xref: /freebsd/lib/libc/gen/getvfsbyname.3 (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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28.Dd August 16, 2018
29.Dt GETVFSBYNAME 3
30.Os
31.Sh NAME
32.Nm getvfsbyname
33.Nd get information about a file system
34.Sh LIBRARY
35.Lb libc
36.Sh SYNOPSIS
37.In sys/param.h
38.In sys/mount.h
39.Ft int
40.Fn getvfsbyname "const char *name" "struct xvfsconf *vfc"
41.Sh DESCRIPTION
42The
43.Fn getvfsbyname
44function provides access to information about a
45file system module that is configured in the kernel.
46If successful,
47the requested file system
48.Fa xvfsconf
49is returned in the location pointed to by
50.Fa vfc .
51The fields in a
52.Dq Li struct xvfsconf
53are defined as follows:
54.Pp
55.Bl -tag -compact -width vfc_refcount
56.It vfc_name
57the name of the file system
58.It vfc_typenum
59the file system type number assigned by the kernel
60.It vfc_refcount
61the number of active mount points using the file system
62.It vfc_flags
63flag bits, as described below
64.El
65.Pp
66The flags are defined as follows:
67.Pp
68.Bl -tag -width VFCF_DELEGADMIN -compact
69.It Dv VFCF_STATIC
70statically compiled into kernel
71.It Dv VFCF_NETWORK
72may get data over the network
73.It Dv VFCF_READONLY
74writes are not implemented
75.It Dv VFCF_SYNTHETIC
76data does not represent real files
77.It Dv VFCF_LOOPBACK
78aliases some other mounted FS
79.It Dv VFCF_UNICODE
80stores file names as Unicode
81.It Dv VFCF_JAIL
82can be mounted from within a jail if
83.Va allow.mount
84and
85.Va allow.mount.<vfc_name>
86jail parameters are set
87.It Dv VFCF_DELEGADMIN
88supports delegated administration if
89.Va vfs.usermount
90sysctl is set to
91.Dv 1
92.El
93.Sh RETURN VALUES
94.Rv -std getvfsbyname
95.Sh ERRORS
96The following errors may be reported:
97.Bl -tag -width Er
98.It Bq Er ENOENT
99The
100.Fa name
101argument
102specifies a file system that is unknown or not configured in the kernel.
103.El
104.Sh SEE ALSO
105.Xr jail 2 ,
106.Xr mount 2 ,
107.Xr sysctl 3 ,
108.Xr jail 8 ,
109.Xr mount 8 ,
110.Xr sysctl 8
111.Sh HISTORY
112A variant of the
113.Fn getvfsbyname
114function first appeared in
115.Fx 2.0 .
116