xref: /freebsd/share/man/man9/vhold.9 (revision 8a7314fcb5347f8296a072e0c4f67a9f64303186)
121642577SAlfred Perlstein.\"
221642577SAlfred Perlstein.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
321642577SAlfred Perlstein.\"
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821642577SAlfred Perlstein.\"    notice(s), this list of conditions and the following disclaimer as
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1021642577SAlfred Perlstein.\"    addition of one or more copyright notices.
1121642577SAlfred Perlstein.\" 2. Redistributions in binary form must reproduce the above copyright
1221642577SAlfred Perlstein.\"    notice(s), this list of conditions and the following disclaimer in the
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1421642577SAlfred Perlstein.\"
1521642577SAlfred Perlstein.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
1621642577SAlfred Perlstein.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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2721642577SAlfred Perlstein.\" $FreeBSD$
2821642577SAlfred Perlstein.\"
298ad9c323SMaxim Konovalov.Dd April 1, 2007
3021642577SAlfred Perlstein.Dt VHOLD 9
3121642577SAlfred Perlstein.Os
3221642577SAlfred Perlstein.Sh NAME
338ad9c323SMaxim Konovalov.Nm vhold , vdrop , vdropl
341f620c2eSRuslan Ermilov.Nd "acquire/release a hold on a vnode"
3521642577SAlfred Perlstein.Sh SYNOPSIS
3621642577SAlfred Perlstein.In sys/param.h
3721642577SAlfred Perlstein.In sys/vnode.h
3821642577SAlfred Perlstein.Ft void
3921642577SAlfred Perlstein.Fn vhold "struct vnode *vp"
4021642577SAlfred Perlstein.Ft void
41b03ee585SChad David.Fn vholdl "struct vnode *vp"
42b03ee585SChad David.Ft void
4321642577SAlfred Perlstein.Fn vdrop "struct vnode *vp"
448ad9c323SMaxim Konovalov.Ft void
458ad9c323SMaxim Konovalov.Fn vdropl "struct vnode *vp"
4621642577SAlfred Perlstein.Sh DESCRIPTION
4721642577SAlfred PerlsteinThe
4821642577SAlfred Perlstein.Fn vhold
49b03ee585SChad Davidand
50b03ee585SChad David.Fn vholdl
51b03ee585SChad Davidfunctions increment the
521f620c2eSRuslan Ermilov.Va v_holdcnt
531f620c2eSRuslan Ermilovof the given vnode.
541f620c2eSRuslan ErmilovIf the vnode has already been added to the free list and is still referenced,
5521642577SAlfred Perlsteinit will be removed.
5621642577SAlfred Perlstein.Pp
5721642577SAlfred PerlsteinThe
5821642577SAlfred Perlstein.Fn vdrop
598ad9c323SMaxim Konovalovand
608ad9c323SMaxim Konovalov.Fn vdropl
618ad9c323SMaxim Konovalovfunctions decrement the
621f620c2eSRuslan Ermilov.Va v_holdcnt
631f620c2eSRuslan Ermilovof the vnode.
640167ce0dSCraig RodriguesIf the holdcount is less than or equal to zero prior to calling
658ad9c323SMaxim Konovalov.Fn vdrop
668ad9c323SMaxim Konovalovor
678ad9c323SMaxim Konovalov.Fn vdropl ,
6821642577SAlfred Perlsteinthe system will panic.
690167ce0dSCraig RodriguesIf the vnode is no longer referenced, it will be freed.
708ad9c323SMaxim Konovalov.Pp
71b03ee585SChad David.Fn vhold
72b03ee585SChad Davidand
738ad9c323SMaxim Konovalov.Fn vdrop
74b03ee585SChad Davidlock the vnode interlock while
75b03ee585SChad David.Fn vholdl
768ad9c323SMaxim Konovalovand
778ad9c323SMaxim Konovalov.Fn vdropl
78b03ee585SChad Davidexpect the interlock to already be held.
7921642577SAlfred Perlstein.Sh SEE ALSO
80b03ee585SChad David.Xr vnode 9
8121642577SAlfred Perlstein.Sh AUTHORS
82571dba6eSHiten PandyaThis manual page was written by
83*8a7314fcSBaptiste Daroussin.An Chad David Aq Mt davidc@acns.ab.ca .
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