freebsd-nq/share/man/man9/vfs_mountedon.9
Alfred Perlstein ffc0b97fd0 More kernel vfs docco.
Xref vfs_mount(9) from vfs_mount(9)

Submitted by: Chad David <davidc@acns.ab.ca>
PR: docs/32431
2001-12-03 00:25:04 +00:00

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.\"
.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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.\" $FreeBSD$
.\"
.Dd November 21, 2001
.Dt VFS_MOUNTEDON 9
.Os
.Sh NAME
.Nm vfs_mountedon
.Nd "check if the vnode belongs to a mounted filesystem"
.Sh SYNOPSIS
.In sys/param.h
.In sys/vnode.h
.Ft int
.Fn vfs_mountedon "struct vnode *vp"
.Sh DESCRIPTION
.Fn vfs_mountedon
inspects the mount structure in
.Fa vp
to determine if it points to a valid mount point.
If the mount is valid the vnode is considered to be busy.
.Pp
A common use of
.Fn vfs_mountedon
it to call it on device vnodes to determine if they are already associated with
a filesystem.
This is done to prevent multiple mounts on the same device.
.Sh RETURN VALUES
.Dv EBUSY
is returned if the vnode has a valid mount point; otherwise, 0 is returned.
.Sh PSEUDOCODE
.Bd -literal
int
ffs_mountfs(devvp, mp, td, malloctype)
register struct vnode *devvp;
struct mount *mp;
struct thread *td;
struct malloc_type *malloctype;
{
...
error = vfs_mountedon(devvp);
if (error)
return (error);
...
}
.Ed
.Sh AUTHORS
This man page was written by
.An Chad David Aq davidc@acns.ab.ca .