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
22 struct cachefiles_cache;
23 struct cachefiles_object;
24
25 extern 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 */
35 struct 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
50 extern struct kmem_cache *cachefiles_object_jar;
51
52 /*
53 * Cache files cache definition
54 */
55 struct 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 */
95 struct 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 */
106 struct 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 */
117 struct 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 */
cachefiles_state_changed(struct cachefiles_cache * cache)128 static 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 */
137 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
138 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
139
140 /*
141 * daemon.c
142 */
143 extern const struct file_operations cachefiles_daemon_fops;
144
145 extern int cachefiles_has_space(struct cachefiles_cache *cache,
146 unsigned fnr, unsigned bnr);
147
148 /*
149 * interface.c
150 */
151 extern const struct fscache_cache_ops cachefiles_cache_ops;
152
153 /*
154 * key.c
155 */
156 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
157
158 /*
159 * namei.c
160 */
161 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
162 struct cachefiles_object *object,
163 blkcnt_t i_blocks);
164 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
165 struct cachefiles_object *object);
166 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
167 struct cachefiles_object *object,
168 const char *key,
169 struct cachefiles_xattr *auxdata);
170 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
171 struct dentry *dir,
172 const char *name);
173
174 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
175 char *filename);
176
177 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
178 struct dentry *dir, char *filename);
179
180 /*
181 * proc.c
182 */
183 #ifdef CONFIG_CACHEFILES_HISTOGRAM
184 extern atomic_t cachefiles_lookup_histogram[HZ];
185 extern atomic_t cachefiles_mkdir_histogram[HZ];
186 extern atomic_t cachefiles_create_histogram[HZ];
187
188 extern int __init cachefiles_proc_init(void);
189 extern void cachefiles_proc_cleanup(void);
190 static inline
cachefiles_hist(atomic_t histogram[],unsigned long start_jif)191 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
192 {
193 unsigned long jif = jiffies - start_jif;
194 if (jif >= HZ)
195 jif = HZ - 1;
196 atomic_inc(&histogram[jif]);
197 }
198
199 #else
200 #define cachefiles_proc_init() (0)
201 #define cachefiles_proc_cleanup() do {} while (0)
202 #define cachefiles_hist(hist, start_jif) do {} while (0)
203 #endif
204
205 /*
206 * rdwr.c
207 */
208 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
209 struct page *, gfp_t);
210 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
211 struct list_head *, unsigned *,
212 gfp_t);
213 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
214 gfp_t);
215 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
216 struct list_head *, unsigned *, gfp_t);
217 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
218 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
219
220 /*
221 * security.c
222 */
223 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
224 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
225 struct dentry *root,
226 const struct cred **_saved_cred);
227
cachefiles_begin_secure(struct cachefiles_cache * cache,const struct cred ** _saved_cred)228 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
229 const struct cred **_saved_cred)
230 {
231 *_saved_cred = override_creds(cache->cache_cred);
232 }
233
cachefiles_end_secure(struct cachefiles_cache * cache,const struct cred * saved_cred)234 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
235 const struct cred *saved_cred)
236 {
237 revert_creds(saved_cred);
238 }
239
240 /*
241 * xattr.c
242 */
243 extern int cachefiles_check_object_type(struct cachefiles_object *object);
244 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
245 struct cachefiles_xattr *auxdata);
246 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
247 struct cachefiles_xattr *auxdata);
248 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
249 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
250 struct cachefiles_xattr *auxdata);
251 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
252 struct dentry *dentry);
253
254
255 /*
256 * error handling
257 */
258
259 #define cachefiles_io_error(___cache, FMT, ...) \
260 do { \
261 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
262 fscache_io_error(&(___cache)->cache); \
263 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
264 } while (0)
265
266 #define cachefiles_io_error_obj(object, FMT, ...) \
267 do { \
268 struct cachefiles_cache *___cache; \
269 \
270 ___cache = container_of((object)->fscache.cache, \
271 struct cachefiles_cache, cache); \
272 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
273 } while (0)
274
275
276 /*
277 * debug tracing
278 */
279 #define dbgprintk(FMT, ...) \
280 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
281
282 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
283 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
284 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
285
286
287 #if defined(__KDEBUG)
288 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
289 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
290 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
291
292 #elif defined(CONFIG_CACHEFILES_DEBUG)
293 #define _enter(FMT, ...) \
294 do { \
295 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
296 kenter(FMT, ##__VA_ARGS__); \
297 } while (0)
298
299 #define _leave(FMT, ...) \
300 do { \
301 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
302 kleave(FMT, ##__VA_ARGS__); \
303 } while (0)
304
305 #define _debug(FMT, ...) \
306 do { \
307 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
308 kdebug(FMT, ##__VA_ARGS__); \
309 } while (0)
310
311 #else
312 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
313 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
314 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
315 #endif
316
317 #if 1 /* defined(__KDEBUGALL) */
318
319 #define ASSERT(X) \
320 do { \
321 if (unlikely(!(X))) { \
322 pr_err("\n"); \
323 pr_err("Assertion failed\n"); \
324 BUG(); \
325 } \
326 } while (0)
327
328 #define ASSERTCMP(X, OP, Y) \
329 do { \
330 if (unlikely(!((X) OP (Y)))) { \
331 pr_err("\n"); \
332 pr_err("Assertion failed\n"); \
333 pr_err("%lx " #OP " %lx is false\n", \
334 (unsigned long)(X), (unsigned long)(Y)); \
335 BUG(); \
336 } \
337 } while (0)
338
339 #define ASSERTIF(C, X) \
340 do { \
341 if (unlikely((C) && !(X))) { \
342 pr_err("\n"); \
343 pr_err("Assertion failed\n"); \
344 BUG(); \
345 } \
346 } while (0)
347
348 #define ASSERTIFCMP(C, X, OP, Y) \
349 do { \
350 if (unlikely((C) && !((X) OP (Y)))) { \
351 pr_err("\n"); \
352 pr_err("Assertion failed\n"); \
353 pr_err("%lx " #OP " %lx is false\n", \
354 (unsigned long)(X), (unsigned long)(Y)); \
355 BUG(); \
356 } \
357 } while (0)
358
359 #else
360
361 #define ASSERT(X) do {} while (0)
362 #define ASSERTCMP(X, OP, Y) do {} while (0)
363 #define ASSERTIF(C, X) do {} while (0)
364 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
365
366 #endif
367
