Get rid of the weird FSMID update path in the vnode and namecache code.
[dragonfly.git] / sys / sys / namecache.h
CommitLineData
7ea21ed1 1/*
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2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
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34 * Copyright (c) 1989, 1993
35 * The Regents of the University of California. All rights reserved.
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36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 * must display the following acknowledgement:
47 * This product includes software developed by the University of
48 * California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
6b008938 65 * $DragonFly: src/sys/sys/namecache.h,v 1.24 2006/04/25 22:11:29 dillon Exp $
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66 */
67
68#ifndef _SYS_NAMECACHE_H_
69#define _SYS_NAMECACHE_H_
70
71struct vnode;
72
73TAILQ_HEAD(namecache_list, namecache);
74
75/*
76 * The namecache structure is used to manage the filesystem namespace. Most
77 * vnodes cached by the system will reference one or more associated namecache
78 * structures.
79 *
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80 * The namecache is disjoint, there may not always be a path to the system
81 * root through nc_parent links. If a namecache entry has no parent, that
82 * entry will not be hashed and can only be 'found' via '.' or '..'.
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83 *
84 * Because the namecache structure maintains the path through mount points,
85 * null, and union mounts, and other VFS overlays, several namecache
86 * structures may pass through the same vnode. Also note that namespaces
87 * relating to non-existant (i.e. not-yet-created) files/directories may be
88 * locked. Lock coherency is achieved by requiring that the particular
89 * namecache record whos parent represents the physical directory in which
90 * the namespace operation is to occur be the one that is locked. In
91 * overlay cases, the (union, nullfs) VFS, or in namei when crossing a mount
92 * point, may have to obtain multiple namespace record locks to avoid
93 * confusion, but only the one representing the physical directory is passed
94 * into lower layer VOP calls.
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95 *
96 * Many new API VOP operations do not pass vnodes. In these cases the
6ddb7618 97 * operations vector is typically obtained via nc_mount->mnt_vn_use_ops.
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98 */
99struct namecache {
100 LIST_ENTRY(namecache) nc_hash; /* hash chain (nc_parent,name) */
101 TAILQ_ENTRY(namecache) nc_entry; /* scan via nc_parent->nc_list */
102 TAILQ_ENTRY(namecache) nc_vnode; /* scan via vnode->v_namecache */
103 struct namecache_list nc_list; /* list of children */
104 struct namecache *nc_parent; /* namecache entry for parent */
105 struct vnode *nc_vp; /* vnode representing name or NULL */
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106 int nc_refs; /* ref count prevents deletion */
107 u_short nc_flag;
108 u_char nc_nlen; /* The length of the name, 255 max */
109 u_char nc_unused;
110 char *nc_name; /* Separately allocated seg name */
690a3127 111 int nc_error;
1345c2b6 112 int nc_timeout; /* compared against ticks, or 0 */
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113 int nc_exlocks; /* namespace locking */
114 struct thread *nc_locktd; /* namespace locking */
fad57d0e 115 struct mount *nc_mount; /* associated mount for vopops */
7d15906a 116 int64_t nc_fsmid; /* filesystem modified id */
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117};
118
119typedef struct namecache *namecache_t;
120
121/*
122 * Flags in namecache.nc_flag (u_char)
123 */
14c92d03 124#define NCF_LOCKED 0x0001 /* locked namespace */
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125#define NCF_WHITEOUT 0x0002 /* negative entry corresponds to whiteout */
126#define NCF_UNRESOLVED 0x0004 /* invalid or unresolved entry */
127#define NCF_MOUNTPT 0x0008 /* mount point */
128#define NCF_ROOT 0x0010 /* namecache root (static) */
129#define NCF_HASHED 0x0020 /* namecache entry in hash table */
14c92d03 130#define NCF_LOCKREQ 0x0040
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131#define NCF_UNUSED080 0x0080
132#define NCF_ISSYMLINK 0x0100 /* represents a symlink */
133#define NCF_ISDIR 0x0200 /* represents a directory */
e09206ba 134#define NCF_DESTROYED 0x0400 /* name association is considered destroyed */
dc1be39c 135#define NCF_FSMID 0x0800 /* FSMID updated */
7ea21ed1 136
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137/*
138 * cache_inval[_vp]() flags
139 */
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140#define CINV_DESTROY 0x0001 /* flag so cache_nlookup ignores the ncp */
141#define CINV_UNUSED02 0x0002
142#define CINV_CHILDREN 0x0004 /* recursively set children to unresolved */
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143
144#ifdef _KERNEL
145
7ea21ed1 146struct componentname;
690a3127 147struct nlcomponent;
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148struct mount;
149
14c92d03 150void cache_lock(struct namecache *ncp);
fad57d0e 151int cache_lock_nonblock(struct namecache *ncp);
14c92d03 152void cache_unlock(struct namecache *ncp);
690a3127 153void cache_setvp(struct namecache *ncp, struct vnode *vp);
fad57d0e 154void cache_settimeout(struct namecache *ncp, int nticks);
690a3127 155void cache_setunresolved(struct namecache *ncp);
690a3127 156struct namecache *cache_nlookup(struct namecache *par, struct nlcomponent *nlc);
5fd012e0 157struct namecache *cache_allocroot(struct mount *mp, struct vnode *vp);
25cb3304 158int cache_inval(struct namecache *ncp, int flags);
6b008938 159int cache_inval_vp(struct vnode *vp, int flags);
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160void vfs_cache_setroot(struct vnode *vp, struct namecache *ncp);
161
162int cache_resolve(struct namecache *ncp, struct ucred *cred);
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163void cache_purge(struct vnode *vp);
164void cache_purgevfs (struct mount *mp);
9b1b3591 165void cache_validate(struct namecache *ncp);
5fd012e0 166int cache_get_nonblock(struct namecache *ncp);
62d0f1f0 167void cache_cleanneg(int count);
21739618 168struct namecache *cache_get(struct namecache *ncp);
bc0c094e 169struct namecache *cache_hold(struct namecache *ncp);
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170void cache_put(struct namecache *ncp);
171void cache_drop(struct namecache *ncp);
fad57d0e 172void cache_rename(struct namecache *fncp, struct namecache *tncp);
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173int cache_vget(struct namecache *, struct ucred *, int, struct vnode **);
174int cache_vref(struct namecache *, struct ucred *, struct vnode **);
fad57d0e 175struct namecache *cache_fromdvp(struct vnode *, struct ucred *, int);
b6372d22 176int cache_fullpath(struct proc *, struct namecache *, char **, char **);
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177void cache_update_fsmid(struct namecache *);
178void cache_update_fsmid_vp(struct vnode *);
dc1be39c 179int cache_check_fsmid_vp(struct vnode *, int64_t *);
6b008938 180int64_t cache_getnewfsmid(void);
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181
182#endif
183
184#endif