get); |
1da177e4 LT |
1123 | |
1124 | ||
1125 | /* | |
1126 | * support /proc/sunrpc/cache/$CACHENAME/content | |
1127 | * as a seqfile. | |
1128 | * We call ->cache_show passing NULL for the item to | |
1129 | * get a header, then pass each real item in the cache | |
1130 | */ | |
1131 | ||
1132 | struct handle { | |
1133 | struct cache_detail *cd; | |
1134 | }; | |
1135 | ||
1136 | static void *c_start(struct seq_file *m, loff_t *pos) | |
9a429c49 | 1137 | __acquires(cd->hash_lock) |
1da177e4 LT |
1138 | { |
1139 | loff_t n = *pos; | |
1140 | unsigned hash, entry; | |
1141 | struct cache_head *ch; | |
1142 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
cca5172a | 1143 | |
1da177e4 LT |
1144 | |
1145 | read_lock(&cd->hash_lock); | |
1146 | if (!n--) | |
1147 | return SEQ_START_TOKEN; | |
1148 | hash = n >> 32; | |
1149 | entry = n & ((1LL<<32) - 1); | |
1150 | ||
1151 | for (ch=cd->hash_table[hash]; ch; ch=ch->next) | |
1152 | if (!entry--) | |
1153 | return ch; | |
1154 | n &= ~((1LL<<32) - 1); | |
1155 | do { | |
1156 | hash++; | |
1157 | n += 1LL<<32; | |
cca5172a | 1158 | } while(hash < cd->hash_size && |
1da177e4 LT |
1159 | cd->hash_table[hash]==NULL); |
1160 | if (hash >= cd->hash_size) | |
1161 | return NULL; | |
1162 | *pos = n+1; | |
1163 | return cd->hash_table[hash]; | |
1164 | } | |
1165 | ||
1166 | static void *c_next(struct seq_file *m, void *p, loff_t *pos) | |
1167 | { | |
1168 | struct cache_head *ch = p; | |
1169 | int hash = (*pos >> 32); | |
1170 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1171 | ||
1172 | if (p == SEQ_START_TOKEN) | |
1173 | hash = 0; | |
1174 | else if (ch->next == NULL) { | |
1175 | hash++; | |
1176 | *pos += 1LL<<32; | |
1177 | } else { | |
1178 | ++*pos; | |
1179 | return ch->next; | |
1180 | } | |
1181 | *pos &= ~((1LL<<32) - 1); | |
1182 | while (hash < cd->hash_size && | |
1183 | cd->hash_table[hash] == NULL) { | |
1184 | hash++; | |
1185 | *pos += 1LL<<32; | |
1186 | } | |
1187 | if (hash >= cd->hash_size) | |
1188 | return NULL; | |
1189 | ++*pos; | |
1190 | return cd->hash_table[hash]; | |
1191 | } | |
1192 | ||
1193 | static void c_stop(struct seq_file *m, void *p) | |
9a429c49 | 1194 | __releases(cd->hash_lock) |
1da177e4 LT |
1195 | { |
1196 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1197 | read_unlock(&cd->hash_lock); | |
1198 | } | |
1199 | ||
1200 | static int c_show(struct seq_file *m, void *p) | |
1201 | { | |
1202 | struct cache_head *cp = p; | |
1203 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1204 | ||
1205 | if (p == SEQ_START_TOKEN) | |
1206 | return cd->cache_show(m, cd, NULL); | |
1207 | ||
1208 | ifdebug(CACHE) | |
4013edea | 1209 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", |
baab935f | 1210 | cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags); |
1da177e4 LT |
1211 | cache_get(cp); |
1212 | if (cache_check(cd, cp, NULL)) | |
1213 | /* cache_check does a cache_put on failure */ | |
1214 | seq_printf(m, "# "); | |
1215 | else | |
1216 | cache_put(cp, cd); | |
1217 | ||
1218 | return cd->cache_show(m, cd, cp); | |
1219 | } | |
1220 | ||
56b3d975 | 1221 | static const struct seq_operations cache_content_op = { |
1da177e4 LT |
1222 | .start = c_start, |
1223 | .next = c_next, | |
1224 | .stop = c_stop, | |
1225 | .show = c_show, | |
1226 | }; | |
1227 | ||
173912a6 TM |
1228 | static int content_open(struct inode *inode, struct file *file, |
1229 | struct cache_detail *cd) | |
1da177e4 | 1230 | { |
1da177e4 | 1231 | struct handle *han; |
1da177e4 | 1232 | |
f7e86ab9 TM |
1233 | if (!cd || !try_module_get(cd->owner)) |
1234 | return -EACCES; | |
ec931035 | 1235 | han = __seq_open_private(file, &cache_content_op, sizeof(*han)); |
1da177e4 LT |
1236 | if (han == NULL) |
1237 | return -ENOMEM; | |
1238 | ||
1239 | han->cd = cd; | |
ec931035 | 1240 | return 0; |
1da177e4 | 1241 | } |
1da177e4 | 1242 | |
f7e86ab9 TM |
1243 | static int content_release(struct inode *inode, struct file *file, |
1244 | struct cache_detail *cd) | |
1245 | { | |
1246 | int ret = seq_release_private(inode, file); | |
1247 | module_put(cd->owner); | |
1248 | return ret; | |
1249 | } | |
1250 | ||
1251 | static int open_flush(struct inode *inode, struct file *file, | |
1252 | struct cache_detail *cd) | |
1253 | { | |
1254 | if (!cd || !try_module_get(cd->owner)) | |
1255 | return -EACCES; | |
1256 | return nonseekable_open(inode, file); | |
1257 | } | |
1258 | ||
1259 | static int release_flush(struct inode *inode, struct file *file, | |
1260 | struct cache_detail *cd) | |
1261 | { | |
1262 | module_put(cd->owner); | |
1263 | return 0; | |
1264 | } | |
1da177e4 LT |
1265 | |
1266 | static ssize_t read_flush(struct file *file, char __user *buf, | |
173912a6 TM |
1267 | size_t count, loff_t *ppos, |
1268 | struct cache_detail *cd) | |
1da177e4 | 1269 | { |
1da177e4 LT |
1270 | char tbuf[20]; |
1271 | unsigned long p = *ppos; | |
01b2969a | 1272 | size_t len; |
1da177e4 LT |
1273 | |
1274 | sprintf(tbuf, "%lu\n", cd->flush_time); | |
1275 | len = strlen(tbuf); | |
1276 | if (p >= len) | |
1277 | return 0; | |
1278 | len -= p; | |
01b2969a CL |
1279 | if (len > count) |
1280 | len = count; | |
1da177e4 | 1281 | if (copy_to_user(buf, (void*)(tbuf+p), len)) |
01b2969a CL |
1282 | return -EFAULT; |
1283 | *ppos += len; | |
1da177e4 LT |
1284 | return len; |
1285 | } | |
1286 | ||
173912a6 TM |
1287 | static ssize_t write_flush(struct file *file, const char __user *buf, |
1288 | size_t count, loff_t *ppos, | |
1289 | struct cache_detail *cd) | |
1da177e4 | 1290 | { |
1da177e4 LT |
1291 | char tbuf[20]; |
1292 | char *ep; | |
1293 | long flushtime; | |
1294 | if (*ppos || count > sizeof(tbuf)-1) | |
1295 | return -EINVAL; | |
1296 | if (copy_from_user(tbuf, buf, count)) | |
1297 | return -EFAULT; | |
1298 | tbuf[count] = 0; | |
1299 | flushtime = simple_strtoul(tbuf, &ep, 0); | |
1300 | if (*ep && *ep != '\n') | |
1301 | return -EINVAL; | |
1302 | ||
1303 | cd->flush_time = flushtime; | |
1304 | cd->nextcheck = get_seconds(); | |
1305 | cache_flush(); | |
1306 | ||
1307 | *ppos += count; | |
1308 | return count; | |
1309 | } | |
1310 | ||
173912a6 TM |
1311 | static ssize_t cache_read_procfs(struct file *filp, char __user *buf, |
1312 | size_t count, loff_t *ppos) | |
1313 | { | |
1314 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; | |
1315 | ||
1316 | return cache_read(filp, buf, count, ppos, cd); | |
1317 | } | |
1318 | ||
1319 | static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, | |
1320 | size_t count, loff_t *ppos) | |
1321 | { | |
1322 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; | |
1323 | ||
1324 | return cache_write(filp, buf, count, ppos, cd); | |
1325 | } | |
1326 | ||
1327 | static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) | |
1328 | { | |
1329 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; | |
1330 | ||
1331 | return cache_poll(filp, wait, cd); | |
1332 | } | |
1333 | ||
1334 | static int cache_ioctl_procfs(struct inode *inode, struct file *filp, | |
1335 | unsigned int cmd, unsigned long arg) | |
1336 | { | |
1337 | struct cache_detail *cd = PDE(inode)->data; | |
1338 | ||
1339 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1340 | } | |
1341 | ||
1342 | static int cache_open_procfs(struct inode *inode, struct file *filp) | |
1343 | { | |
1344 | struct cache_detail *cd = PDE(inode)->data; | |
1345 | ||
1346 | return cache_open(inode, filp, cd); | |
1347 | } | |
1348 | ||
1349 | static int cache_release_procfs(struct inode *inode, struct file *filp) | |
1350 | { | |
1351 | struct cache_detail *cd = PDE(inode)->data; | |
1352 | ||
1353 | return cache_release(inode, filp, cd); | |
1354 | } | |
1355 | ||
1356 | static const struct file_operations cache_file_operations_procfs = { | |
1357 | .owner = THIS_MODULE, | |
1358 | .llseek = no_llseek, | |
1359 | .read = cache_read_procfs, | |
1360 | .write = cache_write_procfs, | |
1361 | .poll = cache_poll_procfs, | |
1362 | .ioctl = cache_ioctl_procfs, /* for FIONREAD */ | |
1363 | .open = cache_open_procfs, | |
1364 | .release = cache_release_procfs, | |
1da177e4 | 1365 | }; |
173912a6 TM |
1366 | |
1367 | static int content_open_procfs(struct inode *inode, struct file *filp) | |
1368 | { | |
1369 | struct cache_detail *cd = PDE(inode)->data; | |
1370 | ||
1371 | return content_open(inode, filp, cd); | |
1372 | } | |
1373 | ||
f7e86ab9 TM |
1374 | static int content_release_procfs(struct inode *inode, struct file *filp) |
1375 | { | |
1376 | struct cache_detail *cd = PDE(inode)->data; | |
1377 | ||
1378 | return content_release(inode, filp, cd); | |
1379 | } | |
1380 | ||
173912a6 TM |
1381 | static const struct file_operations content_file_operations_procfs = { |
1382 | .open = content_open_procfs, | |
1383 | .read = seq_read, | |
1384 | .llseek = seq_lseek, | |
f7e86ab9 | 1385 | .release = content_release_procfs, |
173912a6 TM |
1386 | }; |
1387 | ||
f7e86ab9 TM |
1388 | static int open_flush_procfs(struct inode *inode, struct file *filp) |
1389 | { | |
1390 | struct cache_detail *cd = PDE(inode)->data; | |
1391 | ||
1392 | return open_flush(inode, filp, cd); | |
1393 | } | |
1394 | ||
1395 | static int release_flush_procfs(struct inode *inode, struct file *filp) | |
1396 | { | |
1397 | struct cache_detail *cd = PDE(inode)->data; | |
1398 | ||
1399 | return release_flush(inode, filp, cd); | |
1400 | } | |
1401 | ||
173912a6 TM |
1402 | static ssize_t read_flush_procfs(struct file *filp, char __user *buf, |
1403 | size_t count, loff_t *ppos) | |
1404 | { | |
1405 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; | |
1406 | ||
1407 | return read_flush(filp, buf, count, ppos, cd); | |
1408 | } | |
1409 | ||
1410 | static ssize_t write_flush_procfs(struct file *filp, | |
1411 | const char __user *buf, | |
1412 | size_t count, loff_t *ppos) | |
1413 | { | |
1414 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; | |
1415 | ||
1416 | return write_flush(filp, buf, count, ppos, cd); | |
1417 | } | |
1418 | ||
1419 | static const struct file_operations cache_flush_operations_procfs = { | |
f7e86ab9 | 1420 | .open = open_flush_procfs, |
173912a6 TM |
1421 | .read = read_flush_procfs, |
1422 | .write = write_flush_procfs, | |
f7e86ab9 | 1423 | .release = release_flush_procfs, |
1da177e4 | 1424 | }; |
173912a6 TM |
1425 | |
1426 | static void remove_cache_proc_entries(struct cache_detail *cd) | |
1427 | { | |
1428 | if (cd->u.procfs.proc_ent == NULL) | |
1429 | return; | |
1430 | if (cd->u.procfs.flush_ent) | |
1431 | remove_proc_entry("flush", cd->u.procfs.proc_ent); | |
1432 | if (cd->u.procfs.channel_ent) | |
1433 | remove_proc_entry("channel", cd->u.procfs.proc_ent); | |
1434 | if (cd->u.procfs.content_ent) | |
1435 | remove_proc_entry("content", cd->u.procfs.proc_ent); | |
1436 | cd->u.procfs.proc_ent = NULL; | |
1437 | remove_proc_entry(cd->name, proc_net_rpc); | |
1438 | } | |
1439 | ||
1440 | #ifdef CONFIG_PROC_FS | |
1441 | static int create_cache_proc_entries(struct cache_detail *cd) | |
1442 | { | |
1443 | struct proc_dir_entry *p; | |
1444 | ||
1445 | cd->u.procfs.proc_ent = proc_mkdir(cd->name, proc_net_rpc); | |
1446 | if (cd->u.procfs.proc_ent == NULL) | |
1447 | goto out_nomem; | |
1448 | cd->u.procfs.channel_ent = NULL; | |
1449 | cd->u.procfs.content_ent = NULL; | |
1450 | ||
1451 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, | |
1452 | cd->u.procfs.proc_ent, | |
1453 | &cache_flush_operations_procfs, cd); | |
1454 | cd->u.procfs.flush_ent = p; | |
1455 | if (p == NULL) | |
1456 | goto out_nomem; | |
1457 | ||
1458 | if (cd->cache_upcall || cd->cache_parse) { | |
1459 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, | |
1460 | cd->u.procfs.proc_ent, | |
1461 | &cache_file_operations_procfs, cd); | |
1462 | cd->u.procfs.channel_ent = p; | |
1463 | if (p == NULL) | |
1464 | goto out_nomem; | |
1465 | } | |
1466 | if (cd->cache_show) { | |
1467 | p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, | |
1468 | cd->u.procfs.proc_ent, | |
1469 | &content_file_operations_procfs, cd); | |
1470 | cd->u.procfs.content_ent = p; | |
1471 | if (p == NULL) | |
1472 | goto out_nomem; | |
1473 | } | |
1474 | return 0; | |
1475 | out_nomem: | |
1476 | remove_cache_proc_entries(cd); | |
1477 | return -ENOMEM; | |
1478 | } | |
1479 | #else /* CONFIG_PROC_FS */ | |
1480 | static int create_cache_proc_entries(struct cache_detail *cd) | |
1481 | { | |
1482 | return 0; | |
1483 | } | |
1484 | #endif | |
1485 | ||
1486 | int cache_register(struct cache_detail *cd) | |
1487 | { | |
1488 | int ret; | |
1489 | ||
1490 | sunrpc_init_cache_detail(cd); | |
1491 | ret = create_cache_proc_entries(cd); | |
1492 | if (ret) | |
1493 | sunrpc_destroy_cache_detail(cd); | |
1494 | return ret; | |
1495 | } | |
1496 | EXPORT_SYMBOL_GPL(cache_register); | |
1497 | ||
1498 | void cache_unregister(struct cache_detail *cd) | |
1499 | { | |
1500 | remove_cache_proc_entries(cd); | |
1501 | sunrpc_destroy_cache_detail(cd); | |
1502 | } | |
1503 | EXPORT_SYMBOL_GPL(cache_unregister); | |
8854e82d TM |
1504 | |
1505 | static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, | |
1506 | size_t count, loff_t *ppos) | |
1507 | { | |
1508 | struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; | |
1509 | ||
1510 | return cache_read(filp, buf, count, ppos, cd); | |
1511 | } | |
1512 | ||
1513 | static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, | |
1514 | size_t count, loff_t *ppos) | |
1515 | { | |
1516 | struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; | |
1517 | ||
1518 | return cache_write(filp, buf, count, ppos, cd); | |
1519 | } | |
1520 | ||
1521 | static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) | |
1522 | { | |
1523 | struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; | |
1524 | ||
1525 | return cache_poll(filp, wait, cd); | |
1526 | } | |
1527 | ||
1528 | static int cache_ioctl_pipefs(struct inode *inode, struct file *filp, | |
1529 | unsigned int cmd, unsigned long arg) | |
1530 | { | |
1531 | struct cache_detail *cd = RPC_I(inode)->private; | |
1532 | ||
1533 | return cache_ioctl(inode, filp, cmd, arg, cd); | |
1534 | } | |
1535 | ||
1536 | static int cache_open_pipefs(struct inode *inode, struct file *filp) | |
1537 | { | |
1538 | struct cache_detail *cd = RPC_I(inode)->private; | |
1539 | ||
1540 | return cache_open(inode, filp, cd); | |
1541 | } | |
1542 | ||
1543 | static int cache_release_pipefs(struct inode *inode, struct file *filp) | |
1544 | { | |
1545 | struct cache_detail *cd = RPC_I(inode)->private; | |
1546 | ||
1547 | return cache_release(inode, filp, cd); | |
1548 | } | |
1549 | ||
1550 | const struct file_operations cache_file_operations_pipefs = { | |
1551 | .owner = THIS_MODULE, | |
1552 | .llseek = no_llseek, | |
1553 | .read = cache_read_pipefs, | |
1554 | .write = cache_write_pipefs, | |
1555 | .poll = cache_poll_pipefs, | |
1556 | .ioctl = cache_ioctl_pipefs, /* for FIONREAD */ | |
1557 | .open = cache_open_pipefs, | |
1558 | .release = cache_release_pipefs, | |
1559 | }; | |
1560 | ||
1561 | static int content_open_pipefs(struct inode *inode, struct file *filp) | |
1562 | { | |
1563 | struct cache_detail *cd = RPC_I(inode)->private; | |
1564 | ||
1565 | return content_open(inode, filp, cd); | |
1566 | } | |
1567 | ||
f7e86ab9 TM |
1568 | static int content_release_pipefs(struct inode *inode, struct file *filp) |
1569 | { | |
1570 | struct cache_detail *cd = RPC_I(inode)->private; | |
1571 | ||
1572 | return content_release(inode, filp, cd); | |
1573 | } | |
1574 | ||
8854e82d TM |
1575 | const struct file_operations content_file_operations_pipefs = { |
1576 | .open = content_open_pipefs, | |
1577 | .read = seq_read, | |
1578 | .llseek = seq_lseek, | |
f7e86ab9 | 1579 | .release = content_release_pipefs, |
8854e82d TM |
1580 | }; |
1581 | ||
f7e86ab9 TM |
1582 | static int open_flush_pipefs(struct inode *inode, struct file *filp) |
1583 | { | |
1584 | struct cache_detail *cd = RPC_I(inode)->private; | |
1585 | ||
1586 | return open_flush(inode, filp, cd); | |
1587 | } | |
1588 | ||
1589 | static int release_flush_pipefs(struct inode *inode, struct file *filp) | |
1590 | { | |
1591 | struct cache_detail *cd = RPC_I(inode)->private; | |
1592 | ||
1593 | return release_flush(inode, filp, cd); | |
1594 | } | |
1595 | ||
8854e82d TM |
1596 | static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, |
1597 | size_t count, loff_t *ppos) | |
1598 | { | |
1599 | struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; | |
1600 | ||
1601 | return read_flush(filp, buf, count, ppos, cd); | |
1602 | } | |
1603 | ||
1604 | static ssize_t write_flush_pipefs(struct file *filp, | |
1605 | const char __user *buf, | |
1606 | size_t count, loff_t *ppos) | |
1607 | { | |
1608 | struct cache_detail *cd = RPC_I(filp->f_path.dentry->d_inode)->private; | |
1609 | ||
1610 | return write_flush(filp, buf, count, ppos, cd); | |
1611 | } | |
1612 | ||
1613 | const struct file_operations cache_flush_operations_pipefs = { | |
f7e86ab9 | 1614 | .open = open_flush_pipefs, |
8854e82d TM |
1615 | .read = read_flush_pipefs, |
1616 | .write = write_flush_pipefs, | |
f7e86ab9 | 1617 | .release = release_flush_pipefs, |
8854e82d TM |
1618 | }; |
1619 | ||
1620 | int sunrpc_cache_register_pipefs(struct dentry *parent, | |
1621 | const char *name, mode_t umode, | |
1622 | struct cache_detail *cd) | |
1623 | { | |
1624 | struct qstr q; | |
1625 | struct dentry *dir; | |
1626 | int ret = 0; | |
1627 | ||
1628 | sunrpc_init_cache_detail(cd); | |
1629 | q.name = name; | |
1630 | q.len = strlen(name); | |
1631 | q.hash = full_name_hash(q.name, q.len); | |
1632 | dir = rpc_create_cache_dir(parent, &q, umode, cd); | |
1633 | if (!IS_ERR(dir)) | |
1634 | cd->u.pipefs.dir = dir; | |
1635 | else { | |
1636 | sunrpc_destroy_cache_detail(cd); | |
1637 | ret = PTR_ERR(dir); | |
1638 | } | |
1639 | return ret; | |
1640 | } | |
1641 | EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); | |
1642 | ||
1643 | void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) | |
1644 | { | |
1645 | rpc_remove_cache_dir(cd->u.pipefs.dir); | |
1646 | cd->u.pipefs.dir = NULL; | |
1647 | sunrpc_destroy_cache_detail(cd); | |
1648 | } | |
1649 | EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); | |
1650 |