Commit | Line | Data |
---|---|---|
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> | |
35 | ||
36 | #define RPCDBG_FACILITY RPCDBG_CACHE | |
37 | ||
e0bb89ef | 38 | static int cache_defer_req(struct cache_req *req, struct cache_head *item); |
1da177e4 LT |
39 | static void cache_revisit_request(struct cache_head *item); |
40 | ||
74cae61a | 41 | static void cache_init(struct cache_head *h) |
1da177e4 LT |
42 | { |
43 | time_t now = get_seconds(); | |
44 | h->next = NULL; | |
45 | h->flags = 0; | |
baab935f | 46 | kref_init(&h->ref); |
1da177e4 LT |
47 | h->expiry_time = now + CACHE_NEW_EXPIRY; |
48 | h->last_refresh = now; | |
49 | } | |
50 | ||
15a5f6bd N |
51 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, |
52 | struct cache_head *key, int hash) | |
53 | { | |
54 | struct cache_head **head, **hp; | |
55 | struct cache_head *new = NULL; | |
56 | ||
57 | head = &detail->hash_table[hash]; | |
58 | ||
59 | read_lock(&detail->hash_lock); | |
60 | ||
61 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
62 | struct cache_head *tmp = *hp; | |
63 | if (detail->match(tmp, key)) { | |
64 | cache_get(tmp); | |
65 | read_unlock(&detail->hash_lock); | |
66 | return tmp; | |
67 | } | |
68 | } | |
69 | read_unlock(&detail->hash_lock); | |
70 | /* Didn't find anything, insert an empty entry */ | |
71 | ||
72 | new = detail->alloc(); | |
73 | if (!new) | |
74 | return NULL; | |
2f34931f NB |
75 | /* must fully initialise 'new', else |
76 | * we might get lose if we need to | |
77 | * cache_put it soon. | |
78 | */ | |
15a5f6bd | 79 | cache_init(new); |
2f34931f | 80 | detail->init(new, key); |
15a5f6bd N |
81 | |
82 | write_lock(&detail->hash_lock); | |
83 | ||
84 | /* check if entry appeared while we slept */ | |
85 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { | |
86 | struct cache_head *tmp = *hp; | |
87 | if (detail->match(tmp, key)) { | |
88 | cache_get(tmp); | |
89 | write_unlock(&detail->hash_lock); | |
baab935f | 90 | cache_put(new, detail); |
15a5f6bd N |
91 | return tmp; |
92 | } | |
93 | } | |
15a5f6bd N |
94 | new->next = *head; |
95 | *head = new; | |
96 | detail->entries++; | |
97 | cache_get(new); | |
98 | write_unlock(&detail->hash_lock); | |
99 | ||
100 | return new; | |
101 | } | |
24c3767e | 102 | EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); |
15a5f6bd | 103 | |
ebd0cb1a N |
104 | |
105 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch); | |
106 | ||
107 | static int cache_fresh_locked(struct cache_head *head, time_t expiry) | |
108 | { | |
109 | head->expiry_time = expiry; | |
110 | head->last_refresh = get_seconds(); | |
111 | return !test_and_set_bit(CACHE_VALID, &head->flags); | |
112 | } | |
113 | ||
114 | static void cache_fresh_unlocked(struct cache_head *head, | |
115 | struct cache_detail *detail, int new) | |
116 | { | |
117 | if (new) | |
118 | cache_revisit_request(head); | |
119 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { | |
120 | cache_revisit_request(head); | |
121 | queue_loose(detail, head); | |
122 | } | |
123 | } | |
124 | ||
15a5f6bd N |
125 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, |
126 | struct cache_head *new, struct cache_head *old, int hash) | |
127 | { | |
128 | /* The 'old' entry is to be replaced by 'new'. | |
129 | * If 'old' is not VALID, we update it directly, | |
130 | * otherwise we need to replace it | |
131 | */ | |
132 | struct cache_head **head; | |
133 | struct cache_head *tmp; | |
ebd0cb1a | 134 | int is_new; |
15a5f6bd N |
135 | |
136 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
137 | write_lock(&detail->hash_lock); | |
138 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
139 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
140 | set_bit(CACHE_NEGATIVE, &old->flags); | |
141 | else | |
142 | detail->update(old, new); | |
ebd0cb1a | 143 | is_new = cache_fresh_locked(old, new->expiry_time); |
15a5f6bd | 144 | write_unlock(&detail->hash_lock); |
ebd0cb1a | 145 | cache_fresh_unlocked(old, detail, is_new); |
15a5f6bd N |
146 | return old; |
147 | } | |
148 | write_unlock(&detail->hash_lock); | |
149 | } | |
150 | /* We need to insert a new entry */ | |
151 | tmp = detail->alloc(); | |
152 | if (!tmp) { | |
baab935f | 153 | cache_put(old, detail); |
15a5f6bd N |
154 | return NULL; |
155 | } | |
156 | cache_init(tmp); | |
157 | detail->init(tmp, old); | |
158 | head = &detail->hash_table[hash]; | |
159 | ||
160 | write_lock(&detail->hash_lock); | |
161 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
162 | set_bit(CACHE_NEGATIVE, &tmp->flags); | |
163 | else | |
164 | detail->update(tmp, new); | |
165 | tmp->next = *head; | |
166 | *head = tmp; | |
f2d39586 | 167 | detail->entries++; |
15a5f6bd | 168 | cache_get(tmp); |
ebd0cb1a N |
169 | is_new = cache_fresh_locked(tmp, new->expiry_time); |
170 | cache_fresh_locked(old, 0); | |
15a5f6bd | 171 | write_unlock(&detail->hash_lock); |
ebd0cb1a N |
172 | cache_fresh_unlocked(tmp, detail, is_new); |
173 | cache_fresh_unlocked(old, detail, 0); | |
baab935f | 174 | cache_put(old, detail); |
15a5f6bd N |
175 | return tmp; |
176 | } | |
24c3767e | 177 | EXPORT_SYMBOL_GPL(sunrpc_cache_update); |
1da177e4 | 178 | |
bc74b4f5 TM |
179 | static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) |
180 | { | |
181 | if (!cd->cache_upcall) | |
182 | return -EINVAL; | |
183 | return cd->cache_upcall(cd, h); | |
184 | } | |
185 | ||
1da177e4 LT |
186 | /* |
187 | * This is the generic cache management routine for all | |
188 | * the authentication caches. | |
189 | * It checks the currency of a cache item and will (later) | |
190 | * initiate an upcall to fill it if needed. | |
191 | * | |
192 | * | |
193 | * Returns 0 if the cache_head can be used, or cache_puts it and returns | |
194 | * -EAGAIN if upcall is pending, | |
e0bb89ef | 195 | * -ETIMEDOUT if upcall failed and should be retried, |
1da177e4 LT |
196 | * -ENOENT if cache entry was negative |
197 | */ | |
198 | int cache_check(struct cache_detail *detail, | |
199 | struct cache_head *h, struct cache_req *rqstp) | |
200 | { | |
201 | int rv; | |
202 | long refresh_age, age; | |
203 | ||
204 | /* First decide return status as best we can */ | |
205 | if (!test_bit(CACHE_VALID, &h->flags) || | |
206 | h->expiry_time < get_seconds()) | |
207 | rv = -EAGAIN; | |
208 | else if (detail->flush_time > h->last_refresh) | |
209 | rv = -EAGAIN; | |
210 | else { | |
211 | /* entry is valid */ | |
212 | if (test_bit(CACHE_NEGATIVE, &h->flags)) | |
213 | rv = -ENOENT; | |
214 | else rv = 0; | |
215 | } | |
216 | ||
217 | /* now see if we want to start an upcall */ | |
218 | refresh_age = (h->expiry_time - h->last_refresh); | |
219 | age = get_seconds() - h->last_refresh; | |
220 | ||
221 | if (rqstp == NULL) { | |
222 | if (rv == -EAGAIN) | |
223 | rv = -ENOENT; | |
224 | } else if (rv == -EAGAIN || age > refresh_age/2) { | |
46121cf7 CL |
225 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", |
226 | refresh_age, age); | |
1da177e4 LT |
227 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
228 | switch (cache_make_upcall(detail, h)) { | |
229 | case -EINVAL: | |
230 | clear_bit(CACHE_PENDING, &h->flags); | |
231 | if (rv == -EAGAIN) { | |
232 | set_bit(CACHE_NEGATIVE, &h->flags); | |
ebd0cb1a N |
233 | cache_fresh_unlocked(h, detail, |
234 | cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY)); | |
1da177e4 LT |
235 | rv = -ENOENT; |
236 | } | |
237 | break; | |
238 | ||
239 | case -EAGAIN: | |
240 | clear_bit(CACHE_PENDING, &h->flags); | |
241 | cache_revisit_request(h); | |
242 | break; | |
243 | } | |
244 | } | |
245 | } | |
246 | ||
247 | if (rv == -EAGAIN) | |
e0bb89ef BF |
248 | if (cache_defer_req(rqstp, h) != 0) |
249 | rv = -ETIMEDOUT; | |
1da177e4 | 250 | |
4013edea | 251 | if (rv) |
baab935f | 252 | cache_put(h, detail); |
1da177e4 LT |
253 | return rv; |
254 | } | |
24c3767e | 255 | EXPORT_SYMBOL_GPL(cache_check); |
1da177e4 | 256 | |
1da177e4 LT |
257 | /* |
258 | * caches need to be periodically cleaned. | |
259 | * For this we maintain a list of cache_detail and | |
260 | * a current pointer into that list and into the table | |
261 | * for that entry. | |
262 | * | |
263 | * Each time clean_cache is called it finds the next non-empty entry | |
264 | * in the current table and walks the list in that entry | |
265 | * looking for entries that can be removed. | |
266 | * | |
267 | * An entry gets removed if: | |
268 | * - The expiry is before current time | |
269 | * - The last_refresh time is before the flush_time for that cache | |
270 | * | |
271 | * later we might drop old entries with non-NEVER expiry if that table | |
272 | * is getting 'full' for some definition of 'full' | |
273 | * | |
274 | * The question of "how often to scan a table" is an interesting one | |
275 | * and is answered in part by the use of the "nextcheck" field in the | |
276 | * cache_detail. | |
277 | * When a scan of a table begins, the nextcheck field is set to a time | |
278 | * that is well into the future. | |
279 | * While scanning, if an expiry time is found that is earlier than the | |
280 | * current nextcheck time, nextcheck is set to that expiry time. | |
281 | * If the flush_time is ever set to a time earlier than the nextcheck | |
282 | * time, the nextcheck time is then set to that flush_time. | |
283 | * | |
284 | * A table is then only scanned if the current time is at least | |
285 | * the nextcheck time. | |
cca5172a | 286 | * |
1da177e4 LT |
287 | */ |
288 | ||
289 | static LIST_HEAD(cache_list); | |
290 | static DEFINE_SPINLOCK(cache_list_lock); | |
291 | static struct cache_detail *current_detail; | |
292 | static int current_index; | |
293 | ||
da7071d7 AV |
294 | static const struct file_operations cache_file_operations; |
295 | static const struct file_operations content_file_operations; | |
296 | static const struct file_operations cache_flush_operations; | |
1da177e4 | 297 | |
65f27f38 DH |
298 | static void do_cache_clean(struct work_struct *work); |
299 | static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean); | |
1da177e4 | 300 | |
ffe9386b | 301 | static void remove_cache_proc_entries(struct cache_detail *cd) |
1da177e4 | 302 | { |
ffe9386b BF |
303 | if (cd->proc_ent == NULL) |
304 | return; | |
305 | if (cd->flush_ent) | |
306 | remove_proc_entry("flush", cd->proc_ent); | |
307 | if (cd->channel_ent) | |
308 | remove_proc_entry("channel", cd->proc_ent); | |
309 | if (cd->content_ent) | |
310 | remove_proc_entry("content", cd->proc_ent); | |
311 | cd->proc_ent = NULL; | |
312 | remove_proc_entry(cd->name, proc_net_rpc); | |
313 | } | |
cca5172a | 314 | |
dbf847ec BF |
315 | #ifdef CONFIG_PROC_FS |
316 | static int create_cache_proc_entries(struct cache_detail *cd) | |
ffe9386b BF |
317 | { |
318 | struct proc_dir_entry *p; | |
cca5172a | 319 | |
ffe9386b BF |
320 | cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc); |
321 | if (cd->proc_ent == NULL) | |
dbf847ec | 322 | goto out_nomem; |
ffe9386b BF |
323 | cd->channel_ent = cd->content_ent = NULL; |
324 | ||
e7fe2336 DL |
325 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, |
326 | cd->proc_ent, &cache_flush_operations, cd); | |
ffe9386b BF |
327 | cd->flush_ent = p; |
328 | if (p == NULL) | |
dbf847ec | 329 | goto out_nomem; |
ffe9386b | 330 | |
bc74b4f5 | 331 | if (cd->cache_upcall || cd->cache_parse) { |
e7fe2336 DL |
332 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, |
333 | cd->proc_ent, &cache_file_operations, cd); | |
ffe9386b BF |
334 | cd->channel_ent = p; |
335 | if (p == NULL) | |
dbf847ec | 336 | goto out_nomem; |
1da177e4 | 337 | } |
ffe9386b | 338 | if (cd->cache_show) { |
e7fe2336 DL |
339 | p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, |
340 | cd->proc_ent, &content_file_operations, cd); | |
ffe9386b BF |
341 | cd->content_ent = p; |
342 | if (p == NULL) | |
dbf847ec | 343 | goto out_nomem; |
ffe9386b | 344 | } |
dbf847ec BF |
345 | return 0; |
346 | out_nomem: | |
347 | remove_cache_proc_entries(cd); | |
348 | return -ENOMEM; | |
ffe9386b | 349 | } |
dbf847ec BF |
350 | #else /* CONFIG_PROC_FS */ |
351 | static int create_cache_proc_entries(struct cache_detail *cd) | |
352 | { | |
353 | return 0; | |
354 | } | |
355 | #endif | |
ffe9386b | 356 | |
5b7a1b9f | 357 | static void sunrpc_init_cache_detail(struct cache_detail *cd) |
ffe9386b | 358 | { |
1da177e4 LT |
359 | rwlock_init(&cd->hash_lock); |
360 | INIT_LIST_HEAD(&cd->queue); | |
361 | spin_lock(&cache_list_lock); | |
362 | cd->nextcheck = 0; | |
363 | cd->entries = 0; | |
364 | atomic_set(&cd->readers, 0); | |
365 | cd->last_close = 0; | |
366 | cd->last_warn = -1; | |
367 | list_add(&cd->others, &cache_list); | |
368 | spin_unlock(&cache_list_lock); | |
369 | ||
370 | /* start the cleaning process */ | |
52bad64d | 371 | schedule_delayed_work(&cache_cleaner, 0); |
1da177e4 LT |
372 | } |
373 | ||
5b7a1b9f | 374 | static void sunrpc_destroy_cache_detail(struct cache_detail *cd) |
1da177e4 LT |
375 | { |
376 | cache_purge(cd); | |
377 | spin_lock(&cache_list_lock); | |
378 | write_lock(&cd->hash_lock); | |
379 | if (cd->entries || atomic_read(&cd->inuse)) { | |
380 | write_unlock(&cd->hash_lock); | |
381 | spin_unlock(&cache_list_lock); | |
df95a9d4 | 382 | goto out; |
1da177e4 LT |
383 | } |
384 | if (current_detail == cd) | |
385 | current_detail = NULL; | |
386 | list_del_init(&cd->others); | |
387 | write_unlock(&cd->hash_lock); | |
388 | spin_unlock(&cache_list_lock); | |
1da177e4 LT |
389 | if (list_empty(&cache_list)) { |
390 | /* module must be being unloaded so its safe to kill the worker */ | |
4011cd97 | 391 | cancel_delayed_work_sync(&cache_cleaner); |
1da177e4 | 392 | } |
df95a9d4 BF |
393 | return; |
394 | out: | |
395 | printk(KERN_ERR "nfsd: failed to unregister %s cache\n", cd->name); | |
1da177e4 | 396 | } |
5b7a1b9f TM |
397 | |
398 | int cache_register(struct cache_detail *cd) | |
399 | { | |
400 | int ret; | |
401 | ||
402 | sunrpc_init_cache_detail(cd); | |
403 | ret = create_cache_proc_entries(cd); | |
404 | if (ret) | |
405 | sunrpc_destroy_cache_detail(cd); | |
406 | return ret; | |
407 | } | |
408 | EXPORT_SYMBOL_GPL(cache_register); | |
409 | ||
410 | void cache_unregister(struct cache_detail *cd) | |
411 | { | |
412 | remove_cache_proc_entries(cd); | |
413 | sunrpc_destroy_cache_detail(cd); | |
414 | } | |
24c3767e | 415 | EXPORT_SYMBOL_GPL(cache_unregister); |
1da177e4 LT |
416 | |
417 | /* clean cache tries to find something to clean | |
418 | * and cleans it. | |
419 | * It returns 1 if it cleaned something, | |
420 | * 0 if it didn't find anything this time | |
421 | * -1 if it fell off the end of the list. | |
422 | */ | |
423 | static int cache_clean(void) | |
424 | { | |
425 | int rv = 0; | |
426 | struct list_head *next; | |
427 | ||
428 | spin_lock(&cache_list_lock); | |
429 | ||
430 | /* find a suitable table if we don't already have one */ | |
431 | while (current_detail == NULL || | |
432 | current_index >= current_detail->hash_size) { | |
433 | if (current_detail) | |
434 | next = current_detail->others.next; | |
435 | else | |
436 | next = cache_list.next; | |
437 | if (next == &cache_list) { | |
438 | current_detail = NULL; | |
439 | spin_unlock(&cache_list_lock); | |
440 | return -1; | |
441 | } | |
442 | current_detail = list_entry(next, struct cache_detail, others); | |
443 | if (current_detail->nextcheck > get_seconds()) | |
444 | current_index = current_detail->hash_size; | |
445 | else { | |
446 | current_index = 0; | |
447 | current_detail->nextcheck = get_seconds()+30*60; | |
448 | } | |
449 | } | |
450 | ||
451 | /* find a non-empty bucket in the table */ | |
452 | while (current_detail && | |
453 | current_index < current_detail->hash_size && | |
454 | current_detail->hash_table[current_index] == NULL) | |
455 | current_index++; | |
456 | ||
457 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ | |
cca5172a | 458 | |
1da177e4 LT |
459 | if (current_detail && current_index < current_detail->hash_size) { |
460 | struct cache_head *ch, **cp; | |
461 | struct cache_detail *d; | |
cca5172a | 462 | |
1da177e4 LT |
463 | write_lock(¤t_detail->hash_lock); |
464 | ||
465 | /* Ok, now to clean this strand */ | |
cca5172a | 466 | |
1da177e4 LT |
467 | cp = & current_detail->hash_table[current_index]; |
468 | ch = *cp; | |
469 | for (; ch; cp= & ch->next, ch= *cp) { | |
470 | if (current_detail->nextcheck > ch->expiry_time) | |
471 | current_detail->nextcheck = ch->expiry_time+1; | |
472 | if (ch->expiry_time >= get_seconds() | |
473 | && ch->last_refresh >= current_detail->flush_time | |
474 | ) | |
475 | continue; | |
476 | if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) | |
477 | queue_loose(current_detail, ch); | |
478 | ||
baab935f | 479 | if (atomic_read(&ch->ref.refcount) == 1) |
1da177e4 LT |
480 | break; |
481 | } | |
482 | if (ch) { | |
483 | *cp = ch->next; | |
484 | ch->next = NULL; | |
485 | current_detail->entries--; | |
486 | rv = 1; | |
487 | } | |
488 | write_unlock(¤t_detail->hash_lock); | |
489 | d = current_detail; | |
490 | if (!ch) | |
491 | current_index ++; | |
492 | spin_unlock(&cache_list_lock); | |
493 | if (ch) | |
baab935f | 494 | cache_put(ch, d); |
1da177e4 LT |
495 | } else |
496 | spin_unlock(&cache_list_lock); | |
497 | ||
498 | return rv; | |
499 | } | |
500 | ||
501 | /* | |
502 | * We want to regularly clean the cache, so we need to schedule some work ... | |
503 | */ | |
65f27f38 | 504 | static void do_cache_clean(struct work_struct *work) |
1da177e4 LT |
505 | { |
506 | int delay = 5; | |
507 | if (cache_clean() == -1) | |
6aad89c8 | 508 | delay = round_jiffies_relative(30*HZ); |
1da177e4 LT |
509 | |
510 | if (list_empty(&cache_list)) | |
511 | delay = 0; | |
512 | ||
513 | if (delay) | |
514 | schedule_delayed_work(&cache_cleaner, delay); | |
515 | } | |
516 | ||
517 | ||
cca5172a | 518 | /* |
1da177e4 | 519 | * Clean all caches promptly. This just calls cache_clean |
cca5172a | 520 | * repeatedly until we are sure that every cache has had a chance to |
1da177e4 LT |
521 | * be fully cleaned |
522 | */ | |
523 | void cache_flush(void) | |
524 | { | |
525 | while (cache_clean() != -1) | |
526 | cond_resched(); | |
527 | while (cache_clean() != -1) | |
528 | cond_resched(); | |
529 | } | |
24c3767e | 530 | EXPORT_SYMBOL_GPL(cache_flush); |
1da177e4 LT |
531 | |
532 | void cache_purge(struct cache_detail *detail) | |
533 | { | |
534 | detail->flush_time = LONG_MAX; | |
535 | detail->nextcheck = get_seconds(); | |
536 | cache_flush(); | |
537 | detail->flush_time = 1; | |
538 | } | |
24c3767e | 539 | EXPORT_SYMBOL_GPL(cache_purge); |
1da177e4 LT |
540 | |
541 | ||
542 | /* | |
543 | * Deferral and Revisiting of Requests. | |
544 | * | |
545 | * If a cache lookup finds a pending entry, we | |
546 | * need to defer the request and revisit it later. | |
547 | * All deferred requests are stored in a hash table, | |
548 | * indexed by "struct cache_head *". | |
549 | * As it may be wasteful to store a whole request | |
cca5172a | 550 | * structure, we allow the request to provide a |
1da177e4 LT |
551 | * deferred form, which must contain a |
552 | * 'struct cache_deferred_req' | |
553 | * This cache_deferred_req contains a method to allow | |
554 | * it to be revisited when cache info is available | |
555 | */ | |
556 | ||
557 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) | |
558 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) | |
559 | ||
560 | #define DFR_MAX 300 /* ??? */ | |
561 | ||
562 | static DEFINE_SPINLOCK(cache_defer_lock); | |
563 | static LIST_HEAD(cache_defer_list); | |
564 | static struct list_head cache_defer_hash[DFR_HASHSIZE]; | |
565 | static int cache_defer_cnt; | |
566 | ||
e0bb89ef | 567 | static int cache_defer_req(struct cache_req *req, struct cache_head *item) |
1da177e4 LT |
568 | { |
569 | struct cache_deferred_req *dreq; | |
570 | int hash = DFR_HASH(item); | |
571 | ||
01f3bd1f BF |
572 | if (cache_defer_cnt >= DFR_MAX) { |
573 | /* too much in the cache, randomly drop this one, | |
574 | * or continue and drop the oldest below | |
575 | */ | |
576 | if (net_random()&1) | |
577 | return -ETIMEDOUT; | |
578 | } | |
1da177e4 LT |
579 | dreq = req->defer(req); |
580 | if (dreq == NULL) | |
e0bb89ef | 581 | return -ETIMEDOUT; |
1da177e4 LT |
582 | |
583 | dreq->item = item; | |
1da177e4 LT |
584 | |
585 | spin_lock(&cache_defer_lock); | |
586 | ||
587 | list_add(&dreq->recent, &cache_defer_list); | |
588 | ||
589 | if (cache_defer_hash[hash].next == NULL) | |
590 | INIT_LIST_HEAD(&cache_defer_hash[hash]); | |
591 | list_add(&dreq->hash, &cache_defer_hash[hash]); | |
592 | ||
593 | /* it is in, now maybe clean up */ | |
594 | dreq = NULL; | |
595 | if (++cache_defer_cnt > DFR_MAX) { | |
01f3bd1f BF |
596 | dreq = list_entry(cache_defer_list.prev, |
597 | struct cache_deferred_req, recent); | |
1da177e4 LT |
598 | list_del(&dreq->recent); |
599 | list_del(&dreq->hash); | |
600 | cache_defer_cnt--; | |
601 | } | |
602 | spin_unlock(&cache_defer_lock); | |
603 | ||
604 | if (dreq) { | |
605 | /* there was one too many */ | |
606 | dreq->revisit(dreq, 1); | |
607 | } | |
4013edea | 608 | if (!test_bit(CACHE_PENDING, &item->flags)) { |
1da177e4 LT |
609 | /* must have just been validated... */ |
610 | cache_revisit_request(item); | |
611 | } | |
e0bb89ef | 612 | return 0; |
1da177e4 LT |
613 | } |
614 | ||
615 | static void cache_revisit_request(struct cache_head *item) | |
616 | { | |
617 | struct cache_deferred_req *dreq; | |
618 | struct list_head pending; | |
619 | ||
620 | struct list_head *lp; | |
621 | int hash = DFR_HASH(item); | |
622 | ||
623 | INIT_LIST_HEAD(&pending); | |
624 | spin_lock(&cache_defer_lock); | |
cca5172a | 625 | |
1da177e4 LT |
626 | lp = cache_defer_hash[hash].next; |
627 | if (lp) { | |
628 | while (lp != &cache_defer_hash[hash]) { | |
629 | dreq = list_entry(lp, struct cache_deferred_req, hash); | |
630 | lp = lp->next; | |
631 | if (dreq->item == item) { | |
632 | list_del(&dreq->hash); | |
633 | list_move(&dreq->recent, &pending); | |
634 | cache_defer_cnt--; | |
635 | } | |
636 | } | |
637 | } | |
638 | spin_unlock(&cache_defer_lock); | |
639 | ||
640 | while (!list_empty(&pending)) { | |
641 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
642 | list_del_init(&dreq->recent); | |
643 | dreq->revisit(dreq, 0); | |
644 | } | |
645 | } | |
646 | ||
647 | void cache_clean_deferred(void *owner) | |
648 | { | |
649 | struct cache_deferred_req *dreq, *tmp; | |
650 | struct list_head pending; | |
651 | ||
652 | ||
653 | INIT_LIST_HEAD(&pending); | |
654 | spin_lock(&cache_defer_lock); | |
cca5172a | 655 | |
1da177e4 LT |
656 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { |
657 | if (dreq->owner == owner) { | |
658 | list_del(&dreq->hash); | |
659 | list_move(&dreq->recent, &pending); | |
660 | cache_defer_cnt--; | |
661 | } | |
662 | } | |
663 | spin_unlock(&cache_defer_lock); | |
664 | ||
665 | while (!list_empty(&pending)) { | |
666 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
667 | list_del_init(&dreq->recent); | |
668 | dreq->revisit(dreq, 1); | |
669 | } | |
670 | } | |
671 | ||
672 | /* | |
673 | * communicate with user-space | |
674 | * | |
a490c681 BF |
675 | * We have a magic /proc file - /proc/sunrpc/<cachename>/channel. |
676 | * On read, you get a full request, or block. | |
677 | * On write, an update request is processed. | |
678 | * Poll works if anything to read, and always allows write. | |
1da177e4 | 679 | * |
cca5172a | 680 | * Implemented by linked list of requests. Each open file has |
a490c681 | 681 | * a ->private that also exists in this list. New requests are added |
1da177e4 LT |
682 | * to the end and may wakeup and preceding readers. |
683 | * New readers are added to the head. If, on read, an item is found with | |
684 | * CACHE_UPCALLING clear, we free it from the list. | |
685 | * | |
686 | */ | |
687 | ||
688 | static DEFINE_SPINLOCK(queue_lock); | |
4a3e2f71 | 689 | static DEFINE_MUTEX(queue_io_mutex); |
1da177e4 LT |
690 | |
691 | struct cache_queue { | |
692 | struct list_head list; | |
693 | int reader; /* if 0, then request */ | |
694 | }; | |
695 | struct cache_request { | |
696 | struct cache_queue q; | |
697 | struct cache_head *item; | |
698 | char * buf; | |
699 | int len; | |
700 | int readers; | |
701 | }; | |
702 | struct cache_reader { | |
703 | struct cache_queue q; | |
704 | int offset; /* if non-0, we have a refcnt on next request */ | |
705 | }; | |
706 | ||
707 | static ssize_t | |
708 | cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) | |
709 | { | |
710 | struct cache_reader *rp = filp->private_data; | |
711 | struct cache_request *rq; | |
da77005f TM |
712 | struct inode *inode = filp->f_path.dentry->d_inode; |
713 | struct cache_detail *cd = PDE(inode)->data; | |
1da177e4 LT |
714 | int err; |
715 | ||
716 | if (count == 0) | |
717 | return 0; | |
718 | ||
da77005f | 719 | mutex_lock(&inode->i_mutex); /* protect against multiple concurrent |
1da177e4 LT |
720 | * readers on this file */ |
721 | again: | |
722 | spin_lock(&queue_lock); | |
723 | /* need to find next request */ | |
724 | while (rp->q.list.next != &cd->queue && | |
725 | list_entry(rp->q.list.next, struct cache_queue, list) | |
726 | ->reader) { | |
727 | struct list_head *next = rp->q.list.next; | |
728 | list_move(&rp->q.list, next); | |
729 | } | |
730 | if (rp->q.list.next == &cd->queue) { | |
731 | spin_unlock(&queue_lock); | |
da77005f | 732 | mutex_unlock(&inode->i_mutex); |
09a62660 | 733 | BUG_ON(rp->offset); |
1da177e4 LT |
734 | return 0; |
735 | } | |
736 | rq = container_of(rp->q.list.next, struct cache_request, q.list); | |
09a62660 | 737 | BUG_ON(rq->q.reader); |
1da177e4 LT |
738 | if (rp->offset == 0) |
739 | rq->readers++; | |
740 | spin_unlock(&queue_lock); | |
741 | ||
742 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
743 | err = -EAGAIN; | |
744 | spin_lock(&queue_lock); | |
745 | list_move(&rp->q.list, &rq->q.list); | |
746 | spin_unlock(&queue_lock); | |
747 | } else { | |
748 | if (rp->offset + count > rq->len) | |
749 | count = rq->len - rp->offset; | |
750 | err = -EFAULT; | |
751 | if (copy_to_user(buf, rq->buf + rp->offset, count)) | |
752 | goto out; | |
753 | rp->offset += count; | |
754 | if (rp->offset >= rq->len) { | |
755 | rp->offset = 0; | |
756 | spin_lock(&queue_lock); | |
757 | list_move(&rp->q.list, &rq->q.list); | |
758 | spin_unlock(&queue_lock); | |
759 | } | |
760 | err = 0; | |
761 | } | |
762 | out: | |
763 | if (rp->offset == 0) { | |
764 | /* need to release rq */ | |
765 | spin_lock(&queue_lock); | |
766 | rq->readers--; | |
767 | if (rq->readers == 0 && | |
768 | !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
769 | list_del(&rq->q.list); | |
770 | spin_unlock(&queue_lock); | |
baab935f | 771 | cache_put(rq->item, cd); |
1da177e4 LT |
772 | kfree(rq->buf); |
773 | kfree(rq); | |
774 | } else | |
775 | spin_unlock(&queue_lock); | |
776 | } | |
777 | if (err == -EAGAIN) | |
778 | goto again; | |
da77005f | 779 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
780 | return err ? err : count; |
781 | } | |
782 | ||
da77005f TM |
783 | static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, |
784 | size_t count, struct cache_detail *cd) | |
785 | { | |
786 | ssize_t ret; | |
1da177e4 | 787 | |
da77005f TM |
788 | if (copy_from_user(kaddr, buf, count)) |
789 | return -EFAULT; | |
790 | kaddr[count] = '\0'; | |
791 | ret = cd->cache_parse(cd, kaddr, count); | |
792 | if (!ret) | |
793 | ret = count; | |
794 | return ret; | |
795 | } | |
796 | ||
797 | static ssize_t cache_slow_downcall(const char __user *buf, | |
798 | size_t count, struct cache_detail *cd) | |
1da177e4 | 799 | { |
da77005f TM |
800 | static char write_buf[8192]; /* protected by queue_io_mutex */ |
801 | ssize_t ret = -EINVAL; | |
1da177e4 | 802 | |
1da177e4 | 803 | if (count >= sizeof(write_buf)) |
da77005f | 804 | goto out; |
4a3e2f71 | 805 | mutex_lock(&queue_io_mutex); |
da77005f TM |
806 | ret = cache_do_downcall(write_buf, buf, count, cd); |
807 | mutex_unlock(&queue_io_mutex); | |
808 | out: | |
809 | return ret; | |
810 | } | |
1da177e4 | 811 | |
da77005f TM |
812 | static ssize_t cache_downcall(struct address_space *mapping, |
813 | const char __user *buf, | |
814 | size_t count, struct cache_detail *cd) | |
815 | { | |
816 | struct page *page; | |
817 | char *kaddr; | |
818 | ssize_t ret = -ENOMEM; | |
819 | ||
820 | if (count >= PAGE_CACHE_SIZE) | |
821 | goto out_slow; | |
822 | ||
823 | page = find_or_create_page(mapping, 0, GFP_KERNEL); | |
824 | if (!page) | |
825 | goto out_slow; | |
826 | ||
827 | kaddr = kmap(page); | |
828 | ret = cache_do_downcall(kaddr, buf, count, cd); | |
829 | kunmap(page); | |
830 | unlock_page(page); | |
831 | page_cache_release(page); | |
832 | return ret; | |
833 | out_slow: | |
834 | return cache_slow_downcall(buf, count, cd); | |
835 | } | |
1da177e4 | 836 | |
da77005f TM |
837 | static ssize_t |
838 | cache_write(struct file *filp, const char __user *buf, size_t count, | |
839 | loff_t *ppos) | |
840 | { | |
841 | struct address_space *mapping = filp->f_mapping; | |
842 | struct inode *inode = filp->f_path.dentry->d_inode; | |
843 | struct cache_detail *cd = PDE(inode)->data; | |
844 | ssize_t ret = -EINVAL; | |
845 | ||
846 | if (!cd->cache_parse) | |
847 | goto out; | |
848 | ||
849 | mutex_lock(&inode->i_mutex); | |
850 | ret = cache_downcall(mapping, buf, count, cd); | |
851 | mutex_unlock(&inode->i_mutex); | |
852 | out: | |
853 | return ret; | |
1da177e4 LT |
854 | } |
855 | ||
856 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); | |
857 | ||
858 | static unsigned int | |
859 | cache_poll(struct file *filp, poll_table *wait) | |
860 | { | |
861 | unsigned int mask; | |
862 | struct cache_reader *rp = filp->private_data; | |
863 | struct cache_queue *cq; | |
303b46bb | 864 | struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data; |
1da177e4 LT |
865 | |
866 | poll_wait(filp, &queue_wait, wait); | |
867 | ||
868 | /* alway allow write */ | |
869 | mask = POLL_OUT | POLLWRNORM; | |
870 | ||
871 | if (!rp) | |
872 | return mask; | |
873 | ||
874 | spin_lock(&queue_lock); | |
875 | ||
876 | for (cq= &rp->q; &cq->list != &cd->queue; | |
877 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
878 | if (!cq->reader) { | |
879 | mask |= POLLIN | POLLRDNORM; | |
880 | break; | |
881 | } | |
882 | spin_unlock(&queue_lock); | |
883 | return mask; | |
884 | } | |
885 | ||
886 | static int | |
887 | cache_ioctl(struct inode *ino, struct file *filp, | |
888 | unsigned int cmd, unsigned long arg) | |
889 | { | |
890 | int len = 0; | |
891 | struct cache_reader *rp = filp->private_data; | |
892 | struct cache_queue *cq; | |
893 | struct cache_detail *cd = PDE(ino)->data; | |
894 | ||
895 | if (cmd != FIONREAD || !rp) | |
896 | return -EINVAL; | |
897 | ||
898 | spin_lock(&queue_lock); | |
899 | ||
900 | /* only find the length remaining in current request, | |
901 | * or the length of the next request | |
902 | */ | |
903 | for (cq= &rp->q; &cq->list != &cd->queue; | |
904 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
905 | if (!cq->reader) { | |
906 | struct cache_request *cr = | |
907 | container_of(cq, struct cache_request, q); | |
908 | len = cr->len - rp->offset; | |
909 | break; | |
910 | } | |
911 | spin_unlock(&queue_lock); | |
912 | ||
913 | return put_user(len, (int __user *)arg); | |
914 | } | |
915 | ||
916 | static int | |
917 | cache_open(struct inode *inode, struct file *filp) | |
918 | { | |
919 | struct cache_reader *rp = NULL; | |
920 | ||
921 | nonseekable_open(inode, filp); | |
922 | if (filp->f_mode & FMODE_READ) { | |
923 | struct cache_detail *cd = PDE(inode)->data; | |
924 | ||
925 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); | |
926 | if (!rp) | |
927 | return -ENOMEM; | |
928 | rp->offset = 0; | |
929 | rp->q.reader = 1; | |
930 | atomic_inc(&cd->readers); | |
931 | spin_lock(&queue_lock); | |
932 | list_add(&rp->q.list, &cd->queue); | |
933 | spin_unlock(&queue_lock); | |
934 | } | |
935 | filp->private_data = rp; | |
936 | return 0; | |
937 | } | |
938 | ||
939 | static int | |
940 | cache_release(struct inode *inode, struct file *filp) | |
941 | { | |
942 | struct cache_reader *rp = filp->private_data; | |
943 | struct cache_detail *cd = PDE(inode)->data; | |
944 | ||
945 | if (rp) { | |
946 | spin_lock(&queue_lock); | |
947 | if (rp->offset) { | |
948 | struct cache_queue *cq; | |
949 | for (cq= &rp->q; &cq->list != &cd->queue; | |
950 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
951 | if (!cq->reader) { | |
952 | container_of(cq, struct cache_request, q) | |
953 | ->readers--; | |
954 | break; | |
955 | } | |
956 | rp->offset = 0; | |
957 | } | |
958 | list_del(&rp->q.list); | |
959 | spin_unlock(&queue_lock); | |
960 | ||
961 | filp->private_data = NULL; | |
962 | kfree(rp); | |
963 | ||
964 | cd->last_close = get_seconds(); | |
965 | atomic_dec(&cd->readers); | |
966 | } | |
967 | return 0; | |
968 | } | |
969 | ||
970 | ||
971 | ||
da7071d7 | 972 | static const struct file_operations cache_file_operations = { |
1da177e4 LT |
973 | .owner = THIS_MODULE, |
974 | .llseek = no_llseek, | |
975 | .read = cache_read, | |
976 | .write = cache_write, | |
977 | .poll = cache_poll, | |
978 | .ioctl = cache_ioctl, /* for FIONREAD */ | |
979 | .open = cache_open, | |
980 | .release = cache_release, | |
981 | }; | |
982 | ||
983 | ||
984 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch) | |
985 | { | |
986 | struct cache_queue *cq; | |
987 | spin_lock(&queue_lock); | |
988 | list_for_each_entry(cq, &detail->queue, list) | |
989 | if (!cq->reader) { | |
990 | struct cache_request *cr = container_of(cq, struct cache_request, q); | |
991 | if (cr->item != ch) | |
992 | continue; | |
993 | if (cr->readers != 0) | |
4013edea | 994 | continue; |
1da177e4 LT |
995 | list_del(&cr->q.list); |
996 | spin_unlock(&queue_lock); | |
baab935f | 997 | cache_put(cr->item, detail); |
1da177e4 LT |
998 | kfree(cr->buf); |
999 | kfree(cr); | |
1000 | return; | |
1001 | } | |
1002 | spin_unlock(&queue_lock); | |
1003 | } | |
1004 | ||
1005 | /* | |
1006 | * Support routines for text-based upcalls. | |
1007 | * Fields are separated by spaces. | |
1008 | * Fields are either mangled to quote space tab newline slosh with slosh | |
1009 | * or a hexified with a leading \x | |
1010 | * Record is terminated with newline. | |
1011 | * | |
1012 | */ | |
1013 | ||
1014 | void qword_add(char **bpp, int *lp, char *str) | |
1015 | { | |
1016 | char *bp = *bpp; | |
1017 | int len = *lp; | |
1018 | char c; | |
1019 | ||
1020 | if (len < 0) return; | |
1021 | ||
1022 | while ((c=*str++) && len) | |
1023 | switch(c) { | |
1024 | case ' ': | |
1025 | case '\t': | |
1026 | case '\n': | |
1027 | case '\\': | |
1028 | if (len >= 4) { | |
1029 | *bp++ = '\\'; | |
1030 | *bp++ = '0' + ((c & 0300)>>6); | |
1031 | *bp++ = '0' + ((c & 0070)>>3); | |
1032 | *bp++ = '0' + ((c & 0007)>>0); | |
1033 | } | |
1034 | len -= 4; | |
1035 | break; | |
1036 | default: | |
1037 | *bp++ = c; | |
1038 | len--; | |
1039 | } | |
1040 | if (c || len <1) len = -1; | |
1041 | else { | |
1042 | *bp++ = ' '; | |
1043 | len--; | |
1044 | } | |
1045 | *bpp = bp; | |
1046 | *lp = len; | |
1047 | } | |
24c3767e | 1048 | EXPORT_SYMBOL_GPL(qword_add); |
1da177e4 LT |
1049 | |
1050 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) | |
1051 | { | |
1052 | char *bp = *bpp; | |
1053 | int len = *lp; | |
1054 | ||
1055 | if (len < 0) return; | |
1056 | ||
1057 | if (len > 2) { | |
1058 | *bp++ = '\\'; | |
1059 | *bp++ = 'x'; | |
1060 | len -= 2; | |
1061 | while (blen && len >= 2) { | |
1062 | unsigned char c = *buf++; | |
1063 | *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); | |
1064 | *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); | |
1065 | len -= 2; | |
1066 | blen--; | |
1067 | } | |
1068 | } | |
1069 | if (blen || len<1) len = -1; | |
1070 | else { | |
1071 | *bp++ = ' '; | |
1072 | len--; | |
1073 | } | |
1074 | *bpp = bp; | |
1075 | *lp = len; | |
1076 | } | |
24c3767e | 1077 | EXPORT_SYMBOL_GPL(qword_addhex); |
1da177e4 LT |
1078 | |
1079 | static void warn_no_listener(struct cache_detail *detail) | |
1080 | { | |
1081 | if (detail->last_warn != detail->last_close) { | |
1082 | detail->last_warn = detail->last_close; | |
1083 | if (detail->warn_no_listener) | |
2da8ca26 | 1084 | detail->warn_no_listener(detail, detail->last_close != 0); |
1da177e4 LT |
1085 | } |
1086 | } | |
1087 | ||
1088 | /* | |
bc74b4f5 TM |
1089 | * register an upcall request to user-space and queue it up for read() by the |
1090 | * upcall daemon. | |
1091 | * | |
1da177e4 LT |
1092 | * Each request is at most one page long. |
1093 | */ | |
bc74b4f5 TM |
1094 | int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h, |
1095 | void (*cache_request)(struct cache_detail *, | |
1096 | struct cache_head *, | |
1097 | char **, | |
1098 | int *)) | |
1da177e4 LT |
1099 | { |
1100 | ||
1101 | char *buf; | |
1102 | struct cache_request *crq; | |
1103 | char *bp; | |
1104 | int len; | |
1105 | ||
1da177e4 LT |
1106 | if (atomic_read(&detail->readers) == 0 && |
1107 | detail->last_close < get_seconds() - 30) { | |
1108 | warn_no_listener(detail); | |
1109 | return -EINVAL; | |
1110 | } | |
1111 | ||
1112 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1113 | if (!buf) | |
1114 | return -EAGAIN; | |
1115 | ||
1116 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); | |
1117 | if (!crq) { | |
1118 | kfree(buf); | |
1119 | return -EAGAIN; | |
1120 | } | |
1121 | ||
1122 | bp = buf; len = PAGE_SIZE; | |
1123 | ||
bc74b4f5 | 1124 | cache_request(detail, h, &bp, &len); |
1da177e4 LT |
1125 | |
1126 | if (len < 0) { | |
1127 | kfree(buf); | |
1128 | kfree(crq); | |
1129 | return -EAGAIN; | |
1130 | } | |
1131 | crq->q.reader = 0; | |
1132 | crq->item = cache_get(h); | |
1133 | crq->buf = buf; | |
1134 | crq->len = PAGE_SIZE - len; | |
1135 | crq->readers = 0; | |
1136 | spin_lock(&queue_lock); | |
1137 | list_add_tail(&crq->q.list, &detail->queue); | |
1138 | spin_unlock(&queue_lock); | |
1139 | wake_up(&queue_wait); | |
1140 | return 0; | |
1141 | } | |
bc74b4f5 | 1142 | EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); |
1da177e4 LT |
1143 | |
1144 | /* | |
1145 | * parse a message from user-space and pass it | |
1146 | * to an appropriate cache | |
1147 | * Messages are, like requests, separated into fields by | |
1148 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal | |
1149 | * | |
cca5172a | 1150 | * Message is |
1da177e4 LT |
1151 | * reply cachename expiry key ... content.... |
1152 | * | |
cca5172a | 1153 | * key and content are both parsed by cache |
1da177e4 LT |
1154 | */ |
1155 | ||
1156 | #define isodigit(c) (isdigit(c) && c <= '7') | |
1157 | int qword_get(char **bpp, char *dest, int bufsize) | |
1158 | { | |
1159 | /* return bytes copied, or -1 on error */ | |
1160 | char *bp = *bpp; | |
1161 | int len = 0; | |
1162 | ||
1163 | while (*bp == ' ') bp++; | |
1164 | ||
1165 | if (bp[0] == '\\' && bp[1] == 'x') { | |
1166 | /* HEX STRING */ | |
1167 | bp += 2; | |
1168 | while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { | |
1169 | int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; | |
1170 | bp++; | |
1171 | byte <<= 4; | |
1172 | byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; | |
1173 | *dest++ = byte; | |
1174 | bp++; | |
1175 | len++; | |
1176 | } | |
1177 | } else { | |
1178 | /* text with \nnn octal quoting */ | |
1179 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { | |
1180 | if (*bp == '\\' && | |
1181 | isodigit(bp[1]) && (bp[1] <= '3') && | |
1182 | isodigit(bp[2]) && | |
1183 | isodigit(bp[3])) { | |
1184 | int byte = (*++bp -'0'); | |
1185 | bp++; | |
1186 | byte = (byte << 3) | (*bp++ - '0'); | |
1187 | byte = (byte << 3) | (*bp++ - '0'); | |
1188 | *dest++ = byte; | |
1189 | len++; | |
1190 | } else { | |
1191 | *dest++ = *bp++; | |
1192 | len++; | |
1193 | } | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') | |
1198 | return -1; | |
1199 | while (*bp == ' ') bp++; | |
1200 | *bpp = bp; | |
1201 | *dest = '\0'; | |
1202 | return len; | |
1203 | } | |
24c3767e | 1204 | EXPORT_SYMBOL_GPL(qword_get); |
1da177e4 LT |
1205 | |
1206 | ||
1207 | /* | |
1208 | * support /proc/sunrpc/cache/$CACHENAME/content | |
1209 | * as a seqfile. | |
1210 | * We call ->cache_show passing NULL for the item to | |
1211 | * get a header, then pass each real item in the cache | |
1212 | */ | |
1213 | ||
1214 | struct handle { | |
1215 | struct cache_detail *cd; | |
1216 | }; | |
1217 | ||
1218 | static void *c_start(struct seq_file *m, loff_t *pos) | |
9a429c49 | 1219 | __acquires(cd->hash_lock) |
1da177e4 LT |
1220 | { |
1221 | loff_t n = *pos; | |
1222 | unsigned hash, entry; | |
1223 | struct cache_head *ch; | |
1224 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
cca5172a | 1225 | |
1da177e4 LT |
1226 | |
1227 | read_lock(&cd->hash_lock); | |
1228 | if (!n--) | |
1229 | return SEQ_START_TOKEN; | |
1230 | hash = n >> 32; | |
1231 | entry = n & ((1LL<<32) - 1); | |
1232 | ||
1233 | for (ch=cd->hash_table[hash]; ch; ch=ch->next) | |
1234 | if (!entry--) | |
1235 | return ch; | |
1236 | n &= ~((1LL<<32) - 1); | |
1237 | do { | |
1238 | hash++; | |
1239 | n += 1LL<<32; | |
cca5172a | 1240 | } while(hash < cd->hash_size && |
1da177e4 LT |
1241 | cd->hash_table[hash]==NULL); |
1242 | if (hash >= cd->hash_size) | |
1243 | return NULL; | |
1244 | *pos = n+1; | |
1245 | return cd->hash_table[hash]; | |
1246 | } | |
1247 | ||
1248 | static void *c_next(struct seq_file *m, void *p, loff_t *pos) | |
1249 | { | |
1250 | struct cache_head *ch = p; | |
1251 | int hash = (*pos >> 32); | |
1252 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1253 | ||
1254 | if (p == SEQ_START_TOKEN) | |
1255 | hash = 0; | |
1256 | else if (ch->next == NULL) { | |
1257 | hash++; | |
1258 | *pos += 1LL<<32; | |
1259 | } else { | |
1260 | ++*pos; | |
1261 | return ch->next; | |
1262 | } | |
1263 | *pos &= ~((1LL<<32) - 1); | |
1264 | while (hash < cd->hash_size && | |
1265 | cd->hash_table[hash] == NULL) { | |
1266 | hash++; | |
1267 | *pos += 1LL<<32; | |
1268 | } | |
1269 | if (hash >= cd->hash_size) | |
1270 | return NULL; | |
1271 | ++*pos; | |
1272 | return cd->hash_table[hash]; | |
1273 | } | |
1274 | ||
1275 | static void c_stop(struct seq_file *m, void *p) | |
9a429c49 | 1276 | __releases(cd->hash_lock) |
1da177e4 LT |
1277 | { |
1278 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1279 | read_unlock(&cd->hash_lock); | |
1280 | } | |
1281 | ||
1282 | static int c_show(struct seq_file *m, void *p) | |
1283 | { | |
1284 | struct cache_head *cp = p; | |
1285 | struct cache_detail *cd = ((struct handle*)m->private)->cd; | |
1286 | ||
1287 | if (p == SEQ_START_TOKEN) | |
1288 | return cd->cache_show(m, cd, NULL); | |
1289 | ||
1290 | ifdebug(CACHE) | |
4013edea | 1291 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", |
baab935f | 1292 | cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags); |
1da177e4 LT |
1293 | cache_get(cp); |
1294 | if (cache_check(cd, cp, NULL)) | |
1295 | /* cache_check does a cache_put on failure */ | |
1296 | seq_printf(m, "# "); | |
1297 | else | |
1298 | cache_put(cp, cd); | |
1299 | ||
1300 | return cd->cache_show(m, cd, cp); | |
1301 | } | |
1302 | ||
56b3d975 | 1303 | static const struct seq_operations cache_content_op = { |
1da177e4 LT |
1304 | .start = c_start, |
1305 | .next = c_next, | |
1306 | .stop = c_stop, | |
1307 | .show = c_show, | |
1308 | }; | |
1309 | ||
1310 | static int content_open(struct inode *inode, struct file *file) | |
1311 | { | |
1da177e4 LT |
1312 | struct handle *han; |
1313 | struct cache_detail *cd = PDE(inode)->data; | |
1314 | ||
ec931035 | 1315 | han = __seq_open_private(file, &cache_content_op, sizeof(*han)); |
1da177e4 LT |
1316 | if (han == NULL) |
1317 | return -ENOMEM; | |
1318 | ||
1319 | han->cd = cd; | |
ec931035 | 1320 | return 0; |
1da177e4 | 1321 | } |
1da177e4 | 1322 | |
da7071d7 | 1323 | static const struct file_operations content_file_operations = { |
1da177e4 LT |
1324 | .open = content_open, |
1325 | .read = seq_read, | |
1326 | .llseek = seq_lseek, | |
14690fc6 | 1327 | .release = seq_release_private, |
1da177e4 LT |
1328 | }; |
1329 | ||
1330 | static ssize_t read_flush(struct file *file, char __user *buf, | |
1331 | size_t count, loff_t *ppos) | |
1332 | { | |
303b46bb | 1333 | struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data; |
1da177e4 LT |
1334 | char tbuf[20]; |
1335 | unsigned long p = *ppos; | |
01b2969a | 1336 | size_t len; |
1da177e4 LT |
1337 | |
1338 | sprintf(tbuf, "%lu\n", cd->flush_time); | |
1339 | len = strlen(tbuf); | |
1340 | if (p >= len) | |
1341 | return 0; | |
1342 | len -= p; | |
01b2969a CL |
1343 | if (len > count) |
1344 | len = count; | |
1da177e4 | 1345 | if (copy_to_user(buf, (void*)(tbuf+p), len)) |
01b2969a CL |
1346 | return -EFAULT; |
1347 | *ppos += len; | |
1da177e4 LT |
1348 | return len; |
1349 | } | |
1350 | ||
1351 | static ssize_t write_flush(struct file * file, const char __user * buf, | |
1352 | size_t count, loff_t *ppos) | |
1353 | { | |
303b46bb | 1354 | struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data; |
1da177e4 LT |
1355 | char tbuf[20]; |
1356 | char *ep; | |
1357 | long flushtime; | |
1358 | if (*ppos || count > sizeof(tbuf)-1) | |
1359 | return -EINVAL; | |
1360 | if (copy_from_user(tbuf, buf, count)) | |
1361 | return -EFAULT; | |
1362 | tbuf[count] = 0; | |
1363 | flushtime = simple_strtoul(tbuf, &ep, 0); | |
1364 | if (*ep && *ep != '\n') | |
1365 | return -EINVAL; | |
1366 | ||
1367 | cd->flush_time = flushtime; | |
1368 | cd->nextcheck = get_seconds(); | |
1369 | cache_flush(); | |
1370 | ||
1371 | *ppos += count; | |
1372 | return count; | |
1373 | } | |
1374 | ||
da7071d7 | 1375 | static const struct file_operations cache_flush_operations = { |
1da177e4 LT |
1376 | .open = nonseekable_open, |
1377 | .read = read_flush, | |
1378 | .write = write_flush, | |
1379 | }; |