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;
  48
  49extern void fscache_free_cookie(struct fscache_cookie *);
  50extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
  51                                                   const struct fscache_cookie_def *,
  52                                                   const void *, size_t,
  53                                                   const void *, size_t,
  54                                                   void *, loff_t);
  55extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
  56extern void fscache_cookie_put(struct fscache_cookie *,
  57                               enum fscache_cookie_trace);
  58
  59/*
  60 * fsdef.c
  61 */
  62extern struct fscache_cookie fscache_fsdef_index;
  63extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  64
  65/*
  66 * histogram.c
  67 */
  68#ifdef CONFIG_FSCACHE_HISTOGRAM
  69extern atomic_t fscache_obj_instantiate_histogram[HZ];
  70extern atomic_t fscache_objs_histogram[HZ];
  71extern atomic_t fscache_ops_histogram[HZ];
  72extern atomic_t fscache_retrieval_delay_histogram[HZ];
  73extern atomic_t fscache_retrieval_histogram[HZ];
  74
  75static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  76{
  77        unsigned long jif = jiffies - start_jif;
  78        if (jif >= HZ)
  79                jif = HZ - 1;
  80        atomic_inc(&histogram[jif]);
  81}
  82
  83extern const struct seq_operations fscache_histogram_ops;
  84
  85#else
  86#define fscache_hist(hist, start_jif) do {} while (0)
  87#endif
  88
  89/*
  90 * main.c
  91 */
  92extern unsigned fscache_defer_lookup;
  93extern unsigned fscache_defer_create;
  94extern unsigned fscache_debug;
  95extern struct kobject *fscache_root;
  96extern struct workqueue_struct *fscache_object_wq;
  97extern struct workqueue_struct *fscache_op_wq;
  98DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  99
 100static inline bool fscache_object_congested(void)
 101{
 102        return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
 103}
 104
 105/*
 106 * object.c
 107 */
 108extern void fscache_enqueue_object(struct fscache_object *);
 109
 110/*
 111 * object-list.c
 112 */
 113#ifdef CONFIG_FSCACHE_OBJECT_LIST
 114extern const struct proc_ops fscache_objlist_proc_ops;
 115
 116extern void fscache_objlist_add(struct fscache_object *);
 117extern void fscache_objlist_remove(struct fscache_object *);
 118#else
 119#define fscache_objlist_add(object) do {} while(0)
 120#define fscache_objlist_remove(object) do {} while(0)
 121#endif
 122
 123/*
 124 * operation.c
 125 */
 126extern int fscache_submit_exclusive_op(struct fscache_object *,
 127                                       struct fscache_operation *);
 128extern int fscache_submit_op(struct fscache_object *,
 129                             struct fscache_operation *);
 130extern int fscache_cancel_op(struct fscache_operation *, bool);
 131extern void fscache_cancel_all_ops(struct fscache_object *);
 132extern void fscache_abort_object(struct fscache_object *);
 133extern void fscache_start_operations(struct fscache_object *);
 134extern void fscache_operation_gc(struct work_struct *);
 135
 136/*
 137 * page.c
 138 */
 139extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 140extern int fscache_wait_for_operation_activation(struct fscache_object *,
 141                                                 struct fscache_operation *,
 142                                                 atomic_t *,
 143                                                 atomic_t *);
 144extern void fscache_invalidate_writes(struct fscache_cookie *);
 145
 146/*
 147 * proc.c
 148 */
 149#ifdef CONFIG_PROC_FS
 150extern int __init fscache_proc_init(void);
 151extern void fscache_proc_cleanup(void);
 152#else
 153#define fscache_proc_init()     (0)
 154#define fscache_proc_cleanup()  do {} while (0)
 155#endif
 156
 157/*
 158 * stats.c
 159 */
 160#ifdef CONFIG_FSCACHE_STATS
 161extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 162extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 163
 164extern atomic_t fscache_n_op_pend;
 165extern atomic_t fscache_n_op_run;
 166extern atomic_t fscache_n_op_enqueue;
 167extern atomic_t fscache_n_op_deferred_release;
 168extern atomic_t fscache_n_op_initialised;
 169extern atomic_t fscache_n_op_release;
 170extern atomic_t fscache_n_op_gc;
 171extern atomic_t fscache_n_op_cancelled;
 172extern atomic_t fscache_n_op_rejected;
 173
 174extern atomic_t fscache_n_attr_changed;
 175extern atomic_t fscache_n_attr_changed_ok;
 176extern atomic_t fscache_n_attr_changed_nobufs;
 177extern atomic_t fscache_n_attr_changed_nomem;
 178extern atomic_t fscache_n_attr_changed_calls;
 179
 180extern atomic_t fscache_n_allocs;
 181extern atomic_t fscache_n_allocs_ok;
 182extern atomic_t fscache_n_allocs_wait;
 183extern atomic_t fscache_n_allocs_nobufs;
 184extern atomic_t fscache_n_allocs_intr;
 185extern atomic_t fscache_n_allocs_object_dead;
 186extern atomic_t fscache_n_alloc_ops;
 187extern atomic_t fscache_n_alloc_op_waits;
 188
 189extern atomic_t fscache_n_retrievals;
 190extern atomic_t fscache_n_retrievals_ok;
 191extern atomic_t fscache_n_retrievals_wait;
 192extern atomic_t fscache_n_retrievals_nodata;
 193extern atomic_t fscache_n_retrievals_nobufs;
 194extern atomic_t fscache_n_retrievals_intr;
 195extern atomic_t fscache_n_retrievals_nomem;
 196extern atomic_t fscache_n_retrievals_object_dead;
 197extern atomic_t fscache_n_retrieval_ops;
 198extern atomic_t fscache_n_retrieval_op_waits;
 199
 200extern atomic_t fscache_n_stores;
 201extern atomic_t fscache_n_stores_ok;
 202extern atomic_t fscache_n_stores_again;
 203extern atomic_t fscache_n_stores_nobufs;
 204extern atomic_t fscache_n_stores_oom;
 205extern atomic_t fscache_n_store_ops;
 206extern atomic_t fscache_n_store_calls;
 207extern atomic_t fscache_n_store_pages;
 208extern atomic_t fscache_n_store_radix_deletes;
 209extern atomic_t fscache_n_store_pages_over_limit;
 210
 211extern atomic_t fscache_n_store_vmscan_not_storing;
 212extern atomic_t fscache_n_store_vmscan_gone;
 213extern atomic_t fscache_n_store_vmscan_busy;
 214extern atomic_t fscache_n_store_vmscan_cancelled;
 215extern atomic_t fscache_n_store_vmscan_wait;
 216
 217extern atomic_t fscache_n_marks;
 218extern atomic_t fscache_n_uncaches;
 219
 220extern atomic_t fscache_n_acquires;
 221extern atomic_t fscache_n_acquires_null;
 222extern atomic_t fscache_n_acquires_no_cache;
 223extern atomic_t fscache_n_acquires_ok;
 224extern atomic_t fscache_n_acquires_nobufs;
 225extern atomic_t fscache_n_acquires_oom;
 226
 227extern atomic_t fscache_n_invalidates;
 228extern atomic_t fscache_n_invalidates_run;
 229
 230extern atomic_t fscache_n_updates;
 231extern atomic_t fscache_n_updates_null;
 232extern atomic_t fscache_n_updates_run;
 233
 234extern atomic_t fscache_n_relinquishes;
 235extern atomic_t fscache_n_relinquishes_null;
 236extern atomic_t fscache_n_relinquishes_waitcrt;
 237extern atomic_t fscache_n_relinquishes_retire;
 238
 239extern atomic_t fscache_n_cookie_index;
 240extern atomic_t fscache_n_cookie_data;
 241extern atomic_t fscache_n_cookie_special;
 242
 243extern atomic_t fscache_n_object_alloc;
 244extern atomic_t fscache_n_object_no_alloc;
 245extern atomic_t fscache_n_object_lookups;
 246extern atomic_t fscache_n_object_lookups_negative;
 247extern atomic_t fscache_n_object_lookups_positive;
 248extern atomic_t fscache_n_object_lookups_timed_out;
 249extern atomic_t fscache_n_object_created;
 250extern atomic_t fscache_n_object_avail;
 251extern atomic_t fscache_n_object_dead;
 252
 253extern atomic_t fscache_n_checkaux_none;
 254extern atomic_t fscache_n_checkaux_okay;
 255extern atomic_t fscache_n_checkaux_update;
 256extern atomic_t fscache_n_checkaux_obsolete;
 257
 258extern atomic_t fscache_n_cop_alloc_object;
 259extern atomic_t fscache_n_cop_lookup_object;
 260extern atomic_t fscache_n_cop_lookup_complete;
 261extern atomic_t fscache_n_cop_grab_object;
 262extern atomic_t fscache_n_cop_invalidate_object;
 263extern atomic_t fscache_n_cop_update_object;
 264extern atomic_t fscache_n_cop_drop_object;
 265extern atomic_t fscache_n_cop_put_object;
 266extern atomic_t fscache_n_cop_sync_cache;
 267extern atomic_t fscache_n_cop_attr_changed;
 268extern atomic_t fscache_n_cop_read_or_alloc_page;
 269extern atomic_t fscache_n_cop_read_or_alloc_pages;
 270extern atomic_t fscache_n_cop_allocate_page;
 271extern atomic_t fscache_n_cop_allocate_pages;
 272extern atomic_t fscache_n_cop_write_page;
 273extern atomic_t fscache_n_cop_uncache_page;
 274extern atomic_t fscache_n_cop_dissociate_pages;
 275
 276extern atomic_t fscache_n_cache_no_space_reject;
 277extern atomic_t fscache_n_cache_stale_objects;
 278extern atomic_t fscache_n_cache_retired_objects;
 279extern atomic_t fscache_n_cache_culled_objects;
 280
 281static inline void fscache_stat(atomic_t *stat)
 282{
 283        atomic_inc(stat);
 284}
 285
 286static inline void fscache_stat_d(atomic_t *stat)
 287{
 288        atomic_dec(stat);
 289}
 290
 291#define __fscache_stat(stat) (stat)
 292
 293int fscache_stats_show(struct seq_file *m, void *v);
 294#else
 295
 296#define __fscache_stat(stat) (NULL)
 297#define fscache_stat(stat) do {} while (0)
 298#define fscache_stat_d(stat) do {} while (0)
 299#endif
 300
 301/*
 302 * raise an event on an object
 303 * - if the event is not masked for that object, then the object is
 304 *   queued for attention by the thread pool.
 305 */
 306static inline void fscache_raise_event(struct fscache_object *object,
 307                                       unsigned event)
 308{
 309        BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
 310#if 0
 311        printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
 312               object->debug_id, object->event_mask, (1 << event));
 313#endif
 314        if (!test_and_set_bit(event, &object->events) &&
 315            test_bit(event, &object->event_mask))
 316                fscache_enqueue_object(object);
 317}
 318
 319static inline void fscache_cookie_get(struct fscache_cookie *cookie,
 320                                      enum fscache_cookie_trace where)
 321{
 322        int usage = atomic_inc_return(&cookie->usage);
 323
 324        trace_fscache_cookie(cookie, where, usage);
 325}
 326
 327/*
 328 * get an extra reference to a netfs retrieval context
 329 */
 330static inline
 331void *fscache_get_context(struct fscache_cookie *cookie, void *context)
 332{
 333        if (cookie->def->get_context)
 334                cookie->def->get_context(cookie->netfs_data, context);
 335        return context;
 336}
 337
 338/*
 339 * release a reference to a netfs retrieval context
 340 */
 341static inline
 342void fscache_put_context(struct fscache_cookie *cookie, void *context)
 343{
 344        if (cookie->def->put_context)
 345                cookie->def->put_context(cookie->netfs_data, context);
 346}
 347
 348/*
 349 * Update the auxiliary data on a cookie.
 350 */
 351static inline
 352void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
 353{
 354        void *p;
 355
 356        if (!aux_data)
 357                return;
 358        if (cookie->aux_len <= sizeof(cookie->inline_aux))
 359                p = cookie->inline_aux;
 360        else
 361                p = cookie->aux;
 362
 363        if (memcmp(p, aux_data, cookie->aux_len) != 0) {
 364                memcpy(p, aux_data, cookie->aux_len);
 365                set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
 366        }
 367}
 368
 369/*****************************************************************************/
 370/*
 371 * debug tracing
 372 */
 373#define dbgprintk(FMT, ...) \
 374        printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 375
 376#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 377#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 378#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 379
 380#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 381
 382#ifdef __KDEBUG
 383#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 384#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 385#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 386
 387#elif defined(CONFIG_FSCACHE_DEBUG)
 388#define _enter(FMT, ...)                        \
 389do {                                            \
 390        if (__do_kdebug(ENTER))                 \
 391                kenter(FMT, ##__VA_ARGS__);     \
 392} while (0)
 393
 394#define _leave(FMT, ...)                        \
 395do {                                            \
 396        if (__do_kdebug(LEAVE))                 \
 397                kleave(FMT, ##__VA_ARGS__);     \
 398} while (0)
 399
 400#define _debug(FMT, ...)                        \
 401do {                                            \
 402        if (__do_kdebug(DEBUG))                 \
 403                kdebug(FMT, ##__VA_ARGS__);     \
 404} while (0)
 405
 406#else
 407#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 408#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 409#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 410#endif
 411
 412/*
 413 * determine whether a particular optional debugging point should be logged
 414 * - we need to go through three steps to persuade cpp to correctly join the
 415 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 416 */
 417#define ____do_kdebug(LEVEL, POINT) \
 418        unlikely((fscache_debug & \
 419                  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
 420#define ___do_kdebug(LEVEL, POINT) \
 421        ____do_kdebug(LEVEL, POINT)
 422#define __do_kdebug(POINT) \
 423        ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
 424
 425#define FSCACHE_DEBUG_CACHE     0
 426#define FSCACHE_DEBUG_COOKIE    1
 427#define FSCACHE_DEBUG_PAGE      2
 428#define FSCACHE_DEBUG_OPERATION 3
 429
 430#define FSCACHE_POINT_ENTER     1
 431#define FSCACHE_POINT_LEAVE     2
 432#define FSCACHE_POINT_DEBUG     4
 433
 434#ifndef FSCACHE_DEBUG_LEVEL
 435#define FSCACHE_DEBUG_LEVEL CACHE
 436#endif
 437
 438/*
 439 * assertions
 440 */
 441#if 1 /* defined(__KDEBUGALL) */
 442
 443#define ASSERT(X)                                                       \
 444do {                                                                    \
 445        if (unlikely(!(X))) {                                           \
 446                pr_err("\n");                                   \
 447                pr_err("Assertion failed\n");   \
 448                BUG();                                                  \
 449        }                                                               \
 450} while (0)
 451
 452#define ASSERTCMP(X, OP, Y)                                             \
 453do {                                                                    \
 454        if (unlikely(!((X) OP (Y)))) {                                  \
 455                pr_err("\n");                                   \
 456                pr_err("Assertion failed\n");   \
 457                pr_err("%lx " #OP " %lx is false\n",            \
 458                       (unsigned long)(X), (unsigned long)(Y));         \
 459                BUG();                                                  \
 460        }                                                               \
 461} while (0)
 462
 463#define ASSERTIF(C, X)                                                  \
 464do {                                                                    \
 465        if (unlikely((C) && !(X))) {                                    \
 466                pr_err("\n");                                   \
 467                pr_err("Assertion failed\n");   \
 468                BUG();                                                  \
 469        }                                                               \
 470} while (0)
 471
 472#define ASSERTIFCMP(C, X, OP, Y)                                        \
 473do {                                                                    \
 474        if (unlikely((C) && !((X) OP (Y)))) {                           \
 475                pr_err("\n");                                   \
 476                pr_err("Assertion failed\n");   \
 477                pr_err("%lx " #OP " %lx is false\n",            \
 478                       (unsigned long)(X), (unsigned long)(Y));         \
 479                BUG();                                                  \
 480        }                                                               \
 481} while (0)
 482
 483#else
 484
 485#define ASSERT(X)                       do {} while (0)
 486#define ASSERTCMP(X, OP, Y)             do {} while (0)
 487#define ASSERTIF(C, X)                  do {} while (0)
 488#define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 489
 490#endif /* assert or not */
 491