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 /* 13 * Lock order, in the order in which multiple locks should be obtained: 14 * - fscache_addremove_sem 15 * - cookie->lock 16 * - cookie->parent->lock 17 * - cache->object_list_lock 18 * - object->lock 19 * - object->parent->lock 20 * - cookie->stores_lock 21 * - fscache_thread_lock 22 * 23 */ 24 25 #include <linux/fscache-cache.h> 26 #include <linux/sched.h> 27 28 #define FSCACHE_MIN_THREADS 4 29 #define FSCACHE_MAX_THREADS 32 30 31 /* 32 * cache.c 33 */ 34 extern struct list_head fscache_cache_list; 35 extern struct rw_semaphore fscache_addremove_sem; 36 37 extern struct fscache_cache *fscache_select_cache_for_object( 38 struct fscache_cookie *); 39 40 /* 41 * cookie.c 42 */ 43 extern struct kmem_cache *fscache_cookie_jar; 44 45 extern void fscache_cookie_init_once(void *); 46 extern void __fscache_cookie_put(struct fscache_cookie *); 47 48 /* 49 * fsdef.c 50 */ 51 extern struct fscache_cookie fscache_fsdef_index; 52 extern struct fscache_cookie_def fscache_fsdef_netfs_def; 53 54 /* 55 * histogram.c 56 */ 57 #ifdef CONFIG_FSCACHE_HISTOGRAM 58 extern atomic_t fscache_obj_instantiate_histogram[HZ]; 59 extern atomic_t fscache_objs_histogram[HZ]; 60 extern atomic_t fscache_ops_histogram[HZ]; 61 extern atomic_t fscache_retrieval_delay_histogram[HZ]; 62 extern atomic_t fscache_retrieval_histogram[HZ]; 63 64 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif) 65 { 66 unsigned long jif = jiffies - start_jif; 67 if (jif >= HZ) 68 jif = HZ - 1; 69 atomic_inc(&histogram[jif]); 70 } 71 72 extern const struct file_operations fscache_histogram_fops; 73 74 #else 75 #define fscache_hist(hist, start_jif) do {} while (0) 76 #endif 77 78 /* 79 * main.c 80 */ 81 extern unsigned fscache_defer_lookup; 82 extern unsigned fscache_defer_create; 83 extern unsigned fscache_debug; 84 extern struct kobject *fscache_root; 85 extern struct workqueue_struct *fscache_object_wq; 86 extern struct workqueue_struct *fscache_op_wq; 87 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait); 88 89 static inline bool fscache_object_congested(void) 90 { 91 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq); 92 } 93 94 extern int fscache_wait_bit(void *); 95 extern int fscache_wait_bit_interruptible(void *); 96 97 /* 98 * object.c 99 */ 100 extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5]; 101 102 extern void fscache_withdrawing_object(struct fscache_cache *, 103 struct fscache_object *); 104 extern void fscache_enqueue_object(struct fscache_object *); 105 106 /* 107 * object-list.c 108 */ 109 #ifdef CONFIG_FSCACHE_OBJECT_LIST 110 extern const struct file_operations fscache_objlist_fops; 111 112 extern void fscache_objlist_add(struct fscache_object *); 113 #else 114 #define fscache_objlist_add(object) do {} while(0) 115 #endif 116 117 /* 118 * operation.c 119 */ 120 extern int fscache_submit_exclusive_op(struct fscache_object *, 121 struct fscache_operation *); 122 extern int fscache_submit_op(struct fscache_object *, 123 struct fscache_operation *); 124 extern int fscache_cancel_op(struct fscache_operation *, 125 void (*)(struct fscache_operation *)); 126 extern void fscache_cancel_all_ops(struct fscache_object *); 127 extern void fscache_abort_object(struct fscache_object *); 128 extern void fscache_start_operations(struct fscache_object *); 129 extern void fscache_operation_gc(struct work_struct *); 130 131 /* 132 * page.c 133 */ 134 extern void fscache_invalidate_writes(struct fscache_cookie *); 135 136 /* 137 * proc.c 138 */ 139 #ifdef CONFIG_PROC_FS 140 extern int __init fscache_proc_init(void); 141 extern void fscache_proc_cleanup(void); 142 #else 143 #define fscache_proc_init() (0) 144 #define fscache_proc_cleanup() do {} while (0) 145 #endif 146 147 /* 148 * stats.c 149 */ 150 #ifdef CONFIG_FSCACHE_STATS 151 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS]; 152 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS]; 153 154 extern atomic_t fscache_n_op_pend; 155 extern atomic_t fscache_n_op_run; 156 extern atomic_t fscache_n_op_enqueue; 157 extern atomic_t fscache_n_op_deferred_release; 158 extern atomic_t fscache_n_op_release; 159 extern atomic_t fscache_n_op_gc; 160 extern atomic_t fscache_n_op_cancelled; 161 extern atomic_t fscache_n_op_rejected; 162 163 extern atomic_t fscache_n_attr_changed; 164 extern atomic_t fscache_n_attr_changed_ok; 165 extern atomic_t fscache_n_attr_changed_nobufs; 166 extern atomic_t fscache_n_attr_changed_nomem; 167 extern atomic_t fscache_n_attr_changed_calls; 168 169 extern atomic_t fscache_n_allocs; 170 extern atomic_t fscache_n_allocs_ok; 171 extern atomic_t fscache_n_allocs_wait; 172 extern atomic_t fscache_n_allocs_nobufs; 173 extern atomic_t fscache_n_allocs_intr; 174 extern atomic_t fscache_n_allocs_object_dead; 175 extern atomic_t fscache_n_alloc_ops; 176 extern atomic_t fscache_n_alloc_op_waits; 177 178 extern atomic_t fscache_n_retrievals; 179 extern atomic_t fscache_n_retrievals_ok; 180 extern atomic_t fscache_n_retrievals_wait; 181 extern atomic_t fscache_n_retrievals_nodata; 182 extern atomic_t fscache_n_retrievals_nobufs; 183 extern atomic_t fscache_n_retrievals_intr; 184 extern atomic_t fscache_n_retrievals_nomem; 185 extern atomic_t fscache_n_retrievals_object_dead; 186 extern atomic_t fscache_n_retrieval_ops; 187 extern atomic_t fscache_n_retrieval_op_waits; 188 189 extern atomic_t fscache_n_stores; 190 extern atomic_t fscache_n_stores_ok; 191 extern atomic_t fscache_n_stores_again; 192 extern atomic_t fscache_n_stores_nobufs; 193 extern atomic_t fscache_n_stores_oom; 194 extern atomic_t fscache_n_store_ops; 195 extern atomic_t fscache_n_store_calls; 196 extern atomic_t fscache_n_store_pages; 197 extern atomic_t fscache_n_store_radix_deletes; 198 extern atomic_t fscache_n_store_pages_over_limit; 199 200 extern atomic_t fscache_n_store_vmscan_not_storing; 201 extern atomic_t fscache_n_store_vmscan_gone; 202 extern atomic_t fscache_n_store_vmscan_busy; 203 extern atomic_t fscache_n_store_vmscan_cancelled; 204 extern atomic_t fscache_n_store_vmscan_wait; 205 206 extern atomic_t fscache_n_marks; 207 extern atomic_t fscache_n_uncaches; 208 209 extern atomic_t fscache_n_acquires; 210 extern atomic_t fscache_n_acquires_null; 211 extern atomic_t fscache_n_acquires_no_cache; 212 extern atomic_t fscache_n_acquires_ok; 213 extern atomic_t fscache_n_acquires_nobufs; 214 extern atomic_t fscache_n_acquires_oom; 215 216 extern atomic_t fscache_n_invalidates; 217 extern atomic_t fscache_n_invalidates_run; 218 219 extern atomic_t fscache_n_updates; 220 extern atomic_t fscache_n_updates_null; 221 extern atomic_t fscache_n_updates_run; 222 223 extern atomic_t fscache_n_relinquishes; 224 extern atomic_t fscache_n_relinquishes_null; 225 extern atomic_t fscache_n_relinquishes_waitcrt; 226 extern atomic_t fscache_n_relinquishes_retire; 227 228 extern atomic_t fscache_n_cookie_index; 229 extern atomic_t fscache_n_cookie_data; 230 extern atomic_t fscache_n_cookie_special; 231 232 extern atomic_t fscache_n_object_alloc; 233 extern atomic_t fscache_n_object_no_alloc; 234 extern atomic_t fscache_n_object_lookups; 235 extern atomic_t fscache_n_object_lookups_negative; 236 extern atomic_t fscache_n_object_lookups_positive; 237 extern atomic_t fscache_n_object_lookups_timed_out; 238 extern atomic_t fscache_n_object_created; 239 extern atomic_t fscache_n_object_avail; 240 extern atomic_t fscache_n_object_dead; 241 242 extern atomic_t fscache_n_checkaux_none; 243 extern atomic_t fscache_n_checkaux_okay; 244 extern atomic_t fscache_n_checkaux_update; 245 extern atomic_t fscache_n_checkaux_obsolete; 246 247 extern atomic_t fscache_n_cop_alloc_object; 248 extern atomic_t fscache_n_cop_lookup_object; 249 extern atomic_t fscache_n_cop_lookup_complete; 250 extern atomic_t fscache_n_cop_grab_object; 251 extern atomic_t fscache_n_cop_invalidate_object; 252 extern atomic_t fscache_n_cop_update_object; 253 extern atomic_t fscache_n_cop_drop_object; 254 extern atomic_t fscache_n_cop_put_object; 255 extern atomic_t fscache_n_cop_sync_cache; 256 extern atomic_t fscache_n_cop_attr_changed; 257 extern atomic_t fscache_n_cop_read_or_alloc_page; 258 extern atomic_t fscache_n_cop_read_or_alloc_pages; 259 extern atomic_t fscache_n_cop_allocate_page; 260 extern atomic_t fscache_n_cop_allocate_pages; 261 extern atomic_t fscache_n_cop_write_page; 262 extern atomic_t fscache_n_cop_uncache_page; 263 extern atomic_t fscache_n_cop_dissociate_pages; 264 265 static inline void fscache_stat(atomic_t *stat) 266 { 267 atomic_inc(stat); 268 } 269 270 static inline void fscache_stat_d(atomic_t *stat) 271 { 272 atomic_dec(stat); 273 } 274 275 #define __fscache_stat(stat) (stat) 276 277 extern const struct file_operations fscache_stats_fops; 278 #else 279 280 #define __fscache_stat(stat) (NULL) 281 #define fscache_stat(stat) do {} while (0) 282 #define fscache_stat_d(stat) do {} while (0) 283 #endif 284 285 /* 286 * raise an event on an object 287 * - if the event is not masked for that object, then the object is 288 * queued for attention by the thread pool. 289 */ 290 static inline void fscache_raise_event(struct fscache_object *object, 291 unsigned event) 292 { 293 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS); 294 if (!test_and_set_bit(event, &object->events) && 295 test_bit(event, &object->event_mask)) 296 fscache_enqueue_object(object); 297 } 298 299 /* 300 * drop a reference to a cookie 301 */ 302 static inline void fscache_cookie_put(struct fscache_cookie *cookie) 303 { 304 BUG_ON(atomic_read(&cookie->usage) <= 0); 305 if (atomic_dec_and_test(&cookie->usage)) 306 __fscache_cookie_put(cookie); 307 } 308 309 /* 310 * get an extra reference to a netfs retrieval context 311 */ 312 static inline 313 void *fscache_get_context(struct fscache_cookie *cookie, void *context) 314 { 315 if (cookie->def->get_context) 316 cookie->def->get_context(cookie->netfs_data, context); 317 return context; 318 } 319 320 /* 321 * release a reference to a netfs retrieval context 322 */ 323 static inline 324 void fscache_put_context(struct fscache_cookie *cookie, void *context) 325 { 326 if (cookie->def->put_context) 327 cookie->def->put_context(cookie->netfs_data, context); 328 } 329 330 /*****************************************************************************/ 331 /* 332 * debug tracing 333 */ 334 #define dbgprintk(FMT, ...) \ 335 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 336 337 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 338 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 339 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 340 341 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 342 343 #ifdef __KDEBUG 344 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 345 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 346 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 347 348 #elif defined(CONFIG_FSCACHE_DEBUG) 349 #define _enter(FMT, ...) \ 350 do { \ 351 if (__do_kdebug(ENTER)) \ 352 kenter(FMT, ##__VA_ARGS__); \ 353 } while (0) 354 355 #define _leave(FMT, ...) \ 356 do { \ 357 if (__do_kdebug(LEAVE)) \ 358 kleave(FMT, ##__VA_ARGS__); \ 359 } while (0) 360 361 #define _debug(FMT, ...) \ 362 do { \ 363 if (__do_kdebug(DEBUG)) \ 364 kdebug(FMT, ##__VA_ARGS__); \ 365 } while (0) 366 367 #else 368 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 369 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 370 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 371 #endif 372 373 /* 374 * determine whether a particular optional debugging point should be logged 375 * - we need to go through three steps to persuade cpp to correctly join the 376 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix 377 */ 378 #define ____do_kdebug(LEVEL, POINT) \ 379 unlikely((fscache_debug & \ 380 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3)))) 381 #define ___do_kdebug(LEVEL, POINT) \ 382 ____do_kdebug(LEVEL, POINT) 383 #define __do_kdebug(POINT) \ 384 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT) 385 386 #define FSCACHE_DEBUG_CACHE 0 387 #define FSCACHE_DEBUG_COOKIE 1 388 #define FSCACHE_DEBUG_PAGE 2 389 #define FSCACHE_DEBUG_OPERATION 3 390 391 #define FSCACHE_POINT_ENTER 1 392 #define FSCACHE_POINT_LEAVE 2 393 #define FSCACHE_POINT_DEBUG 4 394 395 #ifndef FSCACHE_DEBUG_LEVEL 396 #define FSCACHE_DEBUG_LEVEL CACHE 397 #endif 398 399 /* 400 * assertions 401 */ 402 #if 1 /* defined(__KDEBUGALL) */ 403 404 #define ASSERT(X) \ 405 do { \ 406 if (unlikely(!(X))) { \ 407 printk(KERN_ERR "\n"); \ 408 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \ 409 BUG(); \ 410 } \ 411 } while (0) 412 413 #define ASSERTCMP(X, OP, Y) \ 414 do { \ 415 if (unlikely(!((X) OP (Y)))) { \ 416 printk(KERN_ERR "\n"); \ 417 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \ 418 printk(KERN_ERR "%lx " #OP " %lx is false\n", \ 419 (unsigned long)(X), (unsigned long)(Y)); \ 420 BUG(); \ 421 } \ 422 } while (0) 423 424 #define ASSERTIF(C, X) \ 425 do { \ 426 if (unlikely((C) && !(X))) { \ 427 printk(KERN_ERR "\n"); \ 428 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \ 429 BUG(); \ 430 } \ 431 } while (0) 432 433 #define ASSERTIFCMP(C, X, OP, Y) \ 434 do { \ 435 if (unlikely((C) && !((X) OP (Y)))) { \ 436 printk(KERN_ERR "\n"); \ 437 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \ 438 printk(KERN_ERR "%lx " #OP " %lx is false\n", \ 439 (unsigned long)(X), (unsigned long)(Y)); \ 440 BUG(); \ 441 } \ 442 } while (0) 443 444 #else 445 446 #define ASSERT(X) do {} while (0) 447 #define ASSERTCMP(X, OP, Y) do {} while (0) 448 #define ASSERTIF(C, X) do {} while (0) 449 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 450 451 #endif /* assert or not */ 452