1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* General netfs cache on cache files internal defs 3 * 4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #ifdef pr_fmt 9 #undef pr_fmt 10 #endif 11 12 #define pr_fmt(fmt) "CacheFiles: " fmt 13 14 15 #include <linux/fscache-cache.h> 16 #include <linux/timer.h> 17 #include <linux/wait_bit.h> 18 #include <linux/cred.h> 19 #include <linux/workqueue.h> 20 #include <linux/security.h> 21 22 struct cachefiles_cache; 23 struct cachefiles_object; 24 25 extern unsigned cachefiles_debug; 26 #define CACHEFILES_DEBUG_KENTER 1 27 #define CACHEFILES_DEBUG_KLEAVE 2 28 #define CACHEFILES_DEBUG_KDEBUG 4 29 30 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) 31 32 /* 33 * node records 34 */ 35 struct cachefiles_object { 36 struct fscache_object fscache; /* fscache handle */ 37 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 38 struct dentry *dentry; /* the file/dir representing this object */ 39 struct dentry *backer; /* backing file */ 40 loff_t i_size; /* object size */ 41 unsigned long flags; 42 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 43 atomic_t usage; /* object usage count */ 44 uint8_t type; /* object type */ 45 uint8_t new; /* T if object new */ 46 spinlock_t work_lock; 47 struct rb_node active_node; /* link in active tree (dentry is key) */ 48 }; 49 50 extern struct kmem_cache *cachefiles_object_jar; 51 52 /* 53 * Cache files cache definition 54 */ 55 struct cachefiles_cache { 56 struct fscache_cache cache; /* FS-Cache record */ 57 struct vfsmount *mnt; /* mountpoint holding the cache */ 58 struct dentry *graveyard; /* directory into which dead objects go */ 59 struct file *cachefilesd; /* manager daemon handle */ 60 const struct cred *cache_cred; /* security override for accessing cache */ 61 struct mutex daemon_mutex; /* command serialisation mutex */ 62 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 63 struct rb_root active_nodes; /* active nodes (can't be culled) */ 64 rwlock_t active_lock; /* lock for active_nodes */ 65 atomic_t gravecounter; /* graveyard uniquifier */ 66 atomic_t f_released; /* number of objects released lately */ 67 atomic_long_t b_released; /* number of blocks released lately */ 68 unsigned frun_percent; /* when to stop culling (% files) */ 69 unsigned fcull_percent; /* when to start culling (% files) */ 70 unsigned fstop_percent; /* when to stop allocating (% files) */ 71 unsigned brun_percent; /* when to stop culling (% blocks) */ 72 unsigned bcull_percent; /* when to start culling (% blocks) */ 73 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 74 unsigned bsize; /* cache's block size */ 75 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 76 uint64_t frun; /* when to stop culling */ 77 uint64_t fcull; /* when to start culling */ 78 uint64_t fstop; /* when to stop allocating */ 79 sector_t brun; /* when to stop culling */ 80 sector_t bcull; /* when to start culling */ 81 sector_t bstop; /* when to stop allocating */ 82 unsigned long flags; 83 #define CACHEFILES_READY 0 /* T if cache prepared */ 84 #define CACHEFILES_DEAD 1 /* T if cache dead */ 85 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 86 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 87 char *rootdirname; /* name of cache root directory */ 88 char *secctx; /* LSM security context */ 89 char *tag; /* cache binding tag */ 90 }; 91 92 /* 93 * backing file read tracking 94 */ 95 struct cachefiles_one_read { 96 wait_queue_entry_t monitor; /* link into monitored waitqueue */ 97 struct page *back_page; /* backing file page we're waiting for */ 98 struct page *netfs_page; /* netfs page we're going to fill */ 99 struct fscache_retrieval *op; /* retrieval op covering this */ 100 struct list_head op_link; /* link in op's todo list */ 101 }; 102 103 /* 104 * backing file write tracking 105 */ 106 struct cachefiles_one_write { 107 struct page *netfs_page; /* netfs page to copy */ 108 struct cachefiles_object *object; 109 struct list_head obj_link; /* link in object's lists */ 110 fscache_rw_complete_t end_io_func; 111 void *context; 112 }; 113 114 /* 115 * auxiliary data xattr buffer 116 */ 117 struct cachefiles_xattr { 118 uint16_t len; 119 uint8_t type; 120 uint8_t data[]; 121 }; 122 123 #include <trace/events/cachefiles.h> 124 125 /* 126 * note change of state for daemon 127 */ 128 static 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 */ 137 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 138 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 139 140 /* 141 * daemon.c 142 */ 143 extern const struct file_operations cachefiles_daemon_fops; 144 145 extern int cachefiles_has_space(struct cachefiles_cache *cache, 146 unsigned fnr, unsigned bnr); 147 148 /* 149 * interface.c 150 */ 151 extern const struct fscache_cache_ops cachefiles_cache_ops; 152 153 void cachefiles_put_object(struct fscache_object *_object, 154 enum fscache_obj_ref_trace why); 155 156 /* 157 * key.c 158 */ 159 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 160 161 /* 162 * namei.c 163 */ 164 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, 165 struct cachefiles_object *object, 166 blkcnt_t i_blocks); 167 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 168 struct cachefiles_object *object); 169 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 170 struct cachefiles_object *object, 171 const char *key, 172 struct cachefiles_xattr *auxdata); 173 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 174 struct dentry *dir, 175 const char *name); 176 177 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 178 char *filename); 179 180 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 181 struct dentry *dir, char *filename); 182 183 /* 184 * proc.c 185 */ 186 #ifdef CONFIG_CACHEFILES_HISTOGRAM 187 extern atomic_t cachefiles_lookup_histogram[HZ]; 188 extern atomic_t cachefiles_mkdir_histogram[HZ]; 189 extern atomic_t cachefiles_create_histogram[HZ]; 190 191 extern int __init cachefiles_proc_init(void); 192 extern void cachefiles_proc_cleanup(void); 193 static inline 194 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 195 { 196 unsigned long jif = jiffies - start_jif; 197 if (jif >= HZ) 198 jif = HZ - 1; 199 atomic_inc(&histogram[jif]); 200 } 201 202 #else 203 #define cachefiles_proc_init() (0) 204 #define cachefiles_proc_cleanup() do {} while (0) 205 #define cachefiles_hist(hist, start_jif) do {} while (0) 206 #endif 207 208 /* 209 * rdwr.c 210 */ 211 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 212 struct page *, gfp_t); 213 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 214 struct list_head *, unsigned *, 215 gfp_t); 216 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 217 gfp_t); 218 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 219 struct list_head *, unsigned *, gfp_t); 220 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 221 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 222 223 /* 224 * rdwr2.c 225 */ 226 extern int cachefiles_begin_read_operation(struct netfs_read_request *, 227 struct fscache_retrieval *); 228 229 /* 230 * security.c 231 */ 232 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 233 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 234 struct dentry *root, 235 const struct cred **_saved_cred); 236 237 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 238 const struct cred **_saved_cred) 239 { 240 *_saved_cred = override_creds(cache->cache_cred); 241 } 242 243 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 244 const struct cred *saved_cred) 245 { 246 revert_creds(saved_cred); 247 } 248 249 /* 250 * xattr.c 251 */ 252 extern int cachefiles_check_object_type(struct cachefiles_object *object); 253 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 254 struct cachefiles_xattr *auxdata); 255 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 256 struct cachefiles_xattr *auxdata); 257 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 258 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 259 struct cachefiles_xattr *auxdata); 260 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 261 struct dentry *dentry); 262 263 264 /* 265 * error handling 266 */ 267 268 #define cachefiles_io_error(___cache, FMT, ...) \ 269 do { \ 270 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 271 fscache_io_error(&(___cache)->cache); \ 272 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 273 } while (0) 274 275 #define cachefiles_io_error_obj(object, FMT, ...) \ 276 do { \ 277 struct cachefiles_cache *___cache; \ 278 \ 279 ___cache = container_of((object)->fscache.cache, \ 280 struct cachefiles_cache, cache); \ 281 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 282 } while (0) 283 284 285 /* 286 * debug tracing 287 */ 288 #define dbgprintk(FMT, ...) \ 289 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 290 291 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 292 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 293 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 294 295 296 #if defined(__KDEBUG) 297 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 298 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 299 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 300 301 #elif defined(CONFIG_CACHEFILES_DEBUG) 302 #define _enter(FMT, ...) \ 303 do { \ 304 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 305 kenter(FMT, ##__VA_ARGS__); \ 306 } while (0) 307 308 #define _leave(FMT, ...) \ 309 do { \ 310 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 311 kleave(FMT, ##__VA_ARGS__); \ 312 } while (0) 313 314 #define _debug(FMT, ...) \ 315 do { \ 316 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 317 kdebug(FMT, ##__VA_ARGS__); \ 318 } while (0) 319 320 #else 321 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 322 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 323 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 324 #endif 325 326 #if 1 /* defined(__KDEBUGALL) */ 327 328 #define ASSERT(X) \ 329 do { \ 330 if (unlikely(!(X))) { \ 331 pr_err("\n"); \ 332 pr_err("Assertion failed\n"); \ 333 BUG(); \ 334 } \ 335 } while (0) 336 337 #define ASSERTCMP(X, OP, Y) \ 338 do { \ 339 if (unlikely(!((X) OP (Y)))) { \ 340 pr_err("\n"); \ 341 pr_err("Assertion failed\n"); \ 342 pr_err("%lx " #OP " %lx is false\n", \ 343 (unsigned long)(X), (unsigned long)(Y)); \ 344 BUG(); \ 345 } \ 346 } while (0) 347 348 #define ASSERTIF(C, X) \ 349 do { \ 350 if (unlikely((C) && !(X))) { \ 351 pr_err("\n"); \ 352 pr_err("Assertion failed\n"); \ 353 BUG(); \ 354 } \ 355 } while (0) 356 357 #define ASSERTIFCMP(C, X, OP, Y) \ 358 do { \ 359 if (unlikely((C) && !((X) OP (Y)))) { \ 360 pr_err("\n"); \ 361 pr_err("Assertion failed\n"); \ 362 pr_err("%lx " #OP " %lx is false\n", \ 363 (unsigned long)(X), (unsigned long)(Y)); \ 364 BUG(); \ 365 } \ 366 } while (0) 367 368 #else 369 370 #define ASSERT(X) do {} while (0) 371 #define ASSERTCMP(X, OP, Y) do {} while (0) 372 #define ASSERTIF(C, X) do {} while (0) 373 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 374 375 #endif 376