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29 * @(#)namei.h 8.5 (Berkeley) 1/9/95
36 #include <sys/queue.h>
39 struct componentname {
41 * Arguments to lookup.
43 u_long cn_nameiop; /* namei operation */
44 u_long cn_flags; /* flags to namei */
45 struct thread *cn_thread;/* thread requesting lookup */
46 struct ucred *cn_cred; /* credentials */
48 * Shared between lookup and commit routines.
50 char *cn_pnbuf; /* pathname buffer */
51 char *cn_nameptr; /* pointer to looked up name */
52 long cn_namelen; /* length of looked up component */
53 long cn_consume; /* chars to consume in lookup() */
57 * Encapsulation of namei parameters.
61 * Arguments to namei/lookup.
63 const char *ni_dirp; /* pathname pointer */
64 enum uio_seg ni_segflg; /* location of pathname */
66 * Arguments to lookup.
68 struct vnode *ni_startdir; /* starting directory */
69 struct vnode *ni_rootdir; /* logical root directory */
70 struct vnode *ni_topdir; /* logical top directory */
72 * Results: returned from/manipulated by lookup
74 struct vnode *ni_vp; /* vnode of result */
75 struct vnode *ni_dvp; /* vnode of intermediate directory */
77 * Shared between namei and lookup/commit routines.
79 size_t ni_pathlen; /* remaining chars in path */
80 char *ni_next; /* next location in pathname */
81 u_long ni_loopcnt; /* count of symlinks encountered */
83 * Lookup parameters: this structure describes the subset of
84 * information from the nameidata structure that is passed
85 * through the VOP interface.
87 struct componentname ni_cnd;
94 #define LOOKUP 0 /* perform name lookup only */
95 #define CREATE 1 /* setup for file creation */
96 #define DELETE 2 /* setup for file deletion */
97 #define RENAME 3 /* setup for file renaming */
98 #define OPMASK 3 /* mask for operation */
100 * namei operational modifier flags, stored in ni_cnd.flags
102 #define LOCKLEAF 0x0004 /* lock inode on return */
103 #define LOCKPARENT 0x0008 /* want parent vnode returned locked */
104 #define WANTPARENT 0x0010 /* want parent vnode returned unlocked */
105 #define NOCACHE 0x0020 /* name must not be left in cache */
106 #define FOLLOW 0x0040 /* follow symbolic links */
107 #define NOOBJ 0x0080 /* don't create object */
108 #define LOCKSHARED 0x0100 /* Shared lock leaf */
109 #define NOFOLLOW 0x0000 /* do not follow symbolic links (pseudo) */
110 #define MODMASK 0x01fc /* mask of operational modifiers */
112 * Namei parameter descriptors.
114 * SAVENAME may be set by either the callers of namei or by VOP_LOOKUP.
115 * If the caller of namei sets the flag (for example execve wants to
116 * know the name of the program that is being executed), then it must
117 * free the buffer. If VOP_LOOKUP sets the flag, then the buffer must
118 * be freed by either the commit routine or the VOP_ABORT routine.
119 * SAVESTART is set only by the callers of namei. It implies SAVENAME
120 * plus the addition of saving the parent directory that contains the
121 * name in ni_startdir. It allows repeated calls to lookup for the
122 * name being sought. The caller is responsible for releasing the
123 * buffer and for vrele'ing ni_startdir.
125 #define RDONLY 0x0000200 /* lookup with read-only semantics */
126 #define HASBUF 0x0000400 /* has allocated pathname buffer */
127 #define SAVENAME 0x0000800 /* save pathname buffer */
128 #define SAVESTART 0x0001000 /* save starting directory */
129 #define ISDOTDOT 0x0002000 /* current component name is .. */
130 #define MAKEENTRY 0x0004000 /* entry is to be added to name cache */
131 #define ISLASTCN 0x0008000 /* this is last component of pathname */
132 #define ISSYMLINK 0x0010000 /* symlink needs interpretation */
133 #define ISWHITEOUT 0x0020000 /* found whiteout */
134 #define DOWHITEOUT 0x0040000 /* do whiteouts */
135 #define WILLBEDIR 0x0080000 /* new files will be dirs; allow trailing / */
136 #define ISUNICODE 0x0100000 /* current component name is unicode*/
137 #define PDIRUNLOCK 0x0200000 /* filesystem lookup() unlocked parent dir */
138 #define NOCROSSMOUNT 0x0400000 /* do not cross mount points */
139 #define NOMACCHECK 0x0800000 /* do not perform MAC checks */
140 #define MPSAFE 0x1000000 /* namei() must acquire Giant if needed. */
141 #define GIANTHELD 0x2000000 /* namei() is holding giant. */
142 #define PARAMASK 0x3fffe00 /* mask of parameter descriptors */
144 #define NDHASGIANT(NDP) (((NDP)->ni_cnd.cn_flags & GIANTHELD) != 0)
147 * Initialization of a nameidata structure.
149 static void NDINIT(struct nameidata *, u_long, u_long, enum uio_seg,
150 const char *, struct thread *);
152 NDINIT(struct nameidata *ndp,
153 u_long op, u_long flags,
158 ndp->ni_cnd.cn_nameiop = op;
159 ndp->ni_cnd.cn_flags = flags;
160 ndp->ni_segflg = segflg;
161 ndp->ni_dirp = namep;
162 ndp->ni_cnd.cn_thread = td;
165 #define NDF_NO_DVP_RELE 0x00000001
166 #define NDF_NO_DVP_UNLOCK 0x00000002
167 #define NDF_NO_DVP_PUT 0x00000003
168 #define NDF_NO_VP_RELE 0x00000004
169 #define NDF_NO_VP_UNLOCK 0x00000008
170 #define NDF_NO_VP_PUT 0x0000000c
171 #define NDF_NO_STARTDIR_RELE 0x00000010
172 #define NDF_NO_FREE_PNBUF 0x00000020
173 #define NDF_ONLY_PNBUF (~NDF_NO_FREE_PNBUF)
175 void NDFREE(struct nameidata *, const u_int);
177 int namei(struct nameidata *ndp);
178 int lookup(struct nameidata *ndp);
179 int relookup(struct vnode *dvp, struct vnode **vpp,
180 struct componentname *cnp);
184 * Stats on usefulness of namei caches.
187 long ncs_goodhits; /* hits that we can really use */
188 long ncs_neghits; /* negative hits that we can use */
189 long ncs_badhits; /* hits we must drop */
190 long ncs_falsehits; /* hits with id mismatch */
191 long ncs_miss; /* misses */
192 long ncs_long; /* long names that ignore cache */
193 long ncs_pass2; /* names found with passes == 2 */
194 long ncs_2passes; /* number of times we attempt it */
197 extern struct nchstats nchstats;
199 #endif /* !_SYS_NAMEI_H_ */