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.Dd October 17, 2025 30.Dt VOP_OPEN 9 31.Os 32.Sh NAME 33.Nm VOP_OPEN , 34.Nm VOP_CLOSE 35.Nd open or close a file 36.Sh SYNOPSIS 37.In sys/param.h 38.In sys/vnode.h 39.Ft int 40.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" "struct file *fp" 41.Ft int 42.Fn VOP_CLOSE "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" 43.Sh DESCRIPTION 44The 45.Fn VOP_OPEN 46entry point is called before a file is accessed by a process and the 47.Fn VOP_CLOSE 48entry point is called after a file is finished with by the process. 49.Pp 50The arguments are: 51.Bl -tag -width mode 52.It Fa vp 53The vnode of the file. 54.It Fa mode 55The access mode required by the calling process. 56.It Fa cred 57The caller's credentials. 58.It Fa td 59The thread which is accessing the file. 60.It Fa fp 61The file being opened. 62.El 63.Pp 64Pointer to the file 65.Fa fp 66is useful for file systems which require such information, e.g., 67.Xr fdescfs 5 . 68Use 69.Ql NULL 70as 71.Fa fp 72argument to 73.Fn VOP_OPEN 74for in-kernel opens. 75.Pp 76The access mode is a set of flags, including 77.Dv FREAD , 78.Dv FWRITE , 79.Dv O_NONBLOCK , 80.Dv O_APPEND . 81.Pp 82The thread 83.Fa td 84passed to 85.Fn VOP_CLOSE 86may be 87.Ql NULL 88if the last reference to the open file is released from a kernel context, e.g., 89the destruction of a socket buffer containing the file reference in a 90.Dv SCM_RIGHTS 91message. 92.Sh LOCKS 93.Fn VOP_OPEN 94expects 95.Fa vp 96to be locked on entry and will leave it locked on return. 97.Pp 98.Fn VOP_CLOSE 99expects at least a reference to be associated with the vnode and does not 100care whether the vnode is locked or not. 101The lock and reference state is left unchanged on return. 102Note that 103.Fa vn_close 104expects an unlocked, referenced vnode and will dereference the vnode prior 105to returning. 106.Sh RETURN VALUES 107Zero is returned on success, otherwise an error code is returned. 108.Sh SEE ALSO 109.Xr vnode 9 , 110.Xr VOP_LOOKUP 9 111.Sh AUTHORS 112This manual page was written by 113.An Doug Rabson . 114