internal.h 12 KB

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  1. /* Internal definitions for FS-Cache
  2. *
  3. * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
  4. * Written by David Howells (dhowells@redhat.com)
  5. *
  6. * This program is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU General Public License
  8. * as published by the Free Software Foundation; either version
  9. * 2 of the License, or (at your option) any later version.
  10. */
  11. /*
  12. * Lock order, in the order in which multiple locks should be obtained:
  13. * - fscache_addremove_sem
  14. * - cookie->lock
  15. * - cookie->parent->lock
  16. * - cache->object_list_lock
  17. * - object->lock
  18. * - object->parent->lock
  19. * - cookie->stores_lock
  20. * - fscache_thread_lock
  21. *
  22. */
  23. #include <linux/fscache-cache.h>
  24. #include <linux/sched.h>
  25. #define FSCACHE_MIN_THREADS 4
  26. #define FSCACHE_MAX_THREADS 32
  27. /*
  28. * cache.c
  29. */
  30. extern struct list_head fscache_cache_list;
  31. extern struct rw_semaphore fscache_addremove_sem;
  32. extern struct fscache_cache *fscache_select_cache_for_object(
  33. struct fscache_cookie *);
  34. /*
  35. * cookie.c
  36. */
  37. extern struct kmem_cache *fscache_cookie_jar;
  38. extern void fscache_cookie_init_once(void *);
  39. extern void __fscache_cookie_put(struct fscache_cookie *);
  40. /*
  41. * fsdef.c
  42. */
  43. extern struct fscache_cookie fscache_fsdef_index;
  44. extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  45. /*
  46. * histogram.c
  47. */
  48. #ifdef CONFIG_FSCACHE_HISTOGRAM
  49. extern atomic_t fscache_obj_instantiate_histogram[HZ];
  50. extern atomic_t fscache_objs_histogram[HZ];
  51. extern atomic_t fscache_ops_histogram[HZ];
  52. extern atomic_t fscache_retrieval_delay_histogram[HZ];
  53. extern atomic_t fscache_retrieval_histogram[HZ];
  54. static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  55. {
  56. unsigned long jif = jiffies - start_jif;
  57. if (jif >= HZ)
  58. jif = HZ - 1;
  59. atomic_inc(&histogram[jif]);
  60. }
  61. extern const struct file_operations fscache_histogram_fops;
  62. #else
  63. #define fscache_hist(hist, start_jif) do {} while (0)
  64. #endif
  65. /*
  66. * main.c
  67. */
  68. extern unsigned fscache_defer_lookup;
  69. extern unsigned fscache_defer_create;
  70. extern unsigned fscache_debug;
  71. extern struct kobject *fscache_root;
  72. extern struct workqueue_struct *fscache_object_wq;
  73. extern struct workqueue_struct *fscache_op_wq;
  74. DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  75. static inline bool fscache_object_congested(void)
  76. {
  77. return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  78. }
  79. extern int fscache_wait_bit(void *);
  80. extern int fscache_wait_bit_interruptible(void *);
  81. /*
  82. * object.c
  83. */
  84. extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
  85. extern void fscache_withdrawing_object(struct fscache_cache *,
  86. struct fscache_object *);
  87. extern void fscache_enqueue_object(struct fscache_object *);
  88. /*
  89. * object-list.c
  90. */
  91. #ifdef CONFIG_FSCACHE_OBJECT_LIST
  92. extern const struct file_operations fscache_objlist_fops;
  93. extern void fscache_objlist_add(struct fscache_object *);
  94. #else
  95. #define fscache_objlist_add(object) do {} while(0)
  96. #endif
  97. /*
  98. * operation.c
  99. */
  100. extern int fscache_submit_exclusive_op(struct fscache_object *,
  101. struct fscache_operation *);
  102. extern int fscache_submit_op(struct fscache_object *,
  103. struct fscache_operation *);
  104. extern int fscache_cancel_op(struct fscache_operation *);
  105. extern void fscache_abort_object(struct fscache_object *);
  106. extern void fscache_start_operations(struct fscache_object *);
  107. extern void fscache_operation_gc(struct work_struct *);
  108. /*
  109. * proc.c
  110. */
  111. #ifdef CONFIG_PROC_FS
  112. extern int __init fscache_proc_init(void);
  113. extern void fscache_proc_cleanup(void);
  114. #else
  115. #define fscache_proc_init() (0)
  116. #define fscache_proc_cleanup() do {} while (0)
  117. #endif
  118. /*
  119. * stats.c
  120. */
  121. #ifdef CONFIG_FSCACHE_STATS
  122. extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
  123. extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
  124. extern atomic_t fscache_n_op_pend;
  125. extern atomic_t fscache_n_op_run;
  126. extern atomic_t fscache_n_op_enqueue;
  127. extern atomic_t fscache_n_op_deferred_release;
  128. extern atomic_t fscache_n_op_release;
  129. extern atomic_t fscache_n_op_gc;
  130. extern atomic_t fscache_n_op_cancelled;
  131. extern atomic_t fscache_n_op_rejected;
  132. extern atomic_t fscache_n_attr_changed;
  133. extern atomic_t fscache_n_attr_changed_ok;
  134. extern atomic_t fscache_n_attr_changed_nobufs;
  135. extern atomic_t fscache_n_attr_changed_nomem;
  136. extern atomic_t fscache_n_attr_changed_calls;
  137. extern atomic_t fscache_n_allocs;
  138. extern atomic_t fscache_n_allocs_ok;
  139. extern atomic_t fscache_n_allocs_wait;
  140. extern atomic_t fscache_n_allocs_nobufs;
  141. extern atomic_t fscache_n_allocs_intr;
  142. extern atomic_t fscache_n_allocs_object_dead;
  143. extern atomic_t fscache_n_alloc_ops;
  144. extern atomic_t fscache_n_alloc_op_waits;
  145. extern atomic_t fscache_n_retrievals;
  146. extern atomic_t fscache_n_retrievals_ok;
  147. extern atomic_t fscache_n_retrievals_wait;
  148. extern atomic_t fscache_n_retrievals_nodata;
  149. extern atomic_t fscache_n_retrievals_nobufs;
  150. extern atomic_t fscache_n_retrievals_intr;
  151. extern atomic_t fscache_n_retrievals_nomem;
  152. extern atomic_t fscache_n_retrievals_object_dead;
  153. extern atomic_t fscache_n_retrieval_ops;
  154. extern atomic_t fscache_n_retrieval_op_waits;
  155. extern atomic_t fscache_n_stores;
  156. extern atomic_t fscache_n_stores_ok;
  157. extern atomic_t fscache_n_stores_again;
  158. extern atomic_t fscache_n_stores_nobufs;
  159. extern atomic_t fscache_n_stores_oom;
  160. extern atomic_t fscache_n_store_ops;
  161. extern atomic_t fscache_n_store_calls;
  162. extern atomic_t fscache_n_store_pages;
  163. extern atomic_t fscache_n_store_radix_deletes;
  164. extern atomic_t fscache_n_store_pages_over_limit;
  165. extern atomic_t fscache_n_store_vmscan_not_storing;
  166. extern atomic_t fscache_n_store_vmscan_gone;
  167. extern atomic_t fscache_n_store_vmscan_busy;
  168. extern atomic_t fscache_n_store_vmscan_cancelled;
  169. extern atomic_t fscache_n_marks;
  170. extern atomic_t fscache_n_uncaches;
  171. extern atomic_t fscache_n_acquires;
  172. extern atomic_t fscache_n_acquires_null;
  173. extern atomic_t fscache_n_acquires_no_cache;
  174. extern atomic_t fscache_n_acquires_ok;
  175. extern atomic_t fscache_n_acquires_nobufs;
  176. extern atomic_t fscache_n_acquires_oom;
  177. extern atomic_t fscache_n_updates;
  178. extern atomic_t fscache_n_updates_null;
  179. extern atomic_t fscache_n_updates_run;
  180. extern atomic_t fscache_n_relinquishes;
  181. extern atomic_t fscache_n_relinquishes_null;
  182. extern atomic_t fscache_n_relinquishes_waitcrt;
  183. extern atomic_t fscache_n_relinquishes_retire;
  184. extern atomic_t fscache_n_cookie_index;
  185. extern atomic_t fscache_n_cookie_data;
  186. extern atomic_t fscache_n_cookie_special;
  187. extern atomic_t fscache_n_object_alloc;
  188. extern atomic_t fscache_n_object_no_alloc;
  189. extern atomic_t fscache_n_object_lookups;
  190. extern atomic_t fscache_n_object_lookups_negative;
  191. extern atomic_t fscache_n_object_lookups_positive;
  192. extern atomic_t fscache_n_object_lookups_timed_out;
  193. extern atomic_t fscache_n_object_created;
  194. extern atomic_t fscache_n_object_avail;
  195. extern atomic_t fscache_n_object_dead;
  196. extern atomic_t fscache_n_checkaux_none;
  197. extern atomic_t fscache_n_checkaux_okay;
  198. extern atomic_t fscache_n_checkaux_update;
  199. extern atomic_t fscache_n_checkaux_obsolete;
  200. extern atomic_t fscache_n_cop_alloc_object;
  201. extern atomic_t fscache_n_cop_lookup_object;
  202. extern atomic_t fscache_n_cop_lookup_complete;
  203. extern atomic_t fscache_n_cop_grab_object;
  204. extern atomic_t fscache_n_cop_update_object;
  205. extern atomic_t fscache_n_cop_drop_object;
  206. extern atomic_t fscache_n_cop_put_object;
  207. extern atomic_t fscache_n_cop_sync_cache;
  208. extern atomic_t fscache_n_cop_attr_changed;
  209. extern atomic_t fscache_n_cop_read_or_alloc_page;
  210. extern atomic_t fscache_n_cop_read_or_alloc_pages;
  211. extern atomic_t fscache_n_cop_allocate_page;
  212. extern atomic_t fscache_n_cop_allocate_pages;
  213. extern atomic_t fscache_n_cop_write_page;
  214. extern atomic_t fscache_n_cop_uncache_page;
  215. extern atomic_t fscache_n_cop_dissociate_pages;
  216. static inline void fscache_stat(atomic_t *stat)
  217. {
  218. atomic_inc(stat);
  219. }
  220. static inline void fscache_stat_d(atomic_t *stat)
  221. {
  222. atomic_dec(stat);
  223. }
  224. #define __fscache_stat(stat) (stat)
  225. extern const struct file_operations fscache_stats_fops;
  226. #else
  227. #define __fscache_stat(stat) (NULL)
  228. #define fscache_stat(stat) do {} while (0)
  229. #define fscache_stat_d(stat) do {} while (0)
  230. #endif
  231. /*
  232. * raise an event on an object
  233. * - if the event is not masked for that object, then the object is
  234. * queued for attention by the thread pool.
  235. */
  236. static inline void fscache_raise_event(struct fscache_object *object,
  237. unsigned event)
  238. {
  239. if (!test_and_set_bit(event, &object->events) &&
  240. test_bit(event, &object->event_mask))
  241. fscache_enqueue_object(object);
  242. }
  243. /*
  244. * drop a reference to a cookie
  245. */
  246. static inline void fscache_cookie_put(struct fscache_cookie *cookie)
  247. {
  248. BUG_ON(atomic_read(&cookie->usage) <= 0);
  249. if (atomic_dec_and_test(&cookie->usage))
  250. __fscache_cookie_put(cookie);
  251. }
  252. /*
  253. * get an extra reference to a netfs retrieval context
  254. */
  255. static inline
  256. void *fscache_get_context(struct fscache_cookie *cookie, void *context)
  257. {
  258. if (cookie->def->get_context)
  259. cookie->def->get_context(cookie->netfs_data, context);
  260. return context;
  261. }
  262. /*
  263. * release a reference to a netfs retrieval context
  264. */
  265. static inline
  266. void fscache_put_context(struct fscache_cookie *cookie, void *context)
  267. {
  268. if (cookie->def->put_context)
  269. cookie->def->put_context(cookie->netfs_data, context);
  270. }
  271. /*****************************************************************************/
  272. /*
  273. * debug tracing
  274. */
  275. #define dbgprintk(FMT, ...) \
  276. printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
  277. #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  278. #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  279. #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
  280. #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
  281. #ifdef __KDEBUG
  282. #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
  283. #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
  284. #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
  285. #elif defined(CONFIG_FSCACHE_DEBUG)
  286. #define _enter(FMT, ...) \
  287. do { \
  288. if (__do_kdebug(ENTER)) \
  289. kenter(FMT, ##__VA_ARGS__); \
  290. } while (0)
  291. #define _leave(FMT, ...) \
  292. do { \
  293. if (__do_kdebug(LEAVE)) \
  294. kleave(FMT, ##__VA_ARGS__); \
  295. } while (0)
  296. #define _debug(FMT, ...) \
  297. do { \
  298. if (__do_kdebug(DEBUG)) \
  299. kdebug(FMT, ##__VA_ARGS__); \
  300. } while (0)
  301. #else
  302. #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  303. #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  304. #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
  305. #endif
  306. /*
  307. * determine whether a particular optional debugging point should be logged
  308. * - we need to go through three steps to persuade cpp to correctly join the
  309. * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
  310. */
  311. #define ____do_kdebug(LEVEL, POINT) \
  312. unlikely((fscache_debug & \
  313. (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
  314. #define ___do_kdebug(LEVEL, POINT) \
  315. ____do_kdebug(LEVEL, POINT)
  316. #define __do_kdebug(POINT) \
  317. ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
  318. #define FSCACHE_DEBUG_CACHE 0
  319. #define FSCACHE_DEBUG_COOKIE 1
  320. #define FSCACHE_DEBUG_PAGE 2
  321. #define FSCACHE_DEBUG_OPERATION 3
  322. #define FSCACHE_POINT_ENTER 1
  323. #define FSCACHE_POINT_LEAVE 2
  324. #define FSCACHE_POINT_DEBUG 4
  325. #ifndef FSCACHE_DEBUG_LEVEL
  326. #define FSCACHE_DEBUG_LEVEL CACHE
  327. #endif
  328. /*
  329. * assertions
  330. */
  331. #if 1 /* defined(__KDEBUGALL) */
  332. #define ASSERT(X) \
  333. do { \
  334. if (unlikely(!(X))) { \
  335. printk(KERN_ERR "\n"); \
  336. printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
  337. BUG(); \
  338. } \
  339. } while (0)
  340. #define ASSERTCMP(X, OP, Y) \
  341. do { \
  342. if (unlikely(!((X) OP (Y)))) { \
  343. printk(KERN_ERR "\n"); \
  344. printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
  345. printk(KERN_ERR "%lx " #OP " %lx is false\n", \
  346. (unsigned long)(X), (unsigned long)(Y)); \
  347. BUG(); \
  348. } \
  349. } while (0)
  350. #define ASSERTIF(C, X) \
  351. do { \
  352. if (unlikely((C) && !(X))) { \
  353. printk(KERN_ERR "\n"); \
  354. printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
  355. BUG(); \
  356. } \
  357. } while (0)
  358. #define ASSERTIFCMP(C, X, OP, Y) \
  359. do { \
  360. if (unlikely((C) && !((X) OP (Y)))) { \
  361. printk(KERN_ERR "\n"); \
  362. printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
  363. printk(KERN_ERR "%lx " #OP " %lx is false\n", \
  364. (unsigned long)(X), (unsigned long)(Y)); \
  365. BUG(); \
  366. } \
  367. } while (0)
  368. #else
  369. #define ASSERT(X) do {} while (0)
  370. #define ASSERTCMP(X, OP, Y) do {} while (0)
  371. #define ASSERTIF(C, X) do {} while (0)
  372. #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
  373. #endif /* assert or not */