1/* General netfs cache on cache files internal defs 2 * 3 * Copyright (C) 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 Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 12#ifdef pr_fmt 13#undef pr_fmt 14#endif 15 16#define pr_fmt(fmt) "CacheFiles: " fmt 17 18 19#include <linux/fscache-cache.h> 20#include <linux/timer.h> 21#include <linux/wait.h> 22#include <linux/workqueue.h> 23#include <linux/security.h> 24 25struct cachefiles_cache; 26struct cachefiles_object; 27 28extern unsigned cachefiles_debug; 29#define CACHEFILES_DEBUG_KENTER 1 30#define CACHEFILES_DEBUG_KLEAVE 2 31#define CACHEFILES_DEBUG_KDEBUG 4 32 33#define cachefiles_gfp (__GFP_WAIT | __GFP_NORETRY | __GFP_NOMEMALLOC) 34 35/* 36 * node records 37 */ 38struct cachefiles_object { 39 struct fscache_object fscache; /* fscache handle */ 40 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 41 struct dentry *dentry; /* the file/dir representing this object */ 42 struct dentry *backer; /* backing file */ 43 loff_t i_size; /* object size */ 44 unsigned long flags; 45#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 46#define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */ 47 atomic_t usage; /* object usage count */ 48 uint8_t type; /* object type */ 49 uint8_t new; /* T if object new */ 50 spinlock_t work_lock; 51 struct rb_node active_node; /* link in active tree (dentry is key) */ 52}; 53 54extern struct kmem_cache *cachefiles_object_jar; 55 56/* 57 * Cache files cache definition 58 */ 59struct cachefiles_cache { 60 struct fscache_cache cache; /* FS-Cache record */ 61 struct vfsmount *mnt; /* mountpoint holding the cache */ 62 struct dentry *graveyard; /* directory into which dead objects go */ 63 struct file *cachefilesd; /* manager daemon handle */ 64 const struct cred *cache_cred; /* security override for accessing cache */ 65 struct mutex daemon_mutex; /* command serialisation mutex */ 66 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 67 struct rb_root active_nodes; /* active nodes (can't be culled) */ 68 rwlock_t active_lock; /* lock for active_nodes */ 69 atomic_t gravecounter; /* graveyard uniquifier */ 70 unsigned frun_percent; /* when to stop culling (% files) */ 71 unsigned fcull_percent; /* when to start culling (% files) */ 72 unsigned fstop_percent; /* when to stop allocating (% files) */ 73 unsigned brun_percent; /* when to stop culling (% blocks) */ 74 unsigned bcull_percent; /* when to start culling (% blocks) */ 75 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 76 unsigned bsize; /* cache's block size */ 77 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 78 uint64_t frun; /* when to stop culling */ 79 uint64_t fcull; /* when to start culling */ 80 uint64_t fstop; /* when to stop allocating */ 81 sector_t brun; /* when to stop culling */ 82 sector_t bcull; /* when to start culling */ 83 sector_t bstop; /* when to stop allocating */ 84 unsigned long flags; 85#define CACHEFILES_READY 0 /* T if cache prepared */ 86#define CACHEFILES_DEAD 1 /* T if cache dead */ 87#define CACHEFILES_CULLING 2 /* T if cull engaged */ 88#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 89 char *rootdirname; /* name of cache root directory */ 90 char *secctx; /* LSM security context */ 91 char *tag; /* cache binding tag */ 92}; 93 94/* 95 * backing file read tracking 96 */ 97struct cachefiles_one_read { 98 wait_queue_t monitor; /* link into monitored waitqueue */ 99 struct page *back_page; /* backing file page we're waiting for */ 100 struct page *netfs_page; /* netfs page we're going to fill */ 101 struct fscache_retrieval *op; /* retrieval op covering this */ 102 struct list_head op_link; /* link in op's todo list */ 103}; 104 105/* 106 * backing file write tracking 107 */ 108struct cachefiles_one_write { 109 struct page *netfs_page; /* netfs page to copy */ 110 struct cachefiles_object *object; 111 struct list_head obj_link; /* link in object's lists */ 112 fscache_rw_complete_t end_io_func; 113 void *context; 114}; 115 116/* 117 * auxiliary data xattr buffer 118 */ 119struct cachefiles_xattr { 120 uint16_t len; 121 uint8_t type; 122 uint8_t data[]; 123}; 124 125/* 126 * note change of state for daemon 127 */ 128static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 129{ 130 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 131 wake_up_all(&cache->daemon_pollwq); 132} 133 134/* 135 * bind.c 136 */ 137extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 138extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 139 140/* 141 * daemon.c 142 */ 143extern const struct file_operations cachefiles_daemon_fops; 144 145extern int cachefiles_has_space(struct cachefiles_cache *cache, 146 unsigned fnr, unsigned bnr); 147 148/* 149 * interface.c 150 */ 151extern const struct fscache_cache_ops cachefiles_cache_ops; 152 153/* 154 * key.c 155 */ 156extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 157 158/* 159 * namei.c 160 */ 161extern int cachefiles_delete_object(struct cachefiles_cache *cache, 162 struct cachefiles_object *object); 163extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 164 struct cachefiles_object *object, 165 const char *key, 166 struct cachefiles_xattr *auxdata); 167extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 168 struct dentry *dir, 169 const char *name); 170 171extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 172 char *filename); 173 174extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 175 struct dentry *dir, char *filename); 176 177/* 178 * proc.c 179 */ 180#ifdef CONFIG_CACHEFILES_HISTOGRAM 181extern atomic_t cachefiles_lookup_histogram[HZ]; 182extern atomic_t cachefiles_mkdir_histogram[HZ]; 183extern atomic_t cachefiles_create_histogram[HZ]; 184 185extern int __init cachefiles_proc_init(void); 186extern void cachefiles_proc_cleanup(void); 187static inline 188void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 189{ 190 unsigned long jif = jiffies - start_jif; 191 if (jif >= HZ) 192 jif = HZ - 1; 193 atomic_inc(&histogram[jif]); 194} 195 196#else 197#define cachefiles_proc_init() (0) 198#define cachefiles_proc_cleanup() do {} while (0) 199#define cachefiles_hist(hist, start_jif) do {} while (0) 200#endif 201 202/* 203 * rdwr.c 204 */ 205extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 206 struct page *, gfp_t); 207extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 208 struct list_head *, unsigned *, 209 gfp_t); 210extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 211 gfp_t); 212extern int cachefiles_allocate_pages(struct fscache_retrieval *, 213 struct list_head *, unsigned *, gfp_t); 214extern int cachefiles_write_page(struct fscache_storage *, struct page *); 215extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 216 217/* 218 * security.c 219 */ 220extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 221extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 222 struct dentry *root, 223 const struct cred **_saved_cred); 224 225static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 226 const struct cred **_saved_cred) 227{ 228 *_saved_cred = override_creds(cache->cache_cred); 229} 230 231static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 232 const struct cred *saved_cred) 233{ 234 revert_creds(saved_cred); 235} 236 237/* 238 * xattr.c 239 */ 240extern int cachefiles_check_object_type(struct cachefiles_object *object); 241extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 242 struct cachefiles_xattr *auxdata); 243extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 244 struct cachefiles_xattr *auxdata); 245extern int cachefiles_check_auxdata(struct cachefiles_object *object); 246extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 247 struct cachefiles_xattr *auxdata); 248extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 249 struct dentry *dentry); 250 251 252/* 253 * error handling 254 */ 255 256#define cachefiles_io_error(___cache, FMT, ...) \ 257do { \ 258 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 259 fscache_io_error(&(___cache)->cache); \ 260 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 261} while (0) 262 263#define cachefiles_io_error_obj(object, FMT, ...) \ 264do { \ 265 struct cachefiles_cache *___cache; \ 266 \ 267 ___cache = container_of((object)->fscache.cache, \ 268 struct cachefiles_cache, cache); \ 269 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 270} while (0) 271 272 273/* 274 * debug tracing 275 */ 276#define dbgprintk(FMT, ...) \ 277 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 278 279#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 280#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 281#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 282 283 284#if defined(__KDEBUG) 285#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 286#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 287#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 288 289#elif defined(CONFIG_CACHEFILES_DEBUG) 290#define _enter(FMT, ...) \ 291do { \ 292 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 293 kenter(FMT, ##__VA_ARGS__); \ 294} while (0) 295 296#define _leave(FMT, ...) \ 297do { \ 298 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 299 kleave(FMT, ##__VA_ARGS__); \ 300} while (0) 301 302#define _debug(FMT, ...) \ 303do { \ 304 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 305 kdebug(FMT, ##__VA_ARGS__); \ 306} while (0) 307 308#else 309#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 310#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 311#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 312#endif 313 314#if 1 /* defined(__KDEBUGALL) */ 315 316#define ASSERT(X) \ 317do { \ 318 if (unlikely(!(X))) { \ 319 pr_err("\n"); \ 320 pr_err("Assertion failed\n"); \ 321 BUG(); \ 322 } \ 323} while (0) 324 325#define ASSERTCMP(X, OP, Y) \ 326do { \ 327 if (unlikely(!((X) OP (Y)))) { \ 328 pr_err("\n"); \ 329 pr_err("Assertion failed\n"); \ 330 pr_err("%lx " #OP " %lx is false\n", \ 331 (unsigned long)(X), (unsigned long)(Y)); \ 332 BUG(); \ 333 } \ 334} while (0) 335 336#define ASSERTIF(C, X) \ 337do { \ 338 if (unlikely((C) && !(X))) { \ 339 pr_err("\n"); \ 340 pr_err("Assertion failed\n"); \ 341 BUG(); \ 342 } \ 343} while (0) 344 345#define ASSERTIFCMP(C, X, OP, Y) \ 346do { \ 347 if (unlikely((C) && !((X) OP (Y)))) { \ 348 pr_err("\n"); \ 349 pr_err("Assertion failed\n"); \ 350 pr_err("%lx " #OP " %lx is false\n", \ 351 (unsigned long)(X), (unsigned long)(Y)); \ 352 BUG(); \ 353 } \ 354} while (0) 355 356#else 357 358#define ASSERT(X) do {} while (0) 359#define ASSERTCMP(X, OP, Y) do {} while (0) 360#define ASSERTIF(C, X) do {} while (0) 361#define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 362 363#endif 364