path: root/fs/ocfs2/ocfs2_fs.h

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * ocfs2_fs.h
 *
 * On-disk structures for OCFS2.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License, version 2,  as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef _OCFS2_FS_H
#define _OCFS2_FS_H

/* Version */
#define OCFS2_MAJOR_REV_LEVEL		0
#define OCFS2_MINOR_REV_LEVEL          	90

/*
 * An OCFS2 volume starts this way:
 * Sector 0: Valid ocfs1_vol_disk_hdr that cleanly fails to mount OCFS.
 * Sector 1: Valid ocfs1_vol_label that cleanly fails to mount OCFS.
 * Block OCFS2_SUPER_BLOCK_BLKNO: OCFS2 superblock.
 *
 * All other structures are found from the superblock information.
 *
 * OCFS2_SUPER_BLOCK_BLKNO is in blocks, not sectors.  eg, for a
 * blocksize of 2K, it is 4096 bytes into disk.
 */
#define OCFS2_SUPER_BLOCK_BLKNO		2

/*
 * Cluster size limits. The maximum is kept arbitrarily at 1 MB, and could
 * grow if needed.
 */
#define OCFS2_MIN_CLUSTERSIZE		4096
#define OCFS2_MAX_CLUSTERSIZE		1048576

/*
 * Blocks cannot be bigger than clusters, so the maximum blocksize is the
 * minimum cluster size.
 */
#define OCFS2_MIN_BLOCKSIZE		512
#define OCFS2_MAX_BLOCKSIZE		OCFS2_MIN_CLUSTERSIZE

/* Filesystem magic number */
#define OCFS2_SUPER_MAGIC		0x7461636f

/* Object signatures */
#define OCFS2_SUPER_BLOCK_SIGNATURE	"OCFSV2"
#define OCFS2_INODE_SIGNATURE		"INODE01"
#define OCFS2_EXTENT_BLOCK_SIGNATURE	"EXBLK01"
#define OCFS2_GROUP_DESC_SIGNATURE      "GROUP01"
#define OCFS2_XATTR_BLOCK_SIGNATURE	"XATTR01"
#define OCFS2_DIR_TRAILER_SIGNATURE	"DIRTRL1"
#define OCFS2_DX_ROOT_SIGNATURE		"DXDIR01"
#define OCFS2_DX_LEAF_SIGNATURE		"DXLEAF1"

/* Compatibility flags */
#define OCFS2_HAS_COMPAT_FEATURE(sb,mask)			\
	( OCFS2_SB(sb)->s_feature_compat & (mask) )
#define OCFS2_HAS_RO_COMPAT_FEATURE(sb,mask)			\
	( OCFS2_SB(sb)->s_feature_ro_compat & (mask) )
#define OCFS2_HAS_INCOMPAT_FEATURE(sb,mask)			\
	( OCFS2_SB(sb)->s_feature_incompat & (mask) )
#define OCFS2_SET_COMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_compat |= (mask)
#define OCFS2_SET_RO_COMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_ro_compat |= (mask)
#define OCFS2_SET_INCOMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_incompat |= (mask)
#define OCFS2_CLEAR_COMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_compat &= ~(mask)
#define OCFS2_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_ro_compat &= ~(mask)
#define OCFS2_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
	OCFS2_SB(sb)->s_feature_incompat &= ~(mask)

#define OCFS2_FEATURE_COMPAT_SUPP	(OCFS2_FEATURE_COMPAT_BACKUP_SB	\
					 | OCFS2_FEATURE_COMPAT_JBD2_SB)
#define OCFS2_FEATURE_INCOMPAT_SUPP	(OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT \
					 | OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC \
					 | OCFS2_FEATURE_INCOMPAT_INLINE_DATA \
					 | OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP \
					 | OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK \
					 | OCFS2_FEATURE_INCOMPAT_XATTR \
					 | OCFS2_FEATURE_INCOMPAT_META_ECC)
#define OCFS2_FEATURE_RO_COMPAT_SUPP	(OCFS2_FEATURE_RO_COMPAT_UNWRITTEN \
					 | OCFS2_FEATURE_RO_COMPAT_USRQUOTA \
					 | OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)

/*
 * Heartbeat-only devices are missing journals and other files.  The
 * filesystem driver can't load them, but the library can.  Never put
 * this in OCFS2_FEATURE_INCOMPAT_SUPP, *ever*.
 */
#define OCFS2_FEATURE_INCOMPAT_HEARTBEAT_DEV	0x0002

/*
 * tunefs sets this incompat flag before starting the resize and clears it
 * at the end. This flag protects users from inadvertently mounting the fs
 * after an aborted run without fsck-ing.