1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>, 5 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $DragonFly: src/sys/sys/namecache.h,v 1.4 2004/04/08 22:00:40 dillon Exp $ 36 */ 37 38 #ifndef _SYS_NAMECACHE_H_ 39 #define _SYS_NAMECACHE_H_ 40 41 struct vnode; 42 43 TAILQ_HEAD(namecache_list, namecache); 44 45 /* 46 * The namecache structure is used to manage the filesystem namespace. Most 47 * vnodes cached by the system will reference one or more associated namecache 48 * structures. 49 * 50 * The namecache is disjoint, there may not always be a path to the system 51 * root through nc_parent links. If a namecache entry has no parent, that 52 * entry will not be hashed and can only be 'found' via '.' or '..'. 53 */ 54 struct namecache { 55 LIST_ENTRY(namecache) nc_hash; /* hash chain (nc_parent,name) */ 56 TAILQ_ENTRY(namecache) nc_entry; /* scan via nc_parent->nc_list */ 57 TAILQ_ENTRY(namecache) nc_vnode; /* scan via vnode->v_namecache */ 58 struct namecache_list nc_list; /* list of children */ 59 struct namecache *nc_parent; /* namecache entry for parent */ 60 struct vnode *nc_vp; /* vnode representing name or NULL */ 61 int nc_refs; /* ref count prevents deletion */ 62 u_short nc_flag; 63 u_char nc_nlen; /* The length of the name, 255 max */ 64 u_char nc_unused; 65 char *nc_name; /* Separately allocated seg name */ 66 int nc_timeout; /* compared against ticks, or 0 */ 67 }; 68 69 typedef struct namecache *namecache_t; 70 71 /* 72 * Flags in namecache.nc_flag (u_char) 73 */ 74 #define NCF_NEGATIVE 0x01 /* negative entry */ 75 #define NCF_WHITEOUT 0x02 /* negative entry corresponds to whiteout */ 76 #define NCF_UNRESOLVED 0x04 /* invalid or unresolved entry */ 77 #define NCF_MOUNTPT 0x08 /* mount point */ 78 #define NCF_ROOT 0x10 /* namecache root (static) */ 79 #define NCF_HASHED 0x20 /* namecache entry in hash table */ 80 81 #define CINV_SELF 0x0001 /* invalidate a specific (dvp,vp) entry */ 82 #define CINV_CHILDREN 0x0002 /* invalidate all children of vp */ 83 84 #define NCPNULL ((struct namecache *)NULL) /* placemarker */ 85 #define NCPPNULL ((struct namecache **)NULL) /* placemarker */ 86 87 #ifdef _KERNEL 88 89 struct vop_lookup_args; 90 struct componentname; 91 struct mount; 92 93 int cache_lookup(struct vnode *dvp, struct namecache *par, 94 struct vnode **vpp, struct namecache **ncpp, 95 struct componentname *cnp); 96 void cache_mount(struct vnode *dvp, struct vnode *tvp); 97 void cache_enter(struct vnode *dvp, struct namecache *par, 98 struct vnode *vp, struct componentname *cnp); 99 void vfs_cache_setroot(struct vnode *vp); 100 void cache_purge(struct vnode *vp); 101 void cache_purgevfs (struct mount *mp); 102 void cache_drop(struct namecache *ncp); 103 struct namecache *cache_hold(struct namecache *ncp); 104 int cache_leaf_test (struct vnode *vp); 105 int vfs_cache_lookup(struct vop_lookup_args *ap); 106 int textvp_fullpath (struct proc *p, char **retbuf, char **retfreebuf); 107 108 #endif 109 110 #endif 111