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.h>
22 #include <linux/workqueue.h>
23 #include <linux/security.h>
24
25 struct cachefiles_cache;
26 struct cachefiles_object;
27
28 extern unsigned cachefiles_debug;
29 #define CACHEFILES_DEBUG_KENTER 1
30 #define CACHEFILES_DEBUG_KLEAVE 2
31 #define CACHEFILES_DEBUG_KDEBUG 4
32
33 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
34
35 /*
36 * node records
37 */
38 struct cachefiles_object {
39 struct fscache_object fscache; /* fscache handle */
40 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */
41 struct dentry *dentry; /* the file/dir representing this object */
42 struct dentry *backer; /* backing file */
43 loff_t i_size; /* object size */
44 unsigned long flags;
45 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
46 atomic_t usage; /* object usage count */
47 uint8_t type; /* object type */
48 uint8_t new; /* T if object new */
49 spinlock_t work_lock;
50 struct rb_node active_node; /* link in active tree (dentry is key) */
51 };
52
53 extern struct kmem_cache *cachefiles_object_jar;
54
55 /*
56 * Cache files cache definition
57 */
58 struct cachefiles_cache {
59 struct fscache_cache cache; /* FS-Cache record */
60 struct vfsmount *mnt; /* mountpoint holding the cache */
61 struct dentry *graveyard; /* directory into which dead objects go */
62 struct file *cachefilesd; /* manager daemon handle */
63 const struct cred *cache_cred; /* security override for accessing cache */
64 struct mutex daemon_mutex; /* command serialisation mutex */
65 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
66 struct rb_root active_nodes; /* active nodes (can't be culled) */
67 rwlock_t active_lock; /* lock for active_nodes */
68 atomic_t gravecounter; /* graveyard uniquifier */
69 atomic_t f_released; /* number of objects released lately */
70 atomic_long_t b_released; /* number of blocks released lately */
71 unsigned frun_percent; /* when to stop culling (% files) */
72 unsigned fcull_percent; /* when to start culling (% files) */
73 unsigned fstop_percent; /* when to stop allocating (% files) */
74 unsigned brun_percent; /* when to stop culling (% blocks) */
75 unsigned bcull_percent; /* when to start culling (% blocks) */
76 unsigned bstop_percent; /* when to stop allocating (% blocks) */
77 unsigned bsize; /* cache's block size */
78 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
79 uint64_t frun; /* when to stop culling */
80 uint64_t fcull; /* when to start culling */
81 uint64_t fstop; /* when to stop allocating */
82 sector_t brun; /* when to stop culling */
83 sector_t bcull; /* when to start culling */
84 sector_t bstop; /* when to stop allocating */
85 unsigned long flags;
86 #define CACHEFILES_READY 0 /* T if cache prepared */
87 #define CACHEFILES_DEAD 1 /* T if cache dead */
88 #define CACHEFILES_CULLING 2 /* T if cull engaged */
89 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
90 char *rootdirname; /* name of cache root directory */
91 char *secctx; /* LSM security context */
92 char *tag; /* cache binding tag */
93 };
94
95 /*
96 * backing file read tracking
97 */
98 struct cachefiles_one_read {
99 wait_queue_t monitor; /* link into monitored waitqueue */
100 struct page *back_page; /* backing file page we're waiting for */
101 struct page *netfs_page; /* netfs page we're going to fill */
102 struct fscache_retrieval *op; /* retrieval op covering this */
103 struct list_head op_link; /* link in op's todo list */
104 };
105
106 /*
107 * backing file write tracking
108 */
109 struct cachefiles_one_write {
110 struct page *netfs_page; /* netfs page to copy */
111 struct cachefiles_object *object;
112 struct list_head obj_link; /* link in object's lists */
113 fscache_rw_complete_t end_io_func;
114 void *context;
115 };
116
117 /*
118 * auxiliary data xattr buffer
119 */
120 struct cachefiles_xattr {
121 uint16_t len;
122 uint8_t type;
123 uint8_t data[];
124 };
125
126 /*
127 * note change of state for daemon
128 */
cachefiles_state_changed(struct cachefiles_cache * cache)129 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
130 {
131 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
132 wake_up_all(&cache->daemon_pollwq);
133 }
134
135 /*
136 * bind.c
137 */
138 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
139 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
140
141 /*
142 * daemon.c
143 */
144 extern const struct file_operations cachefiles_daemon_fops;
145
146 extern int cachefiles_has_space(struct cachefiles_cache *cache,
147 unsigned fnr, unsigned bnr);
148
149 /*
150 * interface.c
151 */
152 extern const struct fscache_cache_ops cachefiles_cache_ops;
153
154 /*
155 * key.c
156 */
157 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
158
159 /*
160 * namei.c
161 */
162 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
163 struct cachefiles_object *object,
164 blkcnt_t i_blocks);
165 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
166 struct cachefiles_object *object);
167 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
168 struct cachefiles_object *object,
169 const char *key,
170 struct cachefiles_xattr *auxdata);
171 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
172 struct dentry *dir,
173 const char *name);
174
175 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
176 char *filename);
177
178 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
179 struct dentry *dir, char *filename);
180
181 /*
182 * proc.c
183 */
184 #ifdef CONFIG_CACHEFILES_HISTOGRAM
185 extern atomic_t cachefiles_lookup_histogram[HZ];
186 extern atomic_t cachefiles_mkdir_histogram[HZ];
187 extern atomic_t cachefiles_create_histogram[HZ];
188
189 extern int __init cachefiles_proc_init(void);
190 extern void cachefiles_proc_cleanup(void);
191 static inline
cachefiles_hist(atomic_t histogram[],unsigned long start_jif)192 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
193 {
194 unsigned long jif = jiffies - start_jif;
195 if (jif >= HZ)
196 jif = HZ - 1;
197 atomic_inc(&histogram[jif]);
198 }
199
200 #else
201 #define cachefiles_proc_init() (0)
202 #define cachefiles_proc_cleanup() do {} while (0)
203 #define cachefiles_hist(hist, start_jif) do {} while (0)
204 #endif
205
206 /*
207 * rdwr.c
208 */
209 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
210 struct page *, gfp_t);
211 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
212 struct list_head *, unsigned *,
213 gfp_t);
214 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
215 gfp_t);
216 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
217 struct list_head *, unsigned *, gfp_t);
218 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
219 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
220
221 /*
222 * security.c
223 */
224 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
225 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
226 struct dentry *root,
227 const struct cred **_saved_cred);
228
cachefiles_begin_secure(struct cachefiles_cache * cache,const struct cred ** _saved_cred)229 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
230 const struct cred **_saved_cred)
231 {
232 *_saved_cred = override_creds(cache->cache_cred);
233 }
234
cachefiles_end_secure(struct cachefiles_cache * cache,const struct cred * saved_cred)235 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
236 const struct cred *saved_cred)
237 {
238 revert_creds(saved_cred);
239 }
240
241 /*
242 * xattr.c
243 */
244 extern int cachefiles_check_object_type(struct cachefiles_object *object);
245 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
246 struct cachefiles_xattr *auxdata);
247 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
248 struct cachefiles_xattr *auxdata);
249 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
250 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
251 struct cachefiles_xattr *auxdata);
252 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
253 struct dentry *dentry);
254
255
256 /*
257 * error handling
258 */
259
260 #define cachefiles_io_error(___cache, FMT, ...) \
261 do { \
262 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
263 fscache_io_error(&(___cache)->cache); \
264 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
265 } while (0)
266
267 #define cachefiles_io_error_obj(object, FMT, ...) \
268 do { \
269 struct cachefiles_cache *___cache; \
270 \
271 ___cache = container_of((object)->fscache.cache, \
272 struct cachefiles_cache, cache); \
273 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
274 } while (0)
275
276
277 /*
278 * debug tracing
279 */
280 #define dbgprintk(FMT, ...) \
281 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
282
283 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
284 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
285 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
286
287
288 #if defined(__KDEBUG)
289 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
290 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
291 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
292
293 #elif defined(CONFIG_CACHEFILES_DEBUG)
294 #define _enter(FMT, ...) \
295 do { \
296 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
297 kenter(FMT, ##__VA_ARGS__); \
298 } while (0)
299
300 #define _leave(FMT, ...) \
301 do { \
302 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
303 kleave(FMT, ##__VA_ARGS__); \
304 } while (0)
305
306 #define _debug(FMT, ...) \
307 do { \
308 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
309 kdebug(FMT, ##__VA_ARGS__); \
310 } while (0)
311
312 #else
313 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
314 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
315 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
316 #endif
317
318 #if 1 /* defined(__KDEBUGALL) */
319
320 #define ASSERT(X) \
321 do { \
322 if (unlikely(!(X))) { \
323 pr_err("\n"); \
324 pr_err("Assertion failed\n"); \
325 BUG(); \
326 } \
327 } while (0)
328
329 #define ASSERTCMP(X, OP, Y) \
330 do { \
331 if (unlikely(!((X) OP (Y)))) { \
332 pr_err("\n"); \
333 pr_err("Assertion failed\n"); \
334 pr_err("%lx " #OP " %lx is false\n", \
335 (unsigned long)(X), (unsigned long)(Y)); \
336 BUG(); \
337 } \
338 } while (0)
339
340 #define ASSERTIF(C, X) \
341 do { \
342 if (unlikely((C) && !(X))) { \
343 pr_err("\n"); \
344 pr_err("Assertion failed\n"); \
345 BUG(); \
346 } \
347 } while (0)
348
349 #define ASSERTIFCMP(C, X, OP, Y) \
350 do { \
351 if (unlikely((C) && !((X) OP (Y)))) { \
352 pr_err("\n"); \
353 pr_err("Assertion failed\n"); \
354 pr_err("%lx " #OP " %lx is false\n", \
355 (unsigned long)(X), (unsigned long)(Y)); \
356 BUG(); \
357 } \
358 } while (0)
359
360 #else
361
362 #define ASSERT(X) do {} while (0)
363 #define ASSERTCMP(X, OP, Y) do {} while (0)
364 #define ASSERTIF(C, X) do {} while (0)
365 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
366
367 #endif
368