1 /* General netfs cache on cache files internal defs
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12 #ifdef pr_fmt
13 #undef pr_fmt
14 #endif
15
16 #define pr_fmt(fmt) "CacheFiles: " fmt
17
18
19 #include <linux/fscache-cache.h>
20 #include <linux/timer.h>
21 #include <linux/wait_bit.h>
22 #include <linux/cred.h>
23 #include <linux/workqueue.h>
24 #include <linux/security.h>
25
26 struct cachefiles_cache;
27 struct cachefiles_object;
28
29 extern unsigned cachefiles_debug;
30 #define CACHEFILES_DEBUG_KENTER 1
31 #define CACHEFILES_DEBUG_KLEAVE 2
32 #define CACHEFILES_DEBUG_KDEBUG 4
33
34 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
35
36 /*
37 * node records
38 */
39 struct cachefiles_object {
40 struct fscache_object fscache; /* fscache handle */
41 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */
42 struct dentry *dentry; /* the file/dir representing this object */
43 struct dentry *backer; /* backing file */
44 loff_t i_size; /* object size */
45 unsigned long flags;
46 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
47 atomic_t usage; /* object usage count */
48 uint8_t type; /* object type */
49 uint8_t new; /* T if object new */
50 spinlock_t work_lock;
51 struct rb_node active_node; /* link in active tree (dentry is key) */
52 };
53
54 extern struct kmem_cache *cachefiles_object_jar;
55
56 /*
57 * Cache files cache definition
58 */
59 struct cachefiles_cache {
60 struct fscache_cache cache; /* FS-Cache record */
61 struct vfsmount *mnt; /* mountpoint holding the cache */
62 struct dentry *graveyard; /* directory into which dead objects go */
63 struct file *cachefilesd; /* manager daemon handle */
64 const struct cred *cache_cred; /* security override for accessing cache */
65 struct mutex daemon_mutex; /* command serialisation mutex */
66 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
67 struct rb_root active_nodes; /* active nodes (can't be culled) */
68 rwlock_t active_lock; /* lock for active_nodes */
69 atomic_t gravecounter; /* graveyard uniquifier */
70 atomic_t f_released; /* number of objects released lately */
71 atomic_long_t b_released; /* number of blocks released lately */
72 unsigned frun_percent; /* when to stop culling (% files) */
73 unsigned fcull_percent; /* when to start culling (% files) */
74 unsigned fstop_percent; /* when to stop allocating (% files) */
75 unsigned brun_percent; /* when to stop culling (% blocks) */
76 unsigned bcull_percent; /* when to start culling (% blocks) */
77 unsigned bstop_percent; /* when to stop allocating (% blocks) */
78 unsigned bsize; /* cache's block size */
79 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
80 uint64_t frun; /* when to stop culling */
81 uint64_t fcull; /* when to start culling */
82 uint64_t fstop; /* when to stop allocating */
83 sector_t brun; /* when to stop culling */
84 sector_t bcull; /* when to start culling */
85 sector_t bstop; /* when to stop allocating */
86 unsigned long flags;
87 #define CACHEFILES_READY 0 /* T if cache prepared */
88 #define CACHEFILES_DEAD 1 /* T if cache dead */
89 #define CACHEFILES_CULLING 2 /* T if cull engaged */
90 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
91 char *rootdirname; /* name of cache root directory */
92 char *secctx; /* LSM security context */
93 char *tag; /* cache binding tag */
94 };
95
96 /*
97 * backing file read tracking
98 */
99 struct cachefiles_one_read {
100 wait_queue_entry_t monitor; /* link into monitored waitqueue */
101 struct page *back_page; /* backing file page we're waiting for */
102 struct page *netfs_page; /* netfs page we're going to fill */
103 struct fscache_retrieval *op; /* retrieval op covering this */
104 struct list_head op_link; /* link in op's todo list */
105 };
106
107 /*
108 * backing file write tracking
109 */
110 struct cachefiles_one_write {
111 struct page *netfs_page; /* netfs page to copy */
112 struct cachefiles_object *object;
113 struct list_head obj_link; /* link in object's lists */
114 fscache_rw_complete_t end_io_func;
115 void *context;
116 };
117
118 /*
119 * auxiliary data xattr buffer
120 */
121 struct cachefiles_xattr {
122 uint16_t len;
123 uint8_t type;
124 uint8_t data[];
125 };
126
127 #include <trace/events/cachefiles.h>
128
129 /*
130 * note change of state for daemon
131 */
cachefiles_state_changed(struct cachefiles_cache * cache)132 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
133 {
134 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
135 wake_up_all(&cache->daemon_pollwq);
136 }
137
138 /*
139 * bind.c
140 */
141 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
142 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
143
144 /*
145 * daemon.c
146 */
147 extern const struct file_operations cachefiles_daemon_fops;
148
149 extern int cachefiles_has_space(struct cachefiles_cache *cache,
150 unsigned fnr, unsigned bnr);
151
152 /*
153 * interface.c
154 */
155 extern const struct fscache_cache_ops cachefiles_cache_ops;
156
157 /*
158 * key.c
159 */
160 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
161
162 /*
163 * namei.c
164 */
165 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
166 struct cachefiles_object *object,
167 blkcnt_t i_blocks);
168 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
169 struct cachefiles_object *object);
170 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
171 struct cachefiles_object *object,
172 const char *key,
173 struct cachefiles_xattr *auxdata);
174 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
175 struct dentry *dir,
176 const char *name);
177
178 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
179 char *filename);
180
181 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
182 struct dentry *dir, char *filename);
183
184 /*
185 * proc.c
186 */
187 #ifdef CONFIG_CACHEFILES_HISTOGRAM
188 extern atomic_t cachefiles_lookup_histogram[HZ];
189 extern atomic_t cachefiles_mkdir_histogram[HZ];
190 extern atomic_t cachefiles_create_histogram[HZ];
191
192 extern int __init cachefiles_proc_init(void);
193 extern void cachefiles_proc_cleanup(void);
194 static inline
cachefiles_hist(atomic_t histogram[],unsigned long start_jif)195 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
196 {
197 unsigned long jif = jiffies - start_jif;
198 if (jif >= HZ)
199 jif = HZ - 1;
200 atomic_inc(&histogram[jif]);
201 }
202
203 #else
204 #define cachefiles_proc_init() (0)
205 #define cachefiles_proc_cleanup() do {} while (0)
206 #define cachefiles_hist(hist, start_jif) do {} while (0)
207 #endif
208
209 /*
210 * rdwr.c
211 */
212 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
213 struct page *, gfp_t);
214 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
215 struct list_head *, unsigned *,
216 gfp_t);
217 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
218 gfp_t);
219 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
220 struct list_head *, unsigned *, gfp_t);
221 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
222 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
223
224 /*
225 * security.c
226 */
227 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
228 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
229 struct dentry *root,
230 const struct cred **_saved_cred);
231
cachefiles_begin_secure(struct cachefiles_cache * cache,const struct cred ** _saved_cred)232 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
233 const struct cred **_saved_cred)
234 {
235 *_saved_cred = override_creds(cache->cache_cred);
236 }
237
cachefiles_end_secure(struct cachefiles_cache * cache,const struct cred * saved_cred)238 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
239 const struct cred *saved_cred)
240 {
241 revert_creds(saved_cred);
242 }
243
244 /*
245 * xattr.c
246 */
247 extern int cachefiles_check_object_type(struct cachefiles_object *object);
248 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
249 struct cachefiles_xattr *auxdata);
250 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
251 struct cachefiles_xattr *auxdata);
252 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
253 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
254 struct cachefiles_xattr *auxdata);
255 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
256 struct dentry *dentry);
257
258
259 /*
260 * error handling
261 */
262
263 #define cachefiles_io_error(___cache, FMT, ...) \
264 do { \
265 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
266 fscache_io_error(&(___cache)->cache); \
267 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
268 } while (0)
269
270 #define cachefiles_io_error_obj(object, FMT, ...) \
271 do { \
272 struct cachefiles_cache *___cache; \
273 \
274 ___cache = container_of((object)->fscache.cache, \
275 struct cachefiles_cache, cache); \
276 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
277 } while (0)
278
279
280 /*
281 * debug tracing
282 */
283 #define dbgprintk(FMT, ...) \
284 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
285
286 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
287 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
288 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
289
290
291 #if defined(__KDEBUG)
292 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
293 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
294 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
295
296 #elif defined(CONFIG_CACHEFILES_DEBUG)
297 #define _enter(FMT, ...) \
298 do { \
299 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
300 kenter(FMT, ##__VA_ARGS__); \
301 } while (0)
302
303 #define _leave(FMT, ...) \
304 do { \
305 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
306 kleave(FMT, ##__VA_ARGS__); \
307 } while (0)
308
309 #define _debug(FMT, ...) \
310 do { \
311 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
312 kdebug(FMT, ##__VA_ARGS__); \
313 } while (0)
314
315 #else
316 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
317 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
318 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
319 #endif
320
321 #if 1 /* defined(__KDEBUGALL) */
322
323 #define ASSERT(X) \
324 do { \
325 if (unlikely(!(X))) { \
326 pr_err("\n"); \
327 pr_err("Assertion failed\n"); \
328 BUG(); \
329 } \
330 } while (0)
331
332 #define ASSERTCMP(X, OP, Y) \
333 do { \
334 if (unlikely(!((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 #define ASSERTIF(C, X) \
344 do { \
345 if (unlikely((C) && !(X))) { \
346 pr_err("\n"); \
347 pr_err("Assertion failed\n"); \
348 BUG(); \
349 } \
350 } while (0)
351
352 #define ASSERTIFCMP(C, X, OP, Y) \
353 do { \
354 if (unlikely((C) && !((X) OP (Y)))) { \
355 pr_err("\n"); \
356 pr_err("Assertion failed\n"); \
357 pr_err("%lx " #OP " %lx is false\n", \
358 (unsigned long)(X), (unsigned long)(Y)); \
359 BUG(); \
360 } \
361 } while (0)
362
363 #else
364
365 #define ASSERT(X) do {} while (0)
366 #define ASSERTCMP(X, OP, Y) do {} while (0)
367 #define ASSERTIF(C, X) do {} while (0)
368 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
369
370 #endif
371