LXR linux/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
  22struct cachefiles_cache;
  23struct cachefiles_object;
  24
  25extern 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 */
  35struct 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
  50extern struct kmem_cache *cachefiles_object_jar;
  51
  52/*
  53 * Cache files cache definition
  54 */
  55struct 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 */
  95struct 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 */
 106struct 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 */
 117struct 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 */
 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
 153void cachefiles_put_object(struct fscache_object *_object,
 154                           enum fscache_obj_ref_trace why);
 155
 156/*
 157 * key.c
 158 */
 159extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
 160
 161/*
 162 * namei.c
 163 */
 164extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
 165                                            struct cachefiles_object *object,
 166                                            blkcnt_t i_blocks);
 167extern int cachefiles_delete_object(struct cachefiles_cache *cache,
 168                                    struct cachefiles_object *object);
 169extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
 170                                     struct cachefiles_object *object,
 171                                     const char *key,
 172                                     struct cachefiles_xattr *auxdata);
 173extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 174                                               struct dentry *dir,
 175                                               const char *name);
 176
 177extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 178                           char *filename);
 179
 180extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
 181                                   struct dentry *dir, char *filename);
 182
 183/*
 184 * rdwr.c
 185 */
 186extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
 187                                         struct page *, gfp_t);
 188extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
 189                                          struct list_head *, unsigned *,
 190                                          gfp_t);
 191extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
 192                                    gfp_t);
 193extern int cachefiles_allocate_pages(struct fscache_retrieval *,
 194                                     struct list_head *, unsigned *, gfp_t);
 195extern int cachefiles_write_page(struct fscache_storage *, struct page *);
 196extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
 197
 198/*
 199 * rdwr2.c
 200 */
 201extern int cachefiles_begin_read_operation(struct netfs_read_request *,
 202                                           struct fscache_retrieval *);
 203
 204/*
 205 * security.c
 206 */
 207extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
 208extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
 209                                               struct dentry *root,
 210                                               const struct cred **_saved_cred);
 211
 212static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
 213                                           const struct cred **_saved_cred)
 214{
 215        *_saved_cred = override_creds(cache->cache_cred);
 216}
 217
 218static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
 219                                         const struct cred *saved_cred)
 220{
 221        revert_creds(saved_cred);
 222}
 223
 224/*
 225 * xattr.c
 226 */
 227extern int cachefiles_check_object_type(struct cachefiles_object *object);
 228extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
 229                                       struct cachefiles_xattr *auxdata);
 230extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
 231                                          struct cachefiles_xattr *auxdata);
 232extern int cachefiles_check_auxdata(struct cachefiles_object *object);
 233extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
 234                                         struct cachefiles_xattr *auxdata);
 235extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 236                                          struct dentry *dentry);
 237
 238
 239/*
 240 * error handling
 241 */
 242
 243#define cachefiles_io_error(___cache, FMT, ...)         \
 244do {                                                    \
 245        pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);   \
 246        fscache_io_error(&(___cache)->cache);           \
 247        set_bit(CACHEFILES_DEAD, &(___cache)->flags);   \
 248} while (0)
 249
 250#define cachefiles_io_error_obj(object, FMT, ...)                       \
 251do {                                                                    \
 252        struct cachefiles_cache *___cache;                              \
 253                                                                        \
 254        ___cache = container_of((object)->fscache.cache,                \
 255                                struct cachefiles_cache, cache);        \
 256        cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);              \
 257} while (0)
 258
 259
 260/*
 261 * debug tracing
 262 */
 263#define dbgprintk(FMT, ...) \
 264        printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 265
 266#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 267#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 268#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 269
 270
 271#if defined(__KDEBUG)
 272#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 273#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 274#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 275
 276#elif defined(CONFIG_CACHEFILES_DEBUG)
 277#define _enter(FMT, ...)                                \
 278do {                                                    \
 279        if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
 280                kenter(FMT, ##__VA_ARGS__);             \
 281} while (0)
 282
 283#define _leave(FMT, ...)                                \
 284do {                                                    \
 285        if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
 286                kleave(FMT, ##__VA_ARGS__);             \
 287} while (0)
 288
 289#define _debug(FMT, ...)                                \
 290do {                                                    \
 291        if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
 292                kdebug(FMT, ##__VA_ARGS__);             \
 293} while (0)
 294
 295#else
 296#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 297#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 298#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 299#endif
 300
 301#if 1 /* defined(__KDEBUGALL) */
 302
 303#define ASSERT(X)                                                       \
 304do {                                                                    \
 305        if (unlikely(!(X))) {                                           \
 306                pr_err("\n");                                           \
 307                pr_err("Assertion failed\n");           \
 308                BUG();                                                  \
 309        }                                                               \
 310} while (0)
 311
 312#define ASSERTCMP(X, OP, Y)                                             \
 313do {                                                                    \
 314        if (unlikely(!((X) OP (Y)))) {                                  \
 315                pr_err("\n");                                           \
 316                pr_err("Assertion failed\n");           \
 317                pr_err("%lx " #OP " %lx is false\n",                    \
 318                       (unsigned long)(X), (unsigned long)(Y));         \
 319                BUG();                                                  \
 320        }                                                               \
 321} while (0)
 322
 323#define ASSERTIF(C, X)                                                  \
 324do {                                                                    \
 325        if (unlikely((C) && !(X))) {                                    \
 326                pr_err("\n");                                           \
 327                pr_err("Assertion failed\n");           \
 328                BUG();                                                  \
 329        }                                                               \
 330} while (0)
 331
 332#define ASSERTIFCMP(C, X, OP, Y)                                        \
 333do {                                                                    \
 334        if (unlikely((C) && !((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#else
 344
 345#define ASSERT(X)                       do {} while (0)
 346#define ASSERTCMP(X, OP, Y)             do {} while (0)
 347#define ASSERTIF(C, X)                  do {} while (0)
 348#define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 349
 350#endif
 351