mirror_zfs/lib/libspl/include/sys/mount.h
Suman Chakravartula e18be9a637 Add overlay(-O) mount option support
Linux supports mounting over non-empty directories by default.
In Solaris this is not the case and -O option is required for
zfs mount to mount a zfs filesystem over a non-empty directory.

For compatibility, I've added support for -O option to mount
zfs filesystems over non-empty directories if the user wants
to, just like in Solaris.

I've defined MS_OVERLAY to record it in the flags variable if
the -O option is supplied.  The flags variable passes through
a few functions and its checked before performing the empty
directory check in zfs_mount function.  If -O is given, the
check is not performed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #473
2012-01-12 15:49:38 -08:00

84 lines
2.3 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include_next <sys/mount.h>
#ifndef _LIBSPL_SYS_MOUNT_H
#define _LIBSPL_SYS_MOUNT_H
#include <sys/mntent.h>
#include <assert.h>
#include <string.h>
#include <stdlib.h>
/*
* Some old glibc headers don't define BLKGETSIZE64
* and we don't want to require the kernel headers
*/
#if !defined(BLKGETSIZE64)
#define BLKGETSIZE64 _IOR(0x12, 114, size_t)
#endif
/*
* Some old glibc headers don't correctly define MS_DIRSYNC and
* instead use the enum name S_WRITE. When using these older
* headers define MS_DIRSYNC to be S_WRITE.
*/
#if !defined(MS_DIRSYNC)
#define MS_DIRSYNC S_WRITE
#endif
#define MS_USERS 0x40000000
#define MS_OWNER 0x10000000
#define MS_GROUP 0x08000000
#define MS_COMMENT 0x02000000
/*
* Older glibc <sys/mount.h> headers did not define all the available
* umount2(2) flags. Both MNT_FORCE and MNT_DETACH are supported in the
* kernel back to 2.4.11 so we define them correctly if they are missing.
*/
#ifdef MNT_FORCE
# define MS_FORCE MNT_FORCE
#else
# define MS_FORCE 0x00000001
#endif /* MNT_FORCE */
#ifdef MNT_DETACH
# define MS_DETACH MNT_DETACH
#else
# define MS_DETACH 0x00000002
#endif /* MNT_DETACH */
/*
* Overlay mount is default in Linux, but for solaris/zfs
* compatibility, MS_OVERLAY is defined to explicitly have the user
* provide a flag (-O) to mount over a non empty directory.
*/
#define MS_OVERLAY 0x00000004
#endif /* _LIBSPL_SYS_MOUNT_H */