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