-
Notifications
You must be signed in to change notification settings - Fork 24
/
namei.h
221 lines (207 loc) · 8.51 KB
/
namei.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/* $NetBSD: namei.h,v 1.26 2002/05/12 23:06:28 matt Exp $ */
/*
* Copyright (c) 1985, 1989, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)namei.h 8.5 (Berkeley) 8/20/94
*/
#ifndef _SYS_NAMEI_H_
#define _SYS_NAMEI_H_
#include <sys/queue.h>
/*
* Encapsulation of namei parameters.
*/
struct nameidata {
/*
* Arguments to namei/lookup.
*/
const char *ni_dirp; /* pathname pointer */
enum uio_seg ni_segflg; /* location of pathname */
/* u_long ni_nameiop; namei operation */
/* u_long ni_flags; flags to namei */
/* struct proc *ni_proc; process requesting lookup */
/*
* Arguments to lookup.
*/
/* struct ucred *ni_cred; credentials */
struct vnode *ni_startdir; /* starting directory */
struct vnode *ni_rootdir; /* logical root directory */
/*
* Results: returned from/manipulated by lookup
*/
struct vnode *ni_vp; /* vnode of result */
struct vnode *ni_dvp; /* vnode of intermediate directory */
/*
* Shared between namei and lookup/commit routines.
*/
size_t ni_pathlen; /* remaining chars in path */
const char *ni_next; /* next location in pathname */
u_long ni_loopcnt; /* count of symlinks encountered */
/*
* Lookup parameters: this structure describes the subset of
* information from the nameidata structure that is passed
* through the VOP interface.
*/
struct componentname {
/*
* Arguments to lookup.
*/
u_long cn_nameiop; /* namei operation */
u_long cn_flags; /* flags to namei */
struct proc *cn_proc; /* process requesting lookup */
struct ucred *cn_cred; /* credentials */
/*
* Shared between lookup and commit routines.
*/
char *cn_pnbuf; /* pathname buffer */
const char *cn_nameptr; /* pointer to looked up name */
long cn_namelen; /* length of looked up component */
u_long cn_hash; /* hash value of looked up name */
long cn_consume; /* chars to consume in lookup() */
} ni_cnd;
};
#ifdef _KERNEL
/*
* namei operations
*/
#define LOOKUP 0 /* perform name lookup only */
#define CREATE 1 /* setup for file creation */
#define DELETE 2 /* setup for file deletion */
#define RENAME 3 /* setup for file renaming */
#define OPMASK 3 /* mask for operation */
/*
* namei operational modifier flags, stored in ni_cnd.cn_flags
*/
#define LOCKLEAF 0x0004 /* lock inode on return */
#define LOCKPARENT 0x0008 /* want parent vnode returned locked */
#define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
#define NOCACHE 0x0020 /* name must not be left in cache */
#define FOLLOW 0x0040 /* follow symbolic links */
#define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
#define MODMASK 0x00fc /* mask of operational modifiers */
/*
* Namei parameter descriptors.
*
* SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
* If the caller of namei sets the flag (for example execve wants to
* know the name of the program that is being executed), then it must
* free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
* be freed by either the commit routine or the VOP_ABORT routine.
* SAVESTART is set only by the callers of namei. It implies SAVENAME
* plus the addition of saving the parent directory that contains the
* name in ni_startdir. It allows repeated calls to lookup for the
* name being sought. The caller is responsible for releasing the
* buffer and for vrele'ing ni_startdir.
*/
#define NOCROSSMOUNT 0x0000100 /* do not cross mount points */
#define RDONLY 0x0000200 /* lookup with read-only semantics */
#define HASBUF 0x0000400 /* has allocated pathname buffer */
#define SAVENAME 0x0000800 /* save pathname buffer */
#define SAVESTART 0x0001000 /* save starting directory */
#define ISDOTDOT 0x0002000 /* current component name is .. */
#define MAKEENTRY 0x0004000 /* entry is to be added to name cache */
#define ISLASTCN 0x0008000 /* this is last component of pathname */
#define ISSYMLINK 0x0010000 /* symlink needs interpretation */
#define ISWHITEOUT 0x0020000 /* found whiteout */
#define DOWHITEOUT 0x0040000 /* do whiteouts */
#define REQUIREDIR 0x0080000 /* must be a directory */
#define PDIRUNLOCK 0x0100000 /* vfs_lookup() unlocked parent dir */
#define PARAMASK 0x01fff00 /* mask of parameter descriptors */
/*
* Initialization of an nameidata structure.
*/
#define NDINIT(ndp, op, flags, segflg, namep, p) { \
(ndp)->ni_cnd.cn_nameiop = op; \
(ndp)->ni_cnd.cn_flags = flags; \
(ndp)->ni_segflg = segflg; \
(ndp)->ni_dirp = namep; \
(ndp)->ni_cnd.cn_proc = p; \
(ndp)->ni_cnd.cn_cred = p->p_ucred; \
}
#endif
/*
* This structure describes the elements in the cache of recent
* names looked up by namei. NCHNAMLEN is sized to make structure
* size a power of two to optimize malloc's. Minimum reasonable
* size is 15.
*/
#define NCHNAMLEN 31 /* maximum name segment length we bother with */
struct namecache {
LIST_ENTRY(namecache) nc_hash; /* hash chain */
TAILQ_ENTRY(namecache) nc_lru; /* LRU chain */
LIST_ENTRY(namecache) nc_vhash; /* directory hash chain */
struct vnode *nc_dvp; /* vnode of parent of name */
u_long nc_dvpid; /* capability number of nc_dvp */
struct vnode *nc_vp; /* vnode the name refers to */
u_long nc_vpid; /* capability number of nc_vp */
char nc_nlen; /* length of name */
char nc_name[NCHNAMLEN]; /* segment name */
};
#ifdef _KERNEL
#include <sys/pool.h>
extern struct pool pnbuf_pool; /* pathname buffer pool */
extern struct pool_cache pnbuf_cache; /* pathname buffer cache */
#define PNBUF_GET() pool_cache_get(&pnbuf_cache, PR_WAITOK)
#define PNBUF_PUT(pnb) pool_cache_put(&pnbuf_cache, (pnb))
int namei __P((struct nameidata *ndp));
uint32_t namei_hash __P((const char *, const char **));
int lookup __P((struct nameidata *ndp));
int relookup __P((struct vnode *dvp, struct vnode **vpp,
struct componentname *cnp));
void cache_purge __P((struct vnode *));
int cache_lookup __P((struct vnode *, struct vnode **, struct componentname *));
int cache_revlookup __P((struct vnode *, struct vnode **, char **, char *));
void cache_enter __P((struct vnode *, struct vnode *, struct componentname *));
void nchinit __P((void));
void nchreinit __P((void));
struct mount;
void cache_purgevfs __P((struct mount *));
void namecache_print(struct vnode *, void (*)(const char *, ...));
#endif
/*
* Stats on usefulness of namei caches.
*/
struct nchstats {
long ncs_goodhits; /* hits that we can really use */
long ncs_neghits; /* negative hits that we can use */
long ncs_badhits; /* hits we must drop */
long ncs_falsehits; /* hits with id mismatch */
long ncs_miss; /* misses */
long ncs_long; /* long names that ignore cache */
long ncs_pass2; /* names found with passes == 2 */
long ncs_2passes; /* number of times we attempt it */
long ncs_revhits; /* reverse-cache hits */
long ncs_revmiss; /* reverse-cache misses */
};
#ifdef _KERNEL
extern struct nchstats nchstats;
#endif
#endif /* !_SYS_NAMEI_H_ */