Merge tag 'vfio-v4.10-rc3' of git://github.com/awilliam/linux-vfio
[linux-2.6-block.git] / fs / cachefiles / 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 (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
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12#ifdef pr_fmt
13#undef pr_fmt
14#endif
15
16#define pr_fmt(fmt) "CacheFiles: " fmt
17
18
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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
25struct cachefiles_cache;
26struct cachefiles_object;
27
28extern unsigned cachefiles_debug;
29#define CACHEFILES_DEBUG_KENTER 1
30#define CACHEFILES_DEBUG_KLEAVE 2
31#define CACHEFILES_DEBUG_KDEBUG 4
32
71baba4b 33#define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
5f4f9f4a 34
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35/*
36 * node records
37 */
38struct 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
53extern struct kmem_cache *cachefiles_object_jar;
54
55/*
56 * Cache files cache definition
57 */
58struct 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 */
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69 atomic_t f_released; /* number of objects released lately */
70 atomic_long_t b_released; /* number of blocks released lately */
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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 */
98struct 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 */
109struct 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 */
120struct 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 */
129static 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/*
911e690e 136 * bind.c
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137 */
138extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
139extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
140
141/*
911e690e 142 * daemon.c
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143 */
144extern const struct file_operations cachefiles_daemon_fops;
145
146extern int cachefiles_has_space(struct cachefiles_cache *cache,
147 unsigned fnr, unsigned bnr);
148
149/*
911e690e 150 * interface.c
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151 */
152extern const struct fscache_cache_ops cachefiles_cache_ops;
153
154/*
911e690e 155 * key.c
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156 */
157extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
158
159/*
911e690e 160 * namei.c
9ae326a6 161 */
a5b3a80b 162extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
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163 struct cachefiles_object *object,
164 blkcnt_t i_blocks);
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165extern int cachefiles_delete_object(struct cachefiles_cache *cache,
166 struct cachefiles_object *object);
167extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
168 struct cachefiles_object *object,
169 const char *key,
170 struct cachefiles_xattr *auxdata);
171extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
172 struct dentry *dir,
173 const char *name);
174
175extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
176 char *filename);
177
178extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
179 struct dentry *dir, char *filename);
180
181/*
911e690e 182 * proc.c
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183 */
184#ifdef CONFIG_CACHEFILES_HISTOGRAM
185extern atomic_t cachefiles_lookup_histogram[HZ];
186extern atomic_t cachefiles_mkdir_histogram[HZ];
187extern atomic_t cachefiles_create_histogram[HZ];
188
189extern int __init cachefiles_proc_init(void);
190extern void cachefiles_proc_cleanup(void);
191static inline
192void 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/*
911e690e 207 * rdwr.c
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208 */
209extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
210 struct page *, gfp_t);
211extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
212 struct list_head *, unsigned *,
213 gfp_t);
214extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
215 gfp_t);
216extern int cachefiles_allocate_pages(struct fscache_retrieval *,
217 struct list_head *, unsigned *, gfp_t);
218extern int cachefiles_write_page(struct fscache_storage *, struct page *);
219extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
220
221/*
911e690e 222 * security.c
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223 */
224extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
225extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
226 struct dentry *root,
227 const struct cred **_saved_cred);
228
229static 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
235static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
236 const struct cred *saved_cred)
237{
238 revert_creds(saved_cred);
239}
240
241/*
911e690e 242 * xattr.c
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243 */
244extern int cachefiles_check_object_type(struct cachefiles_object *object);
245extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
246 struct cachefiles_xattr *auxdata);
247extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
248 struct cachefiles_xattr *auxdata);
5002d7be 249extern int cachefiles_check_auxdata(struct cachefiles_object *object);
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250extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
251 struct cachefiles_xattr *auxdata);
252extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
253 struct dentry *dentry);
254
255
256/*
257 * error handling
258 */
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259
260#define cachefiles_io_error(___cache, FMT, ...) \
261do { \
6ff66ac7 262 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
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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, ...) \
268do { \
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
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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, ...) \
295do { \
296 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
297 kenter(FMT, ##__VA_ARGS__); \
298} while (0)
299
300#define _leave(FMT, ...) \
301do { \
302 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
303 kleave(FMT, ##__VA_ARGS__); \
304} while (0)
305
306#define _debug(FMT, ...) \
307do { \
308 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
309 kdebug(FMT, ##__VA_ARGS__); \
310} while (0)
311
312#else
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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__)
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316#endif
317
318#if 1 /* defined(__KDEBUGALL) */
319
320#define ASSERT(X) \
321do { \
322 if (unlikely(!(X))) { \
4e1eb883 323 pr_err("\n"); \
0227d6ab 324 pr_err("Assertion failed\n"); \
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325 BUG(); \
326 } \
327} while (0)
328
329#define ASSERTCMP(X, OP, Y) \
330do { \
331 if (unlikely(!((X) OP (Y)))) { \
4e1eb883 332 pr_err("\n"); \
0227d6ab 333 pr_err("Assertion failed\n"); \
4e1eb883 334 pr_err("%lx " #OP " %lx is false\n", \
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335 (unsigned long)(X), (unsigned long)(Y)); \
336 BUG(); \
337 } \
338} while (0)
339
340#define ASSERTIF(C, X) \
341do { \
342 if (unlikely((C) && !(X))) { \
4e1eb883 343 pr_err("\n"); \
0227d6ab 344 pr_err("Assertion failed\n"); \
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345 BUG(); \
346 } \
347} while (0)
348
349#define ASSERTIFCMP(C, X, OP, Y) \
350do { \
351 if (unlikely((C) && !((X) OP (Y)))) { \
4e1eb883 352 pr_err("\n"); \
0227d6ab 353 pr_err("Assertion failed\n"); \
4e1eb883 354 pr_err("%lx " #OP " %lx is false\n", \
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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