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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 ([email protected])
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
19struct cachefiles_cache;
20struct cachefiles_object;
21
22enum cachefiles_content {
23 /* These values are saved on disk */
24 CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */
25 CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */
26 CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */
27 CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */
28 CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */
29 nr__cachefiles_content
30};
31
32/*
33 * Cached volume representation.
34 */
35struct cachefiles_volume {
36 struct cachefiles_cache *cache;
37 struct list_head cache_link; /* Link in cache->volumes */
38 struct fscache_volume *vcookie; /* The netfs's representation */
39 struct dentry *dentry; /* The volume dentry */
40 struct dentry *fanout[256]; /* Fanout subdirs */
41};
42
43/*
44 * Backing file state.
45 */
46struct cachefiles_object {
47 struct fscache_cookie *cookie; /* Netfs data storage object cookie */
48 struct cachefiles_volume *volume; /* Cache volume that holds this object */
49 struct list_head cache_link; /* Link in cache->*_list */
50 struct file *file; /* The file representing this object */
51 char *d_name; /* Backing file name */
52 unsigned long flags;
53#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */
54 uoff_t object_size; /* Size of the object stored
55 * (independent of cookie->object_size for
56 * coherency reasons)
57 */
58 atomic64_t read_limit; /* Point beyond which uncommitted writes */
59 int debug_id;
60 spinlock_t lock;
61 refcount_t ref;
62 enum cachefiles_content content_info; /* Info about content presence */
63};
64
65/*
66 * Cache files cache definition
67 */
68struct cachefiles_cache {
69 struct fscache_cache *cache; /* Cache cookie */
70 struct vfsmount *mnt; /* mountpoint holding the cache */
71 struct dentry *store; /* Directory into which live objects go */
72 struct dentry *graveyard; /* directory into which dead objects go */
73 struct file *cachefilesd; /* manager daemon handle */
74 struct list_head volumes; /* List of volume objects */
75 struct list_head object_list; /* List of active objects */
76 spinlock_t object_list_lock; /* Lock for volumes and object_list */
77 const struct cred *cache_cred; /* security override for accessing cache */
78 struct mutex daemon_mutex; /* command serialisation mutex */
79 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
80 atomic_t gravecounter; /* graveyard uniquifier */
81 atomic_t f_released; /* number of objects released lately */
82 atomic_long_t b_released; /* number of blocks released lately */
83 atomic_long_t b_writing; /* Number of blocks being written */
84 unsigned frun_percent; /* when to stop culling (% files) */
85 unsigned fcull_percent; /* when to start culling (% files) */
86 unsigned fstop_percent; /* when to stop allocating (% files) */
87 unsigned brun_percent; /* when to stop culling (% blocks) */
88 unsigned bcull_percent; /* when to start culling (% blocks) */
89 unsigned bstop_percent; /* when to stop allocating (% blocks) */
90 unsigned bsize; /* cache's block size */
91 unsigned bshift; /* ilog2(bsize) */
92 uint64_t frun; /* when to stop culling */
93 uint64_t fcull; /* when to start culling */
94 uint64_t fstop; /* when to stop allocating */
95 sector_t brun; /* when to stop culling */
96 sector_t bcull; /* when to start culling */
97 sector_t bstop; /* when to stop allocating */
98 unsigned long flags;
99#define CACHEFILES_READY 0 /* T if cache prepared */
100#define CACHEFILES_DEAD 1 /* T if cache dead */
101#define CACHEFILES_CULLING 2 /* T if cull engaged */
102#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
103 char *rootdirname; /* name of cache root directory */
104 char *tag; /* cache binding tag */
105 u32 secid; /* LSM security id */
106 bool have_secid; /* whether "secid" was set */
107};
108
109#include <trace/events/cachefiles.h>
110
111static inline
112struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
113{
114 return cres->cache_priv2;
115}
116
117static inline
118struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
119{
120 return fscache_cres_cookie(cres)->cache_priv;
121}
122
123/*
124 * note change of state for daemon
125 */
126static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
127{
128 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
129 wake_up_all(&cache->daemon_pollwq);
130}
131
132/*
133 * cache.c
134 */
135extern int cachefiles_add_cache(struct cachefiles_cache *cache);
136extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);
137
138enum cachefiles_has_space_for {
139 cachefiles_has_space_check,
140 cachefiles_has_space_for_write,
141 cachefiles_has_space_for_create,
142};
143extern int cachefiles_has_space(struct cachefiles_cache *cache,
144 unsigned fnr, unsigned bnr,
145 enum cachefiles_has_space_for reason);
146
147/*
148 * daemon.c
149 */
150extern const struct file_operations cachefiles_daemon_fops;
151
152/*
153 * error_inject.c
154 */
155#ifdef CONFIG_CACHEFILES_ERROR_INJECTION
156extern unsigned int cachefiles_error_injection_state;
157extern int cachefiles_register_error_injection(void);
158extern void cachefiles_unregister_error_injection(void);
159
160#else
161#define cachefiles_error_injection_state 0
162
163static inline int cachefiles_register_error_injection(void)
164{
165 return 0;
166}
167
168static inline void cachefiles_unregister_error_injection(void)
169{
170}
171#endif
172
173
174static inline int cachefiles_inject_read_error(void)
175{
176 return cachefiles_error_injection_state & 2 ? -EIO : 0;
177}
178
179static inline int cachefiles_inject_write_error(void)
180{
181 return cachefiles_error_injection_state & 2 ? -EIO :
182 cachefiles_error_injection_state & 1 ? -ENOSPC :
183 0;
184}
185
186static inline int cachefiles_inject_remove_error(void)
187{
188 return cachefiles_error_injection_state & 2 ? -EIO : 0;
189}
190
191/*
192 * interface.c
193 */
194extern const struct fscache_cache_ops cachefiles_cache_ops;
195extern void cachefiles_see_object(struct cachefiles_object *object,
196 enum cachefiles_obj_ref_trace why);
197extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
198 enum cachefiles_obj_ref_trace why);
199extern void cachefiles_put_object(struct cachefiles_object *object,
200 enum cachefiles_obj_ref_trace why);
201
202/*
203 * io.c
204 */
205extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
206 enum fscache_want_state want_state);
207extern int __cachefiles_prepare_write(struct cachefiles_object *object,
208 struct file *file,
209 uoff_t *_start, size_t *_len, size_t upper_len,
210 bool no_space_allocated_yet);
211extern int __cachefiles_write(struct cachefiles_object *object,
212 struct file *file,
213 uoff_t start_pos,
214 struct iov_iter *iter,
215 netfs_io_terminated_t term_func,
216 void *term_func_priv);
217
218/*
219 * key.c
220 */
221extern bool cachefiles_cook_key(struct cachefiles_object *object);
222
223/*
224 * main.c
225 */
226extern struct kmem_cache *cachefiles_object_jar;
227
228/*
229 * namei.c
230 */
231extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
232 struct file *file);
233extern int cachefiles_bury_object(struct cachefiles_cache *cache,
234 struct cachefiles_object *object,
235 struct dentry *dir,
236 struct dentry *rep,
237 enum fscache_why_object_killed why);
238extern int cachefiles_delete_object(struct cachefiles_object *object,
239 enum fscache_why_object_killed why);
240extern bool cachefiles_look_up_object(struct cachefiles_object *object);
241extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
242 struct dentry *dir,
243 const char *name,
244 bool *_is_new);
245extern void cachefiles_put_directory(struct dentry *dir);
246
247extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
248 char *filename);
249
250extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
251 struct dentry *dir, char *filename);
252extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
253extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
254 struct cachefiles_object *object);
255
256/*
257 * security.c
258 */
259extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
260extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
261 struct dentry *root,
262 const struct cred **_saved_cred);
263
264static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
265 const struct cred **_saved_cred)
266{
267 *_saved_cred = override_creds(cache->cache_cred);
268}
269
270static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
271 const struct cred *saved_cred)
272{
273 revert_creds(saved_cred);
274}
275
276/*
277 * volume.c
278 */
279void cachefiles_acquire_volume(struct fscache_volume *volume);
280void cachefiles_free_volume(struct fscache_volume *volume);
281void cachefiles_withdraw_volume(struct cachefiles_volume *volume);
282
283/*
284 * xattr.c
285 */
286int cachefiles_preset_object_xattr(struct cachefiles_object *object, struct file *file);
287extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
288extern int cachefiles_check_auxdata(struct cachefiles_object *object,
289 struct file *file);
290extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
291 struct cachefiles_object *object,
292 struct dentry *dentry);
293extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
294extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
295extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);
296
297/*
298 * Error handling
299 */
300#define cachefiles_io_error(___cache, FMT, ...) \
301do { \
302 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
303 fscache_io_error((___cache)->cache); \
304 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
305} while (0)
306
307#define cachefiles_io_error_obj(object, FMT, ...) \
308do { \
309 struct cachefiles_cache *___cache; \
310 \
311 ___cache = (object)->volume->cache; \
312 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \
313 (object)->debug_id); \
314} while (0)
315
316
317/*
318 * Debug tracing
319 */
320extern unsigned cachefiles_debug;
321#define CACHEFILES_DEBUG_KENTER 1
322#define CACHEFILES_DEBUG_KLEAVE 2
323#define CACHEFILES_DEBUG_KDEBUG 4
324
325#define dbgprintk(FMT, ...) \
326 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
327
328#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
329#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
330#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
331
332
333#if defined(__KDEBUG)
334#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
335#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
336#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
337
338#elif defined(CONFIG_CACHEFILES_DEBUG)
339#define _enter(FMT, ...) \
340do { \
341 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
342 kenter(FMT, ##__VA_ARGS__); \
343} while (0)
344
345#define _leave(FMT, ...) \
346do { \
347 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
348 kleave(FMT, ##__VA_ARGS__); \
349} while (0)
350
351#define _debug(FMT, ...) \
352do { \
353 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
354 kdebug(FMT, ##__VA_ARGS__); \
355} while (0)
356
357#else
358#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
359#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
360#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
361#endif
362
363#if 1 /* defined(__KDEBUGALL) */
364
365#define ASSERT(X) \
366do { \
367 if (unlikely(!(X))) { \
368 pr_err("\n"); \
369 pr_err("Assertion failed\n"); \
370 BUG(); \
371 } \
372} while (0)
373
374#define ASSERTCMP(X, OP, Y) \
375do { \
376 if (unlikely(!((X) OP (Y)))) { \
377 pr_err("\n"); \
378 pr_err("Assertion failed\n"); \
379 pr_err("%lx " #OP " %lx is false\n", \
380 (unsigned long)(X), (unsigned long)(Y)); \
381 BUG(); \
382 } \
383} while (0)
384
385#define ASSERTIF(C, X) \
386do { \
387 if (unlikely((C) && !(X))) { \
388 pr_err("\n"); \
389 pr_err("Assertion failed\n"); \
390 BUG(); \
391 } \
392} while (0)
393
394#define ASSERTIFCMP(C, X, OP, Y) \
395do { \
396 if (unlikely((C) && !((X) OP (Y)))) { \
397 pr_err("\n"); \
398 pr_err("Assertion failed\n"); \
399 pr_err("%lx " #OP " %lx is false\n", \
400 (unsigned long)(X), (unsigned long)(Y)); \
401 BUG(); \
402 } \
403} while (0)
404
405#else
406
407#define ASSERT(X) do {} while (0)
408#define ASSERTCMP(X, OP, Y) do {} while (0)
409#define ASSERTIF(C, X) do {} while (0)
410#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
411
412#endif