LXR linux/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.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