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 #include <linux/fscache-cache.h>
13 #include <linux/timer.h>
14 #include <linux/wait.h>
15 #include <linux/workqueue.h>
16 #include <linux/security.h>
17
18 struct cachefiles_cache;
19 struct cachefiles_object;
20
21 extern unsigned cachefiles_debug;
22 #define CACHEFILES_DEBUG_KENTER 1
23 #define CACHEFILES_DEBUG_KLEAVE 2
24 #define CACHEFILES_DEBUG_KDEBUG 4
25
26 /*
27 * node records
28 */
29 struct cachefiles_object {
30 struct fscache_object fscache; /* fscache handle */
31 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */
32 struct dentry *dentry; /* the file/dir representing this object */
33 struct dentry *backer; /* backing file */
34 loff_t i_size; /* object size */
35 unsigned long flags;
36 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
37 #define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */
38 atomic_t usage; /* object usage count */
39 uint8_t type; /* object type */
40 uint8_t new; /* T if object new */
41 spinlock_t work_lock;
42 struct rb_node active_node; /* link in active tree (dentry is key) */
43 };
44
45 extern struct kmem_cache *cachefiles_object_jar;
46
47 /*
48 * Cache files cache definition
49 */
50 struct cachefiles_cache {
51 struct fscache_cache cache; /* FS-Cache record */
52 struct vfsmount *mnt; /* mountpoint holding the cache */
53 struct dentry *graveyard; /* directory into which dead objects go */
54 struct file *cachefilesd; /* manager daemon handle */
55 const struct cred *cache_cred; /* security override for accessing cache */
56 struct mutex daemon_mutex; /* command serialisation mutex */
57 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
58 struct rb_root active_nodes; /* active nodes (can't be culled) */
59 rwlock_t active_lock; /* lock for active_nodes */
60 atomic_t gravecounter; /* graveyard uniquifier */
61 unsigned frun_percent; /* when to stop culling (% files) */
62 unsigned fcull_percent; /* when to start culling (% files) */
63 unsigned fstop_percent; /* when to stop allocating (% files) */
64 unsigned brun_percent; /* when to stop culling (% blocks) */
65 unsigned bcull_percent; /* when to start culling (% blocks) */
66 unsigned bstop_percent; /* when to stop allocating (% blocks) */
67 unsigned bsize; /* cache's block size */
68 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
69 uint64_t frun; /* when to stop culling */
70 uint64_t fcull; /* when to start culling */
71 uint64_t fstop; /* when to stop allocating */
72 sector_t brun; /* when to stop culling */
73 sector_t bcull; /* when to start culling */
74 sector_t bstop; /* when to stop allocating */
75 unsigned long flags;
76 #define CACHEFILES_READY 0 /* T if cache prepared */
77 #define CACHEFILES_DEAD 1 /* T if cache dead */
78 #define CACHEFILES_CULLING 2 /* T if cull engaged */
79 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
80 char *rootdirname; /* name of cache root directory */
81 char *secctx; /* LSM security context */
82 char *tag; /* cache binding tag */
83 };
84
85 /*
86 * backing file read tracking
87 */
88 struct cachefiles_one_read {
89 wait_queue_t monitor; /* link into monitored waitqueue */
90 struct page *back_page; /* backing file page we're waiting for */
91 struct page *netfs_page; /* netfs page we're going to fill */
92 struct fscache_retrieval *op; /* retrieval op covering this */
93 struct list_head op_link; /* link in op's todo list */
94 };
95
96 /*
97 * backing file write tracking
98 */
99 struct cachefiles_one_write {
100 struct page *netfs_page; /* netfs page to copy */
101 struct cachefiles_object *object;
102 struct list_head obj_link; /* link in object's lists */
103 fscache_rw_complete_t end_io_func;
104 void *context;
105 };
106
107 /*
108 * auxiliary data xattr buffer
109 */
110 struct cachefiles_xattr {
111 uint16_t len;
112 uint8_t type;
113 uint8_t data[];
114 };
115
116 /*
117 * note change of state for daemon
118 */
cachefiles_state_changed(struct cachefiles_cache * cache)119 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
120 {
121 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
122 wake_up_all(&cache->daemon_pollwq);
123 }
124
125 /*
126 * bind.c
127 */
128 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
129 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
130
131 /*
132 * daemon.c
133 */
134 extern const struct file_operations cachefiles_daemon_fops;
135
136 extern int cachefiles_has_space(struct cachefiles_cache *cache,
137 unsigned fnr, unsigned bnr);
138
139 /*
140 * interface.c
141 */
142 extern const struct fscache_cache_ops cachefiles_cache_ops;
143
144 /*
145 * key.c
146 */
147 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
148
149 /*
150 * namei.c
151 */
152 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
153 struct cachefiles_object *object);
154 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
155 struct cachefiles_object *object,
156 const char *key,
157 struct cachefiles_xattr *auxdata);
158 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
159 struct dentry *dir,
160 const char *name);
161
162 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
163 char *filename);
164
165 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
166 struct dentry *dir, char *filename);
167
168 /*
169 * proc.c
170 */
171 #ifdef CONFIG_CACHEFILES_HISTOGRAM
172 extern atomic_t cachefiles_lookup_histogram[HZ];
173 extern atomic_t cachefiles_mkdir_histogram[HZ];
174 extern atomic_t cachefiles_create_histogram[HZ];
175
176 extern int __init cachefiles_proc_init(void);
177 extern void cachefiles_proc_cleanup(void);
178 static inline
cachefiles_hist(atomic_t histogram[],unsigned long start_jif)179 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
180 {
181 unsigned long jif = jiffies - start_jif;
182 if (jif >= HZ)
183 jif = HZ - 1;
184 atomic_inc(&histogram[jif]);
185 }
186
187 #else
188 #define cachefiles_proc_init() (0)
189 #define cachefiles_proc_cleanup() do {} while (0)
190 #define cachefiles_hist(hist, start_jif) do {} while (0)
191 #endif
192
193 /*
194 * rdwr.c
195 */
196 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
197 struct page *, gfp_t);
198 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
199 struct list_head *, unsigned *,
200 gfp_t);
201 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
202 gfp_t);
203 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
204 struct list_head *, unsigned *, gfp_t);
205 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
206 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
207
208 /*
209 * security.c
210 */
211 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
212 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
213 struct dentry *root,
214 const struct cred **_saved_cred);
215
cachefiles_begin_secure(struct cachefiles_cache * cache,const struct cred ** _saved_cred)216 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
217 const struct cred **_saved_cred)
218 {
219 *_saved_cred = override_creds(cache->cache_cred);
220 }
221
cachefiles_end_secure(struct cachefiles_cache * cache,const struct cred * saved_cred)222 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
223 const struct cred *saved_cred)
224 {
225 revert_creds(saved_cred);
226 }
227
228 /*
229 * xattr.c
230 */
231 extern int cachefiles_check_object_type(struct cachefiles_object *object);
232 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
233 struct cachefiles_xattr *auxdata);
234 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
235 struct cachefiles_xattr *auxdata);
236 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
237 struct cachefiles_xattr *auxdata);
238 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
239 struct dentry *dentry);
240
241
242 /*
243 * error handling
244 */
245 #define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__)
246
247 #define cachefiles_io_error(___cache, FMT, ...) \
248 do { \
249 kerror("I/O Error: " FMT, ##__VA_ARGS__); \
250 fscache_io_error(&(___cache)->cache); \
251 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
252 } while (0)
253
254 #define cachefiles_io_error_obj(object, FMT, ...) \
255 do { \
256 struct cachefiles_cache *___cache; \
257 \
258 ___cache = container_of((object)->fscache.cache, \
259 struct cachefiles_cache, cache); \
260 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
261 } while (0)
262
263
264 /*
265 * debug tracing
266 */
267 #define dbgprintk(FMT, ...) \
268 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
269
270 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
271 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
272 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
273
274
275 #if defined(__KDEBUG)
276 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
277 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
278 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
279
280 #elif defined(CONFIG_CACHEFILES_DEBUG)
281 #define _enter(FMT, ...) \
282 do { \
283 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
284 kenter(FMT, ##__VA_ARGS__); \
285 } while (0)
286
287 #define _leave(FMT, ...) \
288 do { \
289 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
290 kleave(FMT, ##__VA_ARGS__); \
291 } while (0)
292
293 #define _debug(FMT, ...) \
294 do { \
295 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
296 kdebug(FMT, ##__VA_ARGS__); \
297 } while (0)
298
299 #else
300 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
301 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
302 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
303 #endif
304
305 #if 1 /* defined(__KDEBUGALL) */
306
307 #define ASSERT(X) \
308 do { \
309 if (unlikely(!(X))) { \
310 printk(KERN_ERR "\n"); \
311 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
312 BUG(); \
313 } \
314 } while (0)
315
316 #define ASSERTCMP(X, OP, Y) \
317 do { \
318 if (unlikely(!((X) OP (Y)))) { \
319 printk(KERN_ERR "\n"); \
320 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
321 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
322 (unsigned long)(X), (unsigned long)(Y)); \
323 BUG(); \
324 } \
325 } while (0)
326
327 #define ASSERTIF(C, X) \
328 do { \
329 if (unlikely((C) && !(X))) { \
330 printk(KERN_ERR "\n"); \
331 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
332 BUG(); \
333 } \
334 } while (0)
335
336 #define ASSERTIFCMP(C, X, OP, Y) \
337 do { \
338 if (unlikely((C) && !((X) OP (Y)))) { \
339 printk(KERN_ERR "\n"); \
340 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
341 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
342 (unsigned long)(X), (unsigned long)(Y)); \
343 BUG(); \
344 } \
345 } while (0)
346
347 #else
348
349 #define ASSERT(X) do {} while (0)
350 #define ASSERTCMP(X, OP, Y) do {} while (0)
351 #define ASSERTIF(C, X) do {} while (0)
352 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
353
354 #endif
355