path: root/fs/ext3/ext3.h

/*
 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
 *
 * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/magic.h>
#include <linux/bug.h>
#include <linux/blockgroup_lock.h>

/*
 * The second extended filesystem constants/structures
 */

/*
 * Define EXT3FS_DEBUG to produce debug messages
 */
#undef EXT3FS_DEBUG

/*
 * Define EXT3_RESERVATION to reserve data blocks for expanding files
 */
#define EXT3_DEFAULT_RESERVE_BLOCKS     8
/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
#define EXT3_MAX_RESERVE_BLOCKS         1027
#define EXT3_RESERVE_WINDOW_NOT_ALLOCATED 0

/*
 * Debug code
 */
#ifdef EXT3FS_DEBUG
#define ext3_debug(f, a...)						\
	do {								\
		printk (KERN_DEBUG "EXT3-fs DEBUG (%s, %d): %s:",	\
			__FILE__, __LINE__, __func__);		\
		printk (KERN_DEBUG f, ## a);				\
	} while (0)
#else
#define ext3_debug(f, a...)	do {} while (0)
#endif

/*
 * Special inodes numbers
 */
#define	EXT3_BAD_INO		 1	/* Bad blocks inode */
#define EXT3_ROOT_INO		 2	/* Root inode */
#define EXT3_BOOT_LOADER_INO	 5	/* Boot loader inode */
#define EXT3_UNDEL_DIR_INO	 6	/* Undelete directory inode */
#define EXT3_RESIZE_INO		 7	/* Reserved group descriptors inode */
#define EXT3_JOURNAL_INO	 8	/* Journal inode */

/* First non-reserved inode for old ext3 filesystems */
#define EXT3_GOOD_OLD_FIRST_INO	11

/*
 * Maximal count of links to a file
 */
#define EXT3_LINK_MAX		32000

/*
 * Macro-instructions used to manage several block sizes
 */
#define EXT3_MIN_BLOCK_SIZE		1024
#define	EXT3_MAX_BLOCK_SIZE		65536
#define EXT3_MIN_BLOCK_LOG_SIZE		10
#define EXT3_BLOCK_SIZE(s)		((s)->s_blocksize)
#define	EXT3_ADDR_PER_BLOCK(s)		(EXT3_BLOCK_SIZE(s) / sizeof (__u32))
#define EXT3_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
#define	EXT3_ADDR_PER_BLOCK_BITS(s)	(EXT3_SB(s)->s_addr_per_block_bits)
#define EXT3_INODE_SIZE(s)		(EXT3_SB(s)->s_inode_size)
#define EXT3_FIRST_INO(s)		(EXT3_SB(s)->s_first_ino)

/*
 * Macro-instructions used to manage fragments
 */
#define EXT3_MIN_FRAG_SIZE		1024
#define	EXT3_MAX_FRAG_SIZE		4096
#define EXT3_MIN_FRAG_LOG_SIZE		  10
#define EXT3_FRAG_SIZE(s)		(EXT3_SB(s)->s_frag_size)
#define EXT3_FRAGS_PER_BLOCK(s)		(EXT3_SB(s)->s_frags_per_block)

/*
 * Structure of a blocks group descriptor
 */
struct ext3_group_desc
{
	__le32	bg_block_bitmap;		/* Blocks bitmap block */
	__le32	bg_inode_bitmap;		/* Inodes bitmap block */
	__le32	bg_inode_table;		/* Inodes table block */
	__le16	bg_free_blocks_count;	/* Free blocks count */
	__le16	bg_free_inodes_count;	/* Free inodes count */
	__le16	bg_used_dirs_count;	/* Directories count */
	__u16	bg_pad;
	__le32	bg_reserved[3];
};

/*
 * Macro-instructions used to manage group descriptors
 */
#define EXT3_BLOCKS_PER_GROUP(s)	(EXT3_SB(s)->s_blocks_per_group)
#define EXT3_DESC_PER_BLOCK(s)		(EXT3_SB(s)->s_desc_per_block)
#define EXT3_INODES_PER_GROUP(s)	(EXT3_SB(s)->s_inodes_per_group)
#define EXT3_DESC_PER_BLOCK_BITS(s)	(EXT3_SB(s)->s_desc_per_block_bits)

/*
 * Constants relative to the data blocks
 */
#define	EXT3_NDIR_BLOCKS		12
#define	EXT3_IND_BLOCK			EXT3_NDIR_BLOCKS
#define	EXT3_DIND_BLOCK			(EXT3_IND_BLOCK + 1)
#define	EXT3_TIND_BLOCK			(EXT3_DIND_BLOCK + 1)
#define	EXT3_N_BLOCKS			(EXT3_TIND_BLOCK + 1)

/*
 * Inode flags
 */
#define	EXT3_SECRM_FL			0x00000001 /* Secure deletion */
#define	EXT3_UNRM_FL			0x00000002 /* Undelete */
#define	EXT3_COMPR_FL			0x00000004 /* Compress file */
#define EXT3_SYNC_FL			0x00000008 /* Synchronous updates */
#define EXT3_IMMUTABLE_FL		0x00000010 /* Immutable file */
#define EXT3_APPEND_FL			0x00000020 /* writes to file may only append */
#define EXT3_NODUMP_FL			0x00000040 /* do not dump file */
#define EXT3_NOATIME_FL			0x00000080 /* do not update atime */
/* Reserved for compression usage... */
#define EXT3_DIRTY_FL			0x00000100
#define EXT3_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
#define EXT3_NOCOMPR_FL			0x00000400 /* Don't compress */
#define EXT3_ECOMPR_FL			0x00000800 /* Compression error */
/* End compression flags --- maybe not all used */
#define EXT3_INDEX_FL			0x00001000 /* hash-indexed directory */
#define EXT3_IMAGIC_FL			0x00002000 /* AFS directory */
#define EXT3_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
#define EXT3_NOTAIL_FL			0x00008000 /* file tail should not be merged */
#define EXT3_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
#define EXT3_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
#define EXT3_RESERVED_FL		0x80000000 /* reserved for ext3 lib */

#define EXT3_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
#define EXT3_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */

/* Flags that should be inherited by new inodes from their parent. */
#define EXT3_FL_INHERITED (EXT3_SECRM_FL | EXT3_UNRM_FL | EXT3_COMPR_FL |\
			   EXT3_SYNC_FL | EXT3_NODUMP_FL |\
			   EXT3_NOATIME_FL | EXT3_COMPRBLK_FL |\
			   EXT3_NOCOMPR_FL | EXT3_JOURNAL_DATA_FL |\
			   EXT3_NOTAIL_FL | EXT3_DIRSYNC_FL)

/* Flags that are appropriate for regular files (all but dir-specific ones). */