freebsd-skq/lib/libc/gen/getvfsbyname.3
pjd bbe899b96e Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.
This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

	Allows regular users to perform ZFS operations, like file system
	creation, snapshot creation, etc.

- L2ARC

	Level 2 cache for ZFS - allows to use additional disks for cache.
	Huge performance improvements mostly for random read of mostly
	static content.

- slog

	Allow to use additional disks for ZFS Intent Log to speed up
	operations like fsync(2).

- vfs.zfs.super_owner

	Allows regular users to perform privileged operations on files stored
	on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

	Not all the flags are supported. This still needs work.

- ZFSBoot

	Support to boot off of ZFS pool. Not finished, AFAIK.

	Submitted by:	dfr

- Snapshot properties

- New failure modes

	Before if write requested failed, system paniced. Now one
	can select from one of three failure modes:
	- panic - panic on write error
	- wait - wait for disk to reappear
	- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

	Just quota and reservation properties, but don't count space consumed
	by children file systems, clones and snapshots.

- Sparse volumes

	ZVOLs that don't reserve space in the pool.

- External attributes

	Compatible with extattr(2).

- NFSv4-ACLs

	Not sure about the status, might not be complete yet.

	Submitted by:	trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from:	OpenSolaris
2008-11-17 20:49:29 +00:00

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Groff

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.\" @(#)kvm_getvfsbyname.3 8.3 (Berkeley) 5/4/95
.\" $FreeBSD$
.\"
.Dd April 5, 2007
.Dt GETVFSBYNAME 3
.Os
.Sh NAME
.Nm getvfsbyname
.Nd get information about a file system
.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
file system module that is configured in the kernel.
If successful,
the requested file system
.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 file system
.It vfc_typenum
the file system type number assigned by the kernel
.It vfc_refcount
the number of active mount points using the file system
.It vfc_flags
flag bits, as described below
.El
.Pp
The flags are defined as follows:
.Pp
.Bl -tag -width VFCF_DELEGADMIN -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
.It Dv VFCF_JAIL
can be mounted from within a jail if
.Va security.jail.mount_allowed
sysctl is set to
.Dv 1
.It Dv VFCF_DELEGADMIN
supports delegated administration if
.Va vfs.usermount
sysctl is set to
.Dv 1
.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
argument
points to an invalid address.
.It Bq Er ENOENT
The
.Fa name
argument
specifies a file system that is unknown or not configured in the kernel.
.El
.Sh SEE ALSO
.Xr jail 2 ,
.Xr mount 2 ,
.Xr sysctl 3 ,
.Xr jail 8 ,
.Xr mount 8 ,
.Xr sysctl 8
.Sh HISTORY
A variant of the
.Fn getvfsbyname
function first appeared in
.Fx 2.0 .