GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / cachefiles / internal.h
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
26 struct cachefiles_cache;
27 struct cachefiles_object;
28
29 extern 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  */
39 struct 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
54 extern struct kmem_cache *cachefiles_object_jar;
55
56 /*
57  * Cache files cache definition
58  */
59 struct 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  */
99 struct 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  */
110 struct 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  */
121 struct 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  */
132 static 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  */
141 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
142 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
143
144 /*
145  * daemon.c
146  */
147 extern const struct file_operations cachefiles_daemon_fops;
148
149 extern int cachefiles_has_space(struct cachefiles_cache *cache,
150                                 unsigned fnr, unsigned bnr);
151
152 /*
153  * interface.c
154  */
155 extern const struct fscache_cache_ops cachefiles_cache_ops;
156
157 /*
158  * key.c
159  */
160 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
161
162 /*
163  * namei.c
164  */
165 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
166                                             struct cachefiles_object *object,
167                                             blkcnt_t i_blocks);
168 extern int cachefiles_delete_object(struct cachefiles_cache *cache,
169                                     struct cachefiles_object *object);
170 extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
171                                      struct cachefiles_object *object,
172                                      const char *key,
173                                      struct cachefiles_xattr *auxdata);
174 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
175                                                struct dentry *dir,
176                                                const char *name);
177
178 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
179                            char *filename);
180
181 extern 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
188 extern atomic_t cachefiles_lookup_histogram[HZ];
189 extern atomic_t cachefiles_mkdir_histogram[HZ];
190 extern atomic_t cachefiles_create_histogram[HZ];
191
192 extern int __init cachefiles_proc_init(void);
193 extern void cachefiles_proc_cleanup(void);
194 static inline
195 void 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  */
212 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
213                                          struct page *, gfp_t);
214 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
215                                           struct list_head *, unsigned *,
216                                           gfp_t);
217 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
218                                     gfp_t);
219 extern int cachefiles_allocate_pages(struct fscache_retrieval *,
220                                      struct list_head *, unsigned *, gfp_t);
221 extern int cachefiles_write_page(struct fscache_storage *, struct page *);
222 extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
223
224 /*
225  * security.c
226  */
227 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
228 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
229                                                struct dentry *root,
230                                                const struct cred **_saved_cred);
231
232 static 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
238 static 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  */
247 extern int cachefiles_check_object_type(struct cachefiles_object *object);
248 extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
249                                        struct cachefiles_xattr *auxdata);
250 extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
251                                           struct cachefiles_xattr *auxdata);
252 extern int cachefiles_check_auxdata(struct cachefiles_object *object);
253 extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
254                                          struct cachefiles_xattr *auxdata);
255 extern 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, ...)         \
264 do {                                                    \
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, ...)                       \
271 do {                                                                    \
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, ...)                                \
298 do {                                                    \
299         if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
300                 kenter(FMT, ##__VA_ARGS__);             \
301 } while (0)
302
303 #define _leave(FMT, ...)                                \
304 do {                                                    \
305         if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
306                 kleave(FMT, ##__VA_ARGS__);             \
307 } while (0)
308
309 #define _debug(FMT, ...)                                \
310 do {                                                    \
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)                                                       \
324 do {                                                                    \
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)                                             \
333 do {                                                                    \
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)                                                  \
344 do {                                                                    \
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)                                        \
353 do {                                                                    \
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