xref: /openbmc/linux/fs/cachefiles/internal.h (revision fa0a497b)
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  */
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 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
165 				    struct cachefiles_object *object);
166 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
167 				     struct cachefiles_object *object,
168 				     const char *key,
169 				     struct cachefiles_xattr *auxdata);
170 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
171 					       struct dentry *dir,
172 					       const char *name);
173 
174 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
175 			   char *filename);
176 
177 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
178 				   struct dentry *dir, char *filename);
179 
180 /*
181  * proc.c
182  */
183 #ifdef CONFIG_CACHEFILES_HISTOGRAM
184 extern atomic_t cachefiles_lookup_histogram[HZ];
185 extern atomic_t cachefiles_mkdir_histogram[HZ];
186 extern atomic_t cachefiles_create_histogram[HZ];
187 
188 extern int __init cachefiles_proc_init(void);
189 extern void cachefiles_proc_cleanup(void);
190 static inline
191 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
192 {
193 	unsigned long jif = jiffies - start_jif;
194 	if (jif >= HZ)
195 		jif = HZ - 1;
196 	atomic_inc(&histogram[jif]);
197 }
198 
199 #else
200 #define cachefiles_proc_init()		(0)
201 #define cachefiles_proc_cleanup()	do {} while (0)
202 #define cachefiles_hist(hist, start_jif) do {} while (0)
203 #endif
204 
205 /*
206  * rdwr.c
207  */
208 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
209 					 struct page *, gfp_t);
210 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
211 					  struct list_head *, unsigned *,
212 					  gfp_t);
213 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
214 				    gfp_t);
215 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
216 				     struct list_head *, unsigned *, gfp_t);
217 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
218 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
219 
220 /*
221  * security.c
222  */
223 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
224 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
225 					       struct dentry *root,
226 					       const struct cred **_saved_cred);
227 
228 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
229 					   const struct cred **_saved_cred)
230 {
231 	*_saved_cred = override_creds(cache->cache_cred);
232 }
233 
234 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
235 					 const struct cred *saved_cred)
236 {
237 	revert_creds(saved_cred);
238 }
239 
240 /*
241  * xattr.c
242  */
243 extern int cachefiles_check_object_type(struct cachefiles_object *object);
244 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
245 				       struct cachefiles_xattr *auxdata);
246 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
247 					  struct cachefiles_xattr *auxdata);
248 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
249 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
250 					 struct cachefiles_xattr *auxdata);
251 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
252 					  struct dentry *dentry);
253 
254 
255 /*
256  * error handling
257  */
258 
259 #define cachefiles_io_error(___cache, FMT, ...)		\
260 do {							\
261 	pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);	\
262 	fscache_io_error(&(___cache)->cache);		\
263 	set_bit(CACHEFILES_DEAD, &(___cache)->flags);	\
264 } while (0)
265 
266 #define cachefiles_io_error_obj(object, FMT, ...)			\
267 do {									\
268 	struct cachefiles_cache *___cache;				\
269 									\
270 	___cache = container_of((object)->fscache.cache,		\
271 				struct cachefiles_cache, cache);	\
272 	cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);		\
273 } while (0)
274 
275 
276 /*
277  * debug tracing
278  */
279 #define dbgprintk(FMT, ...) \
280 	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
281 
282 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
283 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
284 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
285 
286 
287 #if defined(__KDEBUG)
288 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
289 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
290 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
291 
292 #elif defined(CONFIG_CACHEFILES_DEBUG)
293 #define _enter(FMT, ...)				\
294 do {							\
295 	if (cachefiles_debug & CACHEFILES_DEBUG_KENTER)	\
296 		kenter(FMT, ##__VA_ARGS__);		\
297 } while (0)
298 
299 #define _leave(FMT, ...)				\
300 do {							\
301 	if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE)	\
302 		kleave(FMT, ##__VA_ARGS__);		\
303 } while (0)
304 
305 #define _debug(FMT, ...)				\
306 do {							\
307 	if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG)	\
308 		kdebug(FMT, ##__VA_ARGS__);		\
309 } while (0)
310 
311 #else
312 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
313 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
314 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
315 #endif
316 
317 #if 1 /* defined(__KDEBUGALL) */
318 
319 #define ASSERT(X)							\
320 do {									\
321 	if (unlikely(!(X))) {						\
322 		pr_err("\n");						\
323 		pr_err("Assertion failed\n");		\
324 		BUG();							\
325 	}								\
326 } while (0)
327 
328 #define ASSERTCMP(X, OP, Y)						\
329 do {									\
330 	if (unlikely(!((X) OP (Y)))) {					\
331 		pr_err("\n");						\
332 		pr_err("Assertion failed\n");		\
333 		pr_err("%lx " #OP " %lx is false\n",			\
334 		       (unsigned long)(X), (unsigned long)(Y));		\
335 		BUG();							\
336 	}								\
337 } while (0)
338 
339 #define ASSERTIF(C, X)							\
340 do {									\
341 	if (unlikely((C) && !(X))) {					\
342 		pr_err("\n");						\
343 		pr_err("Assertion failed\n");		\
344 		BUG();							\
345 	}								\
346 } while (0)
347 
348 #define ASSERTIFCMP(C, X, OP, Y)					\
349 do {									\
350 	if (unlikely((C) && !((X) OP (Y)))) {				\
351 		pr_err("\n");						\
352 		pr_err("Assertion failed\n");		\
353 		pr_err("%lx " #OP " %lx is false\n",			\
354 		       (unsigned long)(X), (unsigned long)(Y));		\
355 		BUG();							\
356 	}								\
357 } while (0)
358 
359 #else
360 
361 #define ASSERT(X)			do {} while (0)
362 #define ASSERTCMP(X, OP, Y)		do {} while (0)
363 #define ASSERTIF(C, X)			do {} while (0)
364 #define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
365 
366 #endif
367