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internal.h
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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 ([email protected])
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  */
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
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 
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 
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
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