fs/cachefiles/internal.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /* General netfs cache on cache files internal defs
   3  *
   4  * Copyright (C) 2021 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/cred.h>
  17 #include <linux/security.h>
  18 #include <linux/xarray.h>
  19 #include <linux/cachefiles.h>
  20
  21 #define CACHEFILES_DIO_BLOCK_SIZE 4096
  22
  23 struct cachefiles_cache;
  24 struct cachefiles_object;
  25
  26 enum cachefiles_content {
  27         /* These values are saved on disk */
  28         CACHEFILES_CONTENT_NO_DATA      = 0, /* No content stored */
  29         CACHEFILES_CONTENT_SINGLE       = 1, /* Content is monolithic, all is present */
  30         CACHEFILES_CONTENT_ALL          = 2, /* Content is all present, no map */
  31         CACHEFILES_CONTENT_BACKFS_MAP   = 3, /* Content is piecemeal, mapped through backing fs */
  32         CACHEFILES_CONTENT_DIRTY        = 4, /* Content is dirty (only seen on disk) */
  33         nr__cachefiles_content
  34 };
  35
  36 /*
  37  * Cached volume representation.
  38  */
  39 struct cachefiles_volume {
  40         struct cachefiles_cache         *cache;
  41         struct list_head                cache_link;     /* Link in cache->volumes */
  42         struct fscache_volume           *vcookie;       /* The netfs's representation */
  43         struct dentry                   *dentry;        /* The volume dentry */
  44         struct dentry                   *fanout[256];   /* Fanout subdirs */
  45 };
  46
  47 /*
  48  * Backing file state.
  49  */
  50 struct cachefiles_object {
  51         struct fscache_cookie           *cookie;        /* Netfs data storage object cookie */
  52         struct cachefiles_volume        *volume;        /* Cache volume that holds this object */
  53         struct list_head                cache_link;     /* Link in cache->*_list */
  54         struct file                     *file;          /* The file representing this object */
  55         char                            *d_name;        /* Backing file name */
  56         int                             debug_id;
  57         spinlock_t                      lock;
  58         refcount_t                      ref;
  59         u8                              d_name_len;     /* Length of filename */
  60         enum cachefiles_content         content_info:8; /* Info about content presence */
  61         unsigned long                   flags;
  62 #define CACHEFILES_OBJECT_USING_TMPFILE 0               /* Have an unlinked tmpfile */
  63 #ifdef CONFIG_CACHEFILES_ONDEMAND
  64         int                             ondemand_id;
  65 #endif
  66 };
  67
  68 #define CACHEFILES_ONDEMAND_ID_CLOSED   -1
  69
  70 /*
  71  * Cache files cache definition
  72  */
  73 struct cachefiles_cache {
  74         struct fscache_cache            *cache;         /* Cache cookie */
  75         struct vfsmount                 *mnt;           /* mountpoint holding the cache */
  76         struct dentry                   *store;         /* Directory into which live objects go */
  77         struct dentry                   *graveyard;     /* directory into which dead objects go */
  78         struct file                     *cachefilesd;   /* manager daemon handle */
  79         struct list_head                volumes;        /* List of volume objects */
  80         struct list_head                object_list;    /* List of active objects */
  81         spinlock_t                      object_list_lock; /* Lock for volumes and object_list */
  82         const struct cred               *cache_cred;    /* security override for accessing cache */
  83         struct mutex                    daemon_mutex;   /* command serialisation mutex */
  84         wait_queue_head_t               daemon_pollwq;  /* poll waitqueue for daemon */
  85         atomic_t                        gravecounter;   /* graveyard uniquifier */
  86         atomic_t                        f_released;     /* number of objects released lately */
  87         atomic_long_t                   b_released;     /* number of blocks released lately */
  88         atomic_long_t                   b_writing;      /* Number of blocks being written */
  89         unsigned                        frun_percent;   /* when to stop culling (% files) */
  90         unsigned                        fcull_percent;  /* when to start culling (% files) */
  91         unsigned                        fstop_percent;  /* when to stop allocating (% files) */
  92         unsigned                        brun_percent;   /* when to stop culling (% blocks) */
  93         unsigned                        bcull_percent;  /* when to start culling (% blocks) */
  94         unsigned                        bstop_percent;  /* when to stop allocating (% blocks) */
  95         unsigned                        bsize;          /* cache's block size */
  96         unsigned                        bshift;         /* ilog2(bsize) */
  97         uint64_t                        frun;           /* when to stop culling */
  98         uint64_t                        fcull;          /* when to start culling */
  99         uint64_t                        fstop;          /* when to stop allocating */
 100         sector_t                        brun;           /* when to stop culling */
 101         sector_t                        bcull;          /* when to start culling */
 102         sector_t                        bstop;          /* when to stop allocating */
 103         unsigned long                   flags;
 104 #define CACHEFILES_READY                0       /* T if cache prepared */
 105 #define CACHEFILES_DEAD                 1       /* T if cache dead */
 106 #define CACHEFILES_CULLING              2       /* T if cull engaged */
 107 #define CACHEFILES_STATE_CHANGED        3       /* T if state changed (poll trigger) */
 108 #define CACHEFILES_ONDEMAND_MODE        4       /* T if in on-demand read mode */
 109         char                            *rootdirname;   /* name of cache root directory */
 110         char                            *secctx;        /* LSM security context */
 111         char                            *tag;           /* cache binding tag */
 112         refcount_t                      unbind_pincount;/* refcount to do daemon unbind */
 113         struct xarray                   reqs;           /* xarray of pending on-demand requests */
 114         unsigned long                   req_id_next;
 115         struct xarray                   ondemand_ids;   /* xarray for ondemand_id allocation */
 116         u32                             ondemand_id_next;
 117 };
 118
 119 static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)
 120 {
 121         return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&
 122                 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);
 123 }
 124
 125 struct cachefiles_req {
 126         struct cachefiles_object *object;
 127         struct completion done;
 128         int error;
 129         struct cachefiles_msg msg;
 130 };
 131
 132 #define CACHEFILES_REQ_NEW      XA_MARK_1
 133
 134 #include <trace/events/cachefiles.h>
 135
 136 static inline
 137 struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
 138 {
 139         return cres->cache_priv2;
 140 }
 141
 142 static inline
 143 struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
 144 {
 145         return fscache_cres_cookie(cres)->cache_priv;
 146 }
 147
 148 /*
 149  * note change of state for daemon
 150  */
 151 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
 152 {
 153         set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
 154         wake_up_all(&cache->daemon_pollwq);
 155 }
 156
 157 /*
 158  * cache.c
 159  */
 160 extern int cachefiles_add_cache(struct cachefiles_cache *cache);
 161 extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);
 162
 163 enum cachefiles_has_space_for {
 164         cachefiles_has_space_check,
 165         cachefiles_has_space_for_write,
 166         cachefiles_has_space_for_create,
 167 };
 168 extern int cachefiles_has_space(struct cachefiles_cache *cache,
 169                                 unsigned fnr, unsigned bnr,
 170                                 enum cachefiles_has_space_for reason);
 171
 172 /*
 173  * daemon.c
 174  */
 175 extern const struct file_operations cachefiles_daemon_fops;
 176 extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);
 177 extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache);
 178
 179 /*
 180  * error_inject.c
 181  */
 182 #ifdef CONFIG_CACHEFILES_ERROR_INJECTION
 183 extern unsigned int cachefiles_error_injection_state;
 184 extern int cachefiles_register_error_injection(void);
 185 extern void cachefiles_unregister_error_injection(void);
 186
 187 #else
 188 #define cachefiles_error_injection_state 0
 189
 190 static inline int cachefiles_register_error_injection(void)
 191 {
 192         return 0;
 193 }
 194
 195 static inline void cachefiles_unregister_error_injection(void)
 196 {
 197 }
 198 #endif
 199
 200
 201 static inline int cachefiles_inject_read_error(void)
 202 {
 203         return cachefiles_error_injection_state & 2 ? -EIO : 0;
 204 }
 205
 206 static inline int cachefiles_inject_write_error(void)
 207 {
 208         return cachefiles_error_injection_state & 2 ? -EIO :
 209                 cachefiles_error_injection_state & 1 ? -ENOSPC :
 210                 0;
 211 }
 212
 213 static inline int cachefiles_inject_remove_error(void)
 214 {
 215         return cachefiles_error_injection_state & 2 ? -EIO : 0;
 216 }
 217
 218 /*
 219  * interface.c
 220  */
 221 extern const struct fscache_cache_ops cachefiles_cache_ops;
 222 extern void cachefiles_see_object(struct cachefiles_object *object,
 223                                   enum cachefiles_obj_ref_trace why);
 224 extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
 225                                                         enum cachefiles_obj_ref_trace why);
 226 extern void cachefiles_put_object(struct cachefiles_object *object,
 227                                   enum cachefiles_obj_ref_trace why);
 228
 229 /*
 230  * io.c
 231  */
 232 extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
 233                                        enum fscache_want_state want_state);
 234 extern int __cachefiles_prepare_write(struct cachefiles_object *object,
 235                                       struct file *file,
 236                                       loff_t *_start, size_t *_len,
 237                                       bool no_space_allocated_yet);
 238 extern int __cachefiles_write(struct cachefiles_object *object,
 239                               struct file *file,
 240                               loff_t start_pos,
 241                               struct iov_iter *iter,
 242                               netfs_io_terminated_t term_func,
 243                               void *term_func_priv);
 244
 245 /*
 246  * key.c
 247  */
 248 extern bool cachefiles_cook_key(struct cachefiles_object *object);
 249
 250 /*
 251  * main.c
 252  */
 253 extern struct kmem_cache *cachefiles_object_jar;
 254
 255 /*
 256  * namei.c
 257  */
 258 extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
 259                                            struct file *file);
 260 extern int cachefiles_bury_object(struct cachefiles_cache *cache,
 261                                   struct cachefiles_object *object,
 262                                   struct dentry *dir,
 263                                   struct dentry *rep,
 264                                   enum fscache_why_object_killed why);
 265 extern int cachefiles_delete_object(struct cachefiles_object *object,
 266                                     enum fscache_why_object_killed why);
 267 extern bool cachefiles_look_up_object(struct cachefiles_object *object);
 268 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 269                                                struct dentry *dir,
 270                                                const char *name,
 271                                                bool *_is_new);
 272 extern void cachefiles_put_directory(struct dentry *dir);
 273
 274 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 275                            char *filename);
 276
 277 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
 278                                    struct dentry *dir, char *filename);
 279 extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
 280 extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
 281                                       struct cachefiles_object *object);
 282
 283 /*
 284  * ondemand.c
 285  */
 286 #ifdef CONFIG_CACHEFILES_ONDEMAND
 287 extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
 288                                         char __user *_buffer, size_t buflen);
 289
 290 extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
 291                                      char *args);
 292
 293 extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);
 294 extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);
 295
 296 extern int cachefiles_ondemand_read(struct cachefiles_object *object,
 297                                     loff_t pos, size_t len);
 298
 299 #else
 300 static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
 301                                         char __user *_buffer, size_t buflen)
 302 {
 303         return -EOPNOTSUPP;
 304 }
 305
 306 static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object)
 307 {
 308         return 0;
 309 }
 310
 311 static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
 312 {
 313 }
 314
 315 static inline int cachefiles_ondemand_read(struct cachefiles_object *object,
 316                                            loff_t pos, size_t len)
 317 {
 318         return -EOPNOTSUPP;
 319 }
 320 #endif
 321
 322 /*
 323  * security.c
 324  */
 325 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
 326 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
 327                                                struct dentry *root,
 328                                                const struct cred **_saved_cred);
 329
 330 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
 331                                            const struct cred **_saved_cred)
 332 {
 333         *_saved_cred = override_creds(cache->cache_cred);
 334 }
 335
 336 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
 337                                          const struct cred *saved_cred)
 338 {
 339         revert_creds(saved_cred);
 340 }
 341
 342 /*
 343  * volume.c
 344  */
 345 void cachefiles_acquire_volume(struct fscache_volume *volume);
 346 void cachefiles_free_volume(struct fscache_volume *volume);
 347 void cachefiles_withdraw_volume(struct cachefiles_volume *volume);
 348
 349 /*
 350  * xattr.c
 351  */
 352 extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
 353 extern int cachefiles_check_auxdata(struct cachefiles_object *object,
 354                                     struct file *file);
 355 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 356                                           struct cachefiles_object *object,
 357                                           struct dentry *dentry);
 358 extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
 359 extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
 360 extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);
 361
 362 /*
 363  * Error handling
 364  */
 365 #define cachefiles_io_error(___cache, FMT, ...)         \
 366 do {                                                    \
 367         pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);   \
 368         fscache_io_error((___cache)->cache);            \
 369         set_bit(CACHEFILES_DEAD, &(___cache)->flags);   \
 370 } while (0)
 371
 372 #define cachefiles_io_error_obj(object, FMT, ...)                       \
 373 do {                                                                    \
 374         struct cachefiles_cache *___cache;                              \
 375                                                                         \
 376         ___cache = (object)->volume->cache;                             \
 377         cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__,   \
 378                             (object)->debug_id);                        \
 379 } while (0)
 380
 381
 382 /*
 383  * Debug tracing
 384  */
 385 extern unsigned cachefiles_debug;
 386 #define CACHEFILES_DEBUG_KENTER 1
 387 #define CACHEFILES_DEBUG_KLEAVE 2
 388 #define CACHEFILES_DEBUG_KDEBUG 4
 389
 390 #define dbgprintk(FMT, ...) \
 391         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 392
 393 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 394 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 395 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 396
 397
 398 #if defined(__KDEBUG)
 399 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 400 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 401 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 402
 403 #elif defined(CONFIG_CACHEFILES_DEBUG)
 404 #define _enter(FMT, ...)                                \
 405 do {                                                    \
 406         if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
 407                 kenter(FMT, ##__VA_ARGS__);             \
 408 } while (0)
 409
 410 #define _leave(FMT, ...)                                \
 411 do {                                                    \
 412         if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
 413                 kleave(FMT, ##__VA_ARGS__);             \
 414 } while (0)
 415
 416 #define _debug(FMT, ...)                                \
 417 do {                                                    \
 418         if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
 419                 kdebug(FMT, ##__VA_ARGS__);             \
 420 } while (0)
 421
 422 #else
 423 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 424 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 425 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 426 #endif
 427
 428 #if 1 /* defined(__KDEBUGALL) */
 429
 430 #define ASSERT(X)                                                       \
 431 do {                                                                    \
 432         if (unlikely(!(X))) {                                           \
 433                 pr_err("\n");                                           \
 434                 pr_err("Assertion failed\n");           \
 435                 BUG();                                                  \
 436         }                                                               \
 437 } while (0)
 438
 439 #define ASSERTCMP(X, OP, Y)                                             \
 440 do {                                                                    \
 441         if (unlikely(!((X) OP (Y)))) {                                  \
 442                 pr_err("\n");                                           \
 443                 pr_err("Assertion failed\n");           \
 444                 pr_err("%lx " #OP " %lx is false\n",                    \
 445                        (unsigned long)(X), (unsigned long)(Y));         \
 446                 BUG();                                                  \
 447         }                                                               \
 448 } while (0)
 449
 450 #define ASSERTIF(C, X)                                                  \
 451 do {                                                                    \
 452         if (unlikely((C) && !(X))) {                                    \
 453                 pr_err("\n");                                           \
 454                 pr_err("Assertion failed\n");           \
 455                 BUG();                                                  \
 456         }                                                               \
 457 } while (0)
 458
 459 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 460 do {                                                                    \
 461         if (unlikely((C) && !((X) OP (Y)))) {                           \
 462                 pr_err("\n");                                           \
 463                 pr_err("Assertion failed\n");           \
 464                 pr_err("%lx " #OP " %lx is false\n",                    \
 465                        (unsigned long)(X), (unsigned long)(Y));         \
 466                 BUG();                                                  \
 467         }                                                               \
 468 } while (0)
 469
 470 #else
 471
 472 #define ASSERT(X)                       do {} while (0)
 473 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 474 #define ASSERTIF(C, X)                  do {} while (0)
 475 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 476
 477 #endif