1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_DCACHE_H
3 #define __LINUX_DCACHE_H
4
5 #include <linux/atomic.h>
6 #include <linux/list.h>
7 #include <linux/math.h>
8 #include <linux/rculist.h>
9 #include <linux/rculist_bl.h>
10 #include <linux/spinlock.h>
11 #include <linux/seqlock.h>
12 #include <linux/cache.h>
13 #include <linux/rcupdate.h>
14 #include <linux/lockref.h>
15 #include <linux/stringhash.h>
16 #include <linux/wait.h>
17
18 struct path;
19 struct vfsmount;
20
21 /*
22 * linux/include/linux/dcache.h
23 *
24 * Dirent cache data structures
25 *
26 * (C) Copyright 1997 Thomas Schoebel-Theuer,
27 * with heavy changes by Linus Torvalds
28 */
29
30 #define IS_ROOT(x) ((x) == (x)->d_parent)
31
32 /* The hash is always the low bits of hash_len */
33 #ifdef __LITTLE_ENDIAN
34 #define HASH_LEN_DECLARE u32 hash; u32 len
35 #define bytemask_from_count(cnt) (~(~0ul << (cnt)*8))
36 #else
37 #define HASH_LEN_DECLARE u32 len; u32 hash
38 #define bytemask_from_count(cnt) (~(~0ul >> (cnt)*8))
39 #endif
40
41 /*
42 * "quick string" -- eases parameter passing, but more importantly
43 * saves "metadata" about the string (ie length and the hash).
44 *
45 * hash comes first so it snuggles against d_parent in the
46 * dentry.
47 */
48 struct qstr {
49 union {
50 struct {
51 HASH_LEN_DECLARE;
52 };
53 u64 hash_len;
54 };
55 const unsigned char *name;
56 };
57
58 #define QSTR_INIT(n,l) { { { .len = l } }, .name = n }
59
60 extern const struct qstr empty_name;
61 extern const struct qstr slash_name;
62 extern const struct qstr dotdot_name;
63
64 struct dentry_stat_t {
65 long nr_dentry;
66 long nr_unused;
67 long age_limit; /* age in seconds */
68 long want_pages; /* pages requested by system */
69 long nr_negative; /* # of unused negative dentries */
70 long dummy; /* Reserved for future use */
71 };
72 extern struct dentry_stat_t dentry_stat;
73
74 /*
75 * Try to keep struct dentry aligned on 64 byte cachelines (this will
76 * give reasonable cacheline footprint with larger lines without the
77 * large memory footprint increase).
78 */
79 #ifdef CONFIG_64BIT
80 # define DNAME_INLINE_LEN 32 /* 192 bytes */
81 #else
82 # ifdef CONFIG_SMP
83 # define DNAME_INLINE_LEN 36 /* 128 bytes */
84 # else
85 # define DNAME_INLINE_LEN 40 /* 128 bytes */
86 # endif
87 #endif
88
89 #define d_lock d_lockref.lock
90
91 struct dentry {
92 /* RCU lookup touched fields */
93 unsigned int d_flags; /* protected by d_lock */
94 seqcount_spinlock_t d_seq; /* per dentry seqlock */
95 struct hlist_bl_node d_hash; /* lookup hash list */
96 struct dentry *d_parent; /* parent directory */
97 struct qstr d_name;
98 struct inode *d_inode; /* Where the name belongs to - NULL is
99 * negative */
100 unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
101
102 /* Ref lookup also touches following */
103 struct lockref d_lockref; /* per-dentry lock and refcount */
104 const struct dentry_operations *d_op;
105 struct super_block *d_sb; /* The root of the dentry tree */
106 unsigned long d_time; /* used by d_revalidate */
107 void *d_fsdata; /* fs-specific data */
108
109 union {
110 struct list_head d_lru; /* LRU list */
111 wait_queue_head_t *d_wait; /* in-lookup ones only */
112 };
113 struct list_head d_child; /* child of parent list */
114 struct list_head d_subdirs; /* our children */
115 /*
116 * d_alias and d_rcu can share memory
117 */
118 union {
119 struct hlist_node d_alias; /* inode alias list */
120 struct hlist_bl_node d_in_lookup_hash; /* only for in-lookup ones */
121 struct rcu_head d_rcu;
122 } d_u;
123 } __randomize_layout;
124
125 /*
126 * dentry->d_lock spinlock nesting subclasses:
127 *
128 * 0: normal
129 * 1: nested
130 */
131 enum dentry_d_lock_class
132 {
133 DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
134 DENTRY_D_LOCK_NESTED
135 };
136
137 struct dentry_operations {
138 int (*d_revalidate)(struct dentry *, unsigned int);
139 int (*d_weak_revalidate)(struct dentry *, unsigned int);
140 int (*d_hash)(const struct dentry *, struct qstr *);
141 int (*d_compare)(const struct dentry *,
142 unsigned int, const char *, const struct qstr *);
143 int (*d_delete)(const struct dentry *);
144 int (*d_init)(struct dentry *);
145 void (*d_release)(struct dentry *);
146 void (*d_prune)(struct dentry *);
147 void (*d_iput)(struct dentry *, struct inode *);
148 char *(*d_dname)(struct dentry *, char *, int);
149 struct vfsmount *(*d_automount)(struct path *);
150 int (*d_manage)(const struct path *, bool);
151 struct dentry *(*d_real)(struct dentry *, const struct inode *);
152 } ____cacheline_aligned;
153
154 /*
155 * Locking rules for dentry_operations callbacks are to be found in
156 * Documentation/filesystems/locking.rst. Keep it updated!
157 *
158 * FUrther descriptions are found in Documentation/filesystems/vfs.rst.
159 * Keep it updated too!
160 */
161
162 /* d_flags entries */
163 #define DCACHE_OP_HASH 0x00000001
164 #define DCACHE_OP_COMPARE 0x00000002
165 #define DCACHE_OP_REVALIDATE 0x00000004
166 #define DCACHE_OP_DELETE 0x00000008
167 #define DCACHE_OP_PRUNE 0x00000010
168
169 #define DCACHE_DISCONNECTED 0x00000020
170 /* This dentry is possibly not currently connected to the dcache tree, in
171 * which case its parent will either be itself, or will have this flag as
172 * well. nfsd will not use a dentry with this bit set, but will first
173 * endeavour to clear the bit either by discovering that it is connected,
174 * or by performing lookup operations. Any filesystem which supports
175 * nfsd_operations MUST have a lookup function which, if it finds a
176 * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
177 * dentry into place and return that dentry rather than the passed one,
178 * typically using d_splice_alias. */
179
180 #define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */
181
182 #define DCACHE_DONTCACHE 0x00000080 /* Purge from memory on final dput() */
183
184 #define DCACHE_CANT_MOUNT 0x00000100
185 #define DCACHE_GENOCIDE 0x00000200
186 #define DCACHE_SHRINK_LIST 0x00000400
187
188 #define DCACHE_OP_WEAK_REVALIDATE 0x00000800
189
190 #define DCACHE_NFSFS_RENAMED 0x00001000
191 /* this dentry has been "silly renamed" and has to be deleted on the last
192 * dput() */
193 #define DCACHE_COOKIE 0x00002000 /* For use by dcookie subsystem */
194 #define DCACHE_FSNOTIFY_PARENT_WATCHED 0x00004000
195 /* Parent inode is watched by some fsnotify listener */
196
197 #define DCACHE_DENTRY_KILLED 0x00008000
198
199 #define DCACHE_MOUNTED 0x00010000 /* is a mountpoint */
200 #define DCACHE_NEED_AUTOMOUNT 0x00020000 /* handle automount on this dir */
201 #define DCACHE_MANAGE_TRANSIT 0x00040000 /* manage transit from this dirent */
202 #define DCACHE_MANAGED_DENTRY \
203 (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
204
205 #define DCACHE_LRU_LIST 0x00080000
206
207 #define DCACHE_ENTRY_TYPE 0x00700000
208 #define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry (maybe fallthru to nowhere) */
209 #define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */
210 #define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */
211 #define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */
212 #define DCACHE_REGULAR_TYPE 0x00400000 /* Regular file type (or fallthru to such) */
213 #define DCACHE_SPECIAL_TYPE 0x00500000 /* Other file type (or fallthru to such) */
214 #define DCACHE_SYMLINK_TYPE 0x00600000 /* Symlink (or fallthru to such) */
215
216 #define DCACHE_MAY_FREE 0x00800000
217 #define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
218 #define DCACHE_NOKEY_NAME 0x02000000 /* Encrypted name encoded without key */
219 #define DCACHE_OP_REAL 0x04000000
220
221 #define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */
222 #define DCACHE_DENTRY_CURSOR 0x20000000
223 #define DCACHE_NORCU 0x40000000 /* No RCU delay for freeing */
224
225 extern seqlock_t rename_lock;
226
227 /*
228 * These are the low-level FS interfaces to the dcache..
229 */
230 extern void d_instantiate(struct dentry *, struct inode *);
231 extern void d_instantiate_new(struct dentry *, struct inode *);
232 extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
233 extern struct dentry * d_instantiate_anon(struct dentry *, struct inode *);
234 extern void __d_drop(struct dentry *dentry);
235 extern void d_drop(struct dentry *dentry);
236 extern void d_delete(struct dentry *);
237 extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
238
239 /* allocate/de-allocate */
240 extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
241 extern struct dentry * d_alloc_anon(struct super_block *);
242 extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
243 wait_queue_head_t *);
244 extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
245 extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
246 extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
247 extern struct dentry *d_find_any_alias(struct inode *inode);
248 extern struct dentry * d_obtain_alias(struct inode *);
249 extern struct dentry * d_obtain_root(struct inode *);
250 extern void shrink_dcache_sb(struct super_block *);
251 extern void shrink_dcache_parent(struct dentry *);
252 extern void shrink_dcache_for_umount(struct super_block *);
253 extern void d_invalidate(struct dentry *);
254
255 /* only used at mount-time */
256 extern struct dentry * d_make_root(struct inode *);
257
258 /* <clickety>-<click> the ramfs-type tree */
259 extern void d_genocide(struct dentry *);
260
261 extern void d_tmpfile(struct dentry *, struct inode *);
262
263 extern struct dentry *d_find_alias(struct inode *);
264 extern void d_prune_aliases(struct inode *);
265
266 extern struct dentry *d_find_alias_rcu(struct inode *);
267
268 /* test whether we have any submounts in a subdir tree */
269 extern int path_has_submounts(const struct path *);
270
271 /*
272 * This adds the entry to the hash queues.
273 */
274 extern void d_rehash(struct dentry *);
275
276 extern void d_add(struct dentry *, struct inode *);
277
278 /* used for rename() and baskets */
279 extern void d_move(struct dentry *, struct dentry *);
280 extern void d_exchange(struct dentry *, struct dentry *);
281 extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
282
283 /* appendix may either be NULL or be used for transname suffixes */
284 extern struct dentry *d_lookup(const struct dentry *, const struct qstr *);
285 extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
286 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
287 extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
288 const struct qstr *name, unsigned *seq);
289
d_count(const struct dentry * dentry)290 static inline unsigned d_count(const struct dentry *dentry)
291 {
292 return dentry->d_lockref.count;
293 }
294
295 /*
296 * helper function for dentry_operations.d_dname() members
297 */
298 extern __printf(4, 5)
299 char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
300
301 extern char *__d_path(const struct path *, const struct path *, char *, int);
302 extern char *d_absolute_path(const struct path *, char *, int);
303 extern char *d_path(const struct path *, char *, int);
304 extern char *dentry_path_raw(const struct dentry *, char *, int);
305 extern char *dentry_path(const struct dentry *, char *, int);
306
307 /* Allocation counts.. */
308
309 /**
310 * dget, dget_dlock - get a reference to a dentry
311 * @dentry: dentry to get a reference to
312 *
313 * Given a dentry or %NULL pointer increment the reference count
314 * if appropriate and return the dentry. A dentry will not be
315 * destroyed when it has references.
316 */
dget_dlock(struct dentry * dentry)317 static inline struct dentry *dget_dlock(struct dentry *dentry)
318 {
319 if (dentry)
320 dentry->d_lockref.count++;
321 return dentry;
322 }
323
dget(struct dentry * dentry)324 static inline struct dentry *dget(struct dentry *dentry)
325 {
326 if (dentry)
327 lockref_get(&dentry->d_lockref);
328 return dentry;
329 }
330
331 extern struct dentry *dget_parent(struct dentry *dentry);
332
333 /**
334 * d_unhashed - is dentry hashed
335 * @dentry: entry to check
336 *
337 * Returns true if the dentry passed is not currently hashed.
338 */
339
d_unhashed(const struct dentry * dentry)340 static inline int d_unhashed(const struct dentry *dentry)
341 {
342 return hlist_bl_unhashed(&dentry->d_hash);
343 }
344
d_unlinked(const struct dentry * dentry)345 static inline int d_unlinked(const struct dentry *dentry)
346 {
347 return d_unhashed(dentry) && !IS_ROOT(dentry);
348 }
349
cant_mount(const struct dentry * dentry)350 static inline int cant_mount(const struct dentry *dentry)
351 {
352 return (dentry->d_flags & DCACHE_CANT_MOUNT);
353 }
354
dont_mount(struct dentry * dentry)355 static inline void dont_mount(struct dentry *dentry)
356 {
357 spin_lock(&dentry->d_lock);
358 dentry->d_flags |= DCACHE_CANT_MOUNT;
359 spin_unlock(&dentry->d_lock);
360 }
361
362 extern void __d_lookup_done(struct dentry *);
363
d_in_lookup(const struct dentry * dentry)364 static inline int d_in_lookup(const struct dentry *dentry)
365 {
366 return dentry->d_flags & DCACHE_PAR_LOOKUP;
367 }
368
d_lookup_done(struct dentry * dentry)369 static inline void d_lookup_done(struct dentry *dentry)
370 {
371 if (unlikely(d_in_lookup(dentry))) {
372 spin_lock(&dentry->d_lock);
373 __d_lookup_done(dentry);
374 spin_unlock(&dentry->d_lock);
375 }
376 }
377
378 extern void dput(struct dentry *);
379
d_managed(const struct dentry * dentry)380 static inline bool d_managed(const struct dentry *dentry)
381 {
382 return dentry->d_flags & DCACHE_MANAGED_DENTRY;
383 }
384
d_mountpoint(const struct dentry * dentry)385 static inline bool d_mountpoint(const struct dentry *dentry)
386 {
387 return dentry->d_flags & DCACHE_MOUNTED;
388 }
389
390 /*
391 * Directory cache entry type accessor functions.
392 */
__d_entry_type(const struct dentry * dentry)393 static inline unsigned __d_entry_type(const struct dentry *dentry)
394 {
395 return dentry->d_flags & DCACHE_ENTRY_TYPE;
396 }
397
d_is_miss(const struct dentry * dentry)398 static inline bool d_is_miss(const struct dentry *dentry)
399 {
400 return __d_entry_type(dentry) == DCACHE_MISS_TYPE;
401 }
402
d_is_whiteout(const struct dentry * dentry)403 static inline bool d_is_whiteout(const struct dentry *dentry)
404 {
405 return __d_entry_type(dentry) == DCACHE_WHITEOUT_TYPE;
406 }
407
d_can_lookup(const struct dentry * dentry)408 static inline bool d_can_lookup(const struct dentry *dentry)
409 {
410 return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE;
411 }
412
d_is_autodir(const struct dentry * dentry)413 static inline bool d_is_autodir(const struct dentry *dentry)
414 {
415 return __d_entry_type(dentry) == DCACHE_AUTODIR_TYPE;
416 }
417
d_is_dir(const struct dentry * dentry)418 static inline bool d_is_dir(const struct dentry *dentry)
419 {
420 return d_can_lookup(dentry) || d_is_autodir(dentry);
421 }
422
d_is_symlink(const struct dentry * dentry)423 static inline bool d_is_symlink(const struct dentry *dentry)
424 {
425 return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
426 }
427
d_is_reg(const struct dentry * dentry)428 static inline bool d_is_reg(const struct dentry *dentry)
429 {
430 return __d_entry_type(dentry) == DCACHE_REGULAR_TYPE;
431 }
432
d_is_special(const struct dentry * dentry)433 static inline bool d_is_special(const struct dentry *dentry)
434 {
435 return __d_entry_type(dentry) == DCACHE_SPECIAL_TYPE;
436 }
437
d_is_file(const struct dentry * dentry)438 static inline bool d_is_file(const struct dentry *dentry)
439 {
440 return d_is_reg(dentry) || d_is_special(dentry);
441 }
442
d_is_negative(const struct dentry * dentry)443 static inline bool d_is_negative(const struct dentry *dentry)
444 {
445 // TODO: check d_is_whiteout(dentry) also.
446 return d_is_miss(dentry);
447 }
448
d_flags_negative(unsigned flags)449 static inline bool d_flags_negative(unsigned flags)
450 {
451 return (flags & DCACHE_ENTRY_TYPE) == DCACHE_MISS_TYPE;
452 }
453
d_is_positive(const struct dentry * dentry)454 static inline bool d_is_positive(const struct dentry *dentry)
455 {
456 return !d_is_negative(dentry);
457 }
458
459 /**
460 * d_really_is_negative - Determine if a dentry is really negative (ignoring fallthroughs)
461 * @dentry: The dentry in question
462 *
463 * Returns true if the dentry represents either an absent name or a name that
464 * doesn't map to an inode (ie. ->d_inode is NULL). The dentry could represent
465 * a true miss, a whiteout that isn't represented by a 0,0 chardev or a
466 * fallthrough marker in an opaque directory.
467 *
468 * Note! (1) This should be used *only* by a filesystem to examine its own
469 * dentries. It should not be used to look at some other filesystem's
470 * dentries. (2) It should also be used in combination with d_inode() to get
471 * the inode. (3) The dentry may have something attached to ->d_lower and the
472 * type field of the flags may be set to something other than miss or whiteout.
473 */
d_really_is_negative(const struct dentry * dentry)474 static inline bool d_really_is_negative(const struct dentry *dentry)
475 {
476 return dentry->d_inode == NULL;
477 }
478
479 /**
480 * d_really_is_positive - Determine if a dentry is really positive (ignoring fallthroughs)
481 * @dentry: The dentry in question
482 *
483 * Returns true if the dentry represents a name that maps to an inode
484 * (ie. ->d_inode is not NULL). The dentry might still represent a whiteout if
485 * that is represented on medium as a 0,0 chardev.
486 *
487 * Note! (1) This should be used *only* by a filesystem to examine its own
488 * dentries. It should not be used to look at some other filesystem's
489 * dentries. (2) It should also be used in combination with d_inode() to get
490 * the inode.
491 */
d_really_is_positive(const struct dentry * dentry)492 static inline bool d_really_is_positive(const struct dentry *dentry)
493 {
494 return dentry->d_inode != NULL;
495 }
496
simple_positive(const struct dentry * dentry)497 static inline int simple_positive(const struct dentry *dentry)
498 {
499 return d_really_is_positive(dentry) && !d_unhashed(dentry);
500 }
501
502 extern void d_set_fallthru(struct dentry *dentry);
503
d_is_fallthru(const struct dentry * dentry)504 static inline bool d_is_fallthru(const struct dentry *dentry)
505 {
506 return dentry->d_flags & DCACHE_FALLTHRU;
507 }
508
509
510 extern int sysctl_vfs_cache_pressure;
511
vfs_pressure_ratio(unsigned long val)512 static inline unsigned long vfs_pressure_ratio(unsigned long val)
513 {
514 return mult_frac(val, sysctl_vfs_cache_pressure, 100);
515 }
516
517 /**
518 * d_inode - Get the actual inode of this dentry
519 * @dentry: The dentry to query
520 *
521 * This is the helper normal filesystems should use to get at their own inodes
522 * in their own dentries and ignore the layering superimposed upon them.
523 */
d_inode(const struct dentry * dentry)524 static inline struct inode *d_inode(const struct dentry *dentry)
525 {
526 return dentry->d_inode;
527 }
528
529 /**
530 * d_inode_rcu - Get the actual inode of this dentry with READ_ONCE()
531 * @dentry: The dentry to query
532 *
533 * This is the helper normal filesystems should use to get at their own inodes
534 * in their own dentries and ignore the layering superimposed upon them.
535 */
d_inode_rcu(const struct dentry * dentry)536 static inline struct inode *d_inode_rcu(const struct dentry *dentry)
537 {
538 return READ_ONCE(dentry->d_inode);
539 }
540
541 /**
542 * d_backing_inode - Get upper or lower inode we should be using
543 * @upper: The upper layer
544 *
545 * This is the helper that should be used to get at the inode that will be used
546 * if this dentry were to be opened as a file. The inode may be on the upper
547 * dentry or it may be on a lower dentry pinned by the upper.
548 *
549 * Normal filesystems should not use this to access their own inodes.
550 */
d_backing_inode(const struct dentry * upper)551 static inline struct inode *d_backing_inode(const struct dentry *upper)
552 {
553 struct inode *inode = upper->d_inode;
554
555 return inode;
556 }
557
558 /**
559 * d_backing_dentry - Get upper or lower dentry we should be using
560 * @upper: The upper layer
561 *
562 * This is the helper that should be used to get the dentry of the inode that
563 * will be used if this dentry were opened as a file. It may be the upper
564 * dentry or it may be a lower dentry pinned by the upper.
565 *
566 * Normal filesystems should not use this to access their own dentries.
567 */
d_backing_dentry(struct dentry * upper)568 static inline struct dentry *d_backing_dentry(struct dentry *upper)
569 {
570 return upper;
571 }
572
573 /**
574 * d_real - Return the real dentry
575 * @dentry: the dentry to query
576 * @inode: inode to select the dentry from multiple layers (can be NULL)
577 *
578 * If dentry is on a union/overlay, then return the underlying, real dentry.
579 * Otherwise return the dentry itself.
580 *
581 * See also: Documentation/filesystems/vfs.rst
582 */
d_real(struct dentry * dentry,const struct inode * inode)583 static inline struct dentry *d_real(struct dentry *dentry,
584 const struct inode *inode)
585 {
586 if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
587 return dentry->d_op->d_real(dentry, inode);
588 else
589 return dentry;
590 }
591
592 /**
593 * d_real_inode - Return the real inode
594 * @dentry: The dentry to query
595 *
596 * If dentry is on a union/overlay, then return the underlying, real inode.
597 * Otherwise return d_inode().
598 */
d_real_inode(const struct dentry * dentry)599 static inline struct inode *d_real_inode(const struct dentry *dentry)
600 {
601 /* This usage of d_real() results in const dentry */
602 return d_backing_inode(d_real((struct dentry *) dentry, NULL));
603 }
604
605 struct name_snapshot {
606 struct qstr name;
607 unsigned char inline_name[DNAME_INLINE_LEN];
608 };
609 void take_dentry_name_snapshot(struct name_snapshot *, struct dentry *);
610 void release_dentry_name_snapshot(struct name_snapshot *);
611
612 #endif /* __LINUX_DCACHE_H */
613