Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* General netfs cache on cache files internal defs
3 *
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#ifdef pr_fmt
9#undef pr_fmt
10#endif
11
12#define pr_fmt(fmt) "CacheFiles: " fmt
13
14
15#include <linux/fscache-cache.h>
16#include <linux/timer.h>
17#include <linux/wait_bit.h>
18#include <linux/cred.h>
19#include <linux/workqueue.h>
20#include <linux/security.h>
21
22struct cachefiles_cache;
23struct cachefiles_object;
24
25extern unsigned cachefiles_debug;
26#define CACHEFILES_DEBUG_KENTER 1
27#define CACHEFILES_DEBUG_KLEAVE 2
28#define CACHEFILES_DEBUG_KDEBUG 4
29
30#define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
31
32/*
33 * node records
34 */
35struct cachefiles_object {
36 struct fscache_object fscache; /* fscache handle */
37 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */
38 struct dentry *dentry; /* the file/dir representing this object */
39 struct dentry *backer; /* backing file */
40 loff_t i_size; /* object size */
41 unsigned long flags;
42#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
43 atomic_t usage; /* object usage count */
44 uint8_t type; /* object type */
45 uint8_t new; /* T if object new */
46 spinlock_t work_lock;
47 struct rb_node active_node; /* link in active tree (dentry is key) */
48};
49
50extern struct kmem_cache *cachefiles_object_jar;
51
52/*
53 * Cache files cache definition
54 */
55struct cachefiles_cache {
56 struct fscache_cache cache; /* FS-Cache record */
57 struct vfsmount *mnt; /* mountpoint holding the cache */
58 struct dentry *graveyard; /* directory into which dead objects go */
59 struct file *cachefilesd; /* manager daemon handle */
60 const struct cred *cache_cred; /* security override for accessing cache */
61 struct mutex daemon_mutex; /* command serialisation mutex */
62 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
63 struct rb_root active_nodes; /* active nodes (can't be culled) */
64 rwlock_t active_lock; /* lock for active_nodes */
65 atomic_t gravecounter; /* graveyard uniquifier */
66 atomic_t f_released; /* number of objects released lately */
67 atomic_long_t b_released; /* number of blocks released lately */
68 unsigned frun_percent; /* when to stop culling (% files) */
69 unsigned fcull_percent; /* when to start culling (% files) */
70 unsigned fstop_percent; /* when to stop allocating (% files) */
71 unsigned brun_percent; /* when to stop culling (% blocks) */
72 unsigned bcull_percent; /* when to start culling (% blocks) */
73 unsigned bstop_percent; /* when to stop allocating (% blocks) */
74 unsigned bsize; /* cache's block size */
75 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
76 uint64_t frun; /* when to stop culling */
77 uint64_t fcull; /* when to start culling */
78 uint64_t fstop; /* when to stop allocating */
79 sector_t brun; /* when to stop culling */
80 sector_t bcull; /* when to start culling */
81 sector_t bstop; /* when to stop allocating */
82 unsigned long flags;
83#define CACHEFILES_READY 0 /* T if cache prepared */
84#define CACHEFILES_DEAD 1 /* T if cache dead */
85#define CACHEFILES_CULLING 2 /* T if cull engaged */
86#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
87 char *rootdirname; /* name of cache root directory */
88 char *secctx; /* LSM security context */
89 char *tag; /* cache binding tag */
90};
91
92/*
93 * backing file read tracking
94 */
95struct cachefiles_one_read {
96 wait_queue_entry_t monitor; /* link into monitored waitqueue */
97 struct page *back_page; /* backing file page we're waiting for */
98 struct page *netfs_page; /* netfs page we're going to fill */
99 struct fscache_retrieval *op; /* retrieval op covering this */
100 struct list_head op_link; /* link in op's todo list */
101};
102
103/*
104 * backing file write tracking
105 */
106struct cachefiles_one_write {
107 struct page *netfs_page; /* netfs page to copy */
108 struct cachefiles_object *object;
109 struct list_head obj_link; /* link in object's lists */
110 fscache_rw_complete_t end_io_func;
111 void *context;
112};
113
114/*
115 * auxiliary data xattr buffer
116 */
117struct cachefiles_xattr {
118 uint16_t len;
119 uint8_t type;
120 uint8_t data[];
121};
122
123#include <trace/events/cachefiles.h>
124
125/*
126 * note change of state for daemon
127 */
128static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
129{
130 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
131 wake_up_all(&cache->daemon_pollwq);
132}
133
134/*
135 * bind.c
136 */
137extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
138extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
139
140/*
141 * daemon.c
142 */
143extern const struct file_operations cachefiles_daemon_fops;
144
145extern int cachefiles_has_space(struct cachefiles_cache *cache,
146 unsigned fnr, unsigned bnr);
147
148/*
149 * interface.c
150 */
151extern const struct fscache_cache_ops cachefiles_cache_ops;
152
153void cachefiles_put_object(struct fscache_object *_object,
154 enum fscache_obj_ref_trace why);
155
156/*
157 * key.c
158 */
159extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
160
161/*
162 * namei.c
163 */
164extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
165 struct cachefiles_object *object,
166 blkcnt_t i_blocks);
167extern int cachefiles_delete_object(struct cachefiles_cache *cache,
168 struct cachefiles_object *object);
169extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
170 struct cachefiles_object *object,
171 const char *key,
172 struct cachefiles_xattr *auxdata);
173extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
174 struct dentry *dir,
175 const char *name);
176
177extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
178 char *filename);
179
180extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
181 struct dentry *dir, char *filename);
182
183/*
184 * rdwr.c
185 */
186extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
187 struct page *, gfp_t);
188extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
189 struct list_head *, unsigned *,
190 gfp_t);
191extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
192 gfp_t);
193extern int cachefiles_allocate_pages(struct fscache_retrieval *,
194 struct list_head *, unsigned *, gfp_t);
195extern int cachefiles_write_page(struct fscache_storage *, struct page *);
196extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
197
198/*
199 * rdwr2.c
200 */
201extern int cachefiles_begin_read_operation(struct netfs_read_request *,
202 struct fscache_retrieval *);
203
204/*
205 * security.c
206 */
207extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
208extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
209 struct dentry *root,
210 const struct cred **_saved_cred);
211
212static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
213 const struct cred **_saved_cred)
214{
215 *_saved_cred = override_creds(cache->cache_cred);
216}
217
218static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
219 const struct cred *saved_cred)
220{
221 revert_creds(saved_cred);
222}
223
224/*
225 * xattr.c
226 */
227extern int cachefiles_check_object_type(struct cachefiles_object *object);
228extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
229 struct cachefiles_xattr *auxdata);
230extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
231 struct cachefiles_xattr *auxdata);
232extern int cachefiles_check_auxdata(struct cachefiles_object *object);
233extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
234 struct cachefiles_xattr *auxdata);
235extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
236 struct dentry *dentry);
237
238
239/*
240 * error handling
241 */
242
243#define cachefiles_io_error(___cache, FMT, ...) \
244do { \
245 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
246 fscache_io_error(&(___cache)->cache); \
247 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
248} while (0)
249
250#define cachefiles_io_error_obj(object, FMT, ...) \
251do { \
252 struct cachefiles_cache *___cache; \
253 \
254 ___cache = container_of((object)->fscache.cache, \
255 struct cachefiles_cache, cache); \
256 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
257} while (0)
258
259
260/*
261 * debug tracing
262 */
263#define dbgprintk(FMT, ...) \
264 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
265
266#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
267#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
268#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
269
270
271#if defined(__KDEBUG)
272#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
273#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
274#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
275
276#elif defined(CONFIG_CACHEFILES_DEBUG)
277#define _enter(FMT, ...) \
278do { \
279 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
280 kenter(FMT, ##__VA_ARGS__); \
281} while (0)
282
283#define _leave(FMT, ...) \
284do { \
285 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
286 kleave(FMT, ##__VA_ARGS__); \
287} while (0)
288
289#define _debug(FMT, ...) \
290do { \
291 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
292 kdebug(FMT, ##__VA_ARGS__); \
293} while (0)
294
295#else
296#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
297#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
298#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
299#endif
300
301#if 1 /* defined(__KDEBUGALL) */
302
303#define ASSERT(X) \
304do { \
305 if (unlikely(!(X))) { \
306 pr_err("\n"); \
307 pr_err("Assertion failed\n"); \
308 BUG(); \
309 } \
310} while (0)
311
312#define ASSERTCMP(X, OP, Y) \
313do { \
314 if (unlikely(!((X) OP (Y)))) { \
315 pr_err("\n"); \
316 pr_err("Assertion failed\n"); \
317 pr_err("%lx " #OP " %lx is false\n", \
318 (unsigned long)(X), (unsigned long)(Y)); \
319 BUG(); \
320 } \
321} while (0)
322
323#define ASSERTIF(C, X) \
324do { \
325 if (unlikely((C) && !(X))) { \
326 pr_err("\n"); \
327 pr_err("Assertion failed\n"); \
328 BUG(); \
329 } \
330} while (0)
331
332#define ASSERTIFCMP(C, X, OP, Y) \
333do { \
334 if (unlikely((C) && !((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#else
344
345#define ASSERT(X) do {} while (0)
346#define ASSERTCMP(X, OP, Y) do {} while (0)
347#define ASSERTIF(C, X) do {} while (0)
348#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
349
350#endif