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 Fa dvp 48The vnode of the directory. 49.It Fa vp 50The vnode of the file to be linked. 51.It Fa cnp 52Pathname information about the file. 53.El 54.Pp 55The pathname info should 56.Em not 57be released on exit because it is done 58by the caller. 59The directory and file vnodes should 60.Em not 61be released on exit. 62.Sh LOCKS 63.Fn VOP_LINK 64expects the directory and file vnodes to be locked on entry and will leave 65the vnodes locked on return. 66.Sh RETURN VALUES 67Zero is returned if the file was linked successfully, otherwise an 68error is returned. 69.Sh PSEUDOCODE 70.Bd -literal 71int 72vop_link(struct vnode *dvp, struct vnode *vp, struct componentname *cnp) 73{ 74 int error = 0; 75 76 if (vp->v_mount != dvp->v_mount) 77 return (EXDEV); 78 79 if (vp would have too many links) 80 return (EMLINK); 81 82 if (vp is immutable) 83 return (EPERM); 84 85 /* 86 * Increment link count of vp and write back the on-disc version of it. 87 */ 88 ...; 89 90 if (!error) { 91 /* 92 * Add the new name to the directory. 93 */ 94 ...; 95 } 96 97 return error; 98} 99.Ed 100.Sh ERRORS 101.Bl -tag -width Er 102.It Bq Er EMLINK 103The file has too many links. 104.It Bq Er EPERM 105The file is immutable. 106.It Bq Er EXDEV 107A hard link is not possible between different file systems. 108.El 109.Sh SEE ALSO 110.Xr vn_lock 9 , 111.Xr vnode 9 112.Sh AUTHORS 113This manual page was originally written by 114.An Doug Rabson . 115