fs/fscache/internal.h

   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 #ifdef pr_fmt
  26 #undef pr_fmt
  27 #endif
  28
  29 #define pr_fmt(fmt) "FS-Cache: " fmt
  30
  31 #include <linux/fscache-cache.h>
  32 #include <linux/sched.h>
  33
  34 #define FSCACHE_MIN_THREADS     4
  35 #define FSCACHE_MAX_THREADS     32
  36
  37 /*
  38  * cache.c
  39  */
  40 extern struct list_head fscache_cache_list;
  41 extern struct rw_semaphore fscache_addremove_sem;
  42
  43 extern struct fscache_cache *fscache_select_cache_for_object(
  44         struct fscache_cookie *);
  45
  46 /*
  47  * cookie.c
  48  */
  49 extern struct kmem_cache *fscache_cookie_jar;
  50
  51 extern void fscache_cookie_init_once(void *);
  52 extern void __fscache_cookie_put(struct fscache_cookie *);
  53
  54 /*
  55  * fsdef.c
  56  */
  57 extern struct fscache_cookie fscache_fsdef_index;
  58 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  59
  60 /*
  61  * histogram.c
  62  */
  63 #ifdef CONFIG_FSCACHE_HISTOGRAM
  64 extern atomic_t fscache_obj_instantiate_histogram[HZ];
  65 extern atomic_t fscache_objs_histogram[HZ];
  66 extern atomic_t fscache_ops_histogram[HZ];
  67 extern atomic_t fscache_retrieval_delay_histogram[HZ];
  68 extern atomic_t fscache_retrieval_histogram[HZ];
  69
  70 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  71 {
  72         unsigned long jif = jiffies - start_jif;
  73         if (jif >= HZ)
  74                 jif = HZ - 1;
  75         atomic_inc(&histogram[jif]);
  76 }
  77
  78 extern const struct file_operations fscache_histogram_fops;
  79
  80 #else
  81 #define fscache_hist(hist, start_jif) do {} while (0)
  82 #endif
  83
  84 /*
  85  * main.c
  86  */
  87 extern unsigned fscache_defer_lookup;
  88 extern unsigned fscache_defer_create;
  89 extern unsigned fscache_debug;
  90 extern struct kobject *fscache_root;
  91 extern struct workqueue_struct *fscache_object_wq;
  92 extern struct workqueue_struct *fscache_op_wq;
  93 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  94
  95 static inline bool fscache_object_congested(void)
  96 {
  97         return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  98 }
  99
 100 extern int fscache_wait_atomic_t(atomic_t *);
 101
 102 /*
 103  * object.c
 104  */
 105 extern void fscache_enqueue_object(struct fscache_object *);
 106
 107 /*
 108  * object-list.c
 109  */
 110 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 111 extern const struct file_operations fscache_objlist_fops;
 112
 113 extern void fscache_objlist_add(struct fscache_object *);
 114 extern void fscache_objlist_remove(struct fscache_object *);
 115 #else
 116 #define fscache_objlist_add(object) do {} while(0)
 117 #define fscache_objlist_remove(object) do {} while(0)
 118 #endif
 119
 120 /*
 121  * operation.c
 122  */
 123 extern int fscache_submit_exclusive_op(struct fscache_object *,
 124                                        struct fscache_operation *);
 125 extern int fscache_submit_op(struct fscache_object *,
 126                              struct fscache_operation *);
 127 extern int fscache_cancel_op(struct fscache_operation *,
 128                              void (*)(struct fscache_operation *));
 129 extern void fscache_cancel_all_ops(struct fscache_object *);
 130 extern void fscache_abort_object(struct fscache_object *);
 131 extern void fscache_start_operations(struct fscache_object *);
 132 extern void fscache_operation_gc(struct work_struct *);
 133
 134 /*
 135  * page.c
 136  */
 137 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 138 extern int fscache_wait_for_operation_activation(struct fscache_object *,
 139                                                  struct fscache_operation *,
 140                                                  atomic_t *,
 141                                                  atomic_t *,
 142                                                  void (*)(struct fscache_operation *));
 143 extern void fscache_invalidate_writes(struct fscache_cookie *);
 144
 145 /*
 146  * proc.c
 147  */
 148 #ifdef CONFIG_PROC_FS
 149 extern int __init fscache_proc_init(void);
 150 extern void fscache_proc_cleanup(void);
 151 #else
 152 #define fscache_proc_init()     (0)
 153 #define fscache_proc_cleanup()  do {} while (0)
 154 #endif
 155
 156 /*
 157  * stats.c
 158  */
 159 #ifdef CONFIG_FSCACHE_STATS
 160 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 161 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 162
 163 extern atomic_t fscache_n_op_pend;
 164 extern atomic_t fscache_n_op_run;
 165 extern atomic_t fscache_n_op_enqueue;
 166 extern atomic_t fscache_n_op_deferred_release;
 167 extern atomic_t fscache_n_op_release;
 168 extern atomic_t fscache_n_op_gc;
 169 extern atomic_t fscache_n_op_cancelled;
 170 extern atomic_t fscache_n_op_rejected;
 171
 172 extern atomic_t fscache_n_attr_changed;
 173 extern atomic_t fscache_n_attr_changed_ok;
 174 extern atomic_t fscache_n_attr_changed_nobufs;
 175 extern atomic_t fscache_n_attr_changed_nomem;
 176 extern atomic_t fscache_n_attr_changed_calls;
 177
 178 extern atomic_t fscache_n_allocs;
 179 extern atomic_t fscache_n_allocs_ok;
 180 extern atomic_t fscache_n_allocs_wait;
 181 extern atomic_t fscache_n_allocs_nobufs;
 182 extern atomic_t fscache_n_allocs_intr;
 183 extern atomic_t fscache_n_allocs_object_dead;
 184 extern atomic_t fscache_n_alloc_ops;
 185 extern atomic_t fscache_n_alloc_op_waits;
 186
 187 extern atomic_t fscache_n_retrievals;
 188 extern atomic_t fscache_n_retrievals_ok;
 189 extern atomic_t fscache_n_retrievals_wait;
 190 extern atomic_t fscache_n_retrievals_nodata;
 191 extern atomic_t fscache_n_retrievals_nobufs;
 192 extern atomic_t fscache_n_retrievals_intr;
 193 extern atomic_t fscache_n_retrievals_nomem;
 194 extern atomic_t fscache_n_retrievals_object_dead;
 195 extern atomic_t fscache_n_retrieval_ops;
 196 extern atomic_t fscache_n_retrieval_op_waits;
 197
 198 extern atomic_t fscache_n_stores;
 199 extern atomic_t fscache_n_stores_ok;
 200 extern atomic_t fscache_n_stores_again;
 201 extern atomic_t fscache_n_stores_nobufs;
 202 extern atomic_t fscache_n_stores_oom;
 203 extern atomic_t fscache_n_store_ops;
 204 extern atomic_t fscache_n_store_calls;
 205 extern atomic_t fscache_n_store_pages;
 206 extern atomic_t fscache_n_store_radix_deletes;
 207 extern atomic_t fscache_n_store_pages_over_limit;
 208
 209 extern atomic_t fscache_n_store_vmscan_not_storing;
 210 extern atomic_t fscache_n_store_vmscan_gone;
 211 extern atomic_t fscache_n_store_vmscan_busy;
 212 extern atomic_t fscache_n_store_vmscan_cancelled;
 213 extern atomic_t fscache_n_store_vmscan_wait;
 214
 215 extern atomic_t fscache_n_marks;
 216 extern atomic_t fscache_n_uncaches;
 217
 218 extern atomic_t fscache_n_acquires;
 219 extern atomic_t fscache_n_acquires_null;
 220 extern atomic_t fscache_n_acquires_no_cache;
 221 extern atomic_t fscache_n_acquires_ok;
 222 extern atomic_t fscache_n_acquires_nobufs;
 223 extern atomic_t fscache_n_acquires_oom;
 224
 225 extern atomic_t fscache_n_invalidates;
 226 extern atomic_t fscache_n_invalidates_run;
 227
 228 extern atomic_t fscache_n_updates;
 229 extern atomic_t fscache_n_updates_null;
 230 extern atomic_t fscache_n_updates_run;
 231
 232 extern atomic_t fscache_n_relinquishes;
 233 extern atomic_t fscache_n_relinquishes_null;
 234 extern atomic_t fscache_n_relinquishes_waitcrt;
 235 extern atomic_t fscache_n_relinquishes_retire;
 236
 237 extern atomic_t fscache_n_cookie_index;
 238 extern atomic_t fscache_n_cookie_data;
 239 extern atomic_t fscache_n_cookie_special;
 240
 241 extern atomic_t fscache_n_object_alloc;
 242 extern atomic_t fscache_n_object_no_alloc;
 243 extern atomic_t fscache_n_object_lookups;
 244 extern atomic_t fscache_n_object_lookups_negative;
 245 extern atomic_t fscache_n_object_lookups_positive;
 246 extern atomic_t fscache_n_object_lookups_timed_out;
 247 extern atomic_t fscache_n_object_created;
 248 extern atomic_t fscache_n_object_avail;
 249 extern atomic_t fscache_n_object_dead;
 250
 251 extern atomic_t fscache_n_checkaux_none;
 252 extern atomic_t fscache_n_checkaux_okay;
 253 extern atomic_t fscache_n_checkaux_update;
 254 extern atomic_t fscache_n_checkaux_obsolete;
 255
 256 extern atomic_t fscache_n_cop_alloc_object;
 257 extern atomic_t fscache_n_cop_lookup_object;
 258 extern atomic_t fscache_n_cop_lookup_complete;
 259 extern atomic_t fscache_n_cop_grab_object;
 260 extern atomic_t fscache_n_cop_invalidate_object;
 261 extern atomic_t fscache_n_cop_update_object;
 262 extern atomic_t fscache_n_cop_drop_object;
 263 extern atomic_t fscache_n_cop_put_object;
 264 extern atomic_t fscache_n_cop_sync_cache;
 265 extern atomic_t fscache_n_cop_attr_changed;
 266 extern atomic_t fscache_n_cop_read_or_alloc_page;
 267 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 268 extern atomic_t fscache_n_cop_allocate_page;
 269 extern atomic_t fscache_n_cop_allocate_pages;
 270 extern atomic_t fscache_n_cop_write_page;
 271 extern atomic_t fscache_n_cop_uncache_page;
 272 extern atomic_t fscache_n_cop_dissociate_pages;
 273
 274 static inline void fscache_stat(atomic_t *stat)
 275 {
 276         atomic_inc(stat);
 277 }
 278
 279 static inline void fscache_stat_d(atomic_t *stat)
 280 {
 281         atomic_dec(stat);
 282 }
 283
 284 #define __fscache_stat(stat) (stat)
 285
 286 extern const struct file_operations fscache_stats_fops;
 287 #else
 288
 289 #define __fscache_stat(stat) (NULL)
 290 #define fscache_stat(stat) do {} while (0)
 291 #define fscache_stat_d(stat) do {} while (0)
 292 #endif
 293
 294 /*
 295  * raise an event on an object
 296  * - if the event is not masked for that object, then the object is
 297  *   queued for attention by the thread pool.
 298  */
 299 static inline void fscache_raise_event(struct fscache_object *object,
 300                                        unsigned event)
 301 {
 302         BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 303 #if 0
 304         printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 305                object->debug_id, object->event_mask, (1 << event));
 306 #endif
 307         if (!test_and_set_bit(event, &object->events) &&
 308             test_bit(event, &object->event_mask))
 309                 fscache_enqueue_object(object);
 310 }
 311
 312 /*
 313  * drop a reference to a cookie
 314  */
 315 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 316 {
 317         BUG_ON(atomic_read(&cookie->usage) <= 0);
 318         if (atomic_dec_and_test(&cookie->usage))
 319                 __fscache_cookie_put(cookie);
 320 }
 321
 322 /*
 323  * get an extra reference to a netfs retrieval context
 324  */
 325 static inline
 326 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 327 {
 328         if (cookie->def->get_context)
 329                 cookie->def->get_context(cookie->netfs_data, context);
 330         return context;
 331 }
 332
 333 /*
 334  * release a reference to a netfs retrieval context
 335  */
 336 static inline
 337 void fscache_put_context(struct fscache_cookie *cookie, void *context)
 338 {
 339         if (cookie->def->put_context)
 340                 cookie->def->put_context(cookie->netfs_data, context);
 341 }
 342
 343 /*****************************************************************************/
 344 /*
 345  * debug tracing
 346  */
 347 #define dbgprintk(FMT, ...) \
 348         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 349
 350 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 351 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 352 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 353
 354 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 355
 356 #ifdef __KDEBUG
 357 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 358 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 359 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 360
 361 #elif defined(CONFIG_FSCACHE_DEBUG)
 362 #define _enter(FMT, ...)                        \
 363 do {                                            \
 364         if (__do_kdebug(ENTER))                 \
 365                 kenter(FMT, ##__VA_ARGS__);     \
 366 } while (0)
 367
 368 #define _leave(FMT, ...)                        \
 369 do {                                            \
 370         if (__do_kdebug(LEAVE))                 \
 371                 kleave(FMT, ##__VA_ARGS__);     \
 372 } while (0)
 373
 374 #define _debug(FMT, ...)                        \
 375 do {                                            \
 376         if (__do_kdebug(DEBUG))                 \
 377                 kdebug(FMT, ##__VA_ARGS__);     \
 378 } while (0)
 379
 380 #else
 381 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 382 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 383 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 384 #endif
 385
 386 /*
 387  * determine whether a particular optional debugging point should be logged
 388  * - we need to go through three steps to persuade cpp to correctly join the
 389  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 390  */
 391 #define ____do_kdebug(LEVEL, POINT) \
 392         unlikely((fscache_debug & \
 393                   (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 394 #define ___do_kdebug(LEVEL, POINT) \
 395         ____do_kdebug(LEVEL, POINT)
 396 #define __do_kdebug(POINT) \
 397         ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 398
 399 #define FSCACHE_DEBUG_CACHE     0
 400 #define FSCACHE_DEBUG_COOKIE    1
 401 #define FSCACHE_DEBUG_PAGE      2
 402 #define FSCACHE_DEBUG_OPERATION 3
 403
 404 #define FSCACHE_POINT_ENTER     1
 405 #define FSCACHE_POINT_LEAVE     2
 406 #define FSCACHE_POINT_DEBUG     4
 407
 408 #ifndef FSCACHE_DEBUG_LEVEL
 409 #define FSCACHE_DEBUG_LEVEL CACHE
 410 #endif
 411
 412 /*
 413  * assertions
 414  */
 415 #if 1 /* defined(__KDEBUGALL) */
 416
 417 #define ASSERT(X)                                                       \
 418 do {                                                                    \
 419         if (unlikely(!(X))) {                                           \
 420                 pr_err("\n");                                   \
 421                 pr_err("Assertion failed\n");   \
 422                 BUG();                                                  \
 423         }                                                               \
 424 } while (0)
 425
 426 #define ASSERTCMP(X, OP, Y)                                             \
 427 do {                                                                    \
 428         if (unlikely(!((X) OP (Y)))) {                                  \
 429                 pr_err("\n");                                   \
 430                 pr_err("Assertion failed\n");   \
 431                 pr_err("%lx " #OP " %lx is false\n",            \
 432                        (unsigned long)(X), (unsigned long)(Y));         \
 433                 BUG();                                                  \
 434         }                                                               \
 435 } while (0)
 436
 437 #define ASSERTIF(C, X)                                                  \
 438 do {                                                                    \
 439         if (unlikely((C) && !(X))) {                                    \
 440                 pr_err("\n");                                   \
 441                 pr_err("Assertion failed\n");   \
 442                 BUG();                                                  \
 443         }                                                               \
 444 } while (0)
 445
 446 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 447 do {                                                                    \
 448         if (unlikely((C) && !((X) OP (Y)))) {                           \
 449                 pr_err("\n");                                   \
 450                 pr_err("Assertion failed\n");   \
 451                 pr_err("%lx " #OP " %lx is false\n",            \
 452                        (unsigned long)(X), (unsigned long)(Y));         \
 453                 BUG();                                                  \
 454         }                                                               \
 455 } while (0)
 456
 457 #else
 458
 459 #define ASSERT(X)                       do {} while (0)
 460 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 461 #define ASSERTIF(C, X)                  do {} while (0)
 462 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 463
 464 #endif /* assert or not */