Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 29 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <asm/ioctls.h> |
| 31 | #include <linux/sunrpc/types.h> |
| 32 | #include <linux/sunrpc/cache.h> |
| 33 | #include <linux/sunrpc/stats.h> |
| 34 | |
| 35 | #define RPCDBG_FACILITY RPCDBG_CACHE |
| 36 | |
| 37 | static void cache_defer_req(struct cache_req *req, struct cache_head *item); |
| 38 | static void cache_revisit_request(struct cache_head *item); |
| 39 | |
Adrian Bunk | 74cae61 | 2006-03-27 01:15:10 -0800 | [diff] [blame] | 40 | static void cache_init(struct cache_head *h) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | { |
| 42 | time_t now = get_seconds(); |
| 43 | h->next = NULL; |
| 44 | h->flags = 0; |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 45 | kref_init(&h->ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | h->expiry_time = now + CACHE_NEW_EXPIRY; |
| 47 | h->last_refresh = now; |
| 48 | } |
| 49 | |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 50 | struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, |
| 51 | struct cache_head *key, int hash) |
| 52 | { |
| 53 | struct cache_head **head, **hp; |
| 54 | struct cache_head *new = NULL; |
| 55 | |
| 56 | head = &detail->hash_table[hash]; |
| 57 | |
| 58 | read_lock(&detail->hash_lock); |
| 59 | |
| 60 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { |
| 61 | struct cache_head *tmp = *hp; |
| 62 | if (detail->match(tmp, key)) { |
| 63 | cache_get(tmp); |
| 64 | read_unlock(&detail->hash_lock); |
| 65 | return tmp; |
| 66 | } |
| 67 | } |
| 68 | read_unlock(&detail->hash_lock); |
| 69 | /* Didn't find anything, insert an empty entry */ |
| 70 | |
| 71 | new = detail->alloc(); |
| 72 | if (!new) |
| 73 | return NULL; |
| 74 | cache_init(new); |
| 75 | |
| 76 | write_lock(&detail->hash_lock); |
| 77 | |
| 78 | /* check if entry appeared while we slept */ |
| 79 | for (hp=head; *hp != NULL ; hp = &(*hp)->next) { |
| 80 | struct cache_head *tmp = *hp; |
| 81 | if (detail->match(tmp, key)) { |
| 82 | cache_get(tmp); |
| 83 | write_unlock(&detail->hash_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 84 | cache_put(new, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 85 | return tmp; |
| 86 | } |
| 87 | } |
| 88 | detail->init(new, key); |
| 89 | new->next = *head; |
| 90 | *head = new; |
| 91 | detail->entries++; |
| 92 | cache_get(new); |
| 93 | write_unlock(&detail->hash_lock); |
| 94 | |
| 95 | return new; |
| 96 | } |
| 97 | EXPORT_SYMBOL(sunrpc_cache_lookup); |
| 98 | |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 99 | |
| 100 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch); |
| 101 | |
| 102 | static int cache_fresh_locked(struct cache_head *head, time_t expiry) |
| 103 | { |
| 104 | head->expiry_time = expiry; |
| 105 | head->last_refresh = get_seconds(); |
| 106 | return !test_and_set_bit(CACHE_VALID, &head->flags); |
| 107 | } |
| 108 | |
| 109 | static void cache_fresh_unlocked(struct cache_head *head, |
| 110 | struct cache_detail *detail, int new) |
| 111 | { |
| 112 | if (new) |
| 113 | cache_revisit_request(head); |
| 114 | if (test_and_clear_bit(CACHE_PENDING, &head->flags)) { |
| 115 | cache_revisit_request(head); |
| 116 | queue_loose(detail, head); |
| 117 | } |
| 118 | } |
| 119 | |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 120 | struct cache_head *sunrpc_cache_update(struct cache_detail *detail, |
| 121 | struct cache_head *new, struct cache_head *old, int hash) |
| 122 | { |
| 123 | /* The 'old' entry is to be replaced by 'new'. |
| 124 | * If 'old' is not VALID, we update it directly, |
| 125 | * otherwise we need to replace it |
| 126 | */ |
| 127 | struct cache_head **head; |
| 128 | struct cache_head *tmp; |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 129 | int is_new; |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 130 | |
| 131 | if (!test_bit(CACHE_VALID, &old->flags)) { |
| 132 | write_lock(&detail->hash_lock); |
| 133 | if (!test_bit(CACHE_VALID, &old->flags)) { |
| 134 | if (test_bit(CACHE_NEGATIVE, &new->flags)) |
| 135 | set_bit(CACHE_NEGATIVE, &old->flags); |
| 136 | else |
| 137 | detail->update(old, new); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 138 | is_new = cache_fresh_locked(old, new->expiry_time); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 139 | write_unlock(&detail->hash_lock); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 140 | cache_fresh_unlocked(old, detail, is_new); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 141 | return old; |
| 142 | } |
| 143 | write_unlock(&detail->hash_lock); |
| 144 | } |
| 145 | /* We need to insert a new entry */ |
| 146 | tmp = detail->alloc(); |
| 147 | if (!tmp) { |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 148 | cache_put(old, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 149 | return NULL; |
| 150 | } |
| 151 | cache_init(tmp); |
| 152 | detail->init(tmp, old); |
| 153 | head = &detail->hash_table[hash]; |
| 154 | |
| 155 | write_lock(&detail->hash_lock); |
| 156 | if (test_bit(CACHE_NEGATIVE, &new->flags)) |
| 157 | set_bit(CACHE_NEGATIVE, &tmp->flags); |
| 158 | else |
| 159 | detail->update(tmp, new); |
| 160 | tmp->next = *head; |
| 161 | *head = tmp; |
NeilBrown | f2d3958 | 2006-05-22 22:35:25 -0700 | [diff] [blame] | 162 | detail->entries++; |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 163 | cache_get(tmp); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 164 | is_new = cache_fresh_locked(tmp, new->expiry_time); |
| 165 | cache_fresh_locked(old, 0); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 166 | write_unlock(&detail->hash_lock); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 167 | cache_fresh_unlocked(tmp, detail, is_new); |
| 168 | cache_fresh_unlocked(old, detail, 0); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 169 | cache_put(old, detail); |
NeilBrown | 15a5f6b | 2006-03-27 01:15:02 -0800 | [diff] [blame] | 170 | return tmp; |
| 171 | } |
| 172 | EXPORT_SYMBOL(sunrpc_cache_update); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
| 174 | static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h); |
| 175 | /* |
| 176 | * This is the generic cache management routine for all |
| 177 | * the authentication caches. |
| 178 | * It checks the currency of a cache item and will (later) |
| 179 | * initiate an upcall to fill it if needed. |
| 180 | * |
| 181 | * |
| 182 | * Returns 0 if the cache_head can be used, or cache_puts it and returns |
| 183 | * -EAGAIN if upcall is pending, |
| 184 | * -ENOENT if cache entry was negative |
| 185 | */ |
| 186 | int cache_check(struct cache_detail *detail, |
| 187 | struct cache_head *h, struct cache_req *rqstp) |
| 188 | { |
| 189 | int rv; |
| 190 | long refresh_age, age; |
| 191 | |
| 192 | /* First decide return status as best we can */ |
| 193 | if (!test_bit(CACHE_VALID, &h->flags) || |
| 194 | h->expiry_time < get_seconds()) |
| 195 | rv = -EAGAIN; |
| 196 | else if (detail->flush_time > h->last_refresh) |
| 197 | rv = -EAGAIN; |
| 198 | else { |
| 199 | /* entry is valid */ |
| 200 | if (test_bit(CACHE_NEGATIVE, &h->flags)) |
| 201 | rv = -ENOENT; |
| 202 | else rv = 0; |
| 203 | } |
| 204 | |
| 205 | /* now see if we want to start an upcall */ |
| 206 | refresh_age = (h->expiry_time - h->last_refresh); |
| 207 | age = get_seconds() - h->last_refresh; |
| 208 | |
| 209 | if (rqstp == NULL) { |
| 210 | if (rv == -EAGAIN) |
| 211 | rv = -ENOENT; |
| 212 | } else if (rv == -EAGAIN || age > refresh_age/2) { |
| 213 | dprintk("Want update, refage=%ld, age=%ld\n", refresh_age, age); |
| 214 | if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { |
| 215 | switch (cache_make_upcall(detail, h)) { |
| 216 | case -EINVAL: |
| 217 | clear_bit(CACHE_PENDING, &h->flags); |
| 218 | if (rv == -EAGAIN) { |
| 219 | set_bit(CACHE_NEGATIVE, &h->flags); |
NeilBrown | ebd0cb1 | 2006-03-27 01:15:08 -0800 | [diff] [blame] | 220 | cache_fresh_unlocked(h, detail, |
| 221 | cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | rv = -ENOENT; |
| 223 | } |
| 224 | break; |
| 225 | |
| 226 | case -EAGAIN: |
| 227 | clear_bit(CACHE_PENDING, &h->flags); |
| 228 | cache_revisit_request(h); |
| 229 | break; |
| 230 | } |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | if (rv == -EAGAIN) |
| 235 | cache_defer_req(rqstp, h); |
| 236 | |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 237 | if (rv) |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 238 | cache_put(h, detail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | return rv; |
| 240 | } |
| 241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | /* |
| 243 | * caches need to be periodically cleaned. |
| 244 | * For this we maintain a list of cache_detail and |
| 245 | * a current pointer into that list and into the table |
| 246 | * for that entry. |
| 247 | * |
| 248 | * Each time clean_cache is called it finds the next non-empty entry |
| 249 | * in the current table and walks the list in that entry |
| 250 | * looking for entries that can be removed. |
| 251 | * |
| 252 | * An entry gets removed if: |
| 253 | * - The expiry is before current time |
| 254 | * - The last_refresh time is before the flush_time for that cache |
| 255 | * |
| 256 | * later we might drop old entries with non-NEVER expiry if that table |
| 257 | * is getting 'full' for some definition of 'full' |
| 258 | * |
| 259 | * The question of "how often to scan a table" is an interesting one |
| 260 | * and is answered in part by the use of the "nextcheck" field in the |
| 261 | * cache_detail. |
| 262 | * When a scan of a table begins, the nextcheck field is set to a time |
| 263 | * that is well into the future. |
| 264 | * While scanning, if an expiry time is found that is earlier than the |
| 265 | * current nextcheck time, nextcheck is set to that expiry time. |
| 266 | * If the flush_time is ever set to a time earlier than the nextcheck |
| 267 | * time, the nextcheck time is then set to that flush_time. |
| 268 | * |
| 269 | * A table is then only scanned if the current time is at least |
| 270 | * the nextcheck time. |
| 271 | * |
| 272 | */ |
| 273 | |
| 274 | static LIST_HEAD(cache_list); |
| 275 | static DEFINE_SPINLOCK(cache_list_lock); |
| 276 | static struct cache_detail *current_detail; |
| 277 | static int current_index; |
| 278 | |
| 279 | static struct file_operations cache_file_operations; |
| 280 | static struct file_operations content_file_operations; |
| 281 | static struct file_operations cache_flush_operations; |
| 282 | |
| 283 | static void do_cache_clean(void *data); |
| 284 | static DECLARE_WORK(cache_cleaner, do_cache_clean, NULL); |
| 285 | |
| 286 | void cache_register(struct cache_detail *cd) |
| 287 | { |
| 288 | cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc); |
| 289 | if (cd->proc_ent) { |
| 290 | struct proc_dir_entry *p; |
Bruce Allan | f35279d | 2005-09-06 15:17:08 -0700 | [diff] [blame] | 291 | cd->proc_ent->owner = cd->owner; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | cd->channel_ent = cd->content_ent = NULL; |
| 293 | |
| 294 | p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR, |
| 295 | cd->proc_ent); |
| 296 | cd->flush_ent = p; |
| 297 | if (p) { |
| 298 | p->proc_fops = &cache_flush_operations; |
Bruce Allan | f35279d | 2005-09-06 15:17:08 -0700 | [diff] [blame] | 299 | p->owner = cd->owner; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | p->data = cd; |
| 301 | } |
| 302 | |
| 303 | if (cd->cache_request || cd->cache_parse) { |
| 304 | p = create_proc_entry("channel", S_IFREG|S_IRUSR|S_IWUSR, |
| 305 | cd->proc_ent); |
| 306 | cd->channel_ent = p; |
| 307 | if (p) { |
| 308 | p->proc_fops = &cache_file_operations; |
Bruce Allan | f35279d | 2005-09-06 15:17:08 -0700 | [diff] [blame] | 309 | p->owner = cd->owner; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | p->data = cd; |
| 311 | } |
| 312 | } |
| 313 | if (cd->cache_show) { |
| 314 | p = create_proc_entry("content", S_IFREG|S_IRUSR|S_IWUSR, |
| 315 | cd->proc_ent); |
| 316 | cd->content_ent = p; |
| 317 | if (p) { |
| 318 | p->proc_fops = &content_file_operations; |
Bruce Allan | f35279d | 2005-09-06 15:17:08 -0700 | [diff] [blame] | 319 | p->owner = cd->owner; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | p->data = cd; |
| 321 | } |
| 322 | } |
| 323 | } |
| 324 | rwlock_init(&cd->hash_lock); |
| 325 | INIT_LIST_HEAD(&cd->queue); |
| 326 | spin_lock(&cache_list_lock); |
| 327 | cd->nextcheck = 0; |
| 328 | cd->entries = 0; |
| 329 | atomic_set(&cd->readers, 0); |
| 330 | cd->last_close = 0; |
| 331 | cd->last_warn = -1; |
| 332 | list_add(&cd->others, &cache_list); |
| 333 | spin_unlock(&cache_list_lock); |
| 334 | |
| 335 | /* start the cleaning process */ |
| 336 | schedule_work(&cache_cleaner); |
| 337 | } |
| 338 | |
| 339 | int cache_unregister(struct cache_detail *cd) |
| 340 | { |
| 341 | cache_purge(cd); |
| 342 | spin_lock(&cache_list_lock); |
| 343 | write_lock(&cd->hash_lock); |
| 344 | if (cd->entries || atomic_read(&cd->inuse)) { |
| 345 | write_unlock(&cd->hash_lock); |
| 346 | spin_unlock(&cache_list_lock); |
| 347 | return -EBUSY; |
| 348 | } |
| 349 | if (current_detail == cd) |
| 350 | current_detail = NULL; |
| 351 | list_del_init(&cd->others); |
| 352 | write_unlock(&cd->hash_lock); |
| 353 | spin_unlock(&cache_list_lock); |
| 354 | if (cd->proc_ent) { |
| 355 | if (cd->flush_ent) |
| 356 | remove_proc_entry("flush", cd->proc_ent); |
| 357 | if (cd->channel_ent) |
| 358 | remove_proc_entry("channel", cd->proc_ent); |
| 359 | if (cd->content_ent) |
| 360 | remove_proc_entry("content", cd->proc_ent); |
| 361 | |
| 362 | cd->proc_ent = NULL; |
| 363 | remove_proc_entry(cd->name, proc_net_rpc); |
| 364 | } |
| 365 | if (list_empty(&cache_list)) { |
| 366 | /* module must be being unloaded so its safe to kill the worker */ |
| 367 | cancel_delayed_work(&cache_cleaner); |
| 368 | flush_scheduled_work(); |
| 369 | } |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | /* clean cache tries to find something to clean |
| 374 | * and cleans it. |
| 375 | * It returns 1 if it cleaned something, |
| 376 | * 0 if it didn't find anything this time |
| 377 | * -1 if it fell off the end of the list. |
| 378 | */ |
| 379 | static int cache_clean(void) |
| 380 | { |
| 381 | int rv = 0; |
| 382 | struct list_head *next; |
| 383 | |
| 384 | spin_lock(&cache_list_lock); |
| 385 | |
| 386 | /* find a suitable table if we don't already have one */ |
| 387 | while (current_detail == NULL || |
| 388 | current_index >= current_detail->hash_size) { |
| 389 | if (current_detail) |
| 390 | next = current_detail->others.next; |
| 391 | else |
| 392 | next = cache_list.next; |
| 393 | if (next == &cache_list) { |
| 394 | current_detail = NULL; |
| 395 | spin_unlock(&cache_list_lock); |
| 396 | return -1; |
| 397 | } |
| 398 | current_detail = list_entry(next, struct cache_detail, others); |
| 399 | if (current_detail->nextcheck > get_seconds()) |
| 400 | current_index = current_detail->hash_size; |
| 401 | else { |
| 402 | current_index = 0; |
| 403 | current_detail->nextcheck = get_seconds()+30*60; |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | /* find a non-empty bucket in the table */ |
| 408 | while (current_detail && |
| 409 | current_index < current_detail->hash_size && |
| 410 | current_detail->hash_table[current_index] == NULL) |
| 411 | current_index++; |
| 412 | |
| 413 | /* find a cleanable entry in the bucket and clean it, or set to next bucket */ |
| 414 | |
| 415 | if (current_detail && current_index < current_detail->hash_size) { |
| 416 | struct cache_head *ch, **cp; |
| 417 | struct cache_detail *d; |
| 418 | |
| 419 | write_lock(¤t_detail->hash_lock); |
| 420 | |
| 421 | /* Ok, now to clean this strand */ |
| 422 | |
| 423 | cp = & current_detail->hash_table[current_index]; |
| 424 | ch = *cp; |
| 425 | for (; ch; cp= & ch->next, ch= *cp) { |
| 426 | if (current_detail->nextcheck > ch->expiry_time) |
| 427 | current_detail->nextcheck = ch->expiry_time+1; |
| 428 | if (ch->expiry_time >= get_seconds() |
| 429 | && ch->last_refresh >= current_detail->flush_time |
| 430 | ) |
| 431 | continue; |
| 432 | if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) |
| 433 | queue_loose(current_detail, ch); |
| 434 | |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 435 | if (atomic_read(&ch->ref.refcount) == 1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | break; |
| 437 | } |
| 438 | if (ch) { |
| 439 | *cp = ch->next; |
| 440 | ch->next = NULL; |
| 441 | current_detail->entries--; |
| 442 | rv = 1; |
| 443 | } |
| 444 | write_unlock(¤t_detail->hash_lock); |
| 445 | d = current_detail; |
| 446 | if (!ch) |
| 447 | current_index ++; |
| 448 | spin_unlock(&cache_list_lock); |
| 449 | if (ch) |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 450 | cache_put(ch, d); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | } else |
| 452 | spin_unlock(&cache_list_lock); |
| 453 | |
| 454 | return rv; |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * We want to regularly clean the cache, so we need to schedule some work ... |
| 459 | */ |
| 460 | static void do_cache_clean(void *data) |
| 461 | { |
| 462 | int delay = 5; |
| 463 | if (cache_clean() == -1) |
| 464 | delay = 30*HZ; |
| 465 | |
| 466 | if (list_empty(&cache_list)) |
| 467 | delay = 0; |
| 468 | |
| 469 | if (delay) |
| 470 | schedule_delayed_work(&cache_cleaner, delay); |
| 471 | } |
| 472 | |
| 473 | |
| 474 | /* |
| 475 | * Clean all caches promptly. This just calls cache_clean |
| 476 | * repeatedly until we are sure that every cache has had a chance to |
| 477 | * be fully cleaned |
| 478 | */ |
| 479 | void cache_flush(void) |
| 480 | { |
| 481 | while (cache_clean() != -1) |
| 482 | cond_resched(); |
| 483 | while (cache_clean() != -1) |
| 484 | cond_resched(); |
| 485 | } |
| 486 | |
| 487 | void cache_purge(struct cache_detail *detail) |
| 488 | { |
| 489 | detail->flush_time = LONG_MAX; |
| 490 | detail->nextcheck = get_seconds(); |
| 491 | cache_flush(); |
| 492 | detail->flush_time = 1; |
| 493 | } |
| 494 | |
| 495 | |
| 496 | |
| 497 | /* |
| 498 | * Deferral and Revisiting of Requests. |
| 499 | * |
| 500 | * If a cache lookup finds a pending entry, we |
| 501 | * need to defer the request and revisit it later. |
| 502 | * All deferred requests are stored in a hash table, |
| 503 | * indexed by "struct cache_head *". |
| 504 | * As it may be wasteful to store a whole request |
| 505 | * structure, we allow the request to provide a |
| 506 | * deferred form, which must contain a |
| 507 | * 'struct cache_deferred_req' |
| 508 | * This cache_deferred_req contains a method to allow |
| 509 | * it to be revisited when cache info is available |
| 510 | */ |
| 511 | |
| 512 | #define DFR_HASHSIZE (PAGE_SIZE/sizeof(struct list_head)) |
| 513 | #define DFR_HASH(item) ((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE) |
| 514 | |
| 515 | #define DFR_MAX 300 /* ??? */ |
| 516 | |
| 517 | static DEFINE_SPINLOCK(cache_defer_lock); |
| 518 | static LIST_HEAD(cache_defer_list); |
| 519 | static struct list_head cache_defer_hash[DFR_HASHSIZE]; |
| 520 | static int cache_defer_cnt; |
| 521 | |
| 522 | static void cache_defer_req(struct cache_req *req, struct cache_head *item) |
| 523 | { |
| 524 | struct cache_deferred_req *dreq; |
| 525 | int hash = DFR_HASH(item); |
| 526 | |
| 527 | dreq = req->defer(req); |
| 528 | if (dreq == NULL) |
| 529 | return; |
| 530 | |
| 531 | dreq->item = item; |
| 532 | dreq->recv_time = get_seconds(); |
| 533 | |
| 534 | spin_lock(&cache_defer_lock); |
| 535 | |
| 536 | list_add(&dreq->recent, &cache_defer_list); |
| 537 | |
| 538 | if (cache_defer_hash[hash].next == NULL) |
| 539 | INIT_LIST_HEAD(&cache_defer_hash[hash]); |
| 540 | list_add(&dreq->hash, &cache_defer_hash[hash]); |
| 541 | |
| 542 | /* it is in, now maybe clean up */ |
| 543 | dreq = NULL; |
| 544 | if (++cache_defer_cnt > DFR_MAX) { |
| 545 | /* too much in the cache, randomly drop |
| 546 | * first or last |
| 547 | */ |
| 548 | if (net_random()&1) |
| 549 | dreq = list_entry(cache_defer_list.next, |
| 550 | struct cache_deferred_req, |
| 551 | recent); |
| 552 | else |
| 553 | dreq = list_entry(cache_defer_list.prev, |
| 554 | struct cache_deferred_req, |
| 555 | recent); |
| 556 | list_del(&dreq->recent); |
| 557 | list_del(&dreq->hash); |
| 558 | cache_defer_cnt--; |
| 559 | } |
| 560 | spin_unlock(&cache_defer_lock); |
| 561 | |
| 562 | if (dreq) { |
| 563 | /* there was one too many */ |
| 564 | dreq->revisit(dreq, 1); |
| 565 | } |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 566 | if (!test_bit(CACHE_PENDING, &item->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | /* must have just been validated... */ |
| 568 | cache_revisit_request(item); |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | static void cache_revisit_request(struct cache_head *item) |
| 573 | { |
| 574 | struct cache_deferred_req *dreq; |
| 575 | struct list_head pending; |
| 576 | |
| 577 | struct list_head *lp; |
| 578 | int hash = DFR_HASH(item); |
| 579 | |
| 580 | INIT_LIST_HEAD(&pending); |
| 581 | spin_lock(&cache_defer_lock); |
| 582 | |
| 583 | lp = cache_defer_hash[hash].next; |
| 584 | if (lp) { |
| 585 | while (lp != &cache_defer_hash[hash]) { |
| 586 | dreq = list_entry(lp, struct cache_deferred_req, hash); |
| 587 | lp = lp->next; |
| 588 | if (dreq->item == item) { |
| 589 | list_del(&dreq->hash); |
| 590 | list_move(&dreq->recent, &pending); |
| 591 | cache_defer_cnt--; |
| 592 | } |
| 593 | } |
| 594 | } |
| 595 | spin_unlock(&cache_defer_lock); |
| 596 | |
| 597 | while (!list_empty(&pending)) { |
| 598 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); |
| 599 | list_del_init(&dreq->recent); |
| 600 | dreq->revisit(dreq, 0); |
| 601 | } |
| 602 | } |
| 603 | |
| 604 | void cache_clean_deferred(void *owner) |
| 605 | { |
| 606 | struct cache_deferred_req *dreq, *tmp; |
| 607 | struct list_head pending; |
| 608 | |
| 609 | |
| 610 | INIT_LIST_HEAD(&pending); |
| 611 | spin_lock(&cache_defer_lock); |
| 612 | |
| 613 | list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { |
| 614 | if (dreq->owner == owner) { |
| 615 | list_del(&dreq->hash); |
| 616 | list_move(&dreq->recent, &pending); |
| 617 | cache_defer_cnt--; |
| 618 | } |
| 619 | } |
| 620 | spin_unlock(&cache_defer_lock); |
| 621 | |
| 622 | while (!list_empty(&pending)) { |
| 623 | dreq = list_entry(pending.next, struct cache_deferred_req, recent); |
| 624 | list_del_init(&dreq->recent); |
| 625 | dreq->revisit(dreq, 1); |
| 626 | } |
| 627 | } |
| 628 | |
| 629 | /* |
| 630 | * communicate with user-space |
| 631 | * |
| 632 | * We have a magic /proc file - /proc/sunrpc/cache |
| 633 | * On read, you get a full request, or block |
| 634 | * On write, an update request is processed |
| 635 | * Poll works if anything to read, and always allows write |
| 636 | * |
| 637 | * Implemented by linked list of requests. Each open file has |
| 638 | * a ->private that also exists in this list. New request are added |
| 639 | * to the end and may wakeup and preceding readers. |
| 640 | * New readers are added to the head. If, on read, an item is found with |
| 641 | * CACHE_UPCALLING clear, we free it from the list. |
| 642 | * |
| 643 | */ |
| 644 | |
| 645 | static DEFINE_SPINLOCK(queue_lock); |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 646 | static DEFINE_MUTEX(queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | |
| 648 | struct cache_queue { |
| 649 | struct list_head list; |
| 650 | int reader; /* if 0, then request */ |
| 651 | }; |
| 652 | struct cache_request { |
| 653 | struct cache_queue q; |
| 654 | struct cache_head *item; |
| 655 | char * buf; |
| 656 | int len; |
| 657 | int readers; |
| 658 | }; |
| 659 | struct cache_reader { |
| 660 | struct cache_queue q; |
| 661 | int offset; /* if non-0, we have a refcnt on next request */ |
| 662 | }; |
| 663 | |
| 664 | static ssize_t |
| 665 | cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) |
| 666 | { |
| 667 | struct cache_reader *rp = filp->private_data; |
| 668 | struct cache_request *rq; |
| 669 | struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data; |
| 670 | int err; |
| 671 | |
| 672 | if (count == 0) |
| 673 | return 0; |
| 674 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 675 | mutex_lock(&queue_io_mutex); /* protect against multiple concurrent |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | * readers on this file */ |
| 677 | again: |
| 678 | spin_lock(&queue_lock); |
| 679 | /* need to find next request */ |
| 680 | while (rp->q.list.next != &cd->queue && |
| 681 | list_entry(rp->q.list.next, struct cache_queue, list) |
| 682 | ->reader) { |
| 683 | struct list_head *next = rp->q.list.next; |
| 684 | list_move(&rp->q.list, next); |
| 685 | } |
| 686 | if (rp->q.list.next == &cd->queue) { |
| 687 | spin_unlock(&queue_lock); |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 688 | mutex_unlock(&queue_io_mutex); |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 689 | BUG_ON(rp->offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | return 0; |
| 691 | } |
| 692 | rq = container_of(rp->q.list.next, struct cache_request, q.list); |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 693 | BUG_ON(rq->q.reader); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | if (rp->offset == 0) |
| 695 | rq->readers++; |
| 696 | spin_unlock(&queue_lock); |
| 697 | |
| 698 | if (rp->offset == 0 && !test_bit(CACHE_PENDING, &rq->item->flags)) { |
| 699 | err = -EAGAIN; |
| 700 | spin_lock(&queue_lock); |
| 701 | list_move(&rp->q.list, &rq->q.list); |
| 702 | spin_unlock(&queue_lock); |
| 703 | } else { |
| 704 | if (rp->offset + count > rq->len) |
| 705 | count = rq->len - rp->offset; |
| 706 | err = -EFAULT; |
| 707 | if (copy_to_user(buf, rq->buf + rp->offset, count)) |
| 708 | goto out; |
| 709 | rp->offset += count; |
| 710 | if (rp->offset >= rq->len) { |
| 711 | rp->offset = 0; |
| 712 | spin_lock(&queue_lock); |
| 713 | list_move(&rp->q.list, &rq->q.list); |
| 714 | spin_unlock(&queue_lock); |
| 715 | } |
| 716 | err = 0; |
| 717 | } |
| 718 | out: |
| 719 | if (rp->offset == 0) { |
| 720 | /* need to release rq */ |
| 721 | spin_lock(&queue_lock); |
| 722 | rq->readers--; |
| 723 | if (rq->readers == 0 && |
| 724 | !test_bit(CACHE_PENDING, &rq->item->flags)) { |
| 725 | list_del(&rq->q.list); |
| 726 | spin_unlock(&queue_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 727 | cache_put(rq->item, cd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | kfree(rq->buf); |
| 729 | kfree(rq); |
| 730 | } else |
| 731 | spin_unlock(&queue_lock); |
| 732 | } |
| 733 | if (err == -EAGAIN) |
| 734 | goto again; |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 735 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | return err ? err : count; |
| 737 | } |
| 738 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 739 | static char write_buf[8192]; /* protected by queue_io_mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
| 741 | static ssize_t |
| 742 | cache_write(struct file *filp, const char __user *buf, size_t count, |
| 743 | loff_t *ppos) |
| 744 | { |
| 745 | int err; |
| 746 | struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data; |
| 747 | |
| 748 | if (count == 0) |
| 749 | return 0; |
| 750 | if (count >= sizeof(write_buf)) |
| 751 | return -EINVAL; |
| 752 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 753 | mutex_lock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 754 | |
| 755 | if (copy_from_user(write_buf, buf, count)) { |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 756 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | return -EFAULT; |
| 758 | } |
| 759 | write_buf[count] = '\0'; |
| 760 | if (cd->cache_parse) |
| 761 | err = cd->cache_parse(cd, write_buf, count); |
| 762 | else |
| 763 | err = -EINVAL; |
| 764 | |
Arjan van de Ven | 4a3e2f7 | 2006-03-20 22:33:17 -0800 | [diff] [blame] | 765 | mutex_unlock(&queue_io_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | return err ? err : count; |
| 767 | } |
| 768 | |
| 769 | static DECLARE_WAIT_QUEUE_HEAD(queue_wait); |
| 770 | |
| 771 | static unsigned int |
| 772 | cache_poll(struct file *filp, poll_table *wait) |
| 773 | { |
| 774 | unsigned int mask; |
| 775 | struct cache_reader *rp = filp->private_data; |
| 776 | struct cache_queue *cq; |
| 777 | struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data; |
| 778 | |
| 779 | poll_wait(filp, &queue_wait, wait); |
| 780 | |
| 781 | /* alway allow write */ |
| 782 | mask = POLL_OUT | POLLWRNORM; |
| 783 | |
| 784 | if (!rp) |
| 785 | return mask; |
| 786 | |
| 787 | spin_lock(&queue_lock); |
| 788 | |
| 789 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 790 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 791 | if (!cq->reader) { |
| 792 | mask |= POLLIN | POLLRDNORM; |
| 793 | break; |
| 794 | } |
| 795 | spin_unlock(&queue_lock); |
| 796 | return mask; |
| 797 | } |
| 798 | |
| 799 | static int |
| 800 | cache_ioctl(struct inode *ino, struct file *filp, |
| 801 | unsigned int cmd, unsigned long arg) |
| 802 | { |
| 803 | int len = 0; |
| 804 | struct cache_reader *rp = filp->private_data; |
| 805 | struct cache_queue *cq; |
| 806 | struct cache_detail *cd = PDE(ino)->data; |
| 807 | |
| 808 | if (cmd != FIONREAD || !rp) |
| 809 | return -EINVAL; |
| 810 | |
| 811 | spin_lock(&queue_lock); |
| 812 | |
| 813 | /* only find the length remaining in current request, |
| 814 | * or the length of the next request |
| 815 | */ |
| 816 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 817 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 818 | if (!cq->reader) { |
| 819 | struct cache_request *cr = |
| 820 | container_of(cq, struct cache_request, q); |
| 821 | len = cr->len - rp->offset; |
| 822 | break; |
| 823 | } |
| 824 | spin_unlock(&queue_lock); |
| 825 | |
| 826 | return put_user(len, (int __user *)arg); |
| 827 | } |
| 828 | |
| 829 | static int |
| 830 | cache_open(struct inode *inode, struct file *filp) |
| 831 | { |
| 832 | struct cache_reader *rp = NULL; |
| 833 | |
| 834 | nonseekable_open(inode, filp); |
| 835 | if (filp->f_mode & FMODE_READ) { |
| 836 | struct cache_detail *cd = PDE(inode)->data; |
| 837 | |
| 838 | rp = kmalloc(sizeof(*rp), GFP_KERNEL); |
| 839 | if (!rp) |
| 840 | return -ENOMEM; |
| 841 | rp->offset = 0; |
| 842 | rp->q.reader = 1; |
| 843 | atomic_inc(&cd->readers); |
| 844 | spin_lock(&queue_lock); |
| 845 | list_add(&rp->q.list, &cd->queue); |
| 846 | spin_unlock(&queue_lock); |
| 847 | } |
| 848 | filp->private_data = rp; |
| 849 | return 0; |
| 850 | } |
| 851 | |
| 852 | static int |
| 853 | cache_release(struct inode *inode, struct file *filp) |
| 854 | { |
| 855 | struct cache_reader *rp = filp->private_data; |
| 856 | struct cache_detail *cd = PDE(inode)->data; |
| 857 | |
| 858 | if (rp) { |
| 859 | spin_lock(&queue_lock); |
| 860 | if (rp->offset) { |
| 861 | struct cache_queue *cq; |
| 862 | for (cq= &rp->q; &cq->list != &cd->queue; |
| 863 | cq = list_entry(cq->list.next, struct cache_queue, list)) |
| 864 | if (!cq->reader) { |
| 865 | container_of(cq, struct cache_request, q) |
| 866 | ->readers--; |
| 867 | break; |
| 868 | } |
| 869 | rp->offset = 0; |
| 870 | } |
| 871 | list_del(&rp->q.list); |
| 872 | spin_unlock(&queue_lock); |
| 873 | |
| 874 | filp->private_data = NULL; |
| 875 | kfree(rp); |
| 876 | |
| 877 | cd->last_close = get_seconds(); |
| 878 | atomic_dec(&cd->readers); |
| 879 | } |
| 880 | return 0; |
| 881 | } |
| 882 | |
| 883 | |
| 884 | |
| 885 | static struct file_operations cache_file_operations = { |
| 886 | .owner = THIS_MODULE, |
| 887 | .llseek = no_llseek, |
| 888 | .read = cache_read, |
| 889 | .write = cache_write, |
| 890 | .poll = cache_poll, |
| 891 | .ioctl = cache_ioctl, /* for FIONREAD */ |
| 892 | .open = cache_open, |
| 893 | .release = cache_release, |
| 894 | }; |
| 895 | |
| 896 | |
| 897 | static void queue_loose(struct cache_detail *detail, struct cache_head *ch) |
| 898 | { |
| 899 | struct cache_queue *cq; |
| 900 | spin_lock(&queue_lock); |
| 901 | list_for_each_entry(cq, &detail->queue, list) |
| 902 | if (!cq->reader) { |
| 903 | struct cache_request *cr = container_of(cq, struct cache_request, q); |
| 904 | if (cr->item != ch) |
| 905 | continue; |
| 906 | if (cr->readers != 0) |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 907 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | list_del(&cr->q.list); |
| 909 | spin_unlock(&queue_lock); |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 910 | cache_put(cr->item, detail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | kfree(cr->buf); |
| 912 | kfree(cr); |
| 913 | return; |
| 914 | } |
| 915 | spin_unlock(&queue_lock); |
| 916 | } |
| 917 | |
| 918 | /* |
| 919 | * Support routines for text-based upcalls. |
| 920 | * Fields are separated by spaces. |
| 921 | * Fields are either mangled to quote space tab newline slosh with slosh |
| 922 | * or a hexified with a leading \x |
| 923 | * Record is terminated with newline. |
| 924 | * |
| 925 | */ |
| 926 | |
| 927 | void qword_add(char **bpp, int *lp, char *str) |
| 928 | { |
| 929 | char *bp = *bpp; |
| 930 | int len = *lp; |
| 931 | char c; |
| 932 | |
| 933 | if (len < 0) return; |
| 934 | |
| 935 | while ((c=*str++) && len) |
| 936 | switch(c) { |
| 937 | case ' ': |
| 938 | case '\t': |
| 939 | case '\n': |
| 940 | case '\\': |
| 941 | if (len >= 4) { |
| 942 | *bp++ = '\\'; |
| 943 | *bp++ = '0' + ((c & 0300)>>6); |
| 944 | *bp++ = '0' + ((c & 0070)>>3); |
| 945 | *bp++ = '0' + ((c & 0007)>>0); |
| 946 | } |
| 947 | len -= 4; |
| 948 | break; |
| 949 | default: |
| 950 | *bp++ = c; |
| 951 | len--; |
| 952 | } |
| 953 | if (c || len <1) len = -1; |
| 954 | else { |
| 955 | *bp++ = ' '; |
| 956 | len--; |
| 957 | } |
| 958 | *bpp = bp; |
| 959 | *lp = len; |
| 960 | } |
| 961 | |
| 962 | void qword_addhex(char **bpp, int *lp, char *buf, int blen) |
| 963 | { |
| 964 | char *bp = *bpp; |
| 965 | int len = *lp; |
| 966 | |
| 967 | if (len < 0) return; |
| 968 | |
| 969 | if (len > 2) { |
| 970 | *bp++ = '\\'; |
| 971 | *bp++ = 'x'; |
| 972 | len -= 2; |
| 973 | while (blen && len >= 2) { |
| 974 | unsigned char c = *buf++; |
| 975 | *bp++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); |
| 976 | *bp++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); |
| 977 | len -= 2; |
| 978 | blen--; |
| 979 | } |
| 980 | } |
| 981 | if (blen || len<1) len = -1; |
| 982 | else { |
| 983 | *bp++ = ' '; |
| 984 | len--; |
| 985 | } |
| 986 | *bpp = bp; |
| 987 | *lp = len; |
| 988 | } |
| 989 | |
| 990 | static void warn_no_listener(struct cache_detail *detail) |
| 991 | { |
| 992 | if (detail->last_warn != detail->last_close) { |
| 993 | detail->last_warn = detail->last_close; |
| 994 | if (detail->warn_no_listener) |
| 995 | detail->warn_no_listener(detail); |
| 996 | } |
| 997 | } |
| 998 | |
| 999 | /* |
| 1000 | * register an upcall request to user-space. |
| 1001 | * Each request is at most one page long. |
| 1002 | */ |
| 1003 | static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h) |
| 1004 | { |
| 1005 | |
| 1006 | char *buf; |
| 1007 | struct cache_request *crq; |
| 1008 | char *bp; |
| 1009 | int len; |
| 1010 | |
| 1011 | if (detail->cache_request == NULL) |
| 1012 | return -EINVAL; |
| 1013 | |
| 1014 | if (atomic_read(&detail->readers) == 0 && |
| 1015 | detail->last_close < get_seconds() - 30) { |
| 1016 | warn_no_listener(detail); |
| 1017 | return -EINVAL; |
| 1018 | } |
| 1019 | |
| 1020 | buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| 1021 | if (!buf) |
| 1022 | return -EAGAIN; |
| 1023 | |
| 1024 | crq = kmalloc(sizeof (*crq), GFP_KERNEL); |
| 1025 | if (!crq) { |
| 1026 | kfree(buf); |
| 1027 | return -EAGAIN; |
| 1028 | } |
| 1029 | |
| 1030 | bp = buf; len = PAGE_SIZE; |
| 1031 | |
| 1032 | detail->cache_request(detail, h, &bp, &len); |
| 1033 | |
| 1034 | if (len < 0) { |
| 1035 | kfree(buf); |
| 1036 | kfree(crq); |
| 1037 | return -EAGAIN; |
| 1038 | } |
| 1039 | crq->q.reader = 0; |
| 1040 | crq->item = cache_get(h); |
| 1041 | crq->buf = buf; |
| 1042 | crq->len = PAGE_SIZE - len; |
| 1043 | crq->readers = 0; |
| 1044 | spin_lock(&queue_lock); |
| 1045 | list_add_tail(&crq->q.list, &detail->queue); |
| 1046 | spin_unlock(&queue_lock); |
| 1047 | wake_up(&queue_wait); |
| 1048 | return 0; |
| 1049 | } |
| 1050 | |
| 1051 | /* |
| 1052 | * parse a message from user-space and pass it |
| 1053 | * to an appropriate cache |
| 1054 | * Messages are, like requests, separated into fields by |
| 1055 | * spaces and dequotes as \xHEXSTRING or embedded \nnn octal |
| 1056 | * |
| 1057 | * Message is |
| 1058 | * reply cachename expiry key ... content.... |
| 1059 | * |
| 1060 | * key and content are both parsed by cache |
| 1061 | */ |
| 1062 | |
| 1063 | #define isodigit(c) (isdigit(c) && c <= '7') |
| 1064 | int qword_get(char **bpp, char *dest, int bufsize) |
| 1065 | { |
| 1066 | /* return bytes copied, or -1 on error */ |
| 1067 | char *bp = *bpp; |
| 1068 | int len = 0; |
| 1069 | |
| 1070 | while (*bp == ' ') bp++; |
| 1071 | |
| 1072 | if (bp[0] == '\\' && bp[1] == 'x') { |
| 1073 | /* HEX STRING */ |
| 1074 | bp += 2; |
| 1075 | while (isxdigit(bp[0]) && isxdigit(bp[1]) && len < bufsize) { |
| 1076 | int byte = isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; |
| 1077 | bp++; |
| 1078 | byte <<= 4; |
| 1079 | byte |= isdigit(*bp) ? *bp-'0' : toupper(*bp)-'A'+10; |
| 1080 | *dest++ = byte; |
| 1081 | bp++; |
| 1082 | len++; |
| 1083 | } |
| 1084 | } else { |
| 1085 | /* text with \nnn octal quoting */ |
| 1086 | while (*bp != ' ' && *bp != '\n' && *bp && len < bufsize-1) { |
| 1087 | if (*bp == '\\' && |
| 1088 | isodigit(bp[1]) && (bp[1] <= '3') && |
| 1089 | isodigit(bp[2]) && |
| 1090 | isodigit(bp[3])) { |
| 1091 | int byte = (*++bp -'0'); |
| 1092 | bp++; |
| 1093 | byte = (byte << 3) | (*bp++ - '0'); |
| 1094 | byte = (byte << 3) | (*bp++ - '0'); |
| 1095 | *dest++ = byte; |
| 1096 | len++; |
| 1097 | } else { |
| 1098 | *dest++ = *bp++; |
| 1099 | len++; |
| 1100 | } |
| 1101 | } |
| 1102 | } |
| 1103 | |
| 1104 | if (*bp != ' ' && *bp != '\n' && *bp != '\0') |
| 1105 | return -1; |
| 1106 | while (*bp == ' ') bp++; |
| 1107 | *bpp = bp; |
| 1108 | *dest = '\0'; |
| 1109 | return len; |
| 1110 | } |
| 1111 | |
| 1112 | |
| 1113 | /* |
| 1114 | * support /proc/sunrpc/cache/$CACHENAME/content |
| 1115 | * as a seqfile. |
| 1116 | * We call ->cache_show passing NULL for the item to |
| 1117 | * get a header, then pass each real item in the cache |
| 1118 | */ |
| 1119 | |
| 1120 | struct handle { |
| 1121 | struct cache_detail *cd; |
| 1122 | }; |
| 1123 | |
| 1124 | static void *c_start(struct seq_file *m, loff_t *pos) |
| 1125 | { |
| 1126 | loff_t n = *pos; |
| 1127 | unsigned hash, entry; |
| 1128 | struct cache_head *ch; |
| 1129 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1130 | |
| 1131 | |
| 1132 | read_lock(&cd->hash_lock); |
| 1133 | if (!n--) |
| 1134 | return SEQ_START_TOKEN; |
| 1135 | hash = n >> 32; |
| 1136 | entry = n & ((1LL<<32) - 1); |
| 1137 | |
| 1138 | for (ch=cd->hash_table[hash]; ch; ch=ch->next) |
| 1139 | if (!entry--) |
| 1140 | return ch; |
| 1141 | n &= ~((1LL<<32) - 1); |
| 1142 | do { |
| 1143 | hash++; |
| 1144 | n += 1LL<<32; |
| 1145 | } while(hash < cd->hash_size && |
| 1146 | cd->hash_table[hash]==NULL); |
| 1147 | if (hash >= cd->hash_size) |
| 1148 | return NULL; |
| 1149 | *pos = n+1; |
| 1150 | return cd->hash_table[hash]; |
| 1151 | } |
| 1152 | |
| 1153 | static void *c_next(struct seq_file *m, void *p, loff_t *pos) |
| 1154 | { |
| 1155 | struct cache_head *ch = p; |
| 1156 | int hash = (*pos >> 32); |
| 1157 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1158 | |
| 1159 | if (p == SEQ_START_TOKEN) |
| 1160 | hash = 0; |
| 1161 | else if (ch->next == NULL) { |
| 1162 | hash++; |
| 1163 | *pos += 1LL<<32; |
| 1164 | } else { |
| 1165 | ++*pos; |
| 1166 | return ch->next; |
| 1167 | } |
| 1168 | *pos &= ~((1LL<<32) - 1); |
| 1169 | while (hash < cd->hash_size && |
| 1170 | cd->hash_table[hash] == NULL) { |
| 1171 | hash++; |
| 1172 | *pos += 1LL<<32; |
| 1173 | } |
| 1174 | if (hash >= cd->hash_size) |
| 1175 | return NULL; |
| 1176 | ++*pos; |
| 1177 | return cd->hash_table[hash]; |
| 1178 | } |
| 1179 | |
| 1180 | static void c_stop(struct seq_file *m, void *p) |
| 1181 | { |
| 1182 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1183 | read_unlock(&cd->hash_lock); |
| 1184 | } |
| 1185 | |
| 1186 | static int c_show(struct seq_file *m, void *p) |
| 1187 | { |
| 1188 | struct cache_head *cp = p; |
| 1189 | struct cache_detail *cd = ((struct handle*)m->private)->cd; |
| 1190 | |
| 1191 | if (p == SEQ_START_TOKEN) |
| 1192 | return cd->cache_show(m, cd, NULL); |
| 1193 | |
| 1194 | ifdebug(CACHE) |
NeilBrown | 4013ede | 2006-03-27 01:15:07 -0800 | [diff] [blame] | 1195 | seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n", |
NeilBrown | baab935 | 2006-03-27 01:15:09 -0800 | [diff] [blame] | 1196 | cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1197 | cache_get(cp); |
| 1198 | if (cache_check(cd, cp, NULL)) |
| 1199 | /* cache_check does a cache_put on failure */ |
| 1200 | seq_printf(m, "# "); |
| 1201 | else |
| 1202 | cache_put(cp, cd); |
| 1203 | |
| 1204 | return cd->cache_show(m, cd, cp); |
| 1205 | } |
| 1206 | |
| 1207 | static struct seq_operations cache_content_op = { |
| 1208 | .start = c_start, |
| 1209 | .next = c_next, |
| 1210 | .stop = c_stop, |
| 1211 | .show = c_show, |
| 1212 | }; |
| 1213 | |
| 1214 | static int content_open(struct inode *inode, struct file *file) |
| 1215 | { |
| 1216 | int res; |
| 1217 | struct handle *han; |
| 1218 | struct cache_detail *cd = PDE(inode)->data; |
| 1219 | |
| 1220 | han = kmalloc(sizeof(*han), GFP_KERNEL); |
| 1221 | if (han == NULL) |
| 1222 | return -ENOMEM; |
| 1223 | |
| 1224 | han->cd = cd; |
| 1225 | |
| 1226 | res = seq_open(file, &cache_content_op); |
| 1227 | if (res) |
| 1228 | kfree(han); |
| 1229 | else |
| 1230 | ((struct seq_file *)file->private_data)->private = han; |
| 1231 | |
| 1232 | return res; |
| 1233 | } |
| 1234 | static int content_release(struct inode *inode, struct file *file) |
| 1235 | { |
| 1236 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1237 | struct handle *han = m->private; |
| 1238 | kfree(han); |
| 1239 | m->private = NULL; |
| 1240 | return seq_release(inode, file); |
| 1241 | } |
| 1242 | |
| 1243 | static struct file_operations content_file_operations = { |
| 1244 | .open = content_open, |
| 1245 | .read = seq_read, |
| 1246 | .llseek = seq_lseek, |
| 1247 | .release = content_release, |
| 1248 | }; |
| 1249 | |
| 1250 | static ssize_t read_flush(struct file *file, char __user *buf, |
| 1251 | size_t count, loff_t *ppos) |
| 1252 | { |
| 1253 | struct cache_detail *cd = PDE(file->f_dentry->d_inode)->data; |
| 1254 | char tbuf[20]; |
| 1255 | unsigned long p = *ppos; |
| 1256 | int len; |
| 1257 | |
| 1258 | sprintf(tbuf, "%lu\n", cd->flush_time); |
| 1259 | len = strlen(tbuf); |
| 1260 | if (p >= len) |
| 1261 | return 0; |
| 1262 | len -= p; |
| 1263 | if (len > count) len = count; |
| 1264 | if (copy_to_user(buf, (void*)(tbuf+p), len)) |
| 1265 | len = -EFAULT; |
| 1266 | else |
| 1267 | *ppos += len; |
| 1268 | return len; |
| 1269 | } |
| 1270 | |
| 1271 | static ssize_t write_flush(struct file * file, const char __user * buf, |
| 1272 | size_t count, loff_t *ppos) |
| 1273 | { |
| 1274 | struct cache_detail *cd = PDE(file->f_dentry->d_inode)->data; |
| 1275 | char tbuf[20]; |
| 1276 | char *ep; |
| 1277 | long flushtime; |
| 1278 | if (*ppos || count > sizeof(tbuf)-1) |
| 1279 | return -EINVAL; |
| 1280 | if (copy_from_user(tbuf, buf, count)) |
| 1281 | return -EFAULT; |
| 1282 | tbuf[count] = 0; |
| 1283 | flushtime = simple_strtoul(tbuf, &ep, 0); |
| 1284 | if (*ep && *ep != '\n') |
| 1285 | return -EINVAL; |
| 1286 | |
| 1287 | cd->flush_time = flushtime; |
| 1288 | cd->nextcheck = get_seconds(); |
| 1289 | cache_flush(); |
| 1290 | |
| 1291 | *ppos += count; |
| 1292 | return count; |
| 1293 | } |
| 1294 | |
| 1295 | static struct file_operations cache_flush_operations = { |
| 1296 | .open = nonseekable_open, |
| 1297 | .read = read_flush, |
| 1298 | .write = write_flush, |
| 1299 | }; |