xref: /freebsd/lib/libc/gen/getvfsbyname.3 (revision 273c26a3c3bea87a241d6879abd4f991db180bf0)
1.\" Copyright (c) 1995
2.\"	The Regents of the University of California.  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, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 4. Neither the name of the University nor the names of its contributors
13.\"    may be used to endorse or promote products derived from this software
14.\"    without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\"     @(#)kvm_getvfsbyname.3	8.3 (Berkeley) 5/4/95
29.\" $FreeBSD$
30.\"
31.Dd August 30, 2016
32.Dt GETVFSBYNAME 3
33.Os
34.Sh NAME
35.Nm getvfsbyname
36.Nd get information about a file system
37.Sh LIBRARY
38.Lb libc
39.Sh SYNOPSIS
40.In sys/param.h
41.In sys/mount.h
42.Ft int
43.Fn getvfsbyname "const char *name" "struct xvfsconf *vfc"
44.Sh DESCRIPTION
45The
46.Fn getvfsbyname
47function provides access to information about a
48file system module that is configured in the kernel.
49If successful,
50the requested file system
51.Fa xvfsconf
52is returned in the location pointed to by
53.Fa vfc .
54The fields in a
55.Dq Li struct xvfsconf
56are defined as follows:
57.Pp
58.Bl -tag -compact -width vfc_refcount
59.It vfc_name
60the name of the file system
61.It vfc_typenum
62the file system type number assigned by the kernel
63.It vfc_refcount
64the number of active mount points using the file system
65.It vfc_flags
66flag bits, as described below
67.El
68.Pp
69The flags are defined as follows:
70.Pp
71.Bl -tag -width VFCF_DELEGADMIN -compact
72.It Dv VFCF_STATIC
73statically compiled into kernel
74.It Dv VFCF_NETWORK
75may get data over the network
76.It Dv VFCF_READONLY
77writes are not implemented
78.It Dv VFCF_SYNTHETIC
79data does not represent real files
80.It Dv VFCF_LOOPBACK
81aliases some other mounted FS
82.It Dv VFCF_UNICODE
83stores file names as Unicode
84.It Dv VFCF_JAIL
85can be mounted from within a jail if
86.Va security.jail.mount_allowed
87sysctl is set to
88.Dv 1
89.It Dv VFCF_DELEGADMIN
90supports delegated administration if
91.Va vfs.usermount
92sysctl is set to
93.Dv 1
94.El
95.Sh RETURN VALUES
96.Rv -std getvfsbyname
97.Sh ERRORS
98The following errors may be reported:
99.Bl -tag -width Er
100.It Bq Er ENOENT
101The
102.Fa name
103argument
104specifies a file system that is unknown or not configured in the kernel.
105.El
106.Sh SEE ALSO
107.Xr jail 2 ,
108.Xr mount 2 ,
109.Xr sysctl 3 ,
110.Xr jail 8 ,
111.Xr mount 8 ,
112.Xr sysctl 8
113.Sh HISTORY
114A variant of the
115.Fn getvfsbyname
116function first appeared in
117.Fx 2.0 .
118