102 lines
2.9 KiB
Groff
102 lines
2.9 KiB
Groff
.\"
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.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice(s), this list of conditions and the following disclaimer as
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.\" the first lines of this file unmodified other than the possible
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.\" addition of one or more copyright notices.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice(s), this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
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.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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.\" DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd August 29, 2008
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.Dt VFS_BUSY 9
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.Os
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.Sh NAME
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.Nm vfs_busy
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.Nd "marks a mount point as busy"
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.Sh SYNOPSIS
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.In sys/param.h
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.In sys/mount.h
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.Ft int
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.Fn vfs_busy "struct mount *mp" "int flags" "struct mtx *interlkp"
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.Sh DESCRIPTION
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The
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.Fn vfs_busy
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function marks a mount point as busy.
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The purpose of this
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function is to synchronize access to a mount point.
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It also delays unmounting by sleeping on
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.Fa mp
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if the
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.Dv MNTK_UNMOUNT
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flag is set in
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.Fa mp->mnt_kern_flag
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and the
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.Dv LK_NOWAIT
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flag is
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.Em not
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set.
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.Pp
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Its arguments are:
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.Bl -tag -width ".Fa interlkp"
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.It Fa mp
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The mount point to busy.
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.It Fa flags
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Flags controlling how
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.Fn vfs_busy
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should act.
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.Bl -tag -width ".Dv LK_NOWAIT"
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.It Dv LK_NOWAIT
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do not sleep if
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.Dv MNTK_UNMOUNT
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is set.
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.El
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.It Fa interlkp
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The interlock mutex for
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.Fa mp->mount_lock .
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If there is any chance
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the mount point is being unmounted and
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.Dv LK_NOWAIT
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is not set then
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interlock must be valid locked mutex.
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.El
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.Sh LOCKS
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If
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.Fa interlkp
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is a valid pointer it must be locked on entry,
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and it will not be unlocked even in the case of an error.
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.Sh RETURN VALUES
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A 0 value is returned on success.
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If the mount point is being
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unmounted
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.Er ENOENT
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will always be returned.
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.Sh ERRORS
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.Bl -tag -width Er
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.It Bq Er ENOENT
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The mount point is being unmounted
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.Dv ( MNTK_UNMOUNT
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is set).
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.El
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.Sh AUTHORS
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This manual page was written by
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.An Chad David Aq davidc@acns.ab.ca .
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