1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd July 8, 2001 30.Dt VFS_BUSY 9 31.Os 32.Sh NAME 33.Nm vfs_busy 34.Nd "marks a mount point as busy" 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/mount.h 38.Ft int 39.Fn vfs_busy "struct mount *mp" "int flags" "struct mtx *interlkp" "struct thread *td" 40.Sh DESCRIPTION 41The 42.Fn vfs_busy 43function marks a mount point as busy. 44The purpose of this 45function is to synchronize access to a mount point. 46It also delays unmounting by sleeping on 47.Fa mp 48if the 49.Dv MNTK_UNMOUNT 50flag is set in 51.Fa mp->mnt_kern_flag 52and the 53.Dv LK_NOWAIT 54flag is 55.Em not 56set. 57.Pp 58Its arguments are: 59.Bl -tag -width ".Fa interlkp" 60.It Fa mp 61The mount point to busy. 62.It Fa flags 63Flags controlling how 64.Fn vfs_busy 65should act. 66.Bl -tag -width ".Dv LK_NOWAIT" 67.It Dv LK_NOWAIT 68do not sleep if 69.Dv MNTK_UNMOUNT 70is set. 71.El 72.It Fa interlkp 73The interlock mutex for 74.Fa mp->mount_lock . 75If there is any chance 76the mount point is being unmounted and 77.Dv LK_NOWAIT 78is not set then 79interlock must be valid locked mutex. 80.It Fa td 81The thread responsible for this call. 82.El 83.Sh LOCKS 84If 85.Fa interlkp 86is a valid pointer it must be locked on entry, 87and it will not be unlocked even in the case of an error. 88.Sh RETURN VALUES 89A 0 value is returned on success. 90If the mount point is being 91unmounted 92.Er ENOENT 93will always be returned. 94.Sh ERRORS 95.Bl -tag -width Er 96.It Bq Er ENOENT 97The mount point is being unmounted 98.Dv ( MNTK_UNMOUNT 99is set). 100.El 101.Sh AUTHORS 102This manual page was written by 103.An Chad David Aq davidc@acns.ab.ca . 104