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