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) 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