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