Document the mount option handling functions.
Reviewed By: ru
This commit is contained in:
Chad David
parent
e41bcf3cfc
commit
cbd01db412
197
share/man/man9/vfs_getopt.9
Normal file
197
share/man/man9/vfs_getopt.9
Normal file
@ -0,0 +1,197 @@
|
||||
.\"
|
||||
.\" Copyright (C) 2007 Chad David <davidc@acns.ab.ca>. All rights reserved.
|
||||
.\"
|
||||
.\" Redistribution and use in source and binary forms, with or without
|
||||
.\" modification, are permitted provided that the following conditions
|
||||
.\" are met:
|
||||
.\" 1. Redistributions of source code must retain the above copyright
|
||||
.\" notice(s), this list of conditions and the following disclaimer as
|
||||
.\" the first lines of this file unmodified other than the possible
|
||||
.\" addition of one or more copyright notices.
|
||||
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||||
.\" notice(s), this list of conditions and the following disclaimer in the
|
||||
.\" documentation and/or other materials provided with the distribution.
|
||||
.\"
|
||||
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
|
||||
.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||||
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
|
||||
.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||||
.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
||||
.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
|
||||
.\" DAMAGE.
|
||||
.\"
|
||||
.\" $FreeBSD$
|
||||
.\"
|
||||
.Dd February 28, 2007
|
||||
.Dt VFS_GETOPT 9
|
||||
.Os
|
||||
.Sh NAME
|
||||
.Nm vfs_getopt ,
|
||||
.Nm vfs_getopts ,
|
||||
.Nm vfs_flagopt ,
|
||||
.Nm vfs_scanopt ,
|
||||
.Nm vfs_copyopt ,
|
||||
.Nm vfs_filteropt
|
||||
.Nd "manipulate mount options and their values"
|
||||
.Sh SYNOPSIS
|
||||
.In sys/param.h
|
||||
.In sys/mount.h
|
||||
.Ft int
|
||||
.Fo vfs_getopt
|
||||
.Fa "struct vfsoptlist *opts" "const char *name" "void **buf" "int *len"
|
||||
.Fc
|
||||
.Ft "char *"
|
||||
.Fn vfs_getops "struct vfsoptlist *opts" "const char *name" "int *error"
|
||||
.Ft int
|
||||
.Fo vfs_flagopt
|
||||
.Fa "struct vfsoptlist *opts" "const char *name" "u_int *flags" "u_int flag"
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fo vfs_scanopt
|
||||
.Fa "struct vfsoptlist *opts" "const char *name" "const char *fmt" ...
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fo vfs_copyopt
|
||||
.Fa "struct vfsoptlist *opts" "const char *name" "void *dest" "int len"
|
||||
.Fc
|
||||
.Ft int
|
||||
.Fo vfs_filteropt
|
||||
.Fa "struct vfsoptlist *opts" "const char **legal"
|
||||
.Fc
|
||||
.Sh DESCRIPTION
|
||||
The
|
||||
.Fn vfs_getopt
|
||||
function sets
|
||||
.Fa buf
|
||||
to point to the value of the named mount option, and sets
|
||||
.Fa len
|
||||
to the length of the value if it is not
|
||||
.Dv NULL .
|
||||
The
|
||||
.Fa buf
|
||||
argument
|
||||
will point to the actual value, and does not need to be freed or released
|
||||
(and probably should not be modified).
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_getopts
|
||||
function
|
||||
returns the value of the specified option if it is a string (i.e.,
|
||||
.Dv NUL
|
||||
terminated).
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_flagopt
|
||||
function determines if an option exists.
|
||||
If the option does exist, and
|
||||
.Fa flags
|
||||
is not
|
||||
.Dv NULL ,
|
||||
.Fa flag
|
||||
is added to those already set in
|
||||
.Fa flags .
|
||||
If the option does not exist, and
|
||||
.Fa flags
|
||||
is not
|
||||
.Dv NULL ,
|
||||
.Fa flag
|
||||
is removed from those already set in
|
||||
.Fa flags .
|
||||
An example of typical usage is:
|
||||
.Bd -literal
|
||||
if (vfs_flagopt(mp->mnt_optnew, "wormlike", NULL, 0))
|
||||
vfs_flagopt(mp->mnt_optnew, "appendok", &(mp->flags), F_APPENDOK);
|
||||
.Ed
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_scanopt
|
||||
function performs a
|
||||
.Xr vsscanf 3
|
||||
with the options value, using the given format,
|
||||
into the specified variable arguments.
|
||||
The value must be a string (i.e.,
|
||||
.Dv NUL
|
||||
terminated).
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_copyopt
|
||||
function creates a copy of the options value.
|
||||
The
|
||||
.Fa len
|
||||
argument must match the length of the options value exactly
|
||||
(i.e., a larger buffer will still cause
|
||||
.Fn vfs_copyout
|
||||
to fail with
|
||||
.Er EINVAL ) .
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_filteropt
|
||||
function ensures that no unknown options were specified.
|
||||
A option is valid if its name matches one of the names in the
|
||||
list of legal names.
|
||||
An option may be prefixed with 'no', and still be considered valid.
|
||||
.Sh RETURN VALUES
|
||||
The
|
||||
.Fn vfs_getopt
|
||||
function returns 0 if the option was found; otherwise,
|
||||
.Er ENOENT
|
||||
is returned.
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_getops
|
||||
function returns the specified option if it is found, and is
|
||||
.Dv NUL
|
||||
terminated.
|
||||
If the option was found, but is not
|
||||
.Dv NUL
|
||||
terminated,
|
||||
.Fa error
|
||||
is set to
|
||||
.Er EINVAL
|
||||
and
|
||||
.Dv NULL
|
||||
is returned.
|
||||
If the option was not found,
|
||||
.Fa error
|
||||
is set to 0, and
|
||||
.Dv NULL
|
||||
is returned.
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_flagopt
|
||||
function returns 1 if the option was found, and 0 if it was not.
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_scanopt
|
||||
function returns 0 if the option was not found, or was not
|
||||
.Dv NUL
|
||||
terminated; otherwise, the return value of
|
||||
.Xr vsscanf 3
|
||||
is returned.
|
||||
If
|
||||
.Xr vsscanf 3
|
||||
returns 0, it will be returned unchanged; therefore, a return value of 0 does
|
||||
not always mean the option does not exist, or is not a valid string.
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_copyopt
|
||||
function returns 0 if the copy was successful,
|
||||
.Er EINVAL
|
||||
if the option was found but the lengths did not match, and
|
||||
.Er ENOENT
|
||||
if the option was not found.
|
||||
.Pp
|
||||
The
|
||||
.Fn vfs_filteropt
|
||||
function returns 0 if all of the options are legal; otherwise,
|
||||
.Er EINVAL
|
||||
is returned.
|
||||
.Sh AUTHORS
|
||||
This manual page was written by
|
||||
.An Chad David Aq davidc@freebsd.org
|
||||
and
|
||||
.An Ruslan Ermilov Aq ru@freebsd.org
|
||||
Loading…
Reference in New Issue
Block a user