.\"
.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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.\" $FreeBSD: head/share/man/man9/vfs_getvfs.9 267936 2014-06-26 21:44:30Z bapt $
.\"
.Dd November 21, 2001
.Dt VFS_GETVFS 9
.Os
.Sh NAME
.Nm vfs_getvfs
.Nd "returns a mount point given its file system identifier"
.Sh SYNOPSIS
.In sys/param.h
.In sys/mount.h
.Ft "struct mount *"
.Fn vfs_getvfs "fsid_t *fsid"
.Sh DESCRIPTION
The
.Fn vfs_getvfs
function returns the mount point structure for a file system given its file system
identifier.
The file system ID should have been allocated by calling
.Xr vfs_getnewfsid 9 ;
otherwise, it will not be found.
.Pp
A major user of
.Fn vfs_getvfs
is NFS, which uses the
.Vt fsid
as part of file handles in order to determine the
file system a given RPC is for.
If
.Fn vfs_getvfs
fails to find the mount point related to
.Fa fsid ,
the file system is considered stale.
.Sh RETURN VALUES
If
.Fa fsid
is found, the mount point for the ID is returned; otherwise,
.Dv NULL
is returned.
.Sh PSEUDOCODE
.Bd -literal
if ((mp = vfs_getvfs(&fhp->fh_fsid)) == NULL) {
	error = ESTALE;
	goto out;
}
.Ed
.Sh SEE ALSO
.Xr vfs_getnewfsid 9
.Sh AUTHORS
This manual page was written by
.An Chad David Aq Mt davidc@acns.ab.ca .