fs/fscache/internal.h

   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  */
  38 extern struct list_head fscache_cache_list;
  39 extern struct rw_semaphore fscache_addremove_sem;
  40
  41 extern struct fscache_cache *fscache_select_cache_for_object(
  42         struct fscache_cookie *);
  43
  44 /*
  45  * cookie.c
  46  */
  47 extern struct kmem_cache *fscache_cookie_jar;
  48
  49 extern void fscache_free_cookie(struct fscache_cookie *);
  50 extern 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);
  55 extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
  56 extern void fscache_cookie_put(struct fscache_cookie *,
  57                                enum fscache_cookie_trace);
  58
  59 /*
  60  * fsdef.c
  61  */
  62 extern struct fscache_cookie fscache_fsdef_index;
  63 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  64
  65 /*
  66  * histogram.c
  67  */
  68 #ifdef CONFIG_FSCACHE_HISTOGRAM
  69 extern atomic_t fscache_obj_instantiate_histogram[HZ];
  70 extern atomic_t fscache_objs_histogram[HZ];
  71 extern atomic_t fscache_ops_histogram[HZ];
  72 extern atomic_t fscache_retrieval_delay_histogram[HZ];
  73 extern atomic_t fscache_retrieval_histogram[HZ];
  74
  75 static 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
  83 extern 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  */
  92 extern unsigned fscache_defer_lookup;
  93 extern unsigned fscache_defer_create;
  94 extern unsigned fscache_debug;
  95 extern struct kobject *fscache_root;
  96 extern struct workqueue_struct *fscache_object_wq;
  97 extern struct workqueue_struct *fscache_op_wq;
  98 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  99
 100 static inline bool fscache_object_congested(void)
 101 {
 102         return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
 103 }
 104
 105 /*
 106  * object.c
 107  */
 108 extern void fscache_enqueue_object(struct fscache_object *);
 109
 110 /*
 111  * object-list.c
 112  */
 113 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 114 extern const struct proc_ops fscache_objlist_proc_ops;
 115
 116 extern void fscache_objlist_add(struct fscache_object *);
 117 extern 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  */
 126 extern int fscache_submit_exclusive_op(struct fscache_object *,
 127                                        struct fscache_operation *);
 128 extern int fscache_submit_op(struct fscache_object *,
 129                              struct fscache_operation *);
 130 extern int fscache_cancel_op(struct fscache_operation *, bool);
 131 extern void fscache_cancel_all_ops(struct fscache_object *);
 132 extern void fscache_abort_object(struct fscache_object *);
 133 extern void fscache_start_operations(struct fscache_object *);
 134 extern void fscache_operation_gc(struct work_struct *);
 135
 136 /*
 137  * page.c
 138  */
 139 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
 140 extern int fscache_wait_for_operation_activation(struct fscache_object *,
 141                                                  struct fscache_operation *,
 142                                                  atomic_t *,
 143                                                  atomic_t *);
 144 extern void fscache_invalidate_writes(struct fscache_cookie *);
 145
 146 /*
 147  * proc.c
 148  */
 149 #ifdef CONFIG_PROC_FS
 150 extern int __init fscache_proc_init(void);
 151 extern 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
 161 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
 162 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
 163
 164 extern atomic_t fscache_n_op_pend;
 165 extern atomic_t fscache_n_op_run;
 166 extern atomic_t fscache_n_op_enqueue;
 167 extern atomic_t fscache_n_op_deferred_release;
 168 extern atomic_t fscache_n_op_initialised;
 169 extern atomic_t fscache_n_op_release;
 170 extern atomic_t fscache_n_op_gc;
 171 extern atomic_t fscache_n_op_cancelled;
 172 extern atomic_t fscache_n_op_rejected;
 173
 174 extern atomic_t fscache_n_attr_changed;
 175 extern atomic_t fscache_n_attr_changed_ok;
 176 extern atomic_t fscache_n_attr_changed_nobufs;
 177 extern atomic_t fscache_n_attr_changed_nomem;
 178 extern atomic_t fscache_n_attr_changed_calls;
 179
 180 extern atomic_t fscache_n_allocs;
 181 extern atomic_t fscache_n_allocs_ok;
 182 extern atomic_t fscache_n_allocs_wait;
 183 extern atomic_t fscache_n_allocs_nobufs;
 184 extern atomic_t fscache_n_allocs_intr;
 185 extern atomic_t fscache_n_allocs_object_dead;
 186 extern atomic_t fscache_n_alloc_ops;
 187 extern atomic_t fscache_n_alloc_op_waits;
 188
 189 extern atomic_t fscache_n_retrievals;
 190 extern atomic_t fscache_n_retrievals_ok;
 191 extern atomic_t fscache_n_retrievals_wait;
 192 extern atomic_t fscache_n_retrievals_nodata;
 193 extern atomic_t fscache_n_retrievals_nobufs;
 194 extern atomic_t fscache_n_retrievals_intr;
 195 extern atomic_t fscache_n_retrievals_nomem;
 196 extern atomic_t fscache_n_retrievals_object_dead;
 197 extern atomic_t fscache_n_retrieval_ops;
 198 extern atomic_t fscache_n_retrieval_op_waits;
 199
 200 extern atomic_t fscache_n_stores;
 201 extern atomic_t fscache_n_stores_ok;
 202 extern atomic_t fscache_n_stores_again;
 203 extern atomic_t fscache_n_stores_nobufs;
 204 extern atomic_t fscache_n_stores_oom;
 205 extern atomic_t fscache_n_store_ops;
 206 extern atomic_t fscache_n_store_calls;
 207 extern atomic_t fscache_n_store_pages;
 208 extern atomic_t fscache_n_store_radix_deletes;
 209 extern atomic_t fscache_n_store_pages_over_limit;
 210
 211 extern atomic_t fscache_n_store_vmscan_not_storing;
 212 extern atomic_t fscache_n_store_vmscan_gone;
 213 extern atomic_t fscache_n_store_vmscan_busy;
 214 extern atomic_t fscache_n_store_vmscan_cancelled;
 215 extern atomic_t fscache_n_store_vmscan_wait;
 216
 217 extern atomic_t fscache_n_marks;
 218 extern atomic_t fscache_n_uncaches;
 219
 220 extern atomic_t fscache_n_acquires;
 221 extern atomic_t fscache_n_acquires_null;
 222 extern atomic_t fscache_n_acquires_no_cache;
 223 extern atomic_t fscache_n_acquires_ok;
 224 extern atomic_t fscache_n_acquires_nobufs;
 225 extern atomic_t fscache_n_acquires_oom;
 226
 227 extern atomic_t fscache_n_invalidates;
 228 extern atomic_t fscache_n_invalidates_run;
 229
 230 extern atomic_t fscache_n_updates;
 231 extern atomic_t fscache_n_updates_null;
 232 extern atomic_t fscache_n_updates_run;
 233
 234 extern atomic_t fscache_n_relinquishes;
 235 extern atomic_t fscache_n_relinquishes_null;
 236 extern atomic_t fscache_n_relinquishes_waitcrt;
 237 extern atomic_t fscache_n_relinquishes_retire;
 238
 239 extern atomic_t fscache_n_cookie_index;
 240 extern atomic_t fscache_n_cookie_data;
 241 extern atomic_t fscache_n_cookie_special;
 242
 243 extern atomic_t fscache_n_object_alloc;
 244 extern atomic_t fscache_n_object_no_alloc;
 245 extern atomic_t fscache_n_object_lookups;
 246 extern atomic_t fscache_n_object_lookups_negative;
 247 extern atomic_t fscache_n_object_lookups_positive;
 248 extern atomic_t fscache_n_object_lookups_timed_out;
 249 extern atomic_t fscache_n_object_created;
 250 extern atomic_t fscache_n_object_avail;
 251 extern atomic_t fscache_n_object_dead;
 252
 253 extern atomic_t fscache_n_checkaux_none;
 254 extern atomic_t fscache_n_checkaux_okay;
 255 extern atomic_t fscache_n_checkaux_update;
 256 extern atomic_t fscache_n_checkaux_obsolete;
 257
 258 extern atomic_t fscache_n_cop_alloc_object;
 259 extern atomic_t fscache_n_cop_lookup_object;
 260 extern atomic_t fscache_n_cop_lookup_complete;
 261 extern atomic_t fscache_n_cop_grab_object;
 262 extern atomic_t fscache_n_cop_invalidate_object;
 263 extern atomic_t fscache_n_cop_update_object;
 264 extern atomic_t fscache_n_cop_drop_object;
 265 extern atomic_t fscache_n_cop_put_object;
 266 extern atomic_t fscache_n_cop_sync_cache;
 267 extern atomic_t fscache_n_cop_attr_changed;
 268 extern atomic_t fscache_n_cop_read_or_alloc_page;
 269 extern atomic_t fscache_n_cop_read_or_alloc_pages;
 270 extern atomic_t fscache_n_cop_allocate_page;
 271 extern atomic_t fscache_n_cop_allocate_pages;
 272 extern atomic_t fscache_n_cop_write_page;
 273 extern atomic_t fscache_n_cop_uncache_page;
 274 extern atomic_t fscache_n_cop_dissociate_pages;
 275
 276 extern atomic_t fscache_n_cache_no_space_reject;
 277 extern atomic_t fscache_n_cache_stale_objects;
 278 extern atomic_t fscache_n_cache_retired_objects;
 279 extern atomic_t fscache_n_cache_culled_objects;
 280
 281 static inline void fscache_stat(atomic_t *stat)
 282 {
 283         atomic_inc(stat);
 284 }
 285
 286 static inline void fscache_stat_d(atomic_t *stat)
 287 {
 288         atomic_dec(stat);
 289 }
 290
 291 #define __fscache_stat(stat) (stat)
 292
 293 int 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  */
 306 static 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
 319 static 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  */
 330 static inline
 331 void *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  */
 341 static inline
 342 void 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  */
 351 static inline
 352 void 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, ...)                        \
 389 do {                                            \
 390         if (__do_kdebug(ENTER))                 \
 391                 kenter(FMT, ##__VA_ARGS__);     \
 392 } while (0)
 393
 394 #define _leave(FMT, ...)                        \
 395 do {                                            \
 396         if (__do_kdebug(LEAVE))                 \
 397                 kleave(FMT, ##__VA_ARGS__);     \
 398 } while (0)
 399
 400 #define _debug(FMT, ...)                        \
 401 do {                                            \
 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)                                                       \
 444 do {                                                                    \
 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)                                             \
 453 do {                                                                    \
 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)                                                  \
 464 do {                                                                    \
 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)                                        \
 473 do {                                                                    \
 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 */