fs/cachefiles/internal.h

   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_bit.h>
  22 #include <linux/cred.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/security.h>
  25
  26 struct cachefiles_cache;
  27 struct cachefiles_object;
  28
  29 extern unsigned cachefiles_debug;
  30 #define CACHEFILES_DEBUG_KENTER 1
  31 #define CACHEFILES_DEBUG_KLEAVE 2
  32 #define CACHEFILES_DEBUG_KDEBUG 4
  33
  34 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
  35
  36 /*
  37  * node records
  38  */
  39 struct cachefiles_object {
  40         struct fscache_object           fscache;        /* fscache handle */
  41         struct cachefiles_lookup_data   *lookup_data;   /* cached lookup data */
  42         struct dentry                   *dentry;        /* the file/dir representing this object */
  43         struct dentry                   *backer;        /* backing file */
  44         loff_t                          i_size;         /* object size */
  45         unsigned long                   flags;
  46 #define CACHEFILES_OBJECT_ACTIVE        0               /* T if marked active */
  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
  54 extern struct kmem_cache *cachefiles_object_jar;
  55
  56 /*
  57  * Cache files cache definition
  58  */
  59 struct 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         atomic_t                        f_released;     /* number of objects released lately */
  71         atomic_long_t                   b_released;     /* number of blocks released lately */
  72         unsigned                        frun_percent;   /* when to stop culling (% files) */
  73         unsigned                        fcull_percent;  /* when to start culling (% files) */
  74         unsigned                        fstop_percent;  /* when to stop allocating (% files) */
  75         unsigned                        brun_percent;   /* when to stop culling (% blocks) */
  76         unsigned                        bcull_percent;  /* when to start culling (% blocks) */
  77         unsigned                        bstop_percent;  /* when to stop allocating (% blocks) */
  78         unsigned                        bsize;          /* cache's block size */
  79         unsigned                        bshift;         /* min(ilog2(PAGE_SIZE / bsize), 0) */
  80         uint64_t                        frun;           /* when to stop culling */
  81         uint64_t                        fcull;          /* when to start culling */
  82         uint64_t                        fstop;          /* when to stop allocating */
  83         sector_t                        brun;           /* when to stop culling */
  84         sector_t                        bcull;          /* when to start culling */
  85         sector_t                        bstop;          /* when to stop allocating */
  86         unsigned long                   flags;
  87 #define CACHEFILES_READY                0       /* T if cache prepared */
  88 #define CACHEFILES_DEAD                 1       /* T if cache dead */
  89 #define CACHEFILES_CULLING              2       /* T if cull engaged */
  90 #define CACHEFILES_STATE_CHANGED        3       /* T if state changed (poll trigger) */
  91         char                            *rootdirname;   /* name of cache root directory */
  92         char                            *secctx;        /* LSM security context */
  93         char                            *tag;           /* cache binding tag */
  94 };
  95
  96 /*
  97  * backing file read tracking
  98  */
  99 struct cachefiles_one_read {
 100         wait_queue_entry_t                      monitor;        /* link into monitored waitqueue */
 101         struct page                     *back_page;     /* backing file page we're waiting for */
 102         struct page                     *netfs_page;    /* netfs page we're going to fill */
 103         struct fscache_retrieval        *op;            /* retrieval op covering this */
 104         struct list_head                op_link;        /* link in op's todo list */
 105 };
 106
 107 /*
 108  * backing file write tracking
 109  */
 110 struct cachefiles_one_write {
 111         struct page                     *netfs_page;    /* netfs page to copy */
 112         struct cachefiles_object        *object;
 113         struct list_head                obj_link;       /* link in object's lists */
 114         fscache_rw_complete_t           end_io_func;
 115         void                            *context;
 116 };
 117
 118 /*
 119  * auxiliary data xattr buffer
 120  */
 121 struct cachefiles_xattr {
 122         uint16_t                        len;
 123         uint8_t                         type;
 124         uint8_t                         data[];
 125 };
 126
 127 #include <trace/events/cachefiles.h>
 128
 129 /*
 130  * note change of state for daemon
 131  */
 132 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
 133 {
 134         set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
 135         wake_up_all(&cache->daemon_pollwq);
 136 }
 137
 138 /*
 139  * bind.c
 140  */
 141 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
 142 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
 143
 144 /*
 145  * daemon.c
 146  */
 147 extern const struct file_operations cachefiles_daemon_fops;
 148
 149 extern int cachefiles_has_space(struct cachefiles_cache *cache,
 150                                 unsigned fnr, unsigned bnr);
 151
 152 /*
 153  * interface.c
 154  */
 155 extern const struct fscache_cache_ops cachefiles_cache_ops;
 156
 157 /*
 158  * key.c
 159  */
 160 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
 161
 162 /*
 163  * namei.c
 164  */
 165 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
 166                                             struct cachefiles_object *object,
 167                                             blkcnt_t i_blocks);
 168 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
 169                                     struct cachefiles_object *object);
 170 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
 171                                      struct cachefiles_object *object,
 172                                      const char *key,
 173                                      struct cachefiles_xattr *auxdata);
 174 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 175                                                struct dentry *dir,
 176                                                const char *name);
 177
 178 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 179                            char *filename);
 180
 181 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
 182                                    struct dentry *dir, char *filename);
 183
 184 /*
 185  * proc.c
 186  */
 187 #ifdef CONFIG_CACHEFILES_HISTOGRAM
 188 extern atomic_t cachefiles_lookup_histogram[HZ];
 189 extern atomic_t cachefiles_mkdir_histogram[HZ];
 190 extern atomic_t cachefiles_create_histogram[HZ];
 191
 192 extern int __init cachefiles_proc_init(void);
 193 extern void cachefiles_proc_cleanup(void);
 194 static inline
 195 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
 196 {
 197         unsigned long jif = jiffies - start_jif;
 198         if (jif >= HZ)
 199                 jif = HZ - 1;
 200         atomic_inc(&histogram[jif]);
 201 }
 202
 203 #else
 204 #define cachefiles_proc_init()          (0)
 205 #define cachefiles_proc_cleanup()       do {} while (0)
 206 #define cachefiles_hist(hist, start_jif) do {} while (0)
 207 #endif
 208
 209 /*
 210  * rdwr.c
 211  */
 212 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
 213                                          struct page *, gfp_t);
 214 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
 215                                           struct list_head *, unsigned *,
 216                                           gfp_t);
 217 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
 218                                     gfp_t);
 219 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
 220                                      struct list_head *, unsigned *, gfp_t);
 221 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
 222 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
 223
 224 /*
 225  * security.c
 226  */
 227 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
 228 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
 229                                                struct dentry *root,
 230                                                const struct cred **_saved_cred);
 231
 232 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
 233                                            const struct cred **_saved_cred)
 234 {
 235         *_saved_cred = override_creds(cache->cache_cred);
 236 }
 237
 238 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
 239                                          const struct cred *saved_cred)
 240 {
 241         revert_creds(saved_cred);
 242 }
 243
 244 /*
 245  * xattr.c
 246  */
 247 extern int cachefiles_check_object_type(struct cachefiles_object *object);
 248 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
 249                                        struct cachefiles_xattr *auxdata);
 250 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
 251                                           struct cachefiles_xattr *auxdata);
 252 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
 253 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
 254                                          struct cachefiles_xattr *auxdata);
 255 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 256                                           struct dentry *dentry);
 257
 258
 259 /*
 260  * error handling
 261  */
 262
 263 #define cachefiles_io_error(___cache, FMT, ...)         \
 264 do {                                                    \
 265         pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);   \
 266         fscache_io_error(&(___cache)->cache);           \
 267         set_bit(CACHEFILES_DEAD, &(___cache)->flags);   \
 268 } while (0)
 269
 270 #define cachefiles_io_error_obj(object, FMT, ...)                       \
 271 do {                                                                    \
 272         struct cachefiles_cache *___cache;                              \
 273                                                                         \
 274         ___cache = container_of((object)->fscache.cache,                \
 275                                 struct cachefiles_cache, cache);        \
 276         cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);              \
 277 } while (0)
 278
 279
 280 /*
 281  * debug tracing
 282  */
 283 #define dbgprintk(FMT, ...) \
 284         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 285
 286 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 287 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 288 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 289
 290
 291 #if defined(__KDEBUG)
 292 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 293 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 294 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 295
 296 #elif defined(CONFIG_CACHEFILES_DEBUG)
 297 #define _enter(FMT, ...)                                \
 298 do {                                                    \
 299         if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
 300                 kenter(FMT, ##__VA_ARGS__);             \
 301 } while (0)
 302
 303 #define _leave(FMT, ...)                                \
 304 do {                                                    \
 305         if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
 306                 kleave(FMT, ##__VA_ARGS__);             \
 307 } while (0)
 308
 309 #define _debug(FMT, ...)                                \
 310 do {                                                    \
 311         if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
 312                 kdebug(FMT, ##__VA_ARGS__);             \
 313 } while (0)
 314
 315 #else
 316 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 317 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 318 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 319 #endif
 320
 321 #if 1 /* defined(__KDEBUGALL) */
 322
 323 #define ASSERT(X)                                                       \
 324 do {                                                                    \
 325         if (unlikely(!(X))) {                                           \
 326                 pr_err("\n");                                           \
 327                 pr_err("Assertion failed\n");           \
 328                 BUG();                                                  \
 329         }                                                               \
 330 } while (0)
 331
 332 #define ASSERTCMP(X, OP, Y)                                             \
 333 do {                                                                    \
 334         if (unlikely(!((X) OP (Y)))) {                                  \
 335                 pr_err("\n");                                           \
 336                 pr_err("Assertion failed\n");           \
 337                 pr_err("%lx " #OP " %lx is false\n",                    \
 338                        (unsigned long)(X), (unsigned long)(Y));         \
 339                 BUG();                                                  \
 340         }                                                               \
 341 } while (0)
 342
 343 #define ASSERTIF(C, X)                                                  \
 344 do {                                                                    \
 345         if (unlikely((C) && !(X))) {                                    \
 346                 pr_err("\n");                                           \
 347                 pr_err("Assertion failed\n");           \
 348                 BUG();                                                  \
 349         }                                                               \
 350 } while (0)
 351
 352 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 353 do {                                                                    \
 354         if (unlikely((C) && !((X) OP (Y)))) {                           \
 355                 pr_err("\n");                                           \
 356                 pr_err("Assertion failed\n");           \
 357                 pr_err("%lx " #OP " %lx is false\n",                    \
 358                        (unsigned long)(X), (unsigned long)(Y));         \
 359                 BUG();                                                  \
 360         }                                                               \
 361 } while (0)
 362
 363 #else
 364
 365 #define ASSERT(X)                       do {} while (0)
 366 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 367 #define ASSERTIF(C, X)                  do {} while (0)
 368 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 369
 370 #endif