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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/* General netfs cache on cache files internal defs3 *4 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.5 * Written by David Howells (dhowells@redhat.com)6 */7 8#ifdef pr_fmt9#undef pr_fmt10#endif11 12#define pr_fmt(fmt) "CacheFiles: " fmt13 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 409622 23struct cachefiles_cache;24struct cachefiles_object;25 26enum 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_content34};35 36/*37 * Cached volume representation.38 */39struct 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 47enum cachefiles_object_state {48 CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */49 CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */50 CACHEFILES_ONDEMAND_OBJSTATE_REOPENING, /* Object that was closed and is being reopened. */51 CACHEFILES_ONDEMAND_OBJSTATE_DROPPING, /* Object is being dropped. */52};53 54struct cachefiles_ondemand_info {55 struct work_struct ondemand_work;56 int ondemand_id;57 enum cachefiles_object_state state;58 struct cachefiles_object *object;59 spinlock_t lock;60};61 62/*63 * Backing file state.64 */65struct cachefiles_object {66 struct fscache_cookie *cookie; /* Netfs data storage object cookie */67 struct cachefiles_volume *volume; /* Cache volume that holds this object */68 struct list_head cache_link; /* Link in cache->*_list */69 struct file *file; /* The file representing this object */70 char *d_name; /* Backing file name */71 int debug_id;72 spinlock_t lock;73 refcount_t ref;74 u8 d_name_len; /* Length of filename */75 enum cachefiles_content content_info:8; /* Info about content presence */76 unsigned long flags;77#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */78#ifdef CONFIG_CACHEFILES_ONDEMAND79 struct cachefiles_ondemand_info *ondemand;80#endif81};82 83#define CACHEFILES_ONDEMAND_ID_CLOSED -184 85/*86 * Cache files cache definition87 */88struct cachefiles_cache {89 struct fscache_cache *cache; /* Cache cookie */90 struct vfsmount *mnt; /* mountpoint holding the cache */91 struct dentry *store; /* Directory into which live objects go */92 struct dentry *graveyard; /* directory into which dead objects go */93 struct file *cachefilesd; /* manager daemon handle */94 struct list_head volumes; /* List of volume objects */95 struct list_head object_list; /* List of active objects */96 spinlock_t object_list_lock; /* Lock for volumes and object_list */97 const struct cred *cache_cred; /* security override for accessing cache */98 struct mutex daemon_mutex; /* command serialisation mutex */99 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */100 atomic_t gravecounter; /* graveyard uniquifier */101 atomic_t f_released; /* number of objects released lately */102 atomic_long_t b_released; /* number of blocks released lately */103 atomic_long_t b_writing; /* Number of blocks being written */104 unsigned frun_percent; /* when to stop culling (% files) */105 unsigned fcull_percent; /* when to start culling (% files) */106 unsigned fstop_percent; /* when to stop allocating (% files) */107 unsigned brun_percent; /* when to stop culling (% blocks) */108 unsigned bcull_percent; /* when to start culling (% blocks) */109 unsigned bstop_percent; /* when to stop allocating (% blocks) */110 unsigned bsize; /* cache's block size */111 unsigned bshift; /* ilog2(bsize) */112 uint64_t frun; /* when to stop culling */113 uint64_t fcull; /* when to start culling */114 uint64_t fstop; /* when to stop allocating */115 sector_t brun; /* when to stop culling */116 sector_t bcull; /* when to start culling */117 sector_t bstop; /* when to stop allocating */118 unsigned long flags;119#define CACHEFILES_READY 0 /* T if cache prepared */120#define CACHEFILES_DEAD 1 /* T if cache dead */121#define CACHEFILES_CULLING 2 /* T if cull engaged */122#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */123#define CACHEFILES_ONDEMAND_MODE 4 /* T if in on-demand read mode */124 char *rootdirname; /* name of cache root directory */125 char *secctx; /* LSM security context */126 char *tag; /* cache binding tag */127 refcount_t unbind_pincount;/* refcount to do daemon unbind */128 struct xarray reqs; /* xarray of pending on-demand requests */129 unsigned long req_id_next;130 struct xarray ondemand_ids; /* xarray for ondemand_id allocation */131 u32 ondemand_id_next;132 u32 msg_id_next;133};134 135static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)136{137 return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&138 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);139}140 141struct cachefiles_req {142 struct cachefiles_object *object;143 struct completion done;144 refcount_t ref;145 int error;146 struct cachefiles_msg msg;147};148 149#define CACHEFILES_REQ_NEW XA_MARK_1150 151#include <trace/events/cachefiles.h>152 153static inline154struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)155{156 return cres->cache_priv2;157}158 159static inline160struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)161{162 return fscache_cres_cookie(cres)->cache_priv;163}164 165/*166 * note change of state for daemon167 */168static inline void cachefiles_state_changed(struct cachefiles_cache *cache)169{170 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);171 wake_up_all(&cache->daemon_pollwq);172}173 174/*175 * cache.c176 */177extern int cachefiles_add_cache(struct cachefiles_cache *cache);178extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);179 180enum cachefiles_has_space_for {181 cachefiles_has_space_check,182 cachefiles_has_space_for_write,183 cachefiles_has_space_for_create,184};185extern int cachefiles_has_space(struct cachefiles_cache *cache,186 unsigned fnr, unsigned bnr,187 enum cachefiles_has_space_for reason);188 189/*190 * daemon.c191 */192extern const struct file_operations cachefiles_daemon_fops;193extern void cachefiles_flush_reqs(struct cachefiles_cache *cache);194extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);195extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache);196 197/*198 * error_inject.c199 */200#ifdef CONFIG_CACHEFILES_ERROR_INJECTION201extern unsigned int cachefiles_error_injection_state;202extern int cachefiles_register_error_injection(void);203extern void cachefiles_unregister_error_injection(void);204 205#else206#define cachefiles_error_injection_state 0207 208static inline int cachefiles_register_error_injection(void)209{210 return 0;211}212 213static inline void cachefiles_unregister_error_injection(void)214{215}216#endif217 218 219static inline int cachefiles_inject_read_error(void)220{221 return cachefiles_error_injection_state & 2 ? -EIO : 0;222}223 224static inline int cachefiles_inject_write_error(void)225{226 return cachefiles_error_injection_state & 2 ? -EIO :227 cachefiles_error_injection_state & 1 ? -ENOSPC :228 0;229}230 231static inline int cachefiles_inject_remove_error(void)232{233 return cachefiles_error_injection_state & 2 ? -EIO : 0;234}235 236/*237 * interface.c238 */239extern const struct fscache_cache_ops cachefiles_cache_ops;240extern void cachefiles_see_object(struct cachefiles_object *object,241 enum cachefiles_obj_ref_trace why);242extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,243 enum cachefiles_obj_ref_trace why);244extern void cachefiles_put_object(struct cachefiles_object *object,245 enum cachefiles_obj_ref_trace why);246 247/*248 * io.c249 */250extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,251 enum fscache_want_state want_state);252extern int __cachefiles_prepare_write(struct cachefiles_object *object,253 struct file *file,254 loff_t *_start, size_t *_len, size_t upper_len,255 bool no_space_allocated_yet);256extern int __cachefiles_write(struct cachefiles_object *object,257 struct file *file,258 loff_t start_pos,259 struct iov_iter *iter,260 netfs_io_terminated_t term_func,261 void *term_func_priv);262 263/*264 * key.c265 */266extern bool cachefiles_cook_key(struct cachefiles_object *object);267 268/*269 * main.c270 */271extern struct kmem_cache *cachefiles_object_jar;272 273/*274 * namei.c275 */276extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,277 struct file *file);278extern int cachefiles_bury_object(struct cachefiles_cache *cache,279 struct cachefiles_object *object,280 struct dentry *dir,281 struct dentry *rep,282 enum fscache_why_object_killed why);283extern int cachefiles_delete_object(struct cachefiles_object *object,284 enum fscache_why_object_killed why);285extern bool cachefiles_look_up_object(struct cachefiles_object *object);286extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,287 struct dentry *dir,288 const char *name,289 bool *_is_new);290extern void cachefiles_put_directory(struct dentry *dir);291 292extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,293 char *filename);294 295extern int cachefiles_check_in_use(struct cachefiles_cache *cache,296 struct dentry *dir, char *filename);297extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);298extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,299 struct cachefiles_object *object);300 301/*302 * ondemand.c303 */304#ifdef CONFIG_CACHEFILES_ONDEMAND305extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,306 char __user *_buffer, size_t buflen);307 308extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,309 char *args);310 311extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache,312 char *args);313 314extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);315extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);316 317extern int cachefiles_ondemand_read(struct cachefiles_object *object,318 loff_t pos, size_t len);319 320extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,321 struct cachefiles_volume *volume);322extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj);323 324#define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE) \325static inline bool \326cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \327{ \328 return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \329} \330 \331static inline void \332cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \333{ \334 object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \335}336 337CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);338CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);339CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);340CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING);341 342static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)343{344 return cachefiles_ondemand_object_is_reopening(req->object) &&345 req->msg.opcode == CACHEFILES_OP_READ;346}347 348#else349static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,350 char __user *_buffer, size_t buflen)351{352 return -EOPNOTSUPP;353}354 355static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object)356{357 return 0;358}359 360static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object)361{362}363 364static inline int cachefiles_ondemand_read(struct cachefiles_object *object,365 loff_t pos, size_t len)366{367 return -EOPNOTSUPP;368}369 370static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,371 struct cachefiles_volume *volume)372{373 return 0;374}375static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj)376{377}378 379static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)380{381 return false;382}383#endif384 385/*386 * security.c387 */388extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);389extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,390 struct dentry *root,391 const struct cred **_saved_cred);392 393static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,394 const struct cred **_saved_cred)395{396 *_saved_cred = override_creds(cache->cache_cred);397}398 399static inline void cachefiles_end_secure(struct cachefiles_cache *cache,400 const struct cred *saved_cred)401{402 revert_creds(saved_cred);403}404 405/*406 * volume.c407 */408void cachefiles_acquire_volume(struct fscache_volume *volume);409void cachefiles_free_volume(struct fscache_volume *volume);410void cachefiles_withdraw_volume(struct cachefiles_volume *volume);411 412/*413 * xattr.c414 */415extern int cachefiles_set_object_xattr(struct cachefiles_object *object);416extern int cachefiles_check_auxdata(struct cachefiles_object *object,417 struct file *file);418extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,419 struct cachefiles_object *object,420 struct dentry *dentry);421extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);422extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);423extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);424 425/*426 * Error handling427 */428#define cachefiles_io_error(___cache, FMT, ...) \429do { \430 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \431 fscache_io_error((___cache)->cache); \432 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \433 if (cachefiles_in_ondemand_mode(___cache)) \434 cachefiles_flush_reqs(___cache); \435} while (0)436 437#define cachefiles_io_error_obj(object, FMT, ...) \438do { \439 struct cachefiles_cache *___cache; \440 \441 ___cache = (object)->volume->cache; \442 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \443 (object)->debug_id); \444} while (0)445 446 447/*448 * Debug tracing449 */450extern unsigned cachefiles_debug;451#define CACHEFILES_DEBUG_KENTER 1452#define CACHEFILES_DEBUG_KLEAVE 2453#define CACHEFILES_DEBUG_KDEBUG 4454 455#define dbgprintk(FMT, ...) \456 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)457 458#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)459#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)460#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)461 462 463#if defined(__KDEBUG)464#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)465#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)466#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)467 468#elif defined(CONFIG_CACHEFILES_DEBUG)469#define _enter(FMT, ...) \470do { \471 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \472 kenter(FMT, ##__VA_ARGS__); \473} while (0)474 475#define _leave(FMT, ...) \476do { \477 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \478 kleave(FMT, ##__VA_ARGS__); \479} while (0)480 481#define _debug(FMT, ...) \482do { \483 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \484 kdebug(FMT, ##__VA_ARGS__); \485} while (0)486 487#else488#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)489#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)490#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)491#endif492 493#if 1 /* defined(__KDEBUGALL) */494 495#define ASSERT(X) \496do { \497 if (unlikely(!(X))) { \498 pr_err("\n"); \499 pr_err("Assertion failed\n"); \500 BUG(); \501 } \502} while (0)503 504#define ASSERTCMP(X, OP, Y) \505do { \506 if (unlikely(!((X) OP (Y)))) { \507 pr_err("\n"); \508 pr_err("Assertion failed\n"); \509 pr_err("%lx " #OP " %lx is false\n", \510 (unsigned long)(X), (unsigned long)(Y)); \511 BUG(); \512 } \513} while (0)514 515#define ASSERTIF(C, X) \516do { \517 if (unlikely((C) && !(X))) { \518 pr_err("\n"); \519 pr_err("Assertion failed\n"); \520 BUG(); \521 } \522} while (0)523 524#define ASSERTIFCMP(C, X, OP, Y) \525do { \526 if (unlikely((C) && !((X) OP (Y)))) { \527 pr_err("\n"); \528 pr_err("Assertion failed\n"); \529 pr_err("%lx " #OP " %lx is false\n", \530 (unsigned long)(X), (unsigned long)(Y)); \531 BUG(); \532 } \533} while (0)534 535#else536 537#define ASSERT(X) do {} while (0)538#define ASSERTCMP(X, OP, Y) do {} while (0)539#define ASSERTIF(C, X) do {} while (0)540#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)541 542#endif543