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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#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
26struct cachefiles_cache;
27struct cachefiles_object;
28
29extern 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 */
39struct 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
54extern struct kmem_cache *cachefiles_object_jar;
55
56/*
57 * Cache files cache definition
58 */
59struct 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 */
99struct 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 */
110struct 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 */
121struct 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 */
132static 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 */
141extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
142extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
143
144/*
145 * daemon.c
146 */
147extern const struct file_operations cachefiles_daemon_fops;
148
149extern int cachefiles_has_space(struct cachefiles_cache *cache,
150 unsigned fnr, unsigned bnr);
151
152/*
153 * interface.c
154 */
155extern const struct fscache_cache_ops cachefiles_cache_ops;
156
157/*
158 * key.c
159 */
160extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
161
162/*
163 * namei.c
164 */
165extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
166 struct cachefiles_object *object,
167 blkcnt_t i_blocks);
168extern int cachefiles_delete_object(struct cachefiles_cache *cache,
169 struct cachefiles_object *object);
170extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
171 struct cachefiles_object *object,
172 const char *key,
173 struct cachefiles_xattr *auxdata);
174extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
175 struct dentry *dir,
176 const char *name);
177
178extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
179 char *filename);
180
181extern 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
188extern atomic_t cachefiles_lookup_histogram[HZ];
189extern atomic_t cachefiles_mkdir_histogram[HZ];
190extern atomic_t cachefiles_create_histogram[HZ];
191
192extern int __init cachefiles_proc_init(void);
193extern void cachefiles_proc_cleanup(void);
194static inline
195void 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 */
212extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
213 struct page *, gfp_t);
214extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
215 struct list_head *, unsigned *,
216 gfp_t);
217extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
218 gfp_t);
219extern int cachefiles_allocate_pages(struct fscache_retrieval *,
220 struct list_head *, unsigned *, gfp_t);
221extern int cachefiles_write_page(struct fscache_storage *, struct page *);
222extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
223
224/*
225 * security.c
226 */
227extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
228extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
229 struct dentry *root,
230 const struct cred **_saved_cred);
231
232static 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
238static 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 */
247extern int cachefiles_check_object_type(struct cachefiles_object *object);
248extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
249 struct cachefiles_xattr *auxdata);
250extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
251 struct cachefiles_xattr *auxdata);
252extern int cachefiles_check_auxdata(struct cachefiles_object *object);
253extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
254 struct cachefiles_xattr *auxdata);
255extern 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, ...) \
264do { \
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, ...) \
271do { \
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, ...) \
298do { \
299 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
300 kenter(FMT, ##__VA_ARGS__); \
301} while (0)
302
303#define _leave(FMT, ...) \
304do { \
305 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
306 kleave(FMT, ##__VA_ARGS__); \
307} while (0)
308
309#define _debug(FMT, ...) \
310do { \
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) \
324do { \
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) \
333do { \
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) \
344do { \
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) \
353do { \
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