linux/fs/fscache/internal.h
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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/*
  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 */
  40extern struct list_head fscache_cache_list;
  41extern struct rw_semaphore fscache_addremove_sem;
  42
  43extern struct fscache_cache *fscache_select_cache_for_object(
  44        struct fscache_cookie *);
  45
  46/*
  47 * cookie.c
  48 */
  49extern struct kmem_cache *fscache_cookie_jar;
  50
  51extern void fscache_cookie_init_once(void *);
  52extern void __fscache_cookie_put(struct fscache_cookie *);
  53
  54/*
  55 * fsdef.c
  56 */
  57extern struct fscache_cookie fscache_fsdef_index;
  58extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  59
  60/*
  61 * histogram.c
  62 */
  63#ifdef CONFIG_FSCACHE_HISTOGRAM
  64extern atomic_t fscache_obj_instantiate_histogram[HZ];
  65extern atomic_t fscache_objs_histogram[HZ];
  66extern atomic_t fscache_ops_histogram[HZ];
  67extern atomic_t fscache_retrieval_delay_histogram[HZ];
  68extern atomic_t fscache_retrieval_histogram[HZ];
  69
  70static 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
  78extern 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 */
  87extern unsigned fscache_defer_lookup;
  88extern unsigned fscache_defer_create;
  89extern unsigned fscache_debug;
  90extern struct kobject *fscache_root;
  91extern struct workqueue_struct *fscache_object_wq;
  92extern struct workqueue_struct *fscache_op_wq;
  93DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  94
  95static inline bool fscache_object_congested(void)
  96{
  97        return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  98}
  99
 100extern int fscache_wait_atomic_t(atomic_t *);
 101
 102/*
 103 * object.c
 104 */
 105extern void fscache_enqueue_object(struct fscache_object *);
 106
 107/*
 108 * object-list.c
 109 */
 110#ifdef CONFIG_FSCACHE_OBJECT_LIST
 111extern const struct file_operations fscache_objlist_fops;
 112
 113extern void fscache_objlist_add(struct fscache_object *);
 114extern 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 */
 123extern int fscache_submit_exclusive_op(struct fscache_object *,
 124                                       struct fscache_operation *);
 125extern int fscache_submit_op(struct fscache_object *,
 126                             struct fscache_operation *);
 127extern int fscache_cancel_op(struct fscache_operation *, bool);
 128extern void fscache_cancel_all_ops(struct fscache_object *);
 129extern void fscache_abort_object(struct fscache_object *);
 130extern void fscache_start_operations(struct fscache_object *);
 131extern void fscache_operation_gc(struct work_struct *);
 132
 133/*
 134 * page.c
 135 */
 136extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 137extern int fscache_wait_for_operation_activation(struct fscache_object *,
 138                                                 struct fscache_operation *,
 139                                                 atomic_t *,
 140                                                 atomic_t *);
 141extern void fscache_invalidate_writes(struct fscache_cookie *);
 142
 143/*
 144 * proc.c
 145 */
 146#ifdef CONFIG_PROC_FS
 147extern int __init fscache_proc_init(void);
 148extern void fscache_proc_cleanup(void);
 149#else
 150#define fscache_proc_init()     (0)
 151#define fscache_proc_cleanup()  do {} while (0)
 152#endif
 153
 154/*
 155 * stats.c
 156 */
 157#ifdef CONFIG_FSCACHE_STATS
 158extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 159extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 160
 161extern atomic_t fscache_n_op_pend;
 162extern atomic_t fscache_n_op_run;
 163extern atomic_t fscache_n_op_enqueue;
 164extern atomic_t fscache_n_op_deferred_release;
 165extern atomic_t fscache_n_op_initialised;
 166extern atomic_t fscache_n_op_release;
 167extern atomic_t fscache_n_op_gc;
 168extern atomic_t fscache_n_op_cancelled;
 169extern atomic_t fscache_n_op_rejected;
 170
 171extern atomic_t fscache_n_attr_changed;
 172extern atomic_t fscache_n_attr_changed_ok;
 173extern atomic_t fscache_n_attr_changed_nobufs;
 174extern atomic_t fscache_n_attr_changed_nomem;
 175extern atomic_t fscache_n_attr_changed_calls;
 176
 177extern atomic_t fscache_n_allocs;
 178extern atomic_t fscache_n_allocs_ok;
 179extern atomic_t fscache_n_allocs_wait;
 180extern atomic_t fscache_n_allocs_nobufs;
 181extern atomic_t fscache_n_allocs_intr;
 182extern atomic_t fscache_n_allocs_object_dead;
 183extern atomic_t fscache_n_alloc_ops;
 184extern atomic_t fscache_n_alloc_op_waits;
 185
 186extern atomic_t fscache_n_retrievals;
 187extern atomic_t fscache_n_retrievals_ok;
 188extern atomic_t fscache_n_retrievals_wait;
 189extern atomic_t fscache_n_retrievals_nodata;
 190extern atomic_t fscache_n_retrievals_nobufs;
 191extern atomic_t fscache_n_retrievals_intr;
 192extern atomic_t fscache_n_retrievals_nomem;
 193extern atomic_t fscache_n_retrievals_object_dead;
 194extern atomic_t fscache_n_retrieval_ops;
 195extern atomic_t fscache_n_retrieval_op_waits;
 196
 197extern atomic_t fscache_n_stores;
 198extern atomic_t fscache_n_stores_ok;
 199extern atomic_t fscache_n_stores_again;
 200extern atomic_t fscache_n_stores_nobufs;
 201extern atomic_t fscache_n_stores_oom;
 202extern atomic_t fscache_n_store_ops;
 203extern atomic_t fscache_n_store_calls;
 204extern atomic_t fscache_n_store_pages;
 205extern atomic_t fscache_n_store_radix_deletes;
 206extern atomic_t fscache_n_store_pages_over_limit;
 207
 208extern atomic_t fscache_n_store_vmscan_not_storing;
 209extern atomic_t fscache_n_store_vmscan_gone;
 210extern atomic_t fscache_n_store_vmscan_busy;
 211extern atomic_t fscache_n_store_vmscan_cancelled;
 212extern atomic_t fscache_n_store_vmscan_wait;
 213
 214extern atomic_t fscache_n_marks;
 215extern atomic_t fscache_n_uncaches;
 216
 217extern atomic_t fscache_n_acquires;
 218extern atomic_t fscache_n_acquires_null;
 219extern atomic_t fscache_n_acquires_no_cache;
 220extern atomic_t fscache_n_acquires_ok;
 221extern atomic_t fscache_n_acquires_nobufs;
 222extern atomic_t fscache_n_acquires_oom;
 223
 224extern atomic_t fscache_n_invalidates;
 225extern atomic_t fscache_n_invalidates_run;
 226
 227extern atomic_t fscache_n_updates;
 228extern atomic_t fscache_n_updates_null;
 229extern atomic_t fscache_n_updates_run;
 230
 231extern atomic_t fscache_n_relinquishes;
 232extern atomic_t fscache_n_relinquishes_null;
 233extern atomic_t fscache_n_relinquishes_waitcrt;
 234extern atomic_t fscache_n_relinquishes_retire;
 235
 236extern atomic_t fscache_n_cookie_index;
 237extern atomic_t fscache_n_cookie_data;
 238extern atomic_t fscache_n_cookie_special;
 239
 240extern atomic_t fscache_n_object_alloc;
 241extern atomic_t fscache_n_object_no_alloc;
 242extern atomic_t fscache_n_object_lookups;
 243extern atomic_t fscache_n_object_lookups_negative;
 244extern atomic_t fscache_n_object_lookups_positive;
 245extern atomic_t fscache_n_object_lookups_timed_out;
 246extern atomic_t fscache_n_object_created;
 247extern atomic_t fscache_n_object_avail;
 248extern atomic_t fscache_n_object_dead;
 249
 250extern atomic_t fscache_n_checkaux_none;
 251extern atomic_t fscache_n_checkaux_okay;
 252extern atomic_t fscache_n_checkaux_update;
 253extern atomic_t fscache_n_checkaux_obsolete;
 254
 255extern atomic_t fscache_n_cop_alloc_object;
 256extern atomic_t fscache_n_cop_lookup_object;
 257extern atomic_t fscache_n_cop_lookup_complete;
 258extern atomic_t fscache_n_cop_grab_object;
 259extern atomic_t fscache_n_cop_invalidate_object;
 260extern atomic_t fscache_n_cop_update_object;
 261extern atomic_t fscache_n_cop_drop_object;
 262extern atomic_t fscache_n_cop_put_object;
 263extern atomic_t fscache_n_cop_sync_cache;
 264extern atomic_t fscache_n_cop_attr_changed;
 265extern atomic_t fscache_n_cop_read_or_alloc_page;
 266extern atomic_t fscache_n_cop_read_or_alloc_pages;
 267extern atomic_t fscache_n_cop_allocate_page;
 268extern atomic_t fscache_n_cop_allocate_pages;
 269extern atomic_t fscache_n_cop_write_page;
 270extern atomic_t fscache_n_cop_uncache_page;
 271extern atomic_t fscache_n_cop_dissociate_pages;
 272
 273extern atomic_t fscache_n_cache_no_space_reject;
 274extern atomic_t fscache_n_cache_stale_objects;
 275extern atomic_t fscache_n_cache_retired_objects;
 276extern atomic_t fscache_n_cache_culled_objects;
 277
 278static inline void fscache_stat(atomic_t *stat)
 279{
 280        atomic_inc(stat);
 281}
 282
 283static inline void fscache_stat_d(atomic_t *stat)
 284{
 285        atomic_dec(stat);
 286}
 287
 288#define __fscache_stat(stat) (stat)
 289
 290extern const struct file_operations fscache_stats_fops;
 291#else
 292
 293#define __fscache_stat(stat) (NULL)
 294#define fscache_stat(stat) do {} while (0)
 295#define fscache_stat_d(stat) do {} while (0)
 296#endif
 297
 298/*
 299 * raise an event on an object
 300 * - if the event is not masked for that object, then the object is
 301 *   queued for attention by the thread pool.
 302 */
 303static inline void fscache_raise_event(struct fscache_object *object,
 304                                       unsigned event)
 305{
 306        BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 307#if 0
 308        printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 309               object->debug_id, object->event_mask, (1 << event));
 310#endif
 311        if (!test_and_set_bit(event, &object->events) &&
 312            test_bit(event, &object->event_mask))
 313                fscache_enqueue_object(object);
 314}
 315
 316/*
 317 * drop a reference to a cookie
 318 */
 319static inline void fscache_cookie_put(struct fscache_cookie *cookie)
 320{
 321        BUG_ON(atomic_read(&cookie->usage) <= 0);
 322        if (atomic_dec_and_test(&cookie->usage))
 323                __fscache_cookie_put(cookie);
 324}
 325
 326/*
 327 * get an extra reference to a netfs retrieval context
 328 */
 329static inline
 330void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 331{
 332        if (cookie->def->get_context)
 333                cookie->def->get_context(cookie->netfs_data, context);
 334        return context;
 335}
 336
 337/*
 338 * release a reference to a netfs retrieval context
 339 */
 340static inline
 341void fscache_put_context(struct fscache_cookie *cookie, void *context)
 342{
 343        if (cookie->def->put_context)
 344                cookie->def->put_context(cookie->netfs_data, context);
 345}
 346
 347/*****************************************************************************/
 348/*
 349 * debug tracing
 350 */
 351#define dbgprintk(FMT, ...) \
 352        printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 353
 354#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 355#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 356#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 357
 358#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 359
 360#ifdef __KDEBUG
 361#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 362#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 363#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 364
 365#elif defined(CONFIG_FSCACHE_DEBUG)
 366#define _enter(FMT, ...)                        \
 367do {                                            \
 368        if (__do_kdebug(ENTER))                 \
 369                kenter(FMT, ##__VA_ARGS__);     \
 370} while (0)
 371
 372#define _leave(FMT, ...)                        \
 373do {                                            \
 374        if (__do_kdebug(LEAVE))                 \
 375                kleave(FMT, ##__VA_ARGS__);     \
 376} while (0)
 377
 378#define _debug(FMT, ...)                        \
 379do {                                            \
 380        if (__do_kdebug(DEBUG))                 \
 381                kdebug(FMT, ##__VA_ARGS__);     \
 382} while (0)
 383
 384#else
 385#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 386#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 387#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 388#endif
 389
 390/*
 391 * determine whether a particular optional debugging point should be logged
 392 * - we need to go through three steps to persuade cpp to correctly join the
 393 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 394 */
 395#define ____do_kdebug(LEVEL, POINT) \
 396        unlikely((fscache_debug & \
 397                  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 398#define ___do_kdebug(LEVEL, POINT) \
 399        ____do_kdebug(LEVEL, POINT)
 400#define __do_kdebug(POINT) \
 401        ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 402
 403#define FSCACHE_DEBUG_CACHE     0
 404#define FSCACHE_DEBUG_COOKIE    1
 405#define FSCACHE_DEBUG_PAGE      2
 406#define FSCACHE_DEBUG_OPERATION 3
 407
 408#define FSCACHE_POINT_ENTER     1
 409#define FSCACHE_POINT_LEAVE     2
 410#define FSCACHE_POINT_DEBUG     4
 411
 412#ifndef FSCACHE_DEBUG_LEVEL
 413#define FSCACHE_DEBUG_LEVEL CACHE
 414#endif
 415
 416/*
 417 * assertions
 418 */
 419#if 1 /* defined(__KDEBUGALL) */
 420
 421#define ASSERT(X)                                                       \
 422do {                                                                    \
 423        if (unlikely(!(X))) {                                           \
 424                pr_err("\n");                                   \
 425                pr_err("Assertion failed\n");   \
 426                BUG();                                                  \
 427        }                                                               \
 428} while (0)
 429
 430#define ASSERTCMP(X, OP, Y)                                             \
 431do {                                                                    \
 432        if (unlikely(!((X) OP (Y)))) {                                  \
 433                pr_err("\n");                                   \
 434                pr_err("Assertion failed\n");   \
 435                pr_err("%lx " #OP " %lx is false\n",            \
 436                       (unsigned long)(X), (unsigned long)(Y));         \
 437                BUG();                                                  \
 438        }                                                               \
 439} while (0)
 440
 441#define ASSERTIF(C, X)                                                  \
 442do {                                                                    \
 443        if (unlikely((C) && !(X))) {                                    \
 444                pr_err("\n");                                   \
 445                pr_err("Assertion failed\n");   \
 446                BUG();                                                  \
 447        }                                                               \
 448} while (0)
 449
 450#define ASSERTIFCMP(C, X, OP, Y)                                        \
 451do {                                                                    \
 452        if (unlikely((C) && !((X) OP (Y)))) {                           \
 453                pr_err("\n");                                   \
 454                pr_err("Assertion failed\n");   \
 455                pr_err("%lx " #OP " %lx is false\n",            \
 456                       (unsigned long)(X), (unsigned long)(Y));         \
 457                BUG();                                                  \
 458        }                                                               \
 459} while (0)
 460
 461#else
 462
 463#define ASSERT(X)                       do {} while (0)
 464#define ASSERTCMP(X, OP, Y)             do {} while (0)
 465#define ASSERTIF(C, X)                  do {} while (0)
 466#define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 467
 468#endif /* assert or not */
 469