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> | |
1b2e122d | 23 | #include <linux/string_helpers.h> |
7c0f6ba6 | 24 | #include <linux/uaccess.h> |
1da177e4 LT |
25 | #include <linux/poll.h> |
26 | #include <linux/seq_file.h> | |
27 | #include <linux/proc_fs.h> | |
28 | #include <linux/net.h> | |
29 | #include <linux/workqueue.h> | |
4a3e2f71 | 30 | #include <linux/mutex.h> |
da77005f | 31 | #include <linux/pagemap.h> |
1da177e4 LT |
32 | #include <asm/ioctls.h> |
33 | #include <linux/sunrpc/types.h> | |
34 | #include <linux/sunrpc/cache.h> | |
35 | #include <linux/sunrpc/stats.h> | |
8854e82d | 36 | #include <linux/sunrpc/rpc_pipe_fs.h> |
4f42d0d5 | 37 | #include "netns.h" |
1da177e4 LT |
38 | |
39 | #define RPCDBG_FACILITY RPCDBG_CACHE | |
40 | ||
d76d1815 | 41 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item); |
1da177e4 LT |
42 | static void cache_revisit_request(struct cache_head *item); |
43 | ||
77862036 | 44 | static void cache_init(struct cache_head *h, struct cache_detail *detail) |
1da177e4 | 45 | { |
c5b29f88 | 46 | time_t now = seconds_since_boot(); |
129e5824 | 47 | INIT_HLIST_NODE(&h->cache_list); |
1da177e4 | 48 | h->flags = 0; |
baab935f | 49 | kref_init(&h->ref); |
1da177e4 | 50 | h->expiry_time = now + CACHE_NEW_EXPIRY; |
77862036 NB |
51 | if (now <= detail->flush_time) |
52 | /* ensure it isn't already expired */ | |
53 | now = detail->flush_time + 1; | |
1da177e4 LT |
54 | h->last_refresh = now; |
55 | } | |
56 | ||
15a5f6bd N |
57 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, |
58 | struct cache_head *key, int hash) | |
59 | { | |
129e5824 KM |
60 | struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL; |
61 | struct hlist_head *head; | |
15a5f6bd N |
62 | |
63 | head = &detail->hash_table[hash]; | |
64 | ||
65 | read_lock(&detail->hash_lock); | |
66 | ||
129e5824 | 67 | hlist_for_each_entry(tmp, head, cache_list) { |
15a5f6bd | 68 | if (detail->match(tmp, key)) { |
d202cce8 N |
69 | if (cache_is_expired(detail, tmp)) |
70 | /* This entry is expired, we will discard it. */ | |
71 | break; | |
15a5f6bd N |
72 | cache_get(tmp); |
73 | read_unlock(&detail->hash_lock); | |
74 | return tmp; | |
75 | } | |
76 | } | |
77 | read_unlock(&detail->hash_lock); | |
78 | /* Didn't find anything, insert an empty entry */ | |
79 | ||
80 | new = detail->alloc(); | |
81 | if (!new) | |
82 | return NULL; | |
2f34931f NB |
83 | /* must fully initialise 'new', else |
84 | * we might get lose if we need to | |
85 | * cache_put it soon. | |
86 | */ | |
77862036 | 87 | cache_init(new, detail); |
2f34931f | 88 | detail->init(new, key); |
15a5f6bd N |
89 | |
90 | write_lock(&detail->hash_lock); | |
91 | ||
92 | /* check if entry appeared while we slept */ | |
129e5824 | 93 | hlist_for_each_entry(tmp, head, cache_list) { |
15a5f6bd | 94 | if (detail->match(tmp, key)) { |
d202cce8 | 95 | if (cache_is_expired(detail, tmp)) { |
129e5824 | 96 | hlist_del_init(&tmp->cache_list); |
d202cce8 N |
97 | detail->entries --; |
98 | freeme = tmp; | |
99 | break; | |
100 | } | |
15a5f6bd N |
101 | cache_get(tmp); |
102 | write_unlock(&detail->hash_lock); | |
baab935f | 103 | cache_put(new, detail); |
15a5f6bd N |
104 | return tmp; |
105 | } | |
106 | } | |
129e5824 KM |
107 | |
108 | hlist_add_head(&new->cache_list, head); | |
15a5f6bd N |
109 | detail->entries++; |
110 | cache_get(new); | |
111 | write_unlock(&detail->hash_lock); | |
112 | ||
d202cce8 N |
113 | if (freeme) |
114 | cache_put(freeme, detail); | |
15a5f6bd N |
115 | return new; |
116 | } | |
24c3767e | 117 | EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); |
15a5f6bd | 118 | |
ebd0cb1a | 119 | |
f866a819 | 120 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); |
ebd0cb1a | 121 | |
77862036 NB |
122 | static void cache_fresh_locked(struct cache_head *head, time_t expiry, |
123 | struct cache_detail *detail) | |
ebd0cb1a | 124 | { |
77862036 NB |
125 | time_t now = seconds_since_boot(); |
126 | if (now <= detail->flush_time) | |
127 | /* ensure it isn't immediately treated as expired */ | |
128 | now = detail->flush_time + 1; | |
ebd0cb1a | 129 | head->expiry_time = expiry; |
77862036 | 130 | head->last_refresh = now; |
fdef7aa5 | 131 | smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */ |
908329f2 | 132 | set_bit(CACHE_VALID, &head->flags); |
ebd0cb1a N |
133 | } |
134 | ||
135 | static void cache_fresh_unlocked(struct cache_head *head, | |
908329f2 | 136 | struct cache_detail *detail) |
ebd0cb1a | 137 | { |
ebd0cb1a N |
138 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { |
139 | cache_revisit_request(head); | |
f866a819 | 140 | cache_dequeue(detail, head); |
ebd0cb1a N |
141 | } |
142 | } | |
143 | ||
15a5f6bd N |
144 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, |
145 | struct cache_head *new, struct cache_head *old, int hash) | |
146 | { | |
147 | /* The 'old' entry is to be replaced by 'new'. | |
148 | * If 'old' is not VALID, we update it directly, | |
149 | * otherwise we need to replace it | |
150 | */ | |
15a5f6bd N |
151 | struct cache_head *tmp; |
152 | ||
153 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
154 | write_lock(&detail->hash_lock); | |
155 | if (!test_bit(CACHE_VALID, &old->flags)) { | |
156 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
157 | set_bit(CACHE_NEGATIVE, &old->flags); | |
158 | else | |
159 | detail->update(old, new); | |
77862036 | 160 | cache_fresh_locked(old, new->expiry_time, detail); |
15a5f6bd | 161 | write_unlock(&detail->hash_lock); |
908329f2 | 162 | cache_fresh_unlocked(old, detail); |
15a5f6bd N |
163 | return old; |
164 | } | |
165 | write_unlock(&detail->hash_lock); | |
166 | } | |
167 | /* We need to insert a new entry */ | |
168 | tmp = detail->alloc(); | |
169 | if (!tmp) { | |
baab935f | 170 | cache_put(old, detail); |
15a5f6bd N |
171 | return NULL; |
172 | } | |
77862036 | 173 | cache_init(tmp, detail); |
15a5f6bd | 174 | detail->init(tmp, old); |
15a5f6bd N |
175 | |
176 | write_lock(&detail->hash_lock); | |
177 | if (test_bit(CACHE_NEGATIVE, &new->flags)) | |
178 | set_bit(CACHE_NEGATIVE, &tmp->flags); | |
179 | else | |
180 | detail->update(tmp, new); | |
129e5824 | 181 | hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); |
f2d39586 | 182 | detail->entries++; |
15a5f6bd | 183 | cache_get(tmp); |
77862036 NB |
184 | cache_fresh_locked(tmp, new->expiry_time, detail); |
185 | cache_fresh_locked(old, 0, detail); | |
15a5f6bd | 186 | write_unlock(&detail->hash_lock); |
908329f2 N |
187 | cache_fresh_unlocked(tmp, detail); |
188 | cache_fresh_unlocked(old, detail); | |
baab935f | 189 | cache_put(old, detail); |
15a5f6bd N |
190 | return tmp; |
191 | } | |
24c3767e | 192 | EXPORT_SYMBOL_GPL(sunrpc_cache_update); |
1da177e4 | 193 | |
bc74b4f5 TM |
194 | static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) |
195 | { | |
2d438338 SK |
196 | if (cd->cache_upcall) |
197 | return cd->cache_upcall(cd, h); | |
21cd1254 | 198 | return sunrpc_cache_pipe_upcall(cd, h); |
bc74b4f5 | 199 | } |
989a19b9 | 200 | |
b6040f97 | 201 | static inline int cache_is_valid(struct cache_head *h) |
989a19b9 | 202 | { |
d202cce8 | 203 | if (!test_bit(CACHE_VALID, &h->flags)) |
989a19b9 N |
204 | return -EAGAIN; |
205 | else { | |
206 | /* entry is valid */ | |
207 | if (test_bit(CACHE_NEGATIVE, &h->flags)) | |
208 | return -ENOENT; | |
fdef7aa5 BF |
209 | else { |
210 | /* | |
211 | * In combination with write barrier in | |
212 | * sunrpc_cache_update, ensures that anyone | |
213 | * using the cache entry after this sees the | |
214 | * updated contents: | |
215 | */ | |
216 | smp_rmb(); | |
989a19b9 | 217 | return 0; |
fdef7aa5 | 218 | } |
989a19b9 N |
219 | } |
220 | } | |
e9dc1221 | 221 | |
6bab93f8 BF |
222 | static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h) |
223 | { | |
224 | int rv; | |
225 | ||
226 | write_lock(&detail->hash_lock); | |
b6040f97 | 227 | rv = cache_is_valid(h); |
2a1c7f53 N |
228 | if (rv == -EAGAIN) { |
229 | set_bit(CACHE_NEGATIVE, &h->flags); | |
77862036 NB |
230 | cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY, |
231 | detail); | |
2a1c7f53 | 232 | rv = -ENOENT; |
6bab93f8 | 233 | } |
6bab93f8 BF |
234 | write_unlock(&detail->hash_lock); |
235 | cache_fresh_unlocked(h, detail); | |
2a1c7f53 | 236 | return rv; |
6bab93f8 BF |
237 | } |
238 | ||
1da177e4 LT |
239 | /* |
240 | * This is the generic cache management routine for all | |
241 | * the authentication caches. | |
242 | * It checks the currency of a cache item and will (later) | |
243 | * initiate an upcall to fill it if needed. | |
244 | * | |
245 | * | |
246 | * Returns 0 if the cache_head can be used, or cache_puts it and returns | |
989a19b9 N |
247 | * -EAGAIN if upcall is pending and request has been queued |
248 | * -ETIMEDOUT if upcall failed or request could not be queue or | |
249 | * upcall completed but item is still invalid (implying that | |
250 | * the cache item has been replaced with a newer one). | |
1da177e4 LT |
251 | * -ENOENT if cache entry was negative |
252 | */ | |
253 | int cache_check(struct cache_detail *detail, | |
254 | struct cache_head *h, struct cache_req *rqstp) | |
255 | { | |
256 | int rv; | |
257 | long refresh_age, age; | |
258 | ||
259 | /* First decide return status as best we can */ | |
b6040f97 | 260 | rv = cache_is_valid(h); |
1da177e4 LT |
261 | |
262 | /* now see if we want to start an upcall */ | |
263 | refresh_age = (h->expiry_time - h->last_refresh); | |
c5b29f88 | 264 | age = seconds_since_boot() - h->last_refresh; |
1da177e4 LT |
265 | |
266 | if (rqstp == NULL) { | |
267 | if (rv == -EAGAIN) | |
268 | rv = -ENOENT; | |
0bebc633 N |
269 | } else if (rv == -EAGAIN || |
270 | (h->expiry_time != 0 && age > refresh_age/2)) { | |
46121cf7 CL |
271 | dprintk("RPC: Want update, refage=%ld, age=%ld\n", |
272 | refresh_age, age); | |
1da177e4 LT |
273 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
274 | switch (cache_make_upcall(detail, h)) { | |
275 | case -EINVAL: | |
6bab93f8 | 276 | rv = try_to_negate_entry(detail, h); |
1da177e4 | 277 | break; |
1da177e4 | 278 | case -EAGAIN: |
2a1c7f53 | 279 | cache_fresh_unlocked(h, detail); |
1da177e4 LT |
280 | break; |
281 | } | |
282 | } | |
283 | } | |
284 | ||
989a19b9 | 285 | if (rv == -EAGAIN) { |
d76d1815 BF |
286 | if (!cache_defer_req(rqstp, h)) { |
287 | /* | |
288 | * Request was not deferred; handle it as best | |
289 | * we can ourselves: | |
290 | */ | |
b6040f97 | 291 | rv = cache_is_valid(h); |
989a19b9 N |
292 | if (rv == -EAGAIN) |
293 | rv = -ETIMEDOUT; | |
294 | } | |
295 | } | |
4013edea | 296 | if (rv) |
baab935f | 297 | cache_put(h, detail); |
1da177e4 LT |
298 | return rv; |
299 | } | |
24c3767e | 300 | EXPORT_SYMBOL_GPL(cache_check); |
1da177e4 | 301 | |
1da177e4 LT |
302 | /* |
303 | * caches need to be periodically cleaned. | |
304 | * For this we maintain a list of cache_detail and | |
305 | * a current pointer into that list and into the table | |
306 | * for that entry. | |
307 | * | |
013920eb | 308 | * Each time cache_clean is called it finds the next non-empty entry |
1da177e4 LT |
309 | * in the current table and walks the list in that entry |
310 | * looking for entries that can be removed. | |
311 | * | |
312 | * An entry gets removed if: | |
313 | * - The expiry is before current time | |
314 | * - The last_refresh time is before the flush_time for that cache | |
315 | * | |
316 | * later we might drop old entries with non-NEVER expiry if that table | |
317 | * is getting 'full' for some definition of 'full' | |
318 | * | |
319 | * The question of "how often to scan a table" is an interesting one | |
320 | * and is answered in part by the use of the "nextcheck" field in the | |
321 | * cache_detail. | |
322 | * When a scan of a table begins, the nextcheck field is set to a time | |
323 | * that is well into the future. | |
324 | * While scanning, if an expiry time is found that is earlier than the | |
325 | * current nextcheck time, nextcheck is set to that expiry time. | |
326 | * If the flush_time is ever set to a time earlier than the nextcheck | |
327 | * time, the nextcheck time is then set to that flush_time. | |
328 | * | |
329 | * A table is then only scanned if the current time is at least | |
330 | * the nextcheck time. | |
cca5172a | 331 | * |
1da177e4 LT |
332 | */ |
333 | ||
334 | static LIST_HEAD(cache_list); | |
335 | static DEFINE_SPINLOCK(cache_list_lock); | |
336 | static struct cache_detail *current_detail; | |
337 | static int current_index; | |
338 | ||
65f27f38 | 339 | static void do_cache_clean(struct work_struct *work); |
8eab945c | 340 | static struct delayed_work cache_cleaner; |
1da177e4 | 341 | |
820f9442 | 342 | void sunrpc_init_cache_detail(struct cache_detail *cd) |
ffe9386b | 343 | { |
1da177e4 LT |
344 | rwlock_init(&cd->hash_lock); |
345 | INIT_LIST_HEAD(&cd->queue); | |
346 | spin_lock(&cache_list_lock); | |
347 | cd->nextcheck = 0; | |
348 | cd->entries = 0; | |
349 | atomic_set(&cd->readers, 0); | |
350 | cd->last_close = 0; | |
351 | cd->last_warn = -1; | |
352 | list_add(&cd->others, &cache_list); | |
353 | spin_unlock(&cache_list_lock); | |
354 | ||
355 | /* start the cleaning process */ | |
77b00bc0 | 356 | queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0); |
1da177e4 | 357 | } |
820f9442 | 358 | EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail); |
1da177e4 | 359 | |
820f9442 | 360 | void sunrpc_destroy_cache_detail(struct cache_detail *cd) |
1da177e4 LT |
361 | { |
362 | cache_purge(cd); | |
363 | spin_lock(&cache_list_lock); | |
364 | write_lock(&cd->hash_lock); | |
1da177e4 LT |
365 | if (current_detail == cd) |
366 | current_detail = NULL; | |
367 | list_del_init(&cd->others); | |
368 | write_unlock(&cd->hash_lock); | |
369 | spin_unlock(&cache_list_lock); | |
1da177e4 LT |
370 | if (list_empty(&cache_list)) { |
371 | /* module must be being unloaded so its safe to kill the worker */ | |
4011cd97 | 372 | cancel_delayed_work_sync(&cache_cleaner); |
1da177e4 | 373 | } |
1da177e4 | 374 | } |
820f9442 | 375 | EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail); |
1da177e4 LT |
376 | |
377 | /* clean cache tries to find something to clean | |
378 | * and cleans it. | |
379 | * It returns 1 if it cleaned something, | |
380 | * 0 if it didn't find anything this time | |
381 | * -1 if it fell off the end of the list. | |
382 | */ | |
383 | static int cache_clean(void) | |
384 | { | |
385 | int rv = 0; | |
386 | struct list_head *next; | |
387 | ||
388 | spin_lock(&cache_list_lock); | |
389 | ||
390 | /* find a suitable table if we don't already have one */ | |
391 | while (current_detail == NULL || | |
392 | current_index >= current_detail->hash_size) { | |
393 | if (current_detail) | |
394 | next = current_detail->others.next; | |
395 | else | |
396 | next = cache_list.next; | |
397 | if (next == &cache_list) { | |
398 | current_detail = NULL; | |
399 | spin_unlock(&cache_list_lock); | |
400 | return -1; | |
401 | } | |
402 | current_detail = list_entry(next, struct cache_detail, others); | |
c5b29f88 | 403 | if (current_detail->nextcheck > seconds_since_boot()) |
1da177e4 LT |
404 | current_index = current_detail->hash_size; |
405 | else { | |
406 | current_index = 0; | |
c5b29f88 | 407 | current_detail->nextcheck = seconds_since_boot()+30*60; |
1da177e4 LT |
408 | } |
409 | } | |
410 | ||
411 | /* find a non-empty bucket in the table */ | |
412 | while (current_detail && | |
413 | current_index < current_detail->hash_size && | |
129e5824 | 414 | hlist_empty(¤t_detail->hash_table[current_index])) |
1da177e4 LT |
415 | current_index++; |
416 | ||
417 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ | |
cca5172a | 418 | |
1da177e4 | 419 | if (current_detail && current_index < current_detail->hash_size) { |
129e5824 | 420 | struct cache_head *ch = NULL; |
1da177e4 | 421 | struct cache_detail *d; |
129e5824 KM |
422 | struct hlist_head *head; |
423 | struct hlist_node *tmp; | |
cca5172a | 424 | |
1da177e4 LT |
425 | write_lock(¤t_detail->hash_lock); |
426 | ||
427 | /* Ok, now to clean this strand */ | |
cca5172a | 428 | |
129e5824 KM |
429 | head = ¤t_detail->hash_table[current_index]; |
430 | hlist_for_each_entry_safe(ch, tmp, head, cache_list) { | |
1da177e4 LT |
431 | if (current_detail->nextcheck > ch->expiry_time) |
432 | current_detail->nextcheck = ch->expiry_time+1; | |
2f50d8b6 | 433 | if (!cache_is_expired(current_detail, ch)) |
1da177e4 | 434 | continue; |
1da177e4 | 435 | |
129e5824 | 436 | hlist_del_init(&ch->cache_list); |
1da177e4 LT |
437 | current_detail->entries--; |
438 | rv = 1; | |
3af4974e | 439 | break; |
1da177e4 | 440 | } |
3af4974e | 441 | |
1da177e4 LT |
442 | write_unlock(¤t_detail->hash_lock); |
443 | d = current_detail; | |
444 | if (!ch) | |
445 | current_index ++; | |
446 | spin_unlock(&cache_list_lock); | |
5c4d2639 | 447 | if (ch) { |
013920eb | 448 | set_bit(CACHE_CLEANED, &ch->flags); |
2a1c7f53 | 449 | cache_fresh_unlocked(ch, d); |
baab935f | 450 | cache_put(ch, d); |
5c4d2639 | 451 | } |
1da177e4 LT |
452 | } else |
453 | spin_unlock(&cache_list_lock); | |
454 | ||
455 | return rv; | |
456 | } | |
457 | ||
458 | /* | |
459 | * We want to regularly clean the cache, so we need to schedule some work ... | |
460 | */ | |
65f27f38 | 461 | static void do_cache_clean(struct work_struct *work) |
1da177e4 LT |
462 | { |
463 | int delay = 5; | |
464 | if (cache_clean() == -1) | |
6aad89c8 | 465 | delay = round_jiffies_relative(30*HZ); |
1da177e4 LT |
466 | |
467 | if (list_empty(&cache_list)) | |
468 | delay = 0; | |
469 | ||
470 | if (delay) | |
77b00bc0 KW |
471 | queue_delayed_work(system_power_efficient_wq, |
472 | &cache_cleaner, delay); | |
1da177e4 LT |
473 | } |
474 | ||
475 | ||
cca5172a | 476 | /* |
1da177e4 | 477 | * Clean all caches promptly. This just calls cache_clean |
cca5172a | 478 | * repeatedly until we are sure that every cache has had a chance to |
1da177e4 LT |
479 | * be fully cleaned |
480 | */ | |
481 | void cache_flush(void) | |
482 | { | |
483 | while (cache_clean() != -1) | |
484 | cond_resched(); | |
485 | while (cache_clean() != -1) | |
486 | cond_resched(); | |
487 | } | |
24c3767e | 488 | EXPORT_SYMBOL_GPL(cache_flush); |
1da177e4 LT |
489 | |
490 | void cache_purge(struct cache_detail *detail) | |
491 | { | |
471a930a KM |
492 | struct cache_head *ch = NULL; |
493 | struct hlist_head *head = NULL; | |
494 | struct hlist_node *tmp = NULL; | |
495 | int i = 0; | |
496 | ||
497 | write_lock(&detail->hash_lock); | |
498 | if (!detail->entries) { | |
499 | write_unlock(&detail->hash_lock); | |
500 | return; | |
501 | } | |
502 | ||
503 | dprintk("RPC: %d entries in %s cache\n", detail->entries, detail->name); | |
504 | for (i = 0; i < detail->hash_size; i++) { | |
505 | head = &detail->hash_table[i]; | |
506 | hlist_for_each_entry_safe(ch, tmp, head, cache_list) { | |
507 | hlist_del_init(&ch->cache_list); | |
508 | detail->entries--; | |
509 | ||
510 | set_bit(CACHE_CLEANED, &ch->flags); | |
511 | write_unlock(&detail->hash_lock); | |
512 | cache_fresh_unlocked(ch, detail); | |
513 | cache_put(ch, detail); | |
514 | write_lock(&detail->hash_lock); | |
515 | } | |
516 | } | |
517 | write_unlock(&detail->hash_lock); | |
1da177e4 | 518 | } |
24c3767e | 519 | EXPORT_SYMBOL_GPL(cache_purge); |
1da177e4 LT |
520 | |
521 | ||
522 | /* | |
523 | * Deferral and Revisiting of Requests. | |
524 | * | |
525 | * If a cache lookup finds a pending entry, we | |
526 | * need to defer the request and revisit it later. | |
527 | * All deferred requests are stored in a hash table, | |
528 | * indexed by "struct cache_head *". | |
529 | * As it may be wasteful to store a whole request | |
cca5172a | 530 | * structure, we allow the request to provide a |
1da177e4 LT |
531 | * deferred form, which must contain a |
532 | * 'struct cache_deferred_req' | |
533 | * This cache_deferred_req contains a method to allow | |
534 | * it to be revisited when cache info is available | |
535 | */ | |
536 | ||
537 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) | |
538 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) | |
539 | ||
540 | #define DFR_MAX 300 /* ??? */ | |
541 | ||
542 | static DEFINE_SPINLOCK(cache_defer_lock); | |
543 | static LIST_HEAD(cache_defer_list); | |
11174492 | 544 | static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; |
1da177e4 LT |
545 | static int cache_defer_cnt; |
546 | ||
6610f720 BF |
547 | static void __unhash_deferred_req(struct cache_deferred_req *dreq) |
548 | { | |
11174492 | 549 | hlist_del_init(&dreq->hash); |
e33534d5 N |
550 | if (!list_empty(&dreq->recent)) { |
551 | list_del_init(&dreq->recent); | |
552 | cache_defer_cnt--; | |
553 | } | |
6610f720 BF |
554 | } |
555 | ||
556 | static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item) | |
1da177e4 | 557 | { |
1da177e4 LT |
558 | int hash = DFR_HASH(item); |
559 | ||
e33534d5 | 560 | INIT_LIST_HEAD(&dreq->recent); |
11174492 | 561 | hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); |
6610f720 BF |
562 | } |
563 | ||
e33534d5 N |
564 | static void setup_deferral(struct cache_deferred_req *dreq, |
565 | struct cache_head *item, | |
566 | int count_me) | |
1da177e4 | 567 | { |
1da177e4 LT |
568 | |
569 | dreq->item = item; | |
1da177e4 LT |
570 | |
571 | spin_lock(&cache_defer_lock); | |
572 | ||
6610f720 | 573 | __hash_deferred_req(dreq, item); |
1da177e4 | 574 | |
e33534d5 N |
575 | if (count_me) { |
576 | cache_defer_cnt++; | |
577 | list_add(&dreq->recent, &cache_defer_list); | |
1da177e4 | 578 | } |
e33534d5 | 579 | |
1da177e4 LT |
580 | spin_unlock(&cache_defer_lock); |
581 | ||
3211af11 | 582 | } |
f16b6e8d | 583 | |
3211af11 BF |
584 | struct thread_deferred_req { |
585 | struct cache_deferred_req handle; | |
586 | struct completion completion; | |
587 | }; | |
588 | ||
589 | static void cache_restart_thread(struct cache_deferred_req *dreq, int too_many) | |
590 | { | |
591 | struct thread_deferred_req *dr = | |
592 | container_of(dreq, struct thread_deferred_req, handle); | |
593 | complete(&dr->completion); | |
594 | } | |
595 | ||
d29068c4 | 596 | static void cache_wait_req(struct cache_req *req, struct cache_head *item) |
3211af11 BF |
597 | { |
598 | struct thread_deferred_req sleeper; | |
599 | struct cache_deferred_req *dreq = &sleeper.handle; | |
3211af11 BF |
600 | |
601 | sleeper.completion = COMPLETION_INITIALIZER_ONSTACK(sleeper.completion); | |
602 | dreq->revisit = cache_restart_thread; | |
603 | ||
e33534d5 | 604 | setup_deferral(dreq, item, 0); |
3211af11 | 605 | |
d29068c4 | 606 | if (!test_bit(CACHE_PENDING, &item->flags) || |
277f68db | 607 | wait_for_completion_interruptible_timeout( |
3211af11 BF |
608 | &sleeper.completion, req->thread_wait) <= 0) { |
609 | /* The completion wasn't completed, so we need | |
610 | * to clean up | |
611 | */ | |
612 | spin_lock(&cache_defer_lock); | |
11174492 | 613 | if (!hlist_unhashed(&sleeper.handle.hash)) { |
3211af11 BF |
614 | __unhash_deferred_req(&sleeper.handle); |
615 | spin_unlock(&cache_defer_lock); | |
616 | } else { | |
617 | /* cache_revisit_request already removed | |
618 | * this from the hash table, but hasn't | |
619 | * called ->revisit yet. It will very soon | |
620 | * and we need to wait for it. | |
f16b6e8d | 621 | */ |
3211af11 BF |
622 | spin_unlock(&cache_defer_lock); |
623 | wait_for_completion(&sleeper.completion); | |
f16b6e8d | 624 | } |
3211af11 | 625 | } |
3211af11 BF |
626 | } |
627 | ||
e33534d5 | 628 | static void cache_limit_defers(void) |
3211af11 | 629 | { |
e33534d5 N |
630 | /* Make sure we haven't exceed the limit of allowed deferred |
631 | * requests. | |
632 | */ | |
633 | struct cache_deferred_req *discard = NULL; | |
3211af11 | 634 | |
e33534d5 N |
635 | if (cache_defer_cnt <= DFR_MAX) |
636 | return; | |
d29068c4 | 637 | |
e33534d5 N |
638 | spin_lock(&cache_defer_lock); |
639 | ||
640 | /* Consider removing either the first or the last */ | |
641 | if (cache_defer_cnt > DFR_MAX) { | |
63862b5b | 642 | if (prandom_u32() & 1) |
e33534d5 N |
643 | discard = list_entry(cache_defer_list.next, |
644 | struct cache_deferred_req, recent); | |
645 | else | |
646 | discard = list_entry(cache_defer_list.prev, | |
647 | struct cache_deferred_req, recent); | |
648 | __unhash_deferred_req(discard); | |
649 | } | |
650 | spin_unlock(&cache_defer_lock); | |
cd68c374 | 651 | if (discard) |
cd68c374 | 652 | discard->revisit(discard, 1); |
e33534d5 | 653 | } |
cd68c374 | 654 | |
d76d1815 BF |
655 | /* Return true if and only if a deferred request is queued. */ |
656 | static bool cache_defer_req(struct cache_req *req, struct cache_head *item) | |
e33534d5 N |
657 | { |
658 | struct cache_deferred_req *dreq; | |
d29068c4 | 659 | |
3211af11 | 660 | if (req->thread_wait) { |
d29068c4 N |
661 | cache_wait_req(req, item); |
662 | if (!test_bit(CACHE_PENDING, &item->flags)) | |
d76d1815 | 663 | return false; |
1da177e4 | 664 | } |
3211af11 BF |
665 | dreq = req->defer(req); |
666 | if (dreq == NULL) | |
d76d1815 | 667 | return false; |
e33534d5 | 668 | setup_deferral(dreq, item, 1); |
d29068c4 N |
669 | if (!test_bit(CACHE_PENDING, &item->flags)) |
670 | /* Bit could have been cleared before we managed to | |
671 | * set up the deferral, so need to revisit just in case | |
672 | */ | |
673 | cache_revisit_request(item); | |
e33534d5 N |
674 | |
675 | cache_limit_defers(); | |
d76d1815 | 676 | return true; |
1da177e4 LT |
677 | } |
678 | ||
679 | static void cache_revisit_request(struct cache_head *item) | |
680 | { | |
681 | struct cache_deferred_req *dreq; | |
682 | struct list_head pending; | |
b67bfe0d | 683 | struct hlist_node *tmp; |
1da177e4 LT |
684 | int hash = DFR_HASH(item); |
685 | ||
686 | INIT_LIST_HEAD(&pending); | |
687 | spin_lock(&cache_defer_lock); | |
cca5172a | 688 | |
b67bfe0d | 689 | hlist_for_each_entry_safe(dreq, tmp, &cache_defer_hash[hash], hash) |
11174492 N |
690 | if (dreq->item == item) { |
691 | __unhash_deferred_req(dreq); | |
692 | list_add(&dreq->recent, &pending); | |
1da177e4 | 693 | } |
11174492 | 694 | |
1da177e4 LT |
695 | spin_unlock(&cache_defer_lock); |
696 | ||
697 | while (!list_empty(&pending)) { | |
698 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
699 | list_del_init(&dreq->recent); | |
700 | dreq->revisit(dreq, 0); | |
701 | } | |
702 | } | |
703 | ||
704 | void cache_clean_deferred(void *owner) | |
705 | { | |
706 | struct cache_deferred_req *dreq, *tmp; | |
707 | struct list_head pending; | |
708 | ||
709 | ||
710 | INIT_LIST_HEAD(&pending); | |
711 | spin_lock(&cache_defer_lock); | |
cca5172a | 712 | |
1da177e4 LT |
713 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { |
714 | if (dreq->owner == owner) { | |
6610f720 | 715 | __unhash_deferred_req(dreq); |
e95dffa4 | 716 | list_add(&dreq->recent, &pending); |
1da177e4 LT |
717 | } |
718 | } | |
719 | spin_unlock(&cache_defer_lock); | |
720 | ||
721 | while (!list_empty(&pending)) { | |
722 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); | |
723 | list_del_init(&dreq->recent); | |
724 | dreq->revisit(dreq, 1); | |
725 | } | |
726 | } | |
727 | ||
728 | /* | |
729 | * communicate with user-space | |
730 | * | |
6489a8f4 | 731 | * We have a magic /proc file - /proc/net/rpc/<cachename>/channel. |
a490c681 BF |
732 | * On read, you get a full request, or block. |
733 | * On write, an update request is processed. | |
734 | * Poll works if anything to read, and always allows write. | |
1da177e4 | 735 | * |
cca5172a | 736 | * Implemented by linked list of requests. Each open file has |
a490c681 | 737 | * a ->private that also exists in this list. New requests are added |
1da177e4 LT |
738 | * to the end and may wakeup and preceding readers. |
739 | * New readers are added to the head. If, on read, an item is found with | |
740 | * CACHE_UPCALLING clear, we free it from the list. | |
741 | * | |
742 | */ | |
743 | ||
744 | static DEFINE_SPINLOCK(queue_lock); | |
4a3e2f71 | 745 | static DEFINE_MUTEX(queue_io_mutex); |
1da177e4 LT |
746 | |
747 | struct cache_queue { | |
748 | struct list_head list; | |
749 | int reader; /* if 0, then request */ | |
750 | }; | |
751 | struct cache_request { | |
752 | struct cache_queue q; | |
753 | struct cache_head *item; | |
754 | char * buf; | |
755 | int len; | |
756 | int readers; | |
757 | }; | |
758 | struct cache_reader { | |
759 | struct cache_queue q; | |
760 | int offset; /* if non-0, we have a refcnt on next request */ | |
761 | }; | |
762 | ||
d94af6de SK |
763 | static int cache_request(struct cache_detail *detail, |
764 | struct cache_request *crq) | |
765 | { | |
766 | char *bp = crq->buf; | |
767 | int len = PAGE_SIZE; | |
768 | ||
769 | detail->cache_request(detail, crq->item, &bp, &len); | |
770 | if (len < 0) | |
771 | return -EAGAIN; | |
772 | return PAGE_SIZE - len; | |
773 | } | |
774 | ||
173912a6 TM |
775 | static ssize_t cache_read(struct file *filp, char __user *buf, size_t count, |
776 | loff_t *ppos, struct cache_detail *cd) | |
1da177e4 LT |
777 | { |
778 | struct cache_reader *rp = filp->private_data; | |
779 | struct cache_request *rq; | |
496ad9aa | 780 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
781 | int err; |
782 | ||
783 | if (count == 0) | |
784 | return 0; | |
785 | ||
5955102c | 786 | inode_lock(inode); /* protect against multiple concurrent |
1da177e4 LT |
787 | * readers on this file */ |
788 | again: | |
789 | spin_lock(&queue_lock); | |
790 | /* need to find next request */ | |
791 | while (rp->q.list.next != &cd->queue && | |
792 | list_entry(rp->q.list.next, struct cache_queue, list) | |
793 | ->reader) { | |
794 | struct list_head *next = rp->q.list.next; | |
795 | list_move(&rp->q.list, next); | |
796 | } | |
797 | if (rp->q.list.next == &cd->queue) { | |
798 | spin_unlock(&queue_lock); | |
5955102c | 799 | inode_unlock(inode); |
0db74d9a | 800 | WARN_ON_ONCE(rp->offset); |
1da177e4 LT |
801 | return 0; |
802 | } | |
803 | rq = container_of(rp->q.list.next, struct cache_request, q.list); | |
0db74d9a | 804 | WARN_ON_ONCE(rq->q.reader); |
1da177e4 LT |
805 | if (rp->offset == 0) |
806 | rq->readers++; | |
807 | spin_unlock(&queue_lock); | |
808 | ||
d94af6de SK |
809 | if (rq->len == 0) { |
810 | err = cache_request(cd, rq); | |
811 | if (err < 0) | |
812 | goto out; | |
813 | rq->len = err; | |
814 | } | |
815 | ||
1da177e4 LT |
816 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { |
817 | err = -EAGAIN; | |
818 | spin_lock(&queue_lock); | |
819 | list_move(&rp->q.list, &rq->q.list); | |
820 | spin_unlock(&queue_lock); | |
821 | } else { | |
822 | if (rp->offset + count > rq->len) | |
823 | count = rq->len - rp->offset; | |
824 | err = -EFAULT; | |
825 | if (copy_to_user(buf, rq->buf + rp->offset, count)) | |
826 | goto out; | |
827 | rp->offset += count; | |
828 | if (rp->offset >= rq->len) { | |
829 | rp->offset = 0; | |
830 | spin_lock(&queue_lock); | |
831 | list_move(&rp->q.list, &rq->q.list); | |
832 | spin_unlock(&queue_lock); | |
833 | } | |
834 | err = 0; | |
835 | } | |
836 | out: | |
837 | if (rp->offset == 0) { | |
838 | /* need to release rq */ | |
839 | spin_lock(&queue_lock); | |
840 | rq->readers--; | |
841 | if (rq->readers == 0 && | |
842 | !test_bit(CACHE_PENDING, &rq->item->flags)) { | |
843 | list_del(&rq->q.list); | |
844 | spin_unlock(&queue_lock); | |
baab935f | 845 | cache_put(rq->item, cd); |
1da177e4 LT |
846 | kfree(rq->buf); |
847 | kfree(rq); | |
848 | } else | |
849 | spin_unlock(&queue_lock); | |
850 | } | |
851 | if (err == -EAGAIN) | |
852 | goto again; | |
5955102c | 853 | inode_unlock(inode); |
1da177e4 LT |
854 | return err ? err : count; |
855 | } | |
856 | ||
da77005f TM |
857 | static ssize_t cache_do_downcall(char *kaddr, const char __user *buf, |
858 | size_t count, struct cache_detail *cd) | |
859 | { | |
860 | ssize_t ret; | |
1da177e4 | 861 | |
6d8d1749 DC |
862 | if (count == 0) |
863 | return -EINVAL; | |
da77005f TM |
864 | if (copy_from_user(kaddr, buf, count)) |
865 | return -EFAULT; | |
866 | kaddr[count] = '\0'; | |
867 | ret = cd->cache_parse(cd, kaddr, count); | |
868 | if (!ret) | |
869 | ret = count; | |
870 | return ret; | |
871 | } | |
872 | ||
873 | static ssize_t cache_slow_downcall(const char __user *buf, | |
874 | size_t count, struct cache_detail *cd) | |
1da177e4 | 875 | { |
da77005f TM |
876 | static char write_buf[8192]; /* protected by queue_io_mutex */ |
877 | ssize_t ret = -EINVAL; | |
1da177e4 | 878 | |
1da177e4 | 879 | if (count >= sizeof(write_buf)) |
da77005f | 880 | goto out; |
4a3e2f71 | 881 | mutex_lock(&queue_io_mutex); |
da77005f TM |
882 | ret = cache_do_downcall(write_buf, buf, count, cd); |
883 | mutex_unlock(&queue_io_mutex); | |
884 | out: | |
885 | return ret; | |
886 | } | |
1da177e4 | 887 | |
da77005f TM |
888 | static ssize_t cache_downcall(struct address_space *mapping, |
889 | const char __user *buf, | |
890 | size_t count, struct cache_detail *cd) | |
891 | { | |
892 | struct page *page; | |
893 | char *kaddr; | |
894 | ssize_t ret = -ENOMEM; | |
895 | ||
09cbfeaf | 896 | if (count >= PAGE_SIZE) |
da77005f TM |
897 | goto out_slow; |
898 | ||
899 | page = find_or_create_page(mapping, 0, GFP_KERNEL); | |
900 | if (!page) | |
901 | goto out_slow; | |
902 | ||
903 | kaddr = kmap(page); | |
904 | ret = cache_do_downcall(kaddr, buf, count, cd); | |
905 | kunmap(page); | |
906 | unlock_page(page); | |
09cbfeaf | 907 | put_page(page); |
da77005f TM |
908 | return ret; |
909 | out_slow: | |
910 | return cache_slow_downcall(buf, count, cd); | |
911 | } | |
1da177e4 | 912 | |
173912a6 TM |
913 | static ssize_t cache_write(struct file *filp, const char __user *buf, |
914 | size_t count, loff_t *ppos, | |
915 | struct cache_detail *cd) | |
da77005f TM |
916 | { |
917 | struct address_space *mapping = filp->f_mapping; | |
496ad9aa | 918 | struct inode *inode = file_inode(filp); |
da77005f TM |
919 | ssize_t ret = -EINVAL; |
920 | ||
921 | if (!cd->cache_parse) | |
922 | goto out; | |
923 | ||
5955102c | 924 | inode_lock(inode); |
da77005f | 925 | ret = cache_downcall(mapping, buf, count, cd); |
5955102c | 926 | inode_unlock(inode); |
da77005f TM |
927 | out: |
928 | return ret; | |
1da177e4 LT |
929 | } |
930 | ||
931 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); | |
932 | ||
173912a6 TM |
933 | static unsigned int cache_poll(struct file *filp, poll_table *wait, |
934 | struct cache_detail *cd) | |
1da177e4 LT |
935 | { |
936 | unsigned int mask; | |
937 | struct cache_reader *rp = filp->private_data; | |
938 | struct cache_queue *cq; | |
1da177e4 LT |
939 | |
940 | poll_wait(filp, &queue_wait, wait); | |
941 | ||
942 | /* alway allow write */ | |
1711fd9a | 943 | mask = POLLOUT | POLLWRNORM; |
1da177e4 LT |
944 | |
945 | if (!rp) | |
946 | return mask; | |
947 | ||
948 | spin_lock(&queue_lock); | |
949 | ||
950 | for (cq= &rp->q; &cq->list != &cd->queue; | |
951 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
952 | if (!cq->reader) { | |
953 | mask |= POLLIN | POLLRDNORM; | |
954 | break; | |
955 | } | |
956 | spin_unlock(&queue_lock); | |
957 | return mask; | |
958 | } | |
959 | ||
173912a6 TM |
960 | static int cache_ioctl(struct inode *ino, struct file *filp, |
961 | unsigned int cmd, unsigned long arg, | |
962 | struct cache_detail *cd) | |
1da177e4 LT |
963 | { |
964 | int len = 0; | |
965 | struct cache_reader *rp = filp->private_data; | |
966 | struct cache_queue *cq; | |
1da177e4 LT |
967 | |
968 | if (cmd != FIONREAD || !rp) | |
969 | return -EINVAL; | |
970 | ||
971 | spin_lock(&queue_lock); | |
972 | ||
973 | /* only find the length remaining in current request, | |
974 | * or the length of the next request | |
975 | */ | |
976 | for (cq= &rp->q; &cq->list != &cd->queue; | |
977 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
978 | if (!cq->reader) { | |
979 | struct cache_request *cr = | |
980 | container_of(cq, struct cache_request, q); | |
981 | len = cr->len - rp->offset; | |
982 | break; | |
983 | } | |
984 | spin_unlock(&queue_lock); | |
985 | ||
986 | return put_user(len, (int __user *)arg); | |
987 | } | |
988 | ||
173912a6 TM |
989 | static int cache_open(struct inode *inode, struct file *filp, |
990 | struct cache_detail *cd) | |
1da177e4 LT |
991 | { |
992 | struct cache_reader *rp = NULL; | |
993 | ||
f7e86ab9 TM |
994 | if (!cd || !try_module_get(cd->owner)) |
995 | return -EACCES; | |
1da177e4 LT |
996 | nonseekable_open(inode, filp); |
997 | if (filp->f_mode & FMODE_READ) { | |
1da177e4 | 998 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); |
a7823c79 AK |
999 | if (!rp) { |
1000 | module_put(cd->owner); | |
1da177e4 | 1001 | return -ENOMEM; |
a7823c79 | 1002 | } |
1da177e4 LT |
1003 | rp->offset = 0; |
1004 | rp->q.reader = 1; | |
1005 | atomic_inc(&cd->readers); | |
1006 | spin_lock(&queue_lock); | |
1007 | list_add(&rp->q.list, &cd->queue); | |
1008 | spin_unlock(&queue_lock); | |
1009 | } | |
1010 | filp->private_data = rp; | |
1011 | return 0; | |
1012 | } | |
1013 | ||
173912a6 TM |
1014 | static int cache_release(struct inode *inode, struct file *filp, |
1015 | struct cache_detail *cd) | |
1da177e4 LT |
1016 | { |
1017 | struct cache_reader *rp = filp->private_data; | |
1da177e4 LT |
1018 | |
1019 | if (rp) { | |
1020 | spin_lock(&queue_lock); | |
1021 | if (rp->offset) { | |
1022 | struct cache_queue *cq; | |
1023 | for (cq= &rp->q; &cq->list != &cd->queue; | |
1024 | cq = list_entry(cq->list.next, struct cache_queue, list)) | |
1025 | if (!cq->reader) { | |
1026 | container_of(cq, struct cache_request, q) | |
1027 | ->readers--; | |
1028 | break; | |
1029 | } | |
1030 | rp->offset = 0; | |
1031 | } | |
1032 | list_del(&rp->q.list); | |
1033 | spin_unlock(&queue_lock); | |
1034 | ||
1035 | filp->private_data = NULL; | |
1036 | kfree(rp); | |
1037 | ||
c5b29f88 | 1038 | cd->last_close = seconds_since_boot(); |
1da177e4 LT |
1039 | atomic_dec(&cd->readers); |
1040 | } | |
f7e86ab9 | 1041 | module_put(cd->owner); |
1da177e4 LT |
1042 | return 0; |
1043 | } | |
1044 | ||
1045 | ||
1046 | ||
f866a819 | 1047 | static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch) |
1da177e4 | 1048 | { |
f9e1aedc N |
1049 | struct cache_queue *cq, *tmp; |
1050 | struct cache_request *cr; | |
1051 | struct list_head dequeued; | |
1052 | ||
1053 | INIT_LIST_HEAD(&dequeued); | |
1da177e4 | 1054 | spin_lock(&queue_lock); |
f9e1aedc | 1055 | list_for_each_entry_safe(cq, tmp, &detail->queue, list) |
1da177e4 | 1056 | if (!cq->reader) { |
f9e1aedc | 1057 | cr = container_of(cq, struct cache_request, q); |
1da177e4 LT |
1058 | if (cr->item != ch) |
1059 | continue; | |
f9e1aedc N |
1060 | if (test_bit(CACHE_PENDING, &ch->flags)) |
1061 | /* Lost a race and it is pending again */ | |
1062 | break; | |
1da177e4 | 1063 | if (cr->readers != 0) |
4013edea | 1064 | continue; |
f9e1aedc | 1065 | list_move(&cr->q.list, &dequeued); |
1da177e4 LT |
1066 | } |
1067 | spin_unlock(&queue_lock); | |
f9e1aedc N |
1068 | while (!list_empty(&dequeued)) { |
1069 | cr = list_entry(dequeued.next, struct cache_request, q.list); | |
1070 | list_del(&cr->q.list); | |
1071 | cache_put(cr->item, detail); | |
1072 | kfree(cr->buf); | |
1073 | kfree(cr); | |
1074 | } | |
1da177e4 LT |
1075 | } |
1076 | ||
1077 | /* | |
1078 | * Support routines for text-based upcalls. | |
1079 | * Fields are separated by spaces. | |
1080 | * Fields are either mangled to quote space tab newline slosh with slosh | |
1081 | * or a hexified with a leading \x | |
1082 | * Record is terminated with newline. | |
1083 | * | |
1084 | */ | |
1085 | ||
1086 | void qword_add(char **bpp, int *lp, char *str) | |
1087 | { | |
1088 | char *bp = *bpp; | |
1089 | int len = *lp; | |
1b2e122d | 1090 | int ret; |
1da177e4 LT |
1091 | |
1092 | if (len < 0) return; | |
1093 | ||
41416f23 RV |
1094 | ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t"); |
1095 | if (ret >= len) { | |
1096 | bp += len; | |
1b2e122d | 1097 | len = -1; |
41416f23 RV |
1098 | } else { |
1099 | bp += ret; | |
1b2e122d | 1100 | len -= ret; |
1da177e4 LT |
1101 | *bp++ = ' '; |
1102 | len--; | |
1103 | } | |
1104 | *bpp = bp; | |
1105 | *lp = len; | |
1106 | } | |
24c3767e | 1107 | EXPORT_SYMBOL_GPL(qword_add); |
1da177e4 LT |
1108 | |
1109 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) | |
1110 | { | |
1111 | char *bp = *bpp; | |
1112 | int len = *lp; | |
1113 | ||
1114 | if (len < 0) return; | |
1115 | ||
1116 | if (len > 2) { | |
1117 | *bp++ = '\\'; | |
1118 | *bp++ = 'x'; | |
1119 | len -= 2; | |
1120 | while (blen && len >= 2) { | |
056785ea | 1121 | bp = hex_byte_pack(bp, *buf++); |
1da177e4 LT |
1122 | len -= 2; |
1123 | blen--; | |
1124 | } | |
1125 | } | |
1126 | if (blen || len<1) len = -1; | |
1127 | else { | |
1128 | *bp++ = ' '; | |
1129 | len--; | |
1130 | } | |
1131 | *bpp = bp; | |
1132 | *lp = len; | |
1133 | } | |
24c3767e | 1134 | EXPORT_SYMBOL_GPL(qword_addhex); |
1da177e4 LT |
1135 | |
1136 | static void warn_no_listener(struct cache_detail *detail) | |
1137 | { | |
1138 | if (detail->last_warn != detail->last_close) { | |
1139 | detail->last_warn = detail->last_close; | |
1140 | if (detail->warn_no_listener) | |
2da8ca26 | 1141 | detail->warn_no_listener(detail, detail->last_close != 0); |
1da177e4 LT |
1142 | } |
1143 | } | |
1144 | ||
06497524 BF |
1145 | static bool cache_listeners_exist(struct cache_detail *detail) |
1146 | { | |
1147 | if (atomic_read(&detail->readers)) | |
1148 | return true; | |
1149 | if (detail->last_close == 0) | |
1150 | /* This cache was never opened */ | |
1151 | return false; | |
1152 | if (detail->last_close < seconds_since_boot() - 30) | |
1153 | /* | |
1154 | * We allow for the possibility that someone might | |
1155 | * restart a userspace daemon without restarting the | |
1156 | * server; but after 30 seconds, we give up. | |
1157 | */ | |
1158 | return false; | |
1159 | return true; | |
1160 | } | |
1161 | ||
1da177e4 | 1162 | /* |
bc74b4f5 TM |
1163 | * register an upcall request to user-space and queue it up for read() by the |
1164 | * upcall daemon. | |
1165 | * | |
1da177e4 LT |
1166 | * Each request is at most one page long. |
1167 | */ | |
21cd1254 | 1168 | int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) |
1da177e4 LT |
1169 | { |
1170 | ||
1171 | char *buf; | |
1172 | struct cache_request *crq; | |
f9e1aedc | 1173 | int ret = 0; |
1da177e4 | 1174 | |
2d438338 SK |
1175 | if (!detail->cache_request) |
1176 | return -EINVAL; | |
1da177e4 | 1177 | |
06497524 BF |
1178 | if (!cache_listeners_exist(detail)) { |
1179 | warn_no_listener(detail); | |
1180 | return -EINVAL; | |
1da177e4 | 1181 | } |
013920eb N |
1182 | if (test_bit(CACHE_CLEANED, &h->flags)) |
1183 | /* Too late to make an upcall */ | |
1184 | return -EAGAIN; | |
1da177e4 LT |
1185 | |
1186 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
1187 | if (!buf) | |
1188 | return -EAGAIN; | |
1189 | ||
1190 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); | |
1191 | if (!crq) { | |
1192 | kfree(buf); | |
1193 | return -EAGAIN; | |
1194 | } | |
1195 | ||
1da177e4 | 1196 | crq->q.reader = 0; |
1da177e4 | 1197 | crq->buf = buf; |
d94af6de | 1198 | crq->len = 0; |
1da177e4 LT |
1199 | crq->readers = 0; |
1200 | spin_lock(&queue_lock); | |
a6ab1e81 N |
1201 | if (test_bit(CACHE_PENDING, &h->flags)) { |
1202 | crq->item = cache_get(h); | |
f9e1aedc | 1203 | list_add_tail(&crq->q.list, &detail->queue); |
a6ab1e81 | 1204 | } else |
f9e1aedc N |
1205 | /* Lost a race, no longer PENDING, so don't enqueue */ |
1206 | ret = -EAGAIN; | |
1da177e4 LT |
1207 | spin_unlock(&queue_lock); |
1208 | wake_up(&queue_wait); | |
f9e1aedc N |
1209 | if (ret == -EAGAIN) { |
1210 | kfree(buf); | |
1211 | kfree(crq); | |
1212 | } | |
1213 | return ret; | |
1da177e4 | 1214 | } |
bc74b4f5 | 1215 | EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); |
1da177e4 LT |
1216 | |
1217 | /* | |
1218 | * parse a message from user-space and pass it | |
1219 | * to an appropriate cache | |
1220 | * Messages are, like requests, separated into fields by | |
1221 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal | |
1222 | * | |
cca5172a | 1223 | * Message is |
1da177e4 LT |
1224 | * reply cachename expiry key ... content.... |
1225 | * | |
cca5172a | 1226 | * key and content are both parsed by cache |
1da177e4 LT |
1227 | */ |
1228 | ||
1da177e4 LT |
1229 | int qword_get(char **bpp, char *dest, int bufsize) |
1230 | { | |
1231 | /* return bytes copied, or -1 on error */ | |
1232 | char *bp = *bpp; | |
1233 | int len = 0; | |
1234 | ||
1235 | while (*bp == ' ') bp++; | |
1236 | ||
1237 | if (bp[0] == '\\' && bp[1] == 'x') { | |
1238 | /* HEX STRING */ | |
1239 | bp += 2; | |
b7052cd7 | 1240 | while (len < bufsize - 1) { |
e7f483ea AS |
1241 | int h, l; |
1242 | ||
1243 | h = hex_to_bin(bp[0]); | |
1244 | if (h < 0) | |
1245 | break; | |
1246 | ||
1247 | l = hex_to_bin(bp[1]); | |
1248 | if (l < 0) | |
1249 | break; | |
1250 | ||
1251 | *dest++ = (h << 4) | l; | |
1252 | bp += 2; | |
1da177e4 LT |
1253 | len++; |
1254 | } | |
1255 | } else { | |
1256 | /* text with \nnn octal quoting */ | |
1257 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { | |
1258 | if (*bp == '\\' && | |
1259 | isodigit(bp[1]) && (bp[1] <= '3') && | |
1260 | isodigit(bp[2]) && | |
1261 | isodigit(bp[3])) { | |
1262 | int byte = (*++bp -'0'); | |
1263 | bp++; | |
1264 | byte = (byte << 3) | (*bp++ - '0'); | |
1265 | byte = (byte << 3) | (*bp++ - '0'); | |
1266 | *dest++ = byte; | |
1267 | len++; | |
1268 | } else { | |
1269 | *dest++ = *bp++; | |
1270 | len++; | |
1271 | } | |
1272 | } | |
1273 | } | |
1274 | ||
1275 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') | |
1276 | return -1; | |
1277 | while (*bp == ' ') bp++; | |
1278 | *bpp = bp; | |
1279 | *dest = '\0'; | |
1280 | return len; | |
1281 | } | |
24c3767e | 1282 | EXPORT_SYMBOL_GPL(qword_get); |
1da177e4 LT |
1283 | |
1284 | ||
1285 | /* | |
6489a8f4 | 1286 | * support /proc/net/rpc/$CACHENAME/content |
1da177e4 LT |
1287 | * as a seqfile. |
1288 | * We call ->cache_show passing NULL for the item to | |
1289 | * get a header, then pass each real item in the cache | |
1290 | */ | |
1291 | ||
c8c081b7 | 1292 | void *cache_seq_start(struct seq_file *m, loff_t *pos) |
9a429c49 | 1293 | __acquires(cd->hash_lock) |
1da177e4 LT |
1294 | { |
1295 | loff_t n = *pos; | |
95c96174 | 1296 | unsigned int hash, entry; |
1da177e4 | 1297 | struct cache_head *ch; |
9936f2ae | 1298 | struct cache_detail *cd = m->private; |
1da177e4 LT |
1299 | |
1300 | read_lock(&cd->hash_lock); | |
1301 | if (!n--) | |
1302 | return SEQ_START_TOKEN; | |
1303 | hash = n >> 32; | |
1304 | entry = n & ((1LL<<32) - 1); | |
1305 | ||
129e5824 | 1306 | hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list) |
1da177e4 LT |
1307 | if (!entry--) |
1308 | return ch; | |
1309 | n &= ~((1LL<<32) - 1); | |
1310 | do { | |
1311 | hash++; | |
1312 | n += 1LL<<32; | |
cca5172a | 1313 | } while(hash < cd->hash_size && |
129e5824 | 1314 | hlist_empty(&cd->hash_table[hash])); |
1da177e4 LT |
1315 | if (hash >= cd->hash_size) |
1316 | return NULL; | |
1317 | *pos = n+1; | |
129e5824 KM |
1318 | return hlist_entry_safe(cd->hash_table[hash].first, |
1319 | struct cache_head, cache_list); | |
1da177e4 | 1320 | } |
c8c081b7 | 1321 | EXPORT_SYMBOL_GPL(cache_seq_start); |
1da177e4 | 1322 | |
c8c081b7 | 1323 | void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) |
1da177e4 LT |
1324 | { |
1325 | struct cache_head *ch = p; | |
1326 | int hash = (*pos >> 32); | |
9936f2ae | 1327 | struct cache_detail *cd = m->private; |
1da177e4 LT |
1328 | |
1329 | if (p == SEQ_START_TOKEN) | |
1330 | hash = 0; | |
129e5824 | 1331 | else if (ch->cache_list.next == NULL) { |
1da177e4 LT |
1332 | hash++; |
1333 | *pos += 1LL<<32; | |
1334 | } else { | |
1335 | ++*pos; | |
129e5824 KM |
1336 | return hlist_entry_safe(ch->cache_list.next, |
1337 | struct cache_head, cache_list); | |
1da177e4 LT |
1338 | } |
1339 | *pos &= ~((1LL<<32) - 1); | |
1340 | while (hash < cd->hash_size && | |
129e5824 | 1341 | hlist_empty(&cd->hash_table[hash])) { |
1da177e4 LT |
1342 | hash++; |
1343 | *pos += 1LL<<32; | |
1344 | } | |
1345 | if (hash >= cd->hash_size) | |
1346 | return NULL; | |
1347 | ++*pos; | |
129e5824 KM |
1348 | return hlist_entry_safe(cd->hash_table[hash].first, |
1349 | struct cache_head, cache_list); | |
1da177e4 | 1350 | } |
c8c081b7 | 1351 | EXPORT_SYMBOL_GPL(cache_seq_next); |
1da177e4 | 1352 | |
c8c081b7 | 1353 | void cache_seq_stop(struct seq_file *m, void *p) |
9a429c49 | 1354 | __releases(cd->hash_lock) |
1da177e4 | 1355 | { |
9936f2ae | 1356 | struct cache_detail *cd = m->private; |
1da177e4 LT |
1357 | read_unlock(&cd->hash_lock); |
1358 | } | |
c8c081b7 | 1359 | EXPORT_SYMBOL_GPL(cache_seq_stop); |
1da177e4 LT |
1360 | |
1361 | static int c_show(struct seq_file *m, void *p) | |
1362 | { | |
1363 | struct cache_head *cp = p; | |
9936f2ae | 1364 | struct cache_detail *cd = m->private; |
1da177e4 LT |
1365 | |
1366 | if (p == SEQ_START_TOKEN) | |
1367 | return cd->cache_show(m, cd, NULL); | |
1368 | ||
1369 | ifdebug(CACHE) | |
4013edea | 1370 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", |
c5b29f88 | 1371 | convert_to_wallclock(cp->expiry_time), |
2c935bc5 | 1372 | kref_read(&cp->ref), cp->flags); |
1da177e4 LT |
1373 | cache_get(cp); |
1374 | if (cache_check(cd, cp, NULL)) | |
1375 | /* cache_check does a cache_put on failure */ | |
1376 | seq_printf(m, "# "); | |
200724a7 N |
1377 | else { |
1378 | if (cache_is_expired(cd, cp)) | |
1379 | seq_printf(m, "# "); | |
1da177e4 | 1380 | cache_put(cp, cd); |
200724a7 | 1381 | } |
1da177e4 LT |
1382 | |
1383 | return cd->cache_show(m, cd, cp); | |
1384 | } | |
1385 | ||
56b3d975 | 1386 | static const struct seq_operations cache_content_op = { |
c8c081b7 KM |
1387 | .start = cache_seq_start, |
1388 | .next = cache_seq_next, | |
1389 | .stop = cache_seq_stop, | |
1da177e4 LT |
1390 | .show = c_show, |
1391 | }; | |
1392 | ||
173912a6 TM |
1393 | static int content_open(struct inode *inode, struct file *file, |
1394 | struct cache_detail *cd) | |
1da177e4 | 1395 | { |
9936f2ae KM |
1396 | struct seq_file *seq; |
1397 | int err; | |
1da177e4 | 1398 | |
f7e86ab9 TM |
1399 | if (!cd || !try_module_get(cd->owner)) |
1400 | return -EACCES; | |
9936f2ae KM |
1401 | |
1402 | err = seq_open(file, &cache_content_op); | |
1403 | if (err) { | |
a5990ea1 | 1404 | module_put(cd->owner); |
9936f2ae | 1405 | return err; |
a5990ea1 | 1406 | } |
1da177e4 | 1407 | |
9936f2ae KM |
1408 | seq = file->private_data; |
1409 | seq->private = cd; | |
ec931035 | 1410 | return 0; |
1da177e4 | 1411 | } |
1da177e4 | 1412 | |
f7e86ab9 TM |
1413 | static int content_release(struct inode *inode, struct file *file, |
1414 | struct cache_detail *cd) | |
1415 | { | |
9936f2ae | 1416 | int ret = seq_release(inode, file); |
f7e86ab9 TM |
1417 | module_put(cd->owner); |
1418 | return ret; | |
1419 | } | |
1420 | ||
1421 | static int open_flush(struct inode *inode, struct file *file, | |
1422 | struct cache_detail *cd) | |
1423 | { | |
1424 | if (!cd || !try_module_get(cd->owner)) | |
1425 | return -EACCES; | |
1426 | return nonseekable_open(inode, file); | |
1427 | } | |
1428 | ||
1429 | static int release_flush(struct inode *inode, struct file *file, | |
1430 | struct cache_detail *cd) | |
1431 | { | |
1432 | module_put(cd->owner); | |
1433 | return 0; | |
1434 | } | |
1da177e4 LT |
1435 | |
1436 | static ssize_t read_flush(struct file *file, char __user *buf, | |
173912a6 TM |
1437 | size_t count, loff_t *ppos, |
1438 | struct cache_detail *cd) | |
1da177e4 | 1439 | { |
212ba906 | 1440 | char tbuf[22]; |
01b2969a | 1441 | size_t len; |
1da177e4 | 1442 | |
8ccc8691 KM |
1443 | len = snprintf(tbuf, sizeof(tbuf), "%lu\n", |
1444 | convert_to_wallclock(cd->flush_time)); | |
1445 | return simple_read_from_buffer(buf, count, ppos, tbuf, len); | |
1da177e4 LT |
1446 | } |
1447 | ||
173912a6 TM |
1448 | static ssize_t write_flush(struct file *file, const char __user *buf, |
1449 | size_t count, loff_t *ppos, | |
1450 | struct cache_detail *cd) | |
1da177e4 | 1451 | { |
1da177e4 | 1452 | char tbuf[20]; |
c5b29f88 | 1453 | char *bp, *ep; |
77862036 | 1454 | time_t then, now; |
c5b29f88 | 1455 | |
1da177e4 LT |
1456 | if (*ppos || count > sizeof(tbuf)-1) |
1457 | return -EINVAL; | |
1458 | if (copy_from_user(tbuf, buf, count)) | |
1459 | return -EFAULT; | |
1460 | tbuf[count] = 0; | |
c5b29f88 | 1461 | simple_strtoul(tbuf, &ep, 0); |
1da177e4 LT |
1462 | if (*ep && *ep != '\n') |
1463 | return -EINVAL; | |
1464 | ||
c5b29f88 | 1465 | bp = tbuf; |
77862036 NB |
1466 | then = get_expiry(&bp); |
1467 | now = seconds_since_boot(); | |
1468 | cd->nextcheck = now; | |
1469 | /* Can only set flush_time to 1 second beyond "now", or | |
1470 | * possibly 1 second beyond flushtime. This is because | |
1471 | * flush_time never goes backwards so it mustn't get too far | |
1472 | * ahead of time. | |
1473 | */ | |
1474 | if (then >= now) { | |
1475 | /* Want to flush everything, so behave like cache_purge() */ | |
1476 | if (cd->flush_time >= now) | |
1477 | now = cd->flush_time + 1; | |
1478 | then = now; | |
1479 | } | |
1480 | ||
1481 | cd->flush_time = then; | |
1da177e4 LT |
1482 | cache_flush(); |
1483 | ||
1484 | *ppos += count; | |
1485 | return count; | |
1486 | } | |
1487 | ||
173912a6 TM |
1488 | static ssize_t cache_read_procfs(struct file *filp, char __user *buf, |
1489 | size_t count, loff_t *ppos) | |
1490 | { | |
d9dda78b | 1491 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); |
173912a6 TM |
1492 | |
1493 | return cache_read(filp, buf, count, ppos, cd); | |
1494 | } | |
1495 | ||
1496 | static ssize_t cache_write_procfs(struct file *filp, const char __user *buf, | |
1497 | size_t count, loff_t *ppos) | |
1498 | { | |
d9dda78b | 1499 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); |
173912a6 TM |
1500 | |
1501 | return cache_write(filp, buf, count, ppos, cd); | |
1502 | } | |
1503 | ||
1504 | static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait) | |
1505 | { | |
d9dda78b | 1506 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); |
173912a6 TM |
1507 | |
1508 | return cache_poll(filp, wait, cd); | |
1509 | } | |
1510 | ||
d79b6f4d FW |
1511 | static long cache_ioctl_procfs(struct file *filp, |
1512 | unsigned int cmd, unsigned long arg) | |
173912a6 | 1513 | { |
496ad9aa | 1514 | struct inode *inode = file_inode(filp); |
d9dda78b | 1515 | struct cache_detail *cd = PDE_DATA(inode); |
173912a6 | 1516 | |
a6f8dbc6 | 1517 | return cache_ioctl(inode, filp, cmd, arg, cd); |
173912a6 TM |
1518 | } |
1519 | ||
1520 | static int cache_open_procfs(struct inode *inode, struct file *filp) | |
1521 | { | |
d9dda78b | 1522 | struct cache_detail *cd = PDE_DATA(inode); |
173912a6 TM |
1523 | |
1524 | return cache_open(inode, filp, cd); | |
1525 | } | |
1526 | ||
1527 | static int cache_release_procfs(struct inode *inode, struct file *filp) | |
1528 | { | |
d9dda78b | 1529 | struct cache_detail *cd = PDE_DATA(inode); |
173912a6 TM |
1530 | |
1531 | return cache_release(inode, filp, cd); | |
1532 | } | |
1533 | ||
1534 | static const struct file_operations cache_file_operations_procfs = { | |
1535 | .owner = THIS_MODULE, | |
1536 | .llseek = no_llseek, | |
1537 | .read = cache_read_procfs, | |
1538 | .write = cache_write_procfs, | |
1539 | .poll = cache_poll_procfs, | |
d79b6f4d | 1540 | .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */ |
173912a6 TM |
1541 | .open = cache_open_procfs, |
1542 | .release = cache_release_procfs, | |
1da177e4 | 1543 | }; |
173912a6 TM |
1544 | |
1545 | static int content_open_procfs(struct inode *inode, struct file *filp) | |
1546 | { | |
d9dda78b | 1547 | struct cache_detail *cd = PDE_DATA(inode); |
173912a6 TM |
1548 | |
1549 | return content_open(inode, filp, cd); | |
1550 | } | |
1551 | ||
f7e86ab9 TM |
1552 | static int content_release_procfs(struct inode *inode, struct file *filp) |
1553 | { | |
d9dda78b | 1554 | struct cache_detail *cd = PDE_DATA(inode); |
f7e86ab9 TM |
1555 | |
1556 | return content_release(inode, filp, cd); | |
1557 | } | |
1558 | ||
173912a6 TM |
1559 | static const struct file_operations content_file_operations_procfs = { |
1560 | .open = content_open_procfs, | |
1561 | .read = seq_read, | |
1562 | .llseek = seq_lseek, | |
f7e86ab9 | 1563 | .release = content_release_procfs, |
173912a6 TM |
1564 | }; |
1565 | ||
f7e86ab9 TM |
1566 | static int open_flush_procfs(struct inode *inode, struct file *filp) |
1567 | { | |
d9dda78b | 1568 | struct cache_detail *cd = PDE_DATA(inode); |
f7e86ab9 TM |
1569 | |
1570 | return open_flush(inode, filp, cd); | |
1571 | } | |
1572 | ||
1573 | static int release_flush_procfs(struct inode *inode, struct file *filp) | |
1574 | { | |
d9dda78b | 1575 | struct cache_detail *cd = PDE_DATA(inode); |
f7e86ab9 TM |
1576 | |
1577 | return release_flush(inode, filp, cd); | |
1578 | } | |
1579 | ||
173912a6 TM |
1580 | static ssize_t read_flush_procfs(struct file *filp, char __user *buf, |
1581 | size_t count, loff_t *ppos) | |
1582 | { | |
d9dda78b | 1583 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); |
173912a6 TM |
1584 | |
1585 | return read_flush(filp, buf, count, ppos, cd); | |
1586 | } | |
1587 | ||
1588 | static ssize_t write_flush_procfs(struct file *filp, | |
1589 | const char __user *buf, | |
1590 | size_t count, loff_t *ppos) | |
1591 | { | |
d9dda78b | 1592 | struct cache_detail *cd = PDE_DATA(file_inode(filp)); |
173912a6 TM |
1593 | |
1594 | return write_flush(filp, buf, count, ppos, cd); | |
1595 | } | |
1596 | ||
1597 | static const struct file_operations cache_flush_operations_procfs = { | |
f7e86ab9 | 1598 | .open = open_flush_procfs, |
173912a6 TM |
1599 | .read = read_flush_procfs, |
1600 | .write = write_flush_procfs, | |
f7e86ab9 | 1601 | .release = release_flush_procfs, |
6038f373 | 1602 | .llseek = no_llseek, |
1da177e4 | 1603 | }; |
173912a6 | 1604 | |
863d7d9c | 1605 | static void remove_cache_proc_entries(struct cache_detail *cd) |
173912a6 | 1606 | { |
863d7d9c KM |
1607 | if (cd->procfs) { |
1608 | proc_remove(cd->procfs); | |
1609 | cd->procfs = NULL; | |
1610 | } | |
173912a6 TM |
1611 | } |
1612 | ||
1613 | #ifdef CONFIG_PROC_FS | |
593ce16b | 1614 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) |
173912a6 TM |
1615 | { |
1616 | struct proc_dir_entry *p; | |
4f42d0d5 | 1617 | struct sunrpc_net *sn; |
173912a6 | 1618 | |
4f42d0d5 | 1619 | sn = net_generic(net, sunrpc_net_id); |
863d7d9c KM |
1620 | cd->procfs = proc_mkdir(cd->name, sn->proc_net_rpc); |
1621 | if (cd->procfs == NULL) | |
173912a6 | 1622 | goto out_nomem; |
173912a6 TM |
1623 | |
1624 | p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, | |
863d7d9c | 1625 | cd->procfs, &cache_flush_operations_procfs, cd); |
173912a6 TM |
1626 | if (p == NULL) |
1627 | goto out_nomem; | |
1628 | ||
2d438338 | 1629 | if (cd->cache_request || cd->cache_parse) { |
173912a6 | 1630 | p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, |
863d7d9c | 1631 | cd->procfs, &cache_file_operations_procfs, cd); |
173912a6 TM |
1632 | if (p == NULL) |
1633 | goto out_nomem; | |
1634 | } | |
1635 | if (cd->cache_show) { | |
ec168676 | 1636 | p = proc_create_data("content", S_IFREG|S_IRUSR, |
863d7d9c | 1637 | cd->procfs, &content_file_operations_procfs, cd); |
173912a6 TM |
1638 | if (p == NULL) |
1639 | goto out_nomem; | |
1640 | } | |
1641 | return 0; | |
1642 | out_nomem: | |
863d7d9c | 1643 | remove_cache_proc_entries(cd); |
173912a6 TM |
1644 | return -ENOMEM; |
1645 | } | |
1646 | #else /* CONFIG_PROC_FS */ | |
593ce16b | 1647 | static int create_cache_proc_entries(struct cache_detail *cd, struct net *net) |
173912a6 TM |
1648 | { |
1649 | return 0; | |
1650 | } | |
1651 | #endif | |
1652 | ||
8eab945c AB |
1653 | void __init cache_initialize(void) |
1654 | { | |
203b42f7 | 1655 | INIT_DEFERRABLE_WORK(&cache_cleaner, do_cache_clean); |
8eab945c AB |
1656 | } |
1657 | ||
593ce16b | 1658 | int cache_register_net(struct cache_detail *cd, struct net *net) |
173912a6 TM |
1659 | { |
1660 | int ret; | |
1661 | ||
1662 | sunrpc_init_cache_detail(cd); | |
593ce16b | 1663 | ret = create_cache_proc_entries(cd, net); |
173912a6 TM |
1664 | if (ret) |
1665 | sunrpc_destroy_cache_detail(cd); | |
1666 | return ret; | |
1667 | } | |
f5c8593b | 1668 | EXPORT_SYMBOL_GPL(cache_register_net); |
593ce16b | 1669 | |
593ce16b | 1670 | void cache_unregister_net(struct cache_detail *cd, struct net *net) |
173912a6 | 1671 | { |
863d7d9c | 1672 | remove_cache_proc_entries(cd); |
173912a6 TM |
1673 | sunrpc_destroy_cache_detail(cd); |
1674 | } | |
f5c8593b | 1675 | EXPORT_SYMBOL_GPL(cache_unregister_net); |
593ce16b | 1676 | |
0a402d5a SK |
1677 | struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net) |
1678 | { | |
1679 | struct cache_detail *cd; | |
129e5824 | 1680 | int i; |
0a402d5a SK |
1681 | |
1682 | cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL); | |
1683 | if (cd == NULL) | |
1684 | return ERR_PTR(-ENOMEM); | |
1685 | ||
129e5824 | 1686 | cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head), |
0a402d5a SK |
1687 | GFP_KERNEL); |
1688 | if (cd->hash_table == NULL) { | |
1689 | kfree(cd); | |
1690 | return ERR_PTR(-ENOMEM); | |
1691 | } | |
129e5824 KM |
1692 | |
1693 | for (i = 0; i < cd->hash_size; i++) | |
1694 | INIT_HLIST_HEAD(&cd->hash_table[i]); | |
0a402d5a SK |
1695 | cd->net = net; |
1696 | return cd; | |
1697 | } | |
1698 | EXPORT_SYMBOL_GPL(cache_create_net); | |
1699 | ||
1700 | void cache_destroy_net(struct cache_detail *cd, struct net *net) | |
593ce16b | 1701 | { |
0a402d5a SK |
1702 | kfree(cd->hash_table); |
1703 | kfree(cd); | |
593ce16b | 1704 | } |
0a402d5a | 1705 | EXPORT_SYMBOL_GPL(cache_destroy_net); |
8854e82d TM |
1706 | |
1707 | static ssize_t cache_read_pipefs(struct file *filp, char __user *buf, | |
1708 | size_t count, loff_t *ppos) | |
1709 | { | |
496ad9aa | 1710 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; |
8854e82d TM |
1711 | |
1712 | return cache_read(filp, buf, count, ppos, cd); | |
1713 | } | |
1714 | ||
1715 | static ssize_t cache_write_pipefs(struct file *filp, const char __user *buf, | |
1716 | size_t count, loff_t *ppos) | |
1717 | { | |
496ad9aa | 1718 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; |
8854e82d TM |
1719 | |
1720 | return cache_write(filp, buf, count, ppos, cd); | |
1721 | } | |
1722 | ||
1723 | static unsigned int cache_poll_pipefs(struct file *filp, poll_table *wait) | |
1724 | { | |
496ad9aa | 1725 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; |
8854e82d TM |
1726 | |
1727 | return cache_poll(filp, wait, cd); | |
1728 | } | |
1729 | ||
9918ff26 | 1730 | static long cache_ioctl_pipefs(struct file *filp, |
8854e82d TM |
1731 | unsigned int cmd, unsigned long arg) |
1732 | { | |
496ad9aa | 1733 | struct inode *inode = file_inode(filp); |
8854e82d TM |
1734 | struct cache_detail *cd = RPC_I(inode)->private; |
1735 | ||
a6f8dbc6 | 1736 | return cache_ioctl(inode, filp, cmd, arg, cd); |
8854e82d TM |
1737 | } |
1738 | ||
1739 | static int cache_open_pipefs(struct inode *inode, struct file *filp) | |
1740 | { | |
1741 | struct cache_detail *cd = RPC_I(inode)->private; | |
1742 | ||
1743 | return cache_open(inode, filp, cd); | |
1744 | } | |
1745 | ||
1746 | static int cache_release_pipefs(struct inode *inode, struct file *filp) | |
1747 | { | |
1748 | struct cache_detail *cd = RPC_I(inode)->private; | |
1749 | ||
1750 | return cache_release(inode, filp, cd); | |
1751 | } | |
1752 | ||
1753 | const struct file_operations cache_file_operations_pipefs = { | |
1754 | .owner = THIS_MODULE, | |
1755 | .llseek = no_llseek, | |
1756 | .read = cache_read_pipefs, | |
1757 | .write = cache_write_pipefs, | |
1758 | .poll = cache_poll_pipefs, | |
9918ff26 | 1759 | .unlocked_ioctl = cache_ioctl_pipefs, /* for FIONREAD */ |
8854e82d TM |
1760 | .open = cache_open_pipefs, |
1761 | .release = cache_release_pipefs, | |
1762 | }; | |
1763 | ||
1764 | static int content_open_pipefs(struct inode *inode, struct file *filp) | |
1765 | { | |
1766 | struct cache_detail *cd = RPC_I(inode)->private; | |
1767 | ||
1768 | return content_open(inode, filp, cd); | |
1769 | } | |
1770 | ||
f7e86ab9 TM |
1771 | static int content_release_pipefs(struct inode *inode, struct file *filp) |
1772 | { | |
1773 | struct cache_detail *cd = RPC_I(inode)->private; | |
1774 | ||
1775 | return content_release(inode, filp, cd); | |
1776 | } | |
1777 | ||
8854e82d TM |
1778 | const struct file_operations content_file_operations_pipefs = { |
1779 | .open = content_open_pipefs, | |
1780 | .read = seq_read, | |
1781 | .llseek = seq_lseek, | |
f7e86ab9 | 1782 | .release = content_release_pipefs, |
8854e82d TM |
1783 | }; |
1784 | ||
f7e86ab9 TM |
1785 | static int open_flush_pipefs(struct inode *inode, struct file *filp) |
1786 | { | |
1787 | struct cache_detail *cd = RPC_I(inode)->private; | |
1788 | ||
1789 | return open_flush(inode, filp, cd); | |
1790 | } | |
1791 | ||
1792 | static int release_flush_pipefs(struct inode *inode, struct file *filp) | |
1793 | { | |
1794 | struct cache_detail *cd = RPC_I(inode)->private; | |
1795 | ||
1796 | return release_flush(inode, filp, cd); | |
1797 | } | |
1798 | ||
8854e82d TM |
1799 | static ssize_t read_flush_pipefs(struct file *filp, char __user *buf, |
1800 | size_t count, loff_t *ppos) | |
1801 | { | |
496ad9aa | 1802 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; |
8854e82d TM |
1803 | |
1804 | return read_flush(filp, buf, count, ppos, cd); | |
1805 | } | |
1806 | ||
1807 | static ssize_t write_flush_pipefs(struct file *filp, | |
1808 | const char __user *buf, | |
1809 | size_t count, loff_t *ppos) | |
1810 | { | |
496ad9aa | 1811 | struct cache_detail *cd = RPC_I(file_inode(filp))->private; |
8854e82d TM |
1812 | |
1813 | return write_flush(filp, buf, count, ppos, cd); | |
1814 | } | |
1815 | ||
1816 | const struct file_operations cache_flush_operations_pipefs = { | |
f7e86ab9 | 1817 | .open = open_flush_pipefs, |
8854e82d TM |
1818 | .read = read_flush_pipefs, |
1819 | .write = write_flush_pipefs, | |
f7e86ab9 | 1820 | .release = release_flush_pipefs, |
6038f373 | 1821 | .llseek = no_llseek, |
8854e82d TM |
1822 | }; |
1823 | ||
1824 | int sunrpc_cache_register_pipefs(struct dentry *parent, | |
64f1426f | 1825 | const char *name, umode_t umode, |
8854e82d TM |
1826 | struct cache_detail *cd) |
1827 | { | |
a95e691f AV |
1828 | struct dentry *dir = rpc_create_cache_dir(parent, name, umode, cd); |
1829 | if (IS_ERR(dir)) | |
1830 | return PTR_ERR(dir); | |
863d7d9c | 1831 | cd->pipefs = dir; |
a95e691f | 1832 | return 0; |
8854e82d TM |
1833 | } |
1834 | EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs); | |
1835 | ||
1836 | void sunrpc_cache_unregister_pipefs(struct cache_detail *cd) | |
1837 | { | |
863d7d9c KM |
1838 | if (cd->pipefs) { |
1839 | rpc_remove_cache_dir(cd->pipefs); | |
1840 | cd->pipefs = NULL; | |
1841 | } | |
8854e82d TM |
1842 | } |
1843 | EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs); | |
1844 | ||
2b477c00 NB |
1845 | void sunrpc_cache_unhash(struct cache_detail *cd, struct cache_head *h) |
1846 | { | |
1847 | write_lock(&cd->hash_lock); | |
1848 | if (!hlist_unhashed(&h->cache_list)){ | |
1849 | hlist_del_init(&h->cache_list); | |
1850 | cd->entries--; | |
1851 | write_unlock(&cd->hash_lock); | |
1852 | cache_put(h, cd); | |
1853 | } else | |
1854 | write_unlock(&cd->hash_lock); | |
1855 | } | |
1856 | EXPORT_SYMBOL_GPL(sunrpc_cache_unhash); |