1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD$ 30.\" 31.Dd July 24, 1996 32.Os 33.Dt VOP_ATTRIB 9 34.Sh NAME 35.Nm VOP_GETATTR , 36.Nm VOP_SETATTR 37.Nd get and set attributes on a file or directory 38.Sh SYNOPSIS 39.In sys/param.h 40.In sys/vnode.h 41.Ft int 42.Fn VOP_GETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" "struct thread *td" 43.Ft int 44.Fn VOP_SETATTR "struct vnode *vp" "struct vattr *vap" "struct ucred *cred" "struct thread *td" 45.Sh DESCRIPTION 46These entry points manipulate various attributes of a file or directory, 47including file permissions, owner, group, size, 48access time and modification time. 49.Pp 50The arguments are: 51.Bl -tag -width cred 52.It Ar vp 53the vnode of the file 54.It Ar vap 55the attributes of the file 56.It Ar cred 57the user credentials of the calling process 58.It Ar td 59the thread 60.El 61.Pp 62Attributes which are not being modified by 63.Xr VOP_SETATTR 9 64should be set to the value 65.Dv VNOVAL ; 66.Fn VOP_NULL "" 67may be used to clear all the values, and should generally be used to reset 68the contents of 69.Ar *vap 70prior to setting specific values. 71.Sh LOCKS 72.Xr VOP_GETATTR 9 73expects the vnode to be locked on entry and will leave the vnode locked on 74return. 75The lock type can be either shared or exclusive. 76.Pp 77.Xr VOP_SETATTR 9 78expects the vnode to be locked on entry and will leave the vnode locked on 79return. 80The lock type must be exclusive. 81.Sh RETURN VALUES 82.Xr VOP_GETATTR 9 83returns 0 if it was able to retrieve the attribute data via 84.Fa *vap , 85otherwise an appropriate error is returned. 86.Xr VOP_SETATTR 9 87returns zero if the attributes were changed successfully, otherwise an 88appropriate error is returned. 89.Sh PSEUDOCODE 90.Bd -literal 91int 92vop_getattr(struct vnode *vp, struct vattr *vap, 93 struct ucred *cred, struct thread *td) 94{ 95 /* 96 * Fill in the contents of *vap with information from 97 * the filesystem. 98 */ 99 ...; 100 101 return 0; 102} 103 104int 105vop_setattr(struct vnode *vp, struct vattr *vap, 106 struct ucred *cred, struct thread *td) 107{ 108 /* 109 * Check for unsettable attributes. 110 */ 111 if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) || 112 (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) || 113 (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) || 114 ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) { 115 return (EINVAL); 116 } 117 118 if (vap->va_flags != VNOVAL) { 119 /* 120 * Set the immutable and append flags of the file. 121 */ 122 } 123 124 if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) { 125 /* 126 * Change owner and/or group of the file. 127 */ 128 } 129 130 if (vap->va_size != VNOVAL) { 131 /* 132 * Truncate the file to the specified size. 133 */ 134 } 135 136 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) { 137 /* 138 * Change access and/or modification time of file. 139 */ 140 } 141 142 if (vap->va_mode != (mode_t)VNOVAL) { 143 /* 144 * Change permissions of file. 145 */ 146 } 147 148 return 0; 149} 150.Ed 151.Sh ERRORS 152.Bl -tag -width Er 153.It Bq Er EPERM 154The file is immutable 155.It Bq Er EACCES 156Permission denied 157.It Bq Er EROFS 158The filesystem is read-only 159.El 160.Sh SEE ALSO 161.Xr vnode 9 , 162.Xr VOP_ACCESS 9 , 163.Xr VFS 9 164.Sh AUTHORS 165This man page was written by 166.An Doug Rabson . 167