1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd November 21, 2001 30.Dt VFS_GETNEWFSID 9 31.Os 32.Sh NAME 33.Nm vfs_getnewfsid 34.Nd "allocate a new file system identifier" 35.Sh SYNOPSIS 36.In sys/param.h 37.In sys/mount.h 38.Ft void 39.Fn vfs_getnewfsid "struct mount *mp" 40.Sh DESCRIPTION 41The 42.Fn vfs_getnewfsid 43function allocates a new file system identifier for the mount point given. 44File systems typically call 45.Fn vfs_getnewfsid 46in their mount routine in order to acquire a unique ID within the system 47which can later be used to uniquely identify the file system via calls such as 48.Xr vfs_getvfs 9 . 49.Pp 50The actual 51.Vt fsid 52is made up of two 32 bit integers, that are stored in the 53.Vt statfs 54structure of 55.Fa mp . 56The first integer is unique in the set of mounted file systems, 57while the second holds the file system type. 58.Bd -literal 59typedef struct fsid { 60 int32_t val[2]; 61} fsid_t; 62.Ed 63.Sh PSEUDOCODE 64.Bd -literal 65xxx_mount(struct mount *mp, char *path, caddr_t data, 66 struct nameidata *ndp, struct thread *td) 67{ 68 ... 69 vfs_getnewfsid(mp); 70 ... 71} 72.Ed 73.Sh SEE ALSO 74.Xr vfs_getvfs 9 75.Sh AUTHORS 76This manual page was written by 77.An Chad David Aq Mt davidc@acns.ab.ca . 78