xref: /freebsd/lib/libc/gen/getvfsbyname.3 (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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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