1#ifndef __LINUX_DCACHE_H
2#define __LINUX_DCACHE_H
3
4#include <linux/atomic.h>
5#include <linux/list.h>
6#include <linux/rculist.h>
7#include <linux/rculist_bl.h>
8#include <linux/spinlock.h>
9#include <linux/seqlock.h>
10#include <linux/cache.h>
11#include <linux/rcupdate.h>
12#include <linux/lockref.h>
13
14struct nameidata;
15struct path;
16struct vfsmount;
17
18
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20
21
22
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24
25
26
27#define IS_ROOT(x) ((x) == (x)->d_parent)
28
29
30#ifdef __LITTLE_ENDIAN
31 #define HASH_LEN_DECLARE u32 hash; u32 len;
32#else
33 #define HASH_LEN_DECLARE u32 len; u32 hash;
34#endif
35
36
37
38
39
40
41
42
43struct qstr {
44 union {
45 struct {
46 HASH_LEN_DECLARE;
47 };
48 u64 hash_len;
49 };
50 const unsigned char *name;
51};
52
53#define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
54#define hashlen_hash(hashlen) ((u32) (hashlen))
55#define hashlen_len(hashlen) ((u32)((hashlen) >> 32))
56
57struct dentry_stat_t {
58 int nr_dentry;
59 int nr_unused;
60 int age_limit;
61 int want_pages;
62 int dummy[2];
63};
64extern struct dentry_stat_t dentry_stat;
65
66
67
68#define init_name_hash() 0
69
70
71static inline unsigned long
72partial_name_hash(unsigned long c, unsigned long prevhash)
73{
74 return (prevhash + (c << 4) + (c >> 4)) * 11;
75}
76
77
78
79
80
81static inline unsigned long end_name_hash(unsigned long hash)
82{
83 return (unsigned int) hash;
84}
85
86
87extern unsigned int full_name_hash(const unsigned char *, unsigned int);
88
89
90
91
92
93
94#ifdef CONFIG_64BIT
95# define DNAME_INLINE_LEN 32
96#else
97# ifdef CONFIG_SMP
98# define DNAME_INLINE_LEN 36
99# else
100# define DNAME_INLINE_LEN 40
101# endif
102#endif
103
104#define d_lock d_lockref.lock
105
106struct dentry {
107
108 unsigned int d_flags;
109 seqcount_t d_seq;
110 struct hlist_bl_node d_hash;
111 struct dentry *d_parent;
112 struct qstr d_name;
113 struct inode *d_inode;
114
115 unsigned char d_iname[DNAME_INLINE_LEN];
116
117
118 struct lockref d_lockref;
119 const struct dentry_operations *d_op;
120 struct super_block *d_sb;
121 unsigned long d_time;
122 void *d_fsdata;
123
124 struct list_head d_lru;
125
126
127
128 union {
129 struct list_head d_child;
130 struct rcu_head d_rcu;
131 } d_u;
132 struct list_head d_subdirs;
133 struct hlist_node d_alias;
134};
135
136
137
138
139
140
141
142enum dentry_d_lock_class
143{
144 DENTRY_D_LOCK_NORMAL,
145 DENTRY_D_LOCK_NESTED
146};
147
148struct dentry_operations {
149 int (*d_revalidate)(struct dentry *, unsigned int);
150 int (*d_weak_revalidate)(struct dentry *, unsigned int);
151 int (*d_hash)(const struct dentry *, struct qstr *);
152 int (*d_compare)(const struct dentry *, const struct dentry *,
153 unsigned int, const char *, const struct qstr *);
154 int (*d_delete)(const struct dentry *);
155 void (*d_release)(struct dentry *);
156 void (*d_prune)(struct dentry *);
157 void (*d_iput)(struct dentry *, struct inode *);
158 char *(*d_dname)(struct dentry *, char *, int);
159 struct vfsmount *(*d_automount)(struct path *);
160 int (*d_manage)(struct dentry *, bool);
161} ____cacheline_aligned;
162
163
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170
171
172#define DCACHE_OP_HASH 0x0001
173#define DCACHE_OP_COMPARE 0x0002
174#define DCACHE_OP_REVALIDATE 0x0004
175#define DCACHE_OP_DELETE 0x0008
176#define DCACHE_OP_PRUNE 0x0010
177
178#define DCACHE_DISCONNECTED 0x0020
179
180
181
182
183
184
185
186
187
188
189#define DCACHE_REFERENCED 0x0040
190#define DCACHE_RCUACCESS 0x0080
191
192#define DCACHE_CANT_MOUNT 0x0100
193#define DCACHE_GENOCIDE 0x0200
194#define DCACHE_SHRINK_LIST 0x0400
195
196#define DCACHE_OP_WEAK_REVALIDATE 0x0800
197
198#define DCACHE_NFSFS_RENAMED 0x1000
199
200
201#define DCACHE_COOKIE 0x2000
202#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000
203
204
205#define DCACHE_MOUNTED 0x10000
206#define DCACHE_NEED_AUTOMOUNT 0x20000
207#define DCACHE_MANAGE_TRANSIT 0x40000
208#define DCACHE_MANAGED_DENTRY \
209 (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
210
211#define DCACHE_DENTRY_KILLED 0x100000
212
213extern seqlock_t rename_lock;
214
215static inline int dname_external(struct dentry *dentry)
216{
217 return dentry->d_name.name != dentry->d_iname;
218}
219
220
221
222
223extern void d_instantiate(struct dentry *, struct inode *);
224extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
225extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
226extern void __d_drop(struct dentry *dentry);
227extern void d_drop(struct dentry *dentry);
228extern void d_delete(struct dentry *);
229extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
230
231
232extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
233extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
234extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
235extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
236extern struct dentry *d_find_any_alias(struct inode *inode);
237extern struct dentry * d_obtain_alias(struct inode *);
238extern void shrink_dcache_sb(struct super_block *);
239extern void shrink_dcache_parent(struct dentry *);
240extern void shrink_dcache_for_umount(struct super_block *);
241extern int d_invalidate(struct dentry *);
242
243
244extern struct dentry * d_make_root(struct inode *);
245
246
247extern void d_genocide(struct dentry *);
248
249extern void d_tmpfile(struct dentry *, struct inode *);
250
251extern struct dentry *d_find_alias(struct inode *);
252extern void d_prune_aliases(struct inode *);
253
254
255extern int have_submounts(struct dentry *);
256
257
258
259
260extern void d_rehash(struct dentry *);
261
262
263
264
265
266
267
268
269
270
271static inline void d_add(struct dentry *entry, struct inode *inode)
272{
273 d_instantiate(entry, inode);
274 d_rehash(entry);
275}
276
277
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279
280
281
282
283
284
285static inline struct dentry *d_add_unique(struct dentry *entry, struct inode *inode)
286{
287 struct dentry *res;
288
289 res = d_instantiate_unique(entry, inode);
290 d_rehash(res != NULL ? res : entry);
291 return res;
292}
293
294extern void dentry_update_name_case(struct dentry *, struct qstr *);
295
296
297extern void d_move(struct dentry *, struct dentry *);
298extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
299
300
301extern struct dentry *d_lookup(const struct dentry *, const struct qstr *);
302extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
303extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
304extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
305 const struct qstr *name, unsigned *seq);
306
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314
315
316static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
317{
318 int ret = 0;
319
320 assert_spin_locked(&dentry->d_lock);
321 if (!read_seqcount_retry(&dentry->d_seq, seq)) {
322 ret = 1;
323 dentry->d_lockref.count++;
324 }
325
326 return ret;
327}
328
329static inline unsigned d_count(const struct dentry *dentry)
330{
331 return dentry->d_lockref.count;
332}
333
334
335extern int d_validate(struct dentry *, struct dentry *);
336
337
338
339
340extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
341extern char *simple_dname(struct dentry *, char *, int);
342
343extern char *__d_path(const struct path *, const struct path *, char *, int);
344extern char *d_absolute_path(const struct path *, char *, int);
345extern char *d_path(const struct path *, char *, int);
346extern char *dentry_path_raw(struct dentry *, char *, int);
347extern char *dentry_path(struct dentry *, char *, int);
348
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357
358
359static inline struct dentry *dget_dlock(struct dentry *dentry)
360{
361 if (dentry)
362 dentry->d_lockref.count++;
363 return dentry;
364}
365
366static inline struct dentry *dget(struct dentry *dentry)
367{
368 if (dentry)
369 lockref_get(&dentry->d_lockref);
370 return dentry;
371}
372
373extern struct dentry *dget_parent(struct dentry *dentry);
374
375
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377
378
379
380
381
382static inline int d_unhashed(struct dentry *dentry)
383{
384 return hlist_bl_unhashed(&dentry->d_hash);
385}
386
387static inline int d_unlinked(struct dentry *dentry)
388{
389 return d_unhashed(dentry) && !IS_ROOT(dentry);
390}
391
392static inline int cant_mount(struct dentry *dentry)
393{
394 return (dentry->d_flags & DCACHE_CANT_MOUNT);
395}
396
397static inline void dont_mount(struct dentry *dentry)
398{
399 spin_lock(&dentry->d_lock);
400 dentry->d_flags |= DCACHE_CANT_MOUNT;
401 spin_unlock(&dentry->d_lock);
402}
403
404extern void dput(struct dentry *);
405
406static inline bool d_managed(struct dentry *dentry)
407{
408 return dentry->d_flags & DCACHE_MANAGED_DENTRY;
409}
410
411static inline bool d_mountpoint(struct dentry *dentry)
412{
413 return dentry->d_flags & DCACHE_MOUNTED;
414}
415
416extern int sysctl_vfs_cache_pressure;
417
418#endif
419