1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* General netfs cache on cache files internal defs
3 *
4 * Copyright (C) 2021 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/cred.h>
17#include <linux/security.h>
18#include <linux/xarray.h>
19#include <linux/cachefiles.h>
20
21#define CACHEFILES_DIO_BLOCK_SIZE 4096
22
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_content
34};
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
47/*
48 * Backing file state.
49 */
50struct cachefiles_object {
51 struct fscache_cookie *cookie; /* Netfs data storage object cookie */
52 struct cachefiles_volume *volume; /* Cache volume that holds this object */
53 struct list_head cache_link; /* Link in cache->*_list */
54 struct file *file; /* The file representing this object */
55 char *d_name; /* Backing file name */
56 int debug_id;
57 spinlock_t lock;
58 refcount_t ref;
59 u8 d_name_len; /* Length of filename */
60 enum cachefiles_content content_info:8; /* Info about content presence */
61 unsigned long flags;
62#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */
63#ifdef CONFIG_CACHEFILES_ONDEMAND
64 int ondemand_id;
65#endif
66};
67
68#define CACHEFILES_ONDEMAND_ID_CLOSED -1
69
70/*
71 * Cache files cache definition
72 */
73struct cachefiles_cache {
74 struct fscache_cache *cache; /* Cache cookie */
75 struct vfsmount *mnt; /* mountpoint holding the cache */
76 struct dentry *store; /* Directory into which live objects go */
77 struct dentry *graveyard; /* directory into which dead objects go */
78 struct file *cachefilesd; /* manager daemon handle */
79 struct list_head volumes; /* List of volume objects */
80 struct list_head object_list; /* List of active objects */
81 spinlock_t object_list_lock; /* Lock for volumes and object_list */
82 const struct cred *cache_cred; /* security override for accessing cache */
83 struct mutex daemon_mutex; /* command serialisation mutex */
84 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
85 atomic_t gravecounter; /* graveyard uniquifier */
86 atomic_t f_released; /* number of objects released lately */
87 atomic_long_t b_released; /* number of blocks released lately */
88 atomic_long_t b_writing; /* Number of blocks being written */
89 unsigned frun_percent; /* when to stop culling (% files) */
90 unsigned fcull_percent; /* when to start culling (% files) */
91 unsigned fstop_percent; /* when to stop allocating (% files) */
92 unsigned brun_percent; /* when to stop culling (% blocks) */
93 unsigned bcull_percent; /* when to start culling (% blocks) */
94 unsigned bstop_percent; /* when to stop allocating (% blocks) */
95 unsigned bsize; /* cache's block size */
96 unsigned bshift; /* ilog2(bsize) */
97 uint64_t frun; /* when to stop culling */
98 uint64_t fcull; /* when to start culling */
99 uint64_t fstop; /* when to stop allocating */
100 sector_t brun; /* when to stop culling */
101 sector_t bcull; /* when to start culling */
102 sector_t bstop; /* when to stop allocating */
103 unsigned long flags;
104#define CACHEFILES_READY 0 /* T if cache prepared */
105#define CACHEFILES_DEAD 1 /* T if cache dead */
106#define CACHEFILES_CULLING 2 /* T if cull engaged */
107#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
108#define CACHEFILES_ONDEMAND_MODE 4 /* T if in on-demand read mode */
109 char *rootdirname; /* name of cache root directory */
110 char *secctx; /* LSM security context */
111 char *tag; /* cache binding tag */
112 refcount_t unbind_pincount;/* refcount to do daemon unbind */
113 struct xarray reqs; /* xarray of pending on-demand requests */
114 unsigned long req_id_next;
115 struct xarray ondemand_ids; /* xarray for ondemand_id allocation */
116 u32 ondemand_id_next;
117};
118
119static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)
120{
121 return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&
122 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);
123}
124
125struct cachefiles_req {
126 struct cachefiles_object *object;
127 struct completion done;
128 int error;
129 struct cachefiles_msg msg;
130};
131
132#define CACHEFILES_REQ_NEW XA_MARK_1
133
134#include <trace/events/cachefiles.h>
135
136static inline
137struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
138{
139 return cres->cache_priv2;
140}
141
142static inline
143struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
144{
145 return fscache_cres_cookie(cres)->cache_priv;
146}
147
148/*
149 * note change of state for daemon
150 */
151static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
152{
153 set_bit(CACHEFILES_STATE_CHANGED, addr: &cache->flags);
154 wake_up_all(&cache->daemon_pollwq);
155}
156
157/*
158 * cache.c
159 */
160extern int cachefiles_add_cache(struct cachefiles_cache *cache);
161extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);
162
163enum cachefiles_has_space_for {
164 cachefiles_has_space_check,
165 cachefiles_has_space_for_write,
166 cachefiles_has_space_for_create,
167};
168extern int cachefiles_has_space(struct cachefiles_cache *cache,
169 unsigned fnr, unsigned bnr,
170 enum cachefiles_has_space_for reason);
171
172/*
173 * daemon.c
174 */
175extern const struct file_operations cachefiles_daemon_fops;
176extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);
177extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache);
178
179/*
180 * error_inject.c
181 */
182#ifdef CONFIG_CACHEFILES_ERROR_INJECTION
183extern unsigned int cachefiles_error_injection_state;
184extern int cachefiles_register_error_injection(void);
185extern void cachefiles_unregister_error_injection(void);
186
187#else
188#define cachefiles_error_injection_state 0
189
190static inline int cachefiles_register_error_injection(void)
191{
192 return 0;
193}
194
195static inline void cachefiles_unregister_error_injection(void)
196{
197}
198#endif
199
200
201static inline int cachefiles_inject_read_error(void)
202{
203 return cachefiles_error_injection_state & 2 ? -EIO : 0;
204}
205
206static inline int cachefiles_inject_write_error(void)
207{
208 return cachefiles_error_injection_state & 2 ? -EIO :
209 cachefiles_error_injection_state & 1 ? -ENOSPC :
210 0;
211}
212
213static inline int cachefiles_inject_remove_error(void)
214{
215 return cachefiles_error_injection_state & 2 ? -EIO : 0;
216}
217
218/*
219 * interface.c
220 */
221extern const struct fscache_cache_ops cachefiles_cache_ops;
222extern void cachefiles_see_object(struct cachefiles_object *object,
223 enum cachefiles_obj_ref_trace why);
224extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
225 enum cachefiles_obj_ref_trace why);
226extern void cachefiles_put_object(struct cachefiles_object *object,
227 enum cachefiles_obj_ref_trace why);
228
229/*
230 * io.c
231 */
232extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
233 enum fscache_want_state want_state);
234extern int __cachefiles_prepare_write(struct cachefiles_object *object,
235 struct file *file,
236 loff_t *_start, size_t *_len,
237 bool no_space_allocated_yet);
238extern int __cachefiles_write(struct cachefiles_object *object,
239 struct file *file,
240 loff_t start_pos,
241 struct iov_iter *iter,
242 netfs_io_terminated_t term_func,
243 void *term_func_priv);
244
245/*
246 * key.c
247 */
248extern bool cachefiles_cook_key(struct cachefiles_object *object);
249
250/*
251 * main.c
252 */
253extern struct kmem_cache *cachefiles_object_jar;
254
255/*
256 * namei.c
257 */
258extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
259 struct file *file);
260extern int cachefiles_bury_object(struct cachefiles_cache *cache,
261 struct cachefiles_object *object,
262 struct dentry *dir,
263 struct dentry *rep,
264 enum fscache_why_object_killed why);
265extern int cachefiles_delete_object(struct cachefiles_object *object,
266 enum fscache_why_object_killed why);
267extern bool cachefiles_look_up_object(struct cachefiles_object *object);
268extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
269 struct dentry *dir,
270 const char *name,
271 bool *_is_new);
272extern void cachefiles_put_directory(struct dentry *dir);
273
274extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
275 char *filename);
276
277extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
278 struct dentry *dir, char *filename);
279extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
280extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
281 struct cachefiles_object *object);
282
283/*
284 * ondemand.c
285 */
286#ifdef CONFIG_CACHEFILES_ONDEMAND
287extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
288 char __user *_buffer, size_t buflen);
289
290extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
291 char *args);
292
293extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);
294extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);
295
296extern int cachefiles_ondemand_read(struct cachefiles_object *object,
297 loff_t pos, size_t len);
298
299#else
300static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
301 char __user *_buffer, size_t buflen)
302{
303 return -EOPNOTSUPP;
304}
305
306static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object)
307{
308 return 0;
309}
310
311static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
312{
313}
314
315static inline int cachefiles_ondemand_read(struct cachefiles_object *object,
316 loff_t pos, size_t len)
317{
318 return -EOPNOTSUPP;
319}
320#endif
321
322/*
323 * security.c
324 */
325extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
326extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
327 struct dentry *root,
328 const struct cred **_saved_cred);
329
330static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
331 const struct cred **_saved_cred)
332{
333 *_saved_cred = override_creds(cache->cache_cred);
334}
335
336static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
337 const struct cred *saved_cred)
338{
339 revert_creds(saved_cred);
340}
341
342/*
343 * volume.c
344 */
345void cachefiles_acquire_volume(struct fscache_volume *volume);
346void cachefiles_free_volume(struct fscache_volume *volume);
347void cachefiles_withdraw_volume(struct cachefiles_volume *volume);
348
349/*
350 * xattr.c
351 */
352extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
353extern int cachefiles_check_auxdata(struct cachefiles_object *object,
354 struct file *file);
355extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
356 struct cachefiles_object *object,
357 struct dentry *dentry);
358extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
359extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
360extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);
361
362/*
363 * Error handling
364 */
365#define cachefiles_io_error(___cache, FMT, ...) \
366do { \
367 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
368 fscache_io_error((___cache)->cache); \
369 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
370} while (0)
371
372#define cachefiles_io_error_obj(object, FMT, ...) \
373do { \
374 struct cachefiles_cache *___cache; \
375 \
376 ___cache = (object)->volume->cache; \
377 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \
378 (object)->debug_id); \
379} while (0)
380
381
382/*
383 * Debug tracing
384 */
385extern unsigned cachefiles_debug;
386#define CACHEFILES_DEBUG_KENTER 1
387#define CACHEFILES_DEBUG_KLEAVE 2
388#define CACHEFILES_DEBUG_KDEBUG 4
389
390#define dbgprintk(FMT, ...) \
391 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
392
393#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
394#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
395#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
396
397
398#if defined(__KDEBUG)
399#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
400#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
401#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
402
403#elif defined(CONFIG_CACHEFILES_DEBUG)
404#define _enter(FMT, ...) \
405do { \
406 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
407 kenter(FMT, ##__VA_ARGS__); \
408} while (0)
409
410#define _leave(FMT, ...) \
411do { \
412 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
413 kleave(FMT, ##__VA_ARGS__); \
414} while (0)
415
416#define _debug(FMT, ...) \
417do { \
418 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
419 kdebug(FMT, ##__VA_ARGS__); \
420} while (0)
421
422#else
423#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
424#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
425#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
426#endif
427
428#if 1 /* defined(__KDEBUGALL) */
429
430#define ASSERT(X) \
431do { \
432 if (unlikely(!(X))) { \
433 pr_err("\n"); \
434 pr_err("Assertion failed\n"); \
435 BUG(); \
436 } \
437} while (0)
438
439#define ASSERTCMP(X, OP, Y) \
440do { \
441 if (unlikely(!((X) OP (Y)))) { \
442 pr_err("\n"); \
443 pr_err("Assertion failed\n"); \
444 pr_err("%lx " #OP " %lx is false\n", \
445 (unsigned long)(X), (unsigned long)(Y)); \
446 BUG(); \
447 } \
448} while (0)
449
450#define ASSERTIF(C, X) \
451do { \
452 if (unlikely((C) && !(X))) { \
453 pr_err("\n"); \
454 pr_err("Assertion failed\n"); \
455 BUG(); \
456 } \
457} while (0)
458
459#define ASSERTIFCMP(C, X, OP, Y) \
460do { \
461 if (unlikely((C) && !((X) OP (Y)))) { \
462 pr_err("\n"); \
463 pr_err("Assertion failed\n"); \
464 pr_err("%lx " #OP " %lx is false\n", \
465 (unsigned long)(X), (unsigned long)(Y)); \
466 BUG(); \
467 } \
468} while (0)
469
470#else
471
472#define ASSERT(X) do {} while (0)
473#define ASSERTCMP(X, OP, Y) do {} while (0)
474#define ASSERTIF(C, X) do {} while (0)
475#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
476
477#endif
478

source code of linux/fs/cachefiles/internal.h