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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_DCACHE_H
2#define __LINUX_DCACHE_H
3
Arun Sharma600634972011-07-26 16:09:06 -07004#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/list.h>
Franck Bui-Huu82524742008-05-12 21:21:05 +02006#include <linux/rculist.h>
Nick Pigginceb5bdc2011-01-07 17:50:05 +11007#include <linux/rculist_bl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008#include <linux/spinlock.h>
Nick Piggin31e6b012011-01-07 17:49:52 +11009#include <linux/seqlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/cache.h>
11#include <linux/rcupdate.h>
Waiman Long98474232013-08-28 18:24:59 -070012#include <linux/lockref.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14struct nameidata;
Jan Blunckcf28b482008-02-14 19:38:44 -080015struct path;
Linus Torvalds1da177e2005-04-16 15:20:36 -070016struct vfsmount;
17
18/*
19 * linux/include/linux/dcache.h
20 *
21 * Dirent cache data structures
22 *
23 * (C) Copyright 1997 Thomas Schoebel-Theuer,
24 * with heavy changes by Linus Torvalds
25 */
26
27#define IS_ROOT(x) ((x) == (x)->d_parent)
28
Linus Torvalds26fe5752012-05-10 13:14:12 -070029/* The hash is always the low bits of hash_len */
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070036/*
37 * "quick string" -- eases parameter passing, but more importantly
38 * saves "metadata" about the string (ie length and the hash).
39 *
40 * hash comes first so it snuggles against d_parent in the
41 * dentry.
42 */
43struct qstr {
Linus Torvalds26fe5752012-05-10 13:14:12 -070044 union {
45 struct {
46 HASH_LEN_DECLARE;
47 };
48 u64 hash_len;
49 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 const unsigned char *name;
51};
52
Linus Torvalds26fe5752012-05-10 13:14:12 -070053#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070057struct dentry_stat_t {
Glauber Costa3942c072013-08-28 10:17:53 +100058 long nr_dentry;
59 long nr_unused;
60 long age_limit; /* age in seconds */
61 long want_pages; /* pages requested by system */
62 long dummy[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -070063};
64extern struct dentry_stat_t dentry_stat;
65
66/* Name hashing routines. Initial hash value */
67/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
68#define init_name_hash() 0
69
70/* partial hash update function. Assume roughly 4 bits per character */
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 * Finally: cut down the number of bits to a int value (and try to avoid
79 * losing bits)
80 */
81static inline unsigned long end_name_hash(unsigned long hash)
82{
83 return (unsigned int) hash;
84}
85
86/* Compute the hash for a name string. */
Linus Torvalds0145acc2012-03-02 14:32:59 -080087extern unsigned int full_name_hash(const unsigned char *, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Nick Pigginc2452f32008-12-01 09:33:43 +010089/*
90 * Try to keep struct dentry aligned on 64 byte cachelines (this will
91 * give reasonable cacheline footprint with larger lines without the
92 * large memory footprint increase).
93 */
94#ifdef CONFIG_64BIT
Nick Piggin44a7d7a2011-01-07 17:49:56 +110095# define DNAME_INLINE_LEN 32 /* 192 bytes */
Nick Pigginc2452f32008-12-01 09:33:43 +010096#else
Nick Piggin44a7d7a2011-01-07 17:49:56 +110097# ifdef CONFIG_SMP
98# define DNAME_INLINE_LEN 36 /* 128 bytes */
99# else
100# define DNAME_INLINE_LEN 40 /* 128 bytes */
101# endif
Nick Pigginc2452f32008-12-01 09:33:43 +0100102#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Waiman Long98474232013-08-28 18:24:59 -0700104#define d_lock d_lockref.lock
105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106struct dentry {
Nick Piggin44a7d7a2011-01-07 17:49:56 +1100107 /* RCU lookup touched fields */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 unsigned int d_flags; /* protected by d_lock */
Nick Piggin31e6b012011-01-07 17:49:52 +1100109 seqcount_t d_seq; /* per dentry seqlock */
Nick Pigginceb5bdc2011-01-07 17:50:05 +1100110 struct hlist_bl_node d_hash; /* lookup hash list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 struct dentry *d_parent; /* parent directory */
112 struct qstr d_name;
Nick Piggin44a7d7a2011-01-07 17:49:56 +1100113 struct inode *d_inode; /* Where the name belongs to - NULL is
114 * negative */
115 unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
116
117 /* Ref lookup also touches following */
Waiman Long98474232013-08-28 18:24:59 -0700118 struct lockref d_lockref; /* per-dentry lock and refcount */
Nick Piggin44a7d7a2011-01-07 17:49:56 +1100119 const struct dentry_operations *d_op;
120 struct super_block *d_sb; /* The root of the dentry tree */
121 unsigned long d_time; /* used by d_revalidate */
122 void *d_fsdata; /* fs-specific data */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124 struct list_head d_lru; /* LRU list */
Eric Dumazet5160ee62006-01-08 01:03:32 -0800125 /*
126 * d_child and d_rcu can share memory
127 */
128 union {
129 struct list_head d_child; /* child of parent list */
130 struct rcu_head d_rcu;
131 } d_u;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 struct list_head d_subdirs; /* our children */
Al Virob3d9b7a2012-06-09 13:51:19 -0400133 struct hlist_node d_alias; /* inode alias list */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134};
135
Ingo Molnara90b9c02006-07-03 00:25:04 -0700136/*
137 * dentry->d_lock spinlock nesting subclasses:
138 *
139 * 0: normal
140 * 1: nested
141 */
142enum dentry_d_lock_class
143{
144 DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
145 DENTRY_D_LOCK_NESTED
146};
147
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148struct dentry_operations {
Al Viro0b728e12012-06-10 16:03:43 -0400149 int (*d_revalidate)(struct dentry *, unsigned int);
Jeff Laytonecf3d1f2013-02-20 11:19:05 -0500150 int (*d_weak_revalidate)(struct dentry *, unsigned int);
Linus Torvaldsda53be12013-05-21 15:22:44 -0700151 int (*d_hash)(const struct dentry *, struct qstr *);
152 int (*d_compare)(const struct dentry *, const struct dentry *,
Nick Piggin621e1552011-01-07 17:49:27 +1100153 unsigned int, const char *, const struct qstr *);
Nick Pigginfe15ce42011-01-07 17:49:23 +1100154 int (*d_delete)(const struct dentry *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 void (*d_release)(struct dentry *);
Sage Weilf0023bc2011-10-28 10:02:42 -0700156 void (*d_prune)(struct dentry *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 void (*d_iput)(struct dentry *, struct inode *);
Eric Dumazetc23fbb62007-05-08 00:26:18 -0700158 char *(*d_dname)(struct dentry *, char *, int);
David Howells9875cf82011-01-14 18:45:21 +0000159 struct vfsmount *(*d_automount)(struct path *);
Al Viro1aed3e42011-03-18 09:09:02 -0400160 int (*d_manage)(struct dentry *, bool);
Nick Piggin44a7d7a2011-01-07 17:49:56 +1100161} ____cacheline_aligned;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Nick Piggin5eef7fa2011-01-07 17:49:22 +1100163/*
164 * Locking rules for dentry_operations callbacks are to be found in
165 * Documentation/filesystems/Locking. Keep it updated!
166 *
Nick Piggin621e1552011-01-07 17:49:27 +1100167 * FUrther descriptions are found in Documentation/filesystems/vfs.txt.
168 * Keep it updated too!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 */
170
171/* d_flags entries */
Linus Torvalds830c0f02011-08-06 22:41:50 -0700172#define DCACHE_OP_HASH 0x0001
173#define DCACHE_OP_COMPARE 0x0002
174#define DCACHE_OP_REVALIDATE 0x0004
175#define DCACHE_OP_DELETE 0x0008
Sage Weilf0023bc2011-10-28 10:02:42 -0700176#define DCACHE_OP_PRUNE 0x0010
Nick Piggin5f57cbc2011-01-07 17:49:54 +1100177
Sage Weilf0023bc2011-10-28 10:02:42 -0700178#define DCACHE_DISCONNECTED 0x0020
Nick Piggin5f57cbc2011-01-07 17:49:54 +1100179 /* This dentry is possibly not currently connected to the dcache tree, in
180 * which case its parent will either be itself, or will have this flag as
181 * well. nfsd will not use a dentry with this bit set, but will first
182 * endeavour to clear the bit either by discovering that it is connected,
183 * or by performing lookup operations. Any filesystem which supports
184 * nfsd_operations MUST have a lookup function which, if it finds a
185 * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that
186 * dentry into place and return that dentry rather than the passed one,
187 * typically using d_splice_alias. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Sage Weilf0023bc2011-10-28 10:02:42 -0700189#define DCACHE_REFERENCED 0x0040 /* Recently used, don't discard. */
190#define DCACHE_RCUACCESS 0x0080 /* Entry has ever been RCU-visible */
Eric Parisc28f7e52009-05-21 17:01:29 -0400191
Al Virod83c49f2010-04-30 17:17:09 -0400192#define DCACHE_CANT_MOUNT 0x0100
Nick Piggin949854d2011-01-07 17:49:37 +1100193#define DCACHE_GENOCIDE 0x0200
Miklos Szeredieaf5f902012-01-10 18:22:25 +0100194#define DCACHE_SHRINK_LIST 0x0400
Nick Piggin5f57cbc2011-01-07 17:49:54 +1100195
Jeff Laytonecf3d1f2013-02-20 11:19:05 -0500196#define DCACHE_OP_WEAK_REVALIDATE 0x0800
197
Linus Torvalds830c0f02011-08-06 22:41:50 -0700198#define DCACHE_NFSFS_RENAMED 0x1000
199 /* this dentry has been "silly renamed" and has to be deleted on the last
200 * dput() */
201#define DCACHE_COOKIE 0x2000 /* For use by dcookie subsystem */
202#define DCACHE_FSNOTIFY_PARENT_WATCHED 0x4000
203 /* Parent inode is watched by some fsnotify listener */
Nick Pigginfb045ad2011-01-07 17:49:55 +1100204
David Howells9875cf82011-01-14 18:45:21 +0000205#define DCACHE_MOUNTED 0x10000 /* is a mountpoint */
206#define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */
David Howellscc53ce52011-01-14 18:45:26 +0000207#define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */
David Howells9875cf82011-01-14 18:45:21 +0000208#define DCACHE_MANAGED_DENTRY \
David Howellscc53ce52011-01-14 18:45:26 +0000209 (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
David Howells9875cf82011-01-14 18:45:21 +0000210
Linus Torvalds8aab6a22013-09-08 13:26:18 -0700211#define DCACHE_LRU_LIST 0x80000
Miklos Szeredib161dfa62012-09-17 22:31:38 +0200212#define DCACHE_DENTRY_KILLED 0x100000
213
Al Viro74c3cbe2007-07-22 08:04:18 -0400214extern seqlock_t rename_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Al Virof0d3b3d2013-09-05 12:11:29 -0400216static inline int dname_external(const struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
218 return dentry->d_name.name != dentry->d_iname;
219}
220
221/*
222 * These are the low-level FS interfaces to the dcache..
223 */
224extern void d_instantiate(struct dentry *, struct inode *);
225extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
David Howells770bfad2006-08-22 20:06:07 -0400226extern struct dentry * d_materialise_unique(struct dentry *, struct inode *);
Nick Piggin789680d2011-01-07 17:49:30 +1100227extern void __d_drop(struct dentry *dentry);
228extern void d_drop(struct dentry *dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229extern void d_delete(struct dentry *);
Nick Pigginfb045ad2011-01-07 17:49:55 +1100230extern void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232/* allocate/de-allocate */
233extern struct dentry * d_alloc(struct dentry *, const struct qstr *);
Nick Piggin4b936882011-01-07 17:50:07 +1100234extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
Christoph Hellwige45b5902008-08-07 23:49:07 +0200236extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
Sage Weil46f72b32012-01-10 09:04:37 -0800237extern struct dentry *d_find_any_alias(struct inode *inode);
Christoph Hellwig4ea3ada2008-08-11 15:48:57 +0200238extern struct dentry * d_obtain_alias(struct inode *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239extern void shrink_dcache_sb(struct super_block *);
240extern void shrink_dcache_parent(struct dentry *);
David Howellsc636ebd2006-10-11 01:22:19 -0700241extern void shrink_dcache_for_umount(struct super_block *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242extern int d_invalidate(struct dentry *);
243
244/* only used at mount-time */
Al Viroadc0e912012-01-08 16:49:21 -0500245extern struct dentry * d_make_root(struct inode *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247/* <clickety>-<click> the ramfs-type tree */
248extern void d_genocide(struct dentry *);
249
Al Viro60545d02013-06-07 01:20:27 -0400250extern void d_tmpfile(struct dentry *, struct inode *);
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252extern struct dentry *d_find_alias(struct inode *);
253extern void d_prune_aliases(struct inode *);
254
255/* test whether we have any submounts in a subdir tree */
256extern int have_submounts(struct dentry *);
Miklos Szeredi848ac1142013-09-05 11:44:36 +0200257extern int check_submounts_and_drop(struct dentry *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
259/*
260 * This adds the entry to the hash queues.
261 */
262extern void d_rehash(struct dentry *);
263
264/**
265 * d_add - add dentry to hash queues
266 * @entry: dentry to add
267 * @inode: The inode to attach to this dentry
268 *
269 * This adds the entry to the hash queues and initializes @inode.
270 * The entry was actually filled in earlier during d_alloc().
271 */
272
273static inline void d_add(struct dentry *entry, struct inode *inode)
274{
275 d_instantiate(entry, inode);
276 d_rehash(entry);
277}
278
279/**
280 * d_add_unique - add dentry to hash queues without aliasing
281 * @entry: dentry to add
282 * @inode: The inode to attach to this dentry
283 *
284 * This adds the entry to the hash queues and initializes @inode.
285 * The entry was actually filled in earlier during d_alloc().
286 */
287static inline struct dentry *d_add_unique(struct dentry *entry, struct inode *inode)
288{
289 struct dentry *res;
290
291 res = d_instantiate_unique(entry, inode);
292 d_rehash(res != NULL ? res : entry);
293 return res;
294}
295
Nick Pigginfb2d5b82011-01-07 17:49:26 +1100296extern void dentry_update_name_case(struct dentry *, struct qstr *);
297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298/* used for rename() and baskets */
299extern void d_move(struct dentry *, struct dentry *);
OGAWA Hirofumie2761a12008-10-16 07:50:28 +0900300extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
302/* appendix may either be NULL or be used for transname suffixes */
Al Viroda2d8452013-01-24 18:29:34 -0500303extern struct dentry *d_lookup(const struct dentry *, const struct qstr *);
Nick Piggin31e6b012011-01-07 17:49:52 +1100304extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
Al Viroa713ca22013-01-24 18:27:00 -0500305extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
Linus Torvalds8966be92012-03-02 14:23:30 -0800306extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
Linus Torvaldsda53be12013-05-21 15:22:44 -0700307 const struct qstr *name, unsigned *seq);
Nick Piggin31e6b012011-01-07 17:49:52 +1100308
Peng Tao24924a22013-07-18 22:09:08 +0800309static inline unsigned d_count(const struct dentry *dentry)
Al Viro84d08fa2013-07-05 18:59:33 +0400310{
Waiman Long98474232013-08-28 18:24:59 -0700311 return dentry->d_lockref.count;
Al Viro84d08fa2013-07-05 18:59:33 +0400312}
313
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314/* validate "insecure" dentry pointer */
315extern int d_validate(struct dentry *, struct dentry *);
316
Eric Dumazetc23fbb62007-05-08 00:26:18 -0700317/*
318 * helper function for dentry_operations.d_dname() members
319 */
320extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
Al Viro118b2302013-08-24 12:08:17 -0400321extern char *simple_dname(struct dentry *, char *, int);
Eric Dumazetc23fbb62007-05-08 00:26:18 -0700322
Al Viro02125a82011-12-05 08:43:34 -0500323extern char *__d_path(const struct path *, const struct path *, char *, int);
324extern char *d_absolute_path(const struct path *, char *, int);
Jan Engelhardt20d4fdc2008-06-09 16:40:36 -0700325extern char *d_path(const struct path *, char *, int);
Nick Pigginec2447c2011-01-07 17:49:29 +1100326extern char *dentry_path_raw(struct dentry *, char *, int);
Ram Pai6092d042008-03-27 13:06:20 +0100327extern char *dentry_path(struct dentry *, char *, int);
Jan Blunckcf28b482008-02-14 19:38:44 -0800328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329/* Allocation counts.. */
330
331/**
Nick Piggindc0474b2011-01-07 17:49:43 +1100332 * dget, dget_dlock - get a reference to a dentry
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 * @dentry: dentry to get a reference to
334 *
335 * Given a dentry or %NULL pointer increment the reference count
336 * if appropriate and return the dentry. A dentry will not be
Nick Piggindc0474b2011-01-07 17:49:43 +1100337 * destroyed when it has references.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 */
Nick Pigginb7ab39f2011-01-07 17:49:32 +1100339static inline struct dentry *dget_dlock(struct dentry *dentry)
340{
Nick Piggindc0474b2011-01-07 17:49:43 +1100341 if (dentry)
Waiman Long98474232013-08-28 18:24:59 -0700342 dentry->d_lockref.count++;
Nick Pigginb7ab39f2011-01-07 17:49:32 +1100343 return dentry;
344}
Nick Piggin2fd6b7f2011-01-07 17:49:34 +1100345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346static inline struct dentry *dget(struct dentry *dentry)
347{
Waiman Long98474232013-08-28 18:24:59 -0700348 if (dentry)
349 lockref_get(&dentry->d_lockref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return dentry;
351}
352
Nick Pigginb7ab39f2011-01-07 17:49:32 +1100353extern struct dentry *dget_parent(struct dentry *dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
355/**
356 * d_unhashed - is dentry hashed
357 * @dentry: entry to check
358 *
359 * Returns true if the dentry passed is not currently hashed.
360 */
361
Al Virof0d3b3d2013-09-05 12:11:29 -0400362static inline int d_unhashed(const struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
Linus Torvaldsdea36672011-04-24 07:58:46 -0700364 return hlist_bl_unhashed(&dentry->d_hash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365}
366
Al Virof0d3b3d2013-09-05 12:11:29 -0400367static inline int d_unlinked(const struct dentry *dentry)
Alexey Dobriyanf3da3922009-05-04 03:32:03 +0400368{
369 return d_unhashed(dentry) && !IS_ROOT(dentry);
370}
371
Al Virof0d3b3d2013-09-05 12:11:29 -0400372static inline int cant_mount(const struct dentry *dentry)
Al Virod83c49f2010-04-30 17:17:09 -0400373{
374 return (dentry->d_flags & DCACHE_CANT_MOUNT);
375}
376
377static inline void dont_mount(struct dentry *dentry)
378{
379 spin_lock(&dentry->d_lock);
380 dentry->d_flags |= DCACHE_CANT_MOUNT;
381 spin_unlock(&dentry->d_lock);
382}
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384extern void dput(struct dentry *);
385
Al Virof0d3b3d2013-09-05 12:11:29 -0400386static inline bool d_managed(const struct dentry *dentry)
David Howellscc53ce52011-01-14 18:45:26 +0000387{
388 return dentry->d_flags & DCACHE_MANAGED_DENTRY;
389}
390
Al Virof0d3b3d2013-09-05 12:11:29 -0400391static inline bool d_mountpoint(const struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392{
Nick Piggin5f57cbc2011-01-07 17:49:54 +1100393 return dentry->d_flags & DCACHE_MOUNTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394}
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396extern int sysctl_vfs_cache_pressure;
397
Glauber Costa55f841c2013-08-28 10:17:53 +1000398static inline unsigned long vfs_pressure_ratio(unsigned long val)
399{
400 return mult_frac(val, sysctl_vfs_cache_pressure, 100);
401}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402#endif /* __LINUX_DCACHE_H */