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