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