xref: /freebsd/share/man/man9/vfs_busy.9 (revision 1efbe1a4be308848b05965d3c7a81dd14ca3e811)
18981fef8SAlfred Perlstein.\"
28981fef8SAlfred Perlstein.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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288981fef8SAlfred Perlstein.\"
291efbe1a4SAttilio Rao.Dd November 2, 2008
308981fef8SAlfred Perlstein.Dt VFS_BUSY 9
318981fef8SAlfred Perlstein.Os
328981fef8SAlfred Perlstein.Sh NAME
338981fef8SAlfred Perlstein.Nm vfs_busy
3423789024SRuslan Ermilov.Nd "marks a mount point as busy"
358981fef8SAlfred Perlstein.Sh SYNOPSIS
3623789024SRuslan Ermilov.In sys/param.h
3723789024SRuslan Ermilov.In sys/mount.h
388981fef8SAlfred Perlstein.Ft int
391efbe1a4SAttilio Rao.Fn vfs_busy "struct mount *mp" "int flags"
408981fef8SAlfred Perlstein.Sh DESCRIPTION
418981fef8SAlfred PerlsteinThe
4223789024SRuslan Ermilov.Fn vfs_busy
4323789024SRuslan Ermilovfunction marks a mount point as busy.
4423789024SRuslan ErmilovThe purpose of this
4523789024SRuslan Ermilovfunction is to synchronize access to a mount point.
46034709cbSRuslan ErmilovIt also delays unmounting by sleeping on
47034709cbSRuslan Ermilov.Fa mp
48034709cbSRuslan Ermilovif the
4923789024SRuslan Ermilov.Dv MNTK_UNMOUNT
5023789024SRuslan Ermilovflag is set in
5123789024SRuslan Ermilov.Fa mp->mnt_kern_flag
5223789024SRuslan Ermilovand the
5323789024SRuslan Ermilov.Dv LK_NOWAIT
5423789024SRuslan Ermilovflag is
5523789024SRuslan Ermilov.Em not
5623789024SRuslan Ermilovset.
578981fef8SAlfred Perlstein.Pp
588981fef8SAlfred PerlsteinIts arguments are:
591efbe1a4SAttilio Rao.Bl -tag -width ".Fa flags"
6023789024SRuslan Ermilov.It Fa mp
618981fef8SAlfred PerlsteinThe mount point to busy.
6223789024SRuslan Ermilov.It Fa flags
63034709cbSRuslan ErmilovFlags controlling how
64034709cbSRuslan Ermilov.Fn vfs_busy
65034709cbSRuslan Ermilovshould act.
661efbe1a4SAttilio Rao.Bl -tag -width ".Dv MBF_MNTLSTLOCK"
671efbe1a4SAttilio Rao.It Dv MBF_NOWAIT
6823789024SRuslan Ermilovdo not sleep if
6923789024SRuslan Ermilov.Dv MNTK_UNMOUNT
7023789024SRuslan Ermilovis set.
711efbe1a4SAttilio Rao.It Dv MBF_MNTLSTLOCK
721efbe1a4SAttilio Raodrop the mountlist_mtx in the critical path.
7323789024SRuslan Ermilov.El
748981fef8SAlfred Perlstein.El
758981fef8SAlfred Perlstein.Sh RETURN VALUES
7623789024SRuslan ErmilovA 0 value is returned on success.
7723789024SRuslan ErmilovIf the mount point is being
7823789024SRuslan Ermilovunmounted
7923789024SRuslan Ermilov.Er ENOENT
8023789024SRuslan Ermilovwill always be returned.
818981fef8SAlfred Perlstein.Sh ERRORS
8223789024SRuslan Ermilov.Bl -tag -width Er
8323789024SRuslan Ermilov.It Bq Er ENOENT
8423789024SRuslan ErmilovThe mount point is being unmounted
8523789024SRuslan Ermilov.Dv ( MNTK_UNMOUNT
8623789024SRuslan Ermilovis set).
878981fef8SAlfred Perlstein.El
888981fef8SAlfred Perlstein.Sh AUTHORS
8909356c84SHiten PandyaThis manual page was written by
90034709cbSRuslan Ermilov.An Chad David Aq davidc@acns.ab.ca .
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