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_LINK 9 34.Sh NAME 35.Nm VOP_LINK 36.Nd create a new name for a file 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/vnode.h 40.Ft int 41.Fn VOP_LINK "struct vnode *dvp" "struct vnode *vp" "struct componentname *cnp" 42.Sh DESCRIPTION 43This links a new name in the specified directory to an existing file. 44.Pp 45Its arguments are: 46.Bl -tag -width 8n 47.It Ar dvp 48the vnode of the directory 49.It Ar vp 50the vnode of the file to be linked 51.It Ar cnp 52pathname information about the file 53.El 54.Pp 55The pathname info must be released on exit. The directory and 56file vnodes should NOT be released on exit. 57.Sh LOCKS 58The directory, 59.Fa dvp 60is locked on entry and should remain locked on return. 61The file 62.Fa vp 63is not locked on entry and should remain that way on return. 64If your VOP code locks 65.Fa vp , 66it must be sure to unlock prior to returning. 67.Sh RETURN VALUES 68Zero is returned if the file was linked successfully, otherwise an 69error is returned. 70.Sh PSEUDOCODE 71.Bd -literal 72int 73vop_link(struct vnode *dvp, struct vnode *vp, struct componentname *cnp) 74{ 75 int error = 0; 76 77 if (vp->v_mount != dvp->v_mount) { 78 error = EXDEV; 79 goto out2; 80 } 81 if (vp != dvp && (error = VOP_LOCK(vp))) { 82 goto out2; 83 } 84 85 /* 86 * now that we've locked vp, we have to use out1 instead of out2 87 */ 88 89 if (vp would have too many links) { 90 error = EMLINK; 91 goto out1; 92 } 93 94 if (vp is immutable) { 95 error = EPERM; 96 goto out1; 97 } 98 99 /* 100 * Increment link count of vp and write back the on-disc version of it. 101 */ 102 ...; 103 104 if (!error) { 105 /* 106 * Add the new name to the directory. 107 */ 108 ...; 109 } 110 111 free(cnp->cn_pnbuf, M_NAMEI); 112out1: 113 if (vp != dvp) 114 VOP_UNLOCK(vp); 115out2: 116 117 return error; 118} 119.Ed 120.Sh ERRORS 121.Bl -tag -width Er 122.It Bq Er EPERM 123the file is immutable 124.El 125.Sh SEE ALSO 126.Xr vnode 9 , 127.Xr vn_lock 9 128.Sh AUTHORS 129This man page was originally written by 130.An Doug Rabson . 131