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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 (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
18struct cachefiles_cache;
19struct cachefiles_object;
20
21extern 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 */
29struct 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 atomic_t usage; /* object usage count */
38 uint8_t type; /* object type */
39 uint8_t new; /* T if object new */
40 spinlock_t work_lock;
41 struct rb_node active_node; /* link in active tree (dentry is key) */
42};
43
44extern struct kmem_cache *cachefiles_object_jar;
45
46/*
47 * Cache files cache definition
48 */
49struct cachefiles_cache {
50 struct fscache_cache cache; /* FS-Cache record */
51 struct vfsmount *mnt; /* mountpoint holding the cache */
52 struct dentry *graveyard; /* directory into which dead objects go */
53 struct file *cachefilesd; /* manager daemon handle */
54 const struct cred *cache_cred; /* security override for accessing cache */
55 struct mutex daemon_mutex; /* command serialisation mutex */
56 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
57 struct rb_root active_nodes; /* active nodes (can't be culled) */
58 rwlock_t active_lock; /* lock for active_nodes */
59 atomic_t gravecounter; /* graveyard uniquifier */
60 unsigned frun_percent; /* when to stop culling (% files) */
61 unsigned fcull_percent; /* when to start culling (% files) */
62 unsigned fstop_percent; /* when to stop allocating (% files) */
63 unsigned brun_percent; /* when to stop culling (% blocks) */
64 unsigned bcull_percent; /* when to start culling (% blocks) */
65 unsigned bstop_percent; /* when to stop allocating (% blocks) */
66 unsigned bsize; /* cache's block size */
67 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
68 uint64_t frun; /* when to stop culling */
69 uint64_t fcull; /* when to start culling */
70 uint64_t fstop; /* when to stop allocating */
71 sector_t brun; /* when to stop culling */
72 sector_t bcull; /* when to start culling */
73 sector_t bstop; /* when to stop allocating */
74 unsigned long flags;
75#define CACHEFILES_READY 0 /* T if cache prepared */
76#define CACHEFILES_DEAD 1 /* T if cache dead */
77#define CACHEFILES_CULLING 2 /* T if cull engaged */
78#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
79 char *rootdirname; /* name of cache root directory */
80 char *secctx; /* LSM security context */
81 char *tag; /* cache binding tag */
82};
83
84/*
85 * backing file read tracking
86 */
87struct cachefiles_one_read {
88 wait_queue_t monitor; /* link into monitored waitqueue */
89 struct page *back_page; /* backing file page we're waiting for */
90 struct page *netfs_page; /* netfs page we're going to fill */
91 struct fscache_retrieval *op; /* retrieval op covering this */
92 struct list_head op_link; /* link in op's todo list */
93};
94
95/*
96 * backing file write tracking
97 */
98struct cachefiles_one_write {
99 struct page *netfs_page; /* netfs page to copy */
100 struct cachefiles_object *object;
101 struct list_head obj_link; /* link in object's lists */
102 fscache_rw_complete_t end_io_func;
103 void *context;
104};
105
106/*
107 * auxiliary data xattr buffer
108 */
109struct cachefiles_xattr {
110 uint16_t len;
111 uint8_t type;
112 uint8_t data[];
113};
114
115/*
116 * note change of state for daemon
117 */
118static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
119{
120 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
121 wake_up_all(&cache->daemon_pollwq);
122}
123
124/*
125 * cf-bind.c
126 */
127extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
128extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
129
130/*
131 * cf-daemon.c
132 */
133extern const struct file_operations cachefiles_daemon_fops;
134
135extern int cachefiles_has_space(struct cachefiles_cache *cache,
136 unsigned fnr, unsigned bnr);
137
138/*
139 * cf-interface.c
140 */
141extern const struct fscache_cache_ops cachefiles_cache_ops;
142
143/*
144 * cf-key.c
145 */
146extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
147
148/*
149 * cf-namei.c
150 */
151extern int cachefiles_delete_object(struct cachefiles_cache *cache,
152 struct cachefiles_object *object);
153extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
154 struct cachefiles_object *object,
155 const char *key,
156 struct cachefiles_xattr *auxdata);
157extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
158 struct dentry *dir,
159 const char *name);
160
161extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
162 char *filename);
163
164extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
165 struct dentry *dir, char *filename);
166
167/*
168 * cf-proc.c
169 */
170#ifdef CONFIG_CACHEFILES_HISTOGRAM
171extern atomic_t cachefiles_lookup_histogram[HZ];
172extern atomic_t cachefiles_mkdir_histogram[HZ];
173extern atomic_t cachefiles_create_histogram[HZ];
174
175extern int __init cachefiles_proc_init(void);
176extern void cachefiles_proc_cleanup(void);
177static inline
178void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
179{
180 unsigned long jif = jiffies - start_jif;
181 if (jif >= HZ)
182 jif = HZ - 1;
183 atomic_inc(&histogram[jif]);
184}
185
186#else
187#define cachefiles_proc_init() (0)
188#define cachefiles_proc_cleanup() do {} while (0)
189#define cachefiles_hist(hist, start_jif) do {} while (0)
190#endif
191
192/*
193 * cf-rdwr.c
194 */
195extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
196 struct page *, gfp_t);
197extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
198 struct list_head *, unsigned *,
199 gfp_t);
200extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
201 gfp_t);
202extern int cachefiles_allocate_pages(struct fscache_retrieval *,
203 struct list_head *, unsigned *, gfp_t);
204extern int cachefiles_write_page(struct fscache_storage *, struct page *);
205extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
206
207/*
208 * cf-security.c
209 */
210extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
211extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
212 struct dentry *root,
213 const struct cred **_saved_cred);
214
215static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
216 const struct cred **_saved_cred)
217{
218 *_saved_cred = override_creds(cache->cache_cred);
219}
220
221static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
222 const struct cred *saved_cred)
223{
224 revert_creds(saved_cred);
225}
226
227/*
228 * cf-xattr.c
229 */
230extern int cachefiles_check_object_type(struct cachefiles_object *object);
231extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
232 struct cachefiles_xattr *auxdata);
233extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
234 struct cachefiles_xattr *auxdata);
235extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
236 struct cachefiles_xattr *auxdata);
237extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
238 struct dentry *dentry);
239
240
241/*
242 * error handling
243 */
244#define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__)
245
246#define cachefiles_io_error(___cache, FMT, ...) \
247do { \
248 kerror("I/O Error: " FMT, ##__VA_ARGS__); \
249 fscache_io_error(&(___cache)->cache); \
250 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
251} while (0)
252
253#define cachefiles_io_error_obj(object, FMT, ...) \
254do { \
255 struct cachefiles_cache *___cache; \
256 \
257 ___cache = container_of((object)->fscache.cache, \
258 struct cachefiles_cache, cache); \
259 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
260} while (0)
261
262
263/*
264 * debug tracing
265 */
266#define dbgprintk(FMT, ...) \
267 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
268
269/* make sure we maintain the format strings, even when debugging is disabled */
270static inline void _dbprintk(const char *fmt, ...)
271 __attribute__((format(printf, 1, 2)));
272static inline void _dbprintk(const char *fmt, ...)
273{
274}
275
276#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
277#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
278#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
279
280
281#if defined(__KDEBUG)
282#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
283#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
284#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
285
286#elif defined(CONFIG_CACHEFILES_DEBUG)
287#define _enter(FMT, ...) \
288do { \
289 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
290 kenter(FMT, ##__VA_ARGS__); \
291} while (0)
292
293#define _leave(FMT, ...) \
294do { \
295 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
296 kleave(FMT, ##__VA_ARGS__); \
297} while (0)
298
299#define _debug(FMT, ...) \
300do { \
301 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
302 kdebug(FMT, ##__VA_ARGS__); \
303} while (0)
304
305#else
306#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
307#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
308#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
309#endif
310
311#if 1 /* defined(__KDEBUGALL) */
312
313#define ASSERT(X) \
314do { \
315 if (unlikely(!(X))) { \
316 printk(KERN_ERR "\n"); \
317 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
318 BUG(); \
319 } \
320} while (0)
321
322#define ASSERTCMP(X, OP, Y) \
323do { \
324 if (unlikely(!((X) OP (Y)))) { \
325 printk(KERN_ERR "\n"); \
326 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
327 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
328 (unsigned long)(X), (unsigned long)(Y)); \
329 BUG(); \
330 } \
331} while (0)
332
333#define ASSERTIF(C, X) \
334do { \
335 if (unlikely((C) && !(X))) { \
336 printk(KERN_ERR "\n"); \
337 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
338 BUG(); \
339 } \
340} while (0)
341
342#define ASSERTIFCMP(C, X, OP, Y) \
343do { \
344 if (unlikely((C) && !((X) OP (Y)))) { \
345 printk(KERN_ERR "\n"); \
346 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
347 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
348 (unsigned long)(X), (unsigned long)(Y)); \
349 BUG(); \
350 } \
351} while (0)
352
353#else
354
355#define ASSERT(X) do {} while (0)
356#define ASSERTCMP(X, OP, Y) do {} while (0)
357#define ASSERTIF(C, X) do {} while (0)
358#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
359
360#endif