freebsd-nq/lib/libc/gen/getvfsbyname.3
Maxime Henrion 5965373e69 - Introduce a new struct xvfsconf, the userland version of struct vfsconf.
- Make getvfsbyname() take a struct xvfsconf *.
- Convert several consumers of getvfsbyname() to use struct xvfsconf.
- Correct the getvfsbyname.3 manpage.
- Create a new vfs.conflist sysctl to dump all the struct xvfsconf in the
  kernel, and rewrite getvfsbyname() to use this instead of the weird
  existing API.
- Convert some {set,get,end}vfsent() consumers to use the new vfs.conflist
  sysctl.
- Convert a vfsload() call in nfsiod.c to kldload() and remove the useless
  vfsisloadable() and endvfsent() calls.
- Add a warning printf() in vfs_sysctl() to tell people they are using
  an old userland.

After these changes, it's possible to modify struct vfsconf without
breaking the binary compatibility.  Please note that these changes don't
break this compatibility either.

When bp will have updated mount_smbfs(8) with the patch I sent him, there
will be no more consumers of the {set,get,end}vfsent(), vfsisloadable()
and vfsload() API, and I will promptly delete it.
2002-08-10 20:19:04 +00:00

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Groff

.\" Copyright (c) 1995
.\" The Regents of the University of California. All rights reserved.
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.\" may be used to endorse or promote products derived from this software
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.\" @(#)kvm_getvfsbyname.3 8.3 (Berkeley) 5/4/95
.\" $FreeBSD$
.\"
.Dd May 4, 1995
.Dt GETVFSBYNAME 3
.Os
.Sh NAME
.Nm getvfsbyname
.Nd get information about a filesystem
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In sys/mount.h
.Ft int
.Fn getvfsbyname "const char *name" "struct xvfsconf *vfc"
.Sh DESCRIPTION
The
.Fn getvfsbyname
function provides access to information about a
filesystem module that is configured in the kernel.
If successful,
the requested filesystem
.Fa xvfsconf
is returned in the location pointed to by
.Fa vfc .
The fields in a
.Dq Li struct xvfsconf
are defined as follows:
.Pp
.Bl -tag -compact -width vfc_refcount
.It vfc_name
the name of the filesystem
.It vfc_typenum
the filesystem type number assigned by the kernel
.It vfc_refcount
the number of active mount points using the filesystem
.It vfc_flags
flag bits, as described below
.El
.Pp
The flags are defined as follows:
.Pp
.Bl -tag -width VFCF_SYNTHETIC -compact
.It Dv VFCF_STATIC
statically compiled into kernel
.It Dv VFCF_NETWORK
may get data over the network
.It Dv VFCF_READONLY
writes are not implemented
.It Dv VFCF_SYNTHETIC
data does not represent real files
.It Dv VFCF_LOOPBACK
aliases some other mounted FS
.It Dv VFCF_UNICODE
stores file names as Unicode
.El
.Sh RETURN VALUES
.Rv -std getvfsbyname
.Sh ERRORS
The following errors may be reported:
.Bl -tag -width Er
.It Bq Er EFAULT
The
.Fa vfc
pointer contains an invalid address.
.It Bq Er ENOENT
The
.Fa name
specifies a filesystem that is unknown or not configured in the kernel.
.El
.Sh SEE ALSO
.Xr mount 2 ,
.Xr sysctl 3 ,
.Xr mount 8 ,
.Xr sysctl 8
.Sh HISTORY
A variant of the
.Fn getvfsbyname
function first appeared in
.Fx 2.0 .