linux/fs/fscache/internal.h
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   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/* Internal definitions for FS-Cache
   3 *
   4 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
   5 * Written by David Howells (dhowells@redhat.com)
   6 */
   7
   8/*
   9 * Lock order, in the order in which multiple locks should be obtained:
  10 * - fscache_addremove_sem
  11 * - cookie->lock
  12 * - cookie->parent->lock
  13 * - cache->object_list_lock
  14 * - object->lock
  15 * - object->parent->lock
  16 * - cookie->stores_lock
  17 * - fscache_thread_lock
  18 *
  19 */
  20
  21#ifdef pr_fmt
  22#undef pr_fmt
  23#endif
  24
  25#define pr_fmt(fmt) "FS-Cache: " fmt
  26
  27#include <linux/fscache-cache.h>
  28#include <trace/events/fscache.h>
  29#include <linux/sched.h>
  30#include <linux/seq_file.h>
  31
  32#define FSCACHE_MIN_THREADS     4
  33#define FSCACHE_MAX_THREADS     32
  34
  35/*
  36 * cache.c
  37 */
  38extern struct list_head fscache_cache_list;
  39extern struct rw_semaphore fscache_addremove_sem;
  40
  41extern struct fscache_cache *fscache_select_cache_for_object(
  42        struct fscache_cookie *);
  43
  44/*
  45 * cookie.c
  46 */
  47extern struct kmem_cache *fscache_cookie_jar;
  48extern const struct seq_operations fscache_cookies_seq_ops;
  49
  50extern void fscache_free_cookie(struct fscache_cookie *);
  51extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
  52                                                   const struct fscache_cookie_def *,
  53                                                   const void *, size_t,
  54                                                   const void *, size_t,
  55                                                   void *, loff_t);
  56extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
  57extern struct fscache_cookie *fscache_cookie_get(struct fscache_cookie *,
  58                                                 enum fscache_cookie_trace);
  59extern void fscache_cookie_put(struct fscache_cookie *,
  60                               enum fscache_cookie_trace);
  61
  62static inline void fscache_cookie_see(struct fscache_cookie *cookie,
  63                                      enum fscache_cookie_trace where)
  64{
  65        trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
  66                             where);
  67}
  68
  69/*
  70 * fsdef.c
  71 */
  72extern struct fscache_cookie fscache_fsdef_index;
  73extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  74
  75/*
  76 * main.c
  77 */
  78extern unsigned fscache_defer_lookup;
  79extern unsigned fscache_defer_create;
  80extern unsigned fscache_debug;
  81extern struct kobject *fscache_root;
  82extern struct workqueue_struct *fscache_object_wq;
  83extern struct workqueue_struct *fscache_op_wq;
  84DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  85
  86extern unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n);
  87
  88static inline bool fscache_object_congested(void)
  89{
  90        return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  91}
  92
  93/*
  94 * object.c
  95 */
  96extern void fscache_enqueue_object(struct fscache_object *);
  97
  98/*
  99 * operation.c
 100 */
 101extern int fscache_submit_exclusive_op(struct fscache_object *,
 102                                       struct fscache_operation *);
 103extern int fscache_submit_op(struct fscache_object *,
 104                             struct fscache_operation *);
 105extern int fscache_cancel_op(struct fscache_operation *, bool);
 106extern void fscache_cancel_all_ops(struct fscache_object *);
 107extern void fscache_abort_object(struct fscache_object *);
 108extern void fscache_start_operations(struct fscache_object *);
 109extern void fscache_operation_gc(struct work_struct *);
 110
 111/*
 112 * page.c
 113 */
 114extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 115extern int fscache_wait_for_operation_activation(struct fscache_object *,
 116                                                 struct fscache_operation *,
 117                                                 atomic_t *,
 118                                                 atomic_t *);
 119extern void fscache_invalidate_writes(struct fscache_cookie *);
 120struct fscache_retrieval *fscache_alloc_retrieval(struct fscache_cookie *cookie,
 121                                                  struct address_space *mapping,
 122                                                  fscache_rw_complete_t end_io_func,
 123                                                  void *context);
 124
 125/*
 126 * proc.c
 127 */
 128#ifdef CONFIG_PROC_FS
 129extern int __init fscache_proc_init(void);
 130extern void fscache_proc_cleanup(void);
 131#else
 132#define fscache_proc_init()     (0)
 133#define fscache_proc_cleanup()  do {} while (0)
 134#endif
 135
 136/*
 137 * stats.c
 138 */
 139#ifdef CONFIG_FSCACHE_STATS
 140extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 141extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 142
 143extern atomic_t fscache_n_op_pend;
 144extern atomic_t fscache_n_op_run;
 145extern atomic_t fscache_n_op_enqueue;
 146extern atomic_t fscache_n_op_deferred_release;
 147extern atomic_t fscache_n_op_initialised;
 148extern atomic_t fscache_n_op_release;
 149extern atomic_t fscache_n_op_gc;
 150extern atomic_t fscache_n_op_cancelled;
 151extern atomic_t fscache_n_op_rejected;
 152
 153extern atomic_t fscache_n_attr_changed;
 154extern atomic_t fscache_n_attr_changed_ok;
 155extern atomic_t fscache_n_attr_changed_nobufs;
 156extern atomic_t fscache_n_attr_changed_nomem;
 157extern atomic_t fscache_n_attr_changed_calls;
 158
 159extern atomic_t fscache_n_allocs;
 160extern atomic_t fscache_n_allocs_ok;
 161extern atomic_t fscache_n_allocs_wait;
 162extern atomic_t fscache_n_allocs_nobufs;
 163extern atomic_t fscache_n_allocs_intr;
 164extern atomic_t fscache_n_allocs_object_dead;
 165extern atomic_t fscache_n_alloc_ops;
 166extern atomic_t fscache_n_alloc_op_waits;
 167
 168extern atomic_t fscache_n_retrievals;
 169extern atomic_t fscache_n_retrievals_ok;
 170extern atomic_t fscache_n_retrievals_wait;
 171extern atomic_t fscache_n_retrievals_nodata;
 172extern atomic_t fscache_n_retrievals_nobufs;
 173extern atomic_t fscache_n_retrievals_intr;
 174extern atomic_t fscache_n_retrievals_nomem;
 175extern atomic_t fscache_n_retrievals_object_dead;
 176extern atomic_t fscache_n_retrieval_ops;
 177extern atomic_t fscache_n_retrieval_op_waits;
 178
 179extern atomic_t fscache_n_stores;
 180extern atomic_t fscache_n_stores_ok;
 181extern atomic_t fscache_n_stores_again;
 182extern atomic_t fscache_n_stores_nobufs;
 183extern atomic_t fscache_n_stores_oom;
 184extern atomic_t fscache_n_store_ops;
 185extern atomic_t fscache_n_store_calls;
 186extern atomic_t fscache_n_store_pages;
 187extern atomic_t fscache_n_store_radix_deletes;
 188extern atomic_t fscache_n_store_pages_over_limit;
 189
 190extern atomic_t fscache_n_store_vmscan_not_storing;
 191extern atomic_t fscache_n_store_vmscan_gone;
 192extern atomic_t fscache_n_store_vmscan_busy;
 193extern atomic_t fscache_n_store_vmscan_cancelled;
 194extern atomic_t fscache_n_store_vmscan_wait;
 195
 196extern atomic_t fscache_n_marks;
 197extern atomic_t fscache_n_uncaches;
 198
 199extern atomic_t fscache_n_acquires;
 200extern atomic_t fscache_n_acquires_null;
 201extern atomic_t fscache_n_acquires_no_cache;
 202extern atomic_t fscache_n_acquires_ok;
 203extern atomic_t fscache_n_acquires_nobufs;
 204extern atomic_t fscache_n_acquires_oom;
 205
 206extern atomic_t fscache_n_invalidates;
 207extern atomic_t fscache_n_invalidates_run;
 208
 209extern atomic_t fscache_n_updates;
 210extern atomic_t fscache_n_updates_null;
 211extern atomic_t fscache_n_updates_run;
 212
 213extern atomic_t fscache_n_relinquishes;
 214extern atomic_t fscache_n_relinquishes_null;
 215extern atomic_t fscache_n_relinquishes_waitcrt;
 216extern atomic_t fscache_n_relinquishes_retire;
 217
 218extern atomic_t fscache_n_cookie_index;
 219extern atomic_t fscache_n_cookie_data;
 220extern atomic_t fscache_n_cookie_special;
 221
 222extern atomic_t fscache_n_object_alloc;
 223extern atomic_t fscache_n_object_no_alloc;
 224extern atomic_t fscache_n_object_lookups;
 225extern atomic_t fscache_n_object_lookups_negative;
 226extern atomic_t fscache_n_object_lookups_positive;
 227extern atomic_t fscache_n_object_lookups_timed_out;
 228extern atomic_t fscache_n_object_created;
 229extern atomic_t fscache_n_object_avail;
 230extern atomic_t fscache_n_object_dead;
 231
 232extern atomic_t fscache_n_checkaux_none;
 233extern atomic_t fscache_n_checkaux_okay;
 234extern atomic_t fscache_n_checkaux_update;
 235extern atomic_t fscache_n_checkaux_obsolete;
 236
 237extern atomic_t fscache_n_cop_alloc_object;
 238extern atomic_t fscache_n_cop_lookup_object;
 239extern atomic_t fscache_n_cop_lookup_complete;
 240extern atomic_t fscache_n_cop_grab_object;
 241extern atomic_t fscache_n_cop_invalidate_object;
 242extern atomic_t fscache_n_cop_update_object;
 243extern atomic_t fscache_n_cop_drop_object;
 244extern atomic_t fscache_n_cop_put_object;
 245extern atomic_t fscache_n_cop_sync_cache;
 246extern atomic_t fscache_n_cop_attr_changed;
 247extern atomic_t fscache_n_cop_read_or_alloc_page;
 248extern atomic_t fscache_n_cop_read_or_alloc_pages;
 249extern atomic_t fscache_n_cop_allocate_page;
 250extern atomic_t fscache_n_cop_allocate_pages;
 251extern atomic_t fscache_n_cop_write_page;
 252extern atomic_t fscache_n_cop_uncache_page;
 253extern atomic_t fscache_n_cop_dissociate_pages;
 254
 255extern atomic_t fscache_n_cache_no_space_reject;
 256extern atomic_t fscache_n_cache_stale_objects;
 257extern atomic_t fscache_n_cache_retired_objects;
 258extern atomic_t fscache_n_cache_culled_objects;
 259
 260static inline void fscache_stat(atomic_t *stat)
 261{
 262        atomic_inc(stat);
 263}
 264
 265static inline void fscache_stat_d(atomic_t *stat)
 266{
 267        atomic_dec(stat);
 268}
 269
 270#define __fscache_stat(stat) (stat)
 271
 272int fscache_stats_show(struct seq_file *m, void *v);
 273#else
 274
 275#define __fscache_stat(stat) (NULL)
 276#define fscache_stat(stat) do {} while (0)
 277#define fscache_stat_d(stat) do {} while (0)
 278#endif
 279
 280/*
 281 * raise an event on an object
 282 * - if the event is not masked for that object, then the object is
 283 *   queued for attention by the thread pool.
 284 */
 285static inline void fscache_raise_event(struct fscache_object *object,
 286                                       unsigned event)
 287{
 288        BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 289#if 0
 290        printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 291               object->debug_id, object->event_mask, (1 << event));
 292#endif
 293        if (!test_and_set_bit(event, &object->events) &&
 294            test_bit(event, &object->event_mask))
 295                fscache_enqueue_object(object);
 296}
 297
 298/*
 299 * get an extra reference to a netfs retrieval context
 300 */
 301static inline
 302void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 303{
 304        if (cookie->def->get_context)
 305                cookie->def->get_context(cookie->netfs_data, context);
 306        return context;
 307}
 308
 309/*
 310 * release a reference to a netfs retrieval context
 311 */
 312static inline
 313void fscache_put_context(struct fscache_cookie *cookie, void *context)
 314{
 315        if (cookie->def->put_context)
 316                cookie->def->put_context(cookie->netfs_data, context);
 317}
 318
 319/*
 320 * Update the auxiliary data on a cookie.
 321 */
 322static inline
 323void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
 324{
 325        void *p;
 326
 327        if (!aux_data)
 328                return;
 329        if (cookie->aux_len <= sizeof(cookie->inline_aux))
 330                p = cookie->inline_aux;
 331        else
 332                p = cookie->aux;
 333
 334        if (memcmp(p, aux_data, cookie->aux_len) != 0) {
 335                memcpy(p, aux_data, cookie->aux_len);
 336                set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
 337        }
 338}
 339
 340/*****************************************************************************/
 341/*
 342 * debug tracing
 343 */
 344#define dbgprintk(FMT, ...) \
 345        printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 346
 347#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 348#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 349#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 350
 351#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 352
 353#ifdef __KDEBUG
 354#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 355#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 356#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 357
 358#elif defined(CONFIG_FSCACHE_DEBUG)
 359#define _enter(FMT, ...)                        \
 360do {                                            \
 361        if (__do_kdebug(ENTER))                 \
 362                kenter(FMT, ##__VA_ARGS__);     \
 363} while (0)
 364
 365#define _leave(FMT, ...)                        \
 366do {                                            \
 367        if (__do_kdebug(LEAVE))                 \
 368                kleave(FMT, ##__VA_ARGS__);     \
 369} while (0)
 370
 371#define _debug(FMT, ...)                        \
 372do {                                            \
 373        if (__do_kdebug(DEBUG))                 \
 374                kdebug(FMT, ##__VA_ARGS__);     \
 375} while (0)
 376
 377#else
 378#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 379#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 380#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 381#endif
 382
 383/*
 384 * determine whether a particular optional debugging point should be logged
 385 * - we need to go through three steps to persuade cpp to correctly join the
 386 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 387 */
 388#define ____do_kdebug(LEVEL, POINT) \
 389        unlikely((fscache_debug & \
 390                  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 391#define ___do_kdebug(LEVEL, POINT) \
 392        ____do_kdebug(LEVEL, POINT)
 393#define __do_kdebug(POINT) \
 394        ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 395
 396#define FSCACHE_DEBUG_CACHE     0
 397#define FSCACHE_DEBUG_COOKIE    1
 398#define FSCACHE_DEBUG_PAGE      2
 399#define FSCACHE_DEBUG_OPERATION 3
 400
 401#define FSCACHE_POINT_ENTER     1
 402#define FSCACHE_POINT_LEAVE     2
 403#define FSCACHE_POINT_DEBUG     4
 404
 405#ifndef FSCACHE_DEBUG_LEVEL
 406#define FSCACHE_DEBUG_LEVEL CACHE
 407#endif
 408
 409/*
 410 * assertions
 411 */
 412#if 1 /* defined(__KDEBUGALL) */
 413
 414#define ASSERT(X)                                                       \
 415do {                                                                    \
 416        if (unlikely(!(X))) {                                           \
 417                pr_err("\n");                                   \
 418                pr_err("Assertion failed\n");   \
 419                BUG();                                                  \
 420        }                                                               \
 421} while (0)
 422
 423#define ASSERTCMP(X, OP, Y)                                             \
 424do {                                                                    \
 425        if (unlikely(!((X) OP (Y)))) {                                  \
 426                pr_err("\n");                                   \
 427                pr_err("Assertion failed\n");   \
 428                pr_err("%lx " #OP " %lx is false\n",            \
 429                       (unsigned long)(X), (unsigned long)(Y));         \
 430                BUG();                                                  \
 431        }                                                               \
 432} while (0)
 433
 434#define ASSERTIF(C, X)                                                  \
 435do {                                                                    \
 436        if (unlikely((C) && !(X))) {                                    \
 437                pr_err("\n");                                   \
 438                pr_err("Assertion failed\n");   \
 439                BUG();                                                  \
 440        }                                                               \
 441} while (0)
 442
 443#define ASSERTIFCMP(C, X, OP, Y)                                        \
 444do {                                                                    \
 445        if (unlikely((C) && !((X) OP (Y)))) {                           \
 446                pr_err("\n");                                   \
 447                pr_err("Assertion failed\n");   \
 448                pr_err("%lx " #OP " %lx is false\n",            \
 449                       (unsigned long)(X), (unsigned long)(Y));         \
 450                BUG();                                                  \
 451        }                                                               \
 452} while (0)
 453
 454#else
 455
 456#define ASSERT(X)                       do {} while (0)
 457#define ASSERTCMP(X, OP, Y)             do {} while (0)
 458#define ASSERTIF(C, X)                  do {} while (0)
 459#define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 460
 461#endif /* assert or not */
 462