ext4.h 69.7 KB
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/*
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 *  ext4.h
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 *
 * 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
 */

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#ifndef _EXT4_H
#define _EXT4_H
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#include <linux/types.h>
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#include <linux/blkdev.h>
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#include <linux/magic.h>
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#include <linux/jbd2.h>
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#include <linux/quota.h>
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#include <linux/rwsem.h>
#include <linux/rbtree.h>
#include <linux/seqlock.h>
#include <linux/mutex.h>
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#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
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#ifdef __KERNEL__
#include <linux/compat.h>
#endif
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/*
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 * The fourth extended filesystem constants/structures
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 */

/*
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 * Define EXT4FS_DEBUG to produce debug messages
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 */
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#undef EXT4FS_DEBUG
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/*
 * Debug code
 */
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#ifdef EXT4FS_DEBUG
#define ext4_debug(f, a...)						\
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	do {								\
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		printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",	\
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			__FILE__, __LINE__, __func__);			\
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		printk(KERN_DEBUG f, ## a);				\
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	} while (0)
#else
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#define ext4_debug(f, a...)	do {} while (0)
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#endif

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#define EXT4_ERROR_INODE(inode, fmt, a...) \
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	ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)

#define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)			\
	ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
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#define EXT4_ERROR_FILE(file, fmt, a...)	\
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	ext4_error_file(__func__, __LINE__, (file), (fmt), ## a)
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/* data type for block offset of block group */
typedef int ext4_grpblk_t;

/* data type for filesystem-wide blocks number */
typedef unsigned long long ext4_fsblk_t;

/* data type for file logical block number */
typedef __u32 ext4_lblk_t;

/* data type for block group number */
typedef unsigned int ext4_group_t;

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/*
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 * Flags used in mballoc's allocation_context flags field.
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 *
 * Also used to show what's going on for debugging purposes when the
 * flag field is exported via the traceport interface
 */
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/* prefer goal again. length */
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#define EXT4_MB_HINT_MERGE		0x0001
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/* blocks already reserved */
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#define EXT4_MB_HINT_RESERVED		0x0002
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/* metadata is being allocated */
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#define EXT4_MB_HINT_METADATA		0x0004
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/* first blocks in the file */
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#define EXT4_MB_HINT_FIRST		0x0008
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/* search for the best chunk */
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#define EXT4_MB_HINT_BEST		0x0010
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/* data is being allocated */
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#define EXT4_MB_HINT_DATA		0x0020
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/* don't preallocate (for tails) */
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#define EXT4_MB_HINT_NOPREALLOC		0x0040
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/* allocate for locality group */
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#define EXT4_MB_HINT_GROUP_ALLOC	0x0080
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/* allocate goal blocks or none */
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#define EXT4_MB_HINT_GOAL_ONLY		0x0100
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/* goal is meaningful */
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#define EXT4_MB_HINT_TRY_GOAL		0x0200
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/* blocks already pre-reserved by delayed allocation */
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#define EXT4_MB_DELALLOC_RESERVED	0x0400
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/* We are doing stream allocation */
#define EXT4_MB_STREAM_ALLOC		0x0800
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struct ext4_allocation_request {
	/* target inode for block we're allocating */
	struct inode *inode;
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	/* how many blocks we want to allocate */
	unsigned int len;
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	/* logical block in target inode */
	ext4_lblk_t logical;
	/* the closest logical allocated block to the left */
	ext4_lblk_t lleft;
	/* the closest logical allocated block to the right */
	ext4_lblk_t lright;
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	/* phys. target (a hint) */
	ext4_fsblk_t goal;
	/* phys. block for the closest logical allocated block to the left */
	ext4_fsblk_t pleft;
	/* phys. block for the closest logical allocated block to the right */
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	ext4_fsblk_t pright;
	/* flags. see above EXT4_MB_HINT_* */
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	unsigned int flags;
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};

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/*
 * Logical to physical block mapping, used by ext4_map_blocks()
 *
 * This structure is used to pass requests into ext4_map_blocks() as
 * well as to store the information returned by ext4_map_blocks().  It
 * takes less room on the stack than a struct buffer_head.
 */
#define EXT4_MAP_NEW		(1 << BH_New)
#define EXT4_MAP_MAPPED		(1 << BH_Mapped)
#define EXT4_MAP_UNWRITTEN	(1 << BH_Unwritten)
#define EXT4_MAP_BOUNDARY	(1 << BH_Boundary)
#define EXT4_MAP_UNINIT		(1 << BH_Uninit)
#define EXT4_MAP_FLAGS		(EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
				 EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY |\
				 EXT4_MAP_UNINIT)

struct ext4_map_blocks {
	ext4_fsblk_t m_pblk;
	ext4_lblk_t m_lblk;
	unsigned int m_len;
	unsigned int m_flags;
};

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/*
 * For delayed allocation tracking
 */
struct mpage_da_data {
	struct inode *inode;
	sector_t b_blocknr;		/* start block number of extent */
	size_t b_size;			/* size of extent */
	unsigned long b_state;		/* state of the extent */
	unsigned long first_page, next_page;	/* extent of pages */
	struct writeback_control *wbc;
	int io_done;
	int pages_written;
	int retval;
};
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#define	EXT4_IO_UNWRITTEN	0x1
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typedef struct ext4_io_end {
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	struct list_head	list;		/* per-file finished AIO list */
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	struct inode		*inode;		/* file being written to */
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	unsigned int		flag;		/* unwritten or not */
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	struct page		*page;		/* page struct for buffer write */
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	loff_t			offset;		/* offset in the file */
	ssize_t			size;		/* size of the extent */
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	struct work_struct	work;		/* data work queue */
} ext4_io_end_t;

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/*
 * Special inodes numbers
 */
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#define	EXT4_BAD_INO		 1	/* Bad blocks inode */
#define EXT4_ROOT_INO		 2	/* Root inode */
#define EXT4_BOOT_LOADER_INO	 5	/* Boot loader inode */
#define EXT4_UNDEL_DIR_INO	 6	/* Undelete directory inode */
#define EXT4_RESIZE_INO		 7	/* Reserved group descriptors inode */
#define EXT4_JOURNAL_INO	 8	/* Journal inode */
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/* First non-reserved inode for old ext4 filesystems */
#define EXT4_GOOD_OLD_FIRST_INO	11
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/*
 * Maximal count of links to a file
 */
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#define EXT4_LINK_MAX		65000
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/*
 * Macro-instructions used to manage several block sizes
 */
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#define EXT4_MIN_BLOCK_SIZE		1024
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#define	EXT4_MAX_BLOCK_SIZE		65536
#define EXT4_MIN_BLOCK_LOG_SIZE		10
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#ifdef __KERNEL__
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# define EXT4_BLOCK_SIZE(s)		((s)->s_blocksize)
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#else
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# define EXT4_BLOCK_SIZE(s)		(EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
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#endif
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#define	EXT4_ADDR_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / sizeof(__u32))
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#ifdef __KERNEL__
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# define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_blocksize_bits)
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#else
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# define EXT4_BLOCK_SIZE_BITS(s)	((s)->s_log_block_size + 10)
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#endif
#ifdef __KERNEL__
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#define	EXT4_ADDR_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_addr_per_block_bits)
#define EXT4_INODE_SIZE(s)		(EXT4_SB(s)->s_inode_size)
#define EXT4_FIRST_INO(s)		(EXT4_SB(s)->s_first_ino)
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#else
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#define EXT4_INODE_SIZE(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
				 EXT4_GOOD_OLD_INODE_SIZE : \
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				 (s)->s_inode_size)
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#define EXT4_FIRST_INO(s)	(((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
				 EXT4_GOOD_OLD_FIRST_INO : \
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				 (s)->s_first_ino)
#endif
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#define EXT4_BLOCK_ALIGN(size, blkbits)		ALIGN((size), (1 << (blkbits)))
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/*
 * Structure of a blocks group descriptor
 */
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struct ext4_group_desc
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{
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	__le32	bg_block_bitmap_lo;	/* Blocks bitmap block */
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	__le32	bg_inode_bitmap_lo;	/* Inodes bitmap block */
	__le32	bg_inode_table_lo;	/* Inodes table block */
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	__le16	bg_free_blocks_count_lo;/* Free blocks count */
	__le16	bg_free_inodes_count_lo;/* Free inodes count */
	__le16	bg_used_dirs_count_lo;	/* Directories count */
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	__le16	bg_flags;		/* EXT4_BG_flags (INODE_UNINIT, etc) */
	__u32	bg_reserved[2];		/* Likely block/inode bitmap checksum */
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	__le16  bg_itable_unused_lo;	/* Unused inodes count */
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	__le16  bg_checksum;		/* crc16(sb_uuid+group+desc) */
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	__le32	bg_block_bitmap_hi;	/* Blocks bitmap block MSB */
	__le32	bg_inode_bitmap_hi;	/* Inodes bitmap block MSB */
	__le32	bg_inode_table_hi;	/* Inodes table block MSB */
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	__le16	bg_free_blocks_count_hi;/* Free blocks count MSB */
	__le16	bg_free_inodes_count_hi;/* Free inodes count MSB */
	__le16	bg_used_dirs_count_hi;	/* Directories count MSB */
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	__le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
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	__u32	bg_reserved2[3];
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};

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/*
 * Structure of a flex block group info
 */

struct flex_groups {
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	atomic_t free_inodes;
	atomic_t free_blocks;
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	atomic_t used_dirs;
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};

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#define EXT4_BG_INODE_UNINIT	0x0001 /* Inode table/bitmap not in use */
#define EXT4_BG_BLOCK_UNINIT	0x0002 /* Block bitmap not in use */
#define EXT4_BG_INODE_ZEROED	0x0004 /* On-disk itable initialized to zero */

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/*
 * Macro-instructions used to manage group descriptors
 */
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#define EXT4_MIN_DESC_SIZE		32
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#define EXT4_MIN_DESC_SIZE_64BIT	64
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#define	EXT4_MAX_DESC_SIZE		EXT4_MIN_BLOCK_SIZE
#define EXT4_DESC_SIZE(s)		(EXT4_SB(s)->s_desc_size)
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#ifdef __KERNEL__
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# define EXT4_BLOCKS_PER_GROUP(s)	(EXT4_SB(s)->s_blocks_per_group)
# define EXT4_DESC_PER_BLOCK(s)		(EXT4_SB(s)->s_desc_per_block)
# define EXT4_INODES_PER_GROUP(s)	(EXT4_SB(s)->s_inodes_per_group)
# define EXT4_DESC_PER_BLOCK_BITS(s)	(EXT4_SB(s)->s_desc_per_block_bits)
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#else
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# define EXT4_BLOCKS_PER_GROUP(s)	((s)->s_blocks_per_group)
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# define EXT4_DESC_PER_BLOCK(s)		(EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
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# define EXT4_INODES_PER_GROUP(s)	((s)->s_inodes_per_group)
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#endif

/*
 * Constants relative to the data blocks
 */
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#define	EXT4_NDIR_BLOCKS		12
#define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
#define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
#define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
#define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)
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/*
 * Inode flags
 */
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#define	EXT4_SECRM_FL			0x00000001 /* Secure deletion */
#define	EXT4_UNRM_FL			0x00000002 /* Undelete */
#define	EXT4_COMPR_FL			0x00000004 /* Compress file */
#define EXT4_SYNC_FL			0x00000008 /* Synchronous updates */
#define EXT4_IMMUTABLE_FL		0x00000010 /* Immutable file */
#define EXT4_APPEND_FL			0x00000020 /* writes to file may only append */
#define EXT4_NODUMP_FL			0x00000040 /* do not dump file */
#define EXT4_NOATIME_FL			0x00000080 /* do not update atime */
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/* Reserved for compression usage... */
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#define EXT4_DIRTY_FL			0x00000100
#define EXT4_COMPRBLK_FL		0x00000200 /* One or more compressed clusters */
#define EXT4_NOCOMPR_FL			0x00000400 /* Don't compress */
#define EXT4_ECOMPR_FL			0x00000800 /* Compression error */
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/* End compression flags --- maybe not all used */
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#define EXT4_INDEX_FL			0x00001000 /* hash-indexed directory */
#define EXT4_IMAGIC_FL			0x00002000 /* AFS directory */
#define EXT4_JOURNAL_DATA_FL		0x00004000 /* file data should be journaled */
#define EXT4_NOTAIL_FL			0x00008000 /* file tail should not be merged */
#define EXT4_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
#define EXT4_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
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#define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
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#define EXT4_EXTENTS_FL			0x00080000 /* Inode uses extents */
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#define EXT4_EA_INODE_FL	        0x00200000 /* Inode used for large EA */
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#define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
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#define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
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#define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
#define EXT4_FL_USER_MODIFIABLE		0x004B80FF /* User modifiable flags */
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/* Flags that should be inherited by new inodes from their parent. */
#define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
			   EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
			   EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)

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/* Flags that are appropriate for regular files (all but dir-specific ones). */
#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))

/* Flags that are appropriate for non-directories/regular files. */
#define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)

/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
{
	if (S_ISDIR(mode))
		return flags;
	else if (S_ISREG(mode))
		return flags & EXT4_REG_FLMASK;
	else
		return flags & EXT4_OTHER_FLMASK;
}

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/*
 * Inode flags used for atomic set/get
 */
enum {
	EXT4_INODE_SECRM	= 0,	/* Secure deletion */
	EXT4_INODE_UNRM		= 1,	/* Undelete */
	EXT4_INODE_COMPR	= 2,	/* Compress file */
	EXT4_INODE_SYNC		= 3,	/* Synchronous updates */
	EXT4_INODE_IMMUTABLE	= 4,	/* Immutable file */
	EXT4_INODE_APPEND	= 5,	/* writes to file may only append */
	EXT4_INODE_NODUMP	= 6,	/* do not dump file */
	EXT4_INODE_NOATIME	= 7,	/* do not update atime */
/* Reserved for compression usage... */
	EXT4_INODE_DIRTY	= 8,
	EXT4_INODE_COMPRBLK	= 9,	/* One or more compressed clusters */
	EXT4_INODE_NOCOMPR	= 10,	/* Don't compress */
	EXT4_INODE_ECOMPR	= 11,	/* Compression error */
/* End compression flags --- maybe not all used */
	EXT4_INODE_INDEX	= 12,	/* hash-indexed directory */
	EXT4_INODE_IMAGIC	= 13,	/* AFS directory */
	EXT4_INODE_JOURNAL_DATA	= 14,	/* file data should be journaled */
	EXT4_INODE_NOTAIL	= 15,	/* file tail should not be merged */
	EXT4_INODE_DIRSYNC	= 16,	/* dirsync behaviour (directories only) */
	EXT4_INODE_TOPDIR	= 17,	/* Top of directory hierarchies*/
	EXT4_INODE_HUGE_FILE	= 18,	/* Set to each huge file */
	EXT4_INODE_EXTENTS	= 19,	/* Inode uses extents */
	EXT4_INODE_EA_INODE	= 21,	/* Inode used for large EA */
	EXT4_INODE_EOFBLOCKS	= 22,	/* Blocks allocated beyond EOF */
	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
};

#define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
#define CHECK_FLAG_VALUE(FLAG) if (!TEST_FLAG_VALUE(FLAG)) { \
	printk(KERN_EMERG "EXT4 flag fail: " #FLAG ": %d %d\n", \
		EXT4_##FLAG##_FL, EXT4_INODE_##FLAG); BUG_ON(1); }

/*
 * Since it's pretty easy to mix up bit numbers and hex values, and we
 * can't do a compile-time test for ENUM values, we use a run-time
 * test to make sure that EXT4_XXX_FL is consistent with respect to
 * EXT4_INODE_XXX.  If all is well the printk and BUG_ON will all drop
 * out so it won't cost any extra space in the compiled kernel image.
 * But it's important that these values are the same, since we are
 * using EXT4_INODE_XXX to test for the flag values, but EXT4_XX_FL
 * must be consistent with the values of FS_XXX_FL defined in
 * include/linux/fs.h and the on-disk values found in ext2, ext3, and
 * ext4 filesystems, and of course the values defined in e2fsprogs.
 *
 * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
 */
static inline void ext4_check_flag_values(void)
{
	CHECK_FLAG_VALUE(SECRM);
	CHECK_FLAG_VALUE(UNRM);
	CHECK_FLAG_VALUE(COMPR);
	CHECK_FLAG_VALUE(SYNC);
	CHECK_FLAG_VALUE(IMMUTABLE);
	CHECK_FLAG_VALUE(APPEND);
	CHECK_FLAG_VALUE(NODUMP);
	CHECK_FLAG_VALUE(NOATIME);
	CHECK_FLAG_VALUE(DIRTY);
	CHECK_FLAG_VALUE(COMPRBLK);
	CHECK_FLAG_VALUE(NOCOMPR);
	CHECK_FLAG_VALUE(ECOMPR);
	CHECK_FLAG_VALUE(INDEX);
	CHECK_FLAG_VALUE(IMAGIC);
	CHECK_FLAG_VALUE(JOURNAL_DATA);
	CHECK_FLAG_VALUE(NOTAIL);
	CHECK_FLAG_VALUE(DIRSYNC);
	CHECK_FLAG_VALUE(TOPDIR);
	CHECK_FLAG_VALUE(HUGE_FILE);
	CHECK_FLAG_VALUE(EXTENTS);
	CHECK_FLAG_VALUE(EA_INODE);
	CHECK_FLAG_VALUE(EOFBLOCKS);
	CHECK_FLAG_VALUE(RESERVED);
}

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/* Used to pass group descriptor data when online resize is done */
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struct ext4_new_group_input {
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	__u32 group;		/* Group number for this data */
	__u64 block_bitmap;	/* Absolute block number of block bitmap */
	__u64 inode_bitmap;	/* Absolute block number of inode bitmap */
	__u64 inode_table;	/* Absolute block number of inode table start */
	__u32 blocks_count;	/* Total number of blocks in this group */
	__u16 reserved_blocks;	/* Number of reserved blocks in this group */
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	__u16 unused;
};

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#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
struct compat_ext4_new_group_input {
	u32 group;
	compat_u64 block_bitmap;
	compat_u64 inode_bitmap;
	compat_u64 inode_table;
	u32 blocks_count;
	u16 reserved_blocks;
	u16 unused;
};
#endif

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/* The struct ext4_new_group_input in kernel space, with free_blocks_count */
struct ext4_new_group_data {
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	__u32 group;
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	__u64 block_bitmap;
	__u64 inode_bitmap;
	__u64 inode_table;
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	__u32 blocks_count;
	__u16 reserved_blocks;
	__u16 unused;
	__u32 free_blocks_count;
};

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/*
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 * Flags used by ext4_get_blocks()
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 */
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	/* Allocate any needed blocks and/or convert an unitialized
	   extent to be an initialized ext4 */
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#define EXT4_GET_BLOCKS_CREATE			0x0001
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	/* Request the creation of an unitialized extent */
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#define EXT4_GET_BLOCKS_UNINIT_EXT		0x0002
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#define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\
						 EXT4_GET_BLOCKS_CREATE)
	/* Caller is from the delayed allocation writeout path,
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	   so set the magic i_delalloc_reserve_flag after taking the
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	   inode allocation semaphore for */
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#define EXT4_GET_BLOCKS_DELALLOC_RESERVE	0x0004
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	/* caller is from the direct IO path, request to creation of an
	unitialized extents if not allocated, split the uninitialized
	extent if blocks has been preallocated already*/
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#define EXT4_GET_BLOCKS_PRE_IO			0x0008
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#define EXT4_GET_BLOCKS_CONVERT			0x0010
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#define EXT4_GET_BLOCKS_IO_CREATE_EXT		(EXT4_GET_BLOCKS_PRE_IO|\
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					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
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	/* Convert extent to initialized after IO complete */
#define EXT4_GET_BLOCKS_IO_CONVERT_EXT		(EXT4_GET_BLOCKS_CONVERT|\
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					 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
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/*
 * Flags used by ext4_free_blocks
 */
#define EXT4_FREE_BLOCKS_METADATA	0x0001
#define EXT4_FREE_BLOCKS_FORGET		0x0002
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#define EXT4_FREE_BLOCKS_VALIDATED	0x0004
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/*
 * ioctl commands
 */
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#define	EXT4_IOC_GETFLAGS		FS_IOC_GETFLAGS
#define	EXT4_IOC_SETFLAGS		FS_IOC_SETFLAGS
#define	EXT4_IOC_GETVERSION		_IOR('f', 3, long)
#define	EXT4_IOC_SETVERSION		_IOW('f', 4, long)
#define	EXT4_IOC_GETVERSION_OLD		FS_IOC_GETVERSION
#define	EXT4_IOC_SETVERSION_OLD		FS_IOC_SETVERSION
506
#ifdef CONFIG_JBD2_DEBUG
507
#define EXT4_IOC_WAIT_FOR_READONLY	_IOR('f', 99, long)
508
#endif
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#define EXT4_IOC_GETRSVSZ		_IOR('f', 5, long)
#define EXT4_IOC_SETRSVSZ		_IOW('f', 6, long)
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#define EXT4_IOC_GROUP_EXTEND		_IOW('f', 7, unsigned long)
#define EXT4_IOC_GROUP_ADD		_IOW('f', 8, struct ext4_new_group_input)
#define EXT4_IOC_MIGRATE		_IO('f', 9)
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 /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
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 /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
516
#define EXT4_IOC_ALLOC_DA_BLKS		_IO('f', 12)
517
#define EXT4_IOC_MOVE_EXT		_IOWR('f', 15, struct move_extent)
518

519
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
520 521 522
/*
 * ioctl commands in 32 bit emulation
 */
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#define EXT4_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
#define EXT4_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
#define EXT4_IOC32_GETVERSION		_IOR('f', 3, int)
#define EXT4_IOC32_SETVERSION		_IOW('f', 4, int)
#define EXT4_IOC32_GETRSVSZ		_IOR('f', 5, int)
#define EXT4_IOC32_SETRSVSZ		_IOW('f', 6, int)
#define EXT4_IOC32_GROUP_EXTEND		_IOW('f', 7, unsigned int)
530
#define EXT4_IOC32_GROUP_ADD		_IOW('f', 8, struct compat_ext4_new_group_input)
531
#ifdef CONFIG_JBD2_DEBUG
532
#define EXT4_IOC32_WAIT_FOR_READONLY	_IOR('f', 99, int)
533
#endif
534 535
#define EXT4_IOC32_GETVERSION_OLD	FS_IOC32_GETVERSION
#define EXT4_IOC32_SETVERSION_OLD	FS_IOC32_SETVERSION
536
#endif
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/*
 *  Mount options
 */
542
struct ext4_mount_options {
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	unsigned long s_mount_opt;
	uid_t s_resuid;
	gid_t s_resgid;
	unsigned long s_commit_interval;
547
	u32 s_min_batch_time, s_max_batch_time;
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#ifdef CONFIG_QUOTA
	int s_jquota_fmt;
	char *s_qf_names[MAXQUOTAS];
#endif
};

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/* Max physical block we can addres w/o extents */
#define EXT4_MAX_BLOCK_FILE_PHYS	0xFFFFFFFF

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/*
 * Structure of an inode on the disk
 */
560
struct ext4_inode {
561 562
	__le16	i_mode;		/* File mode */
	__le16	i_uid;		/* Low 16 bits of Owner Uid */
563
	__le32	i_size_lo;	/* Size in bytes */
564
	__le32	i_atime;	/* Access time */
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	__le32	i_ctime;	/* Inode Change time */
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	__le32	i_mtime;	/* Modification time */
	__le32	i_dtime;	/* Deletion Time */
	__le16	i_gid;		/* Low 16 bits of Group Id */
	__le16	i_links_count;	/* Links count */
570
	__le32	i_blocks_lo;	/* Blocks count */
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	__le32	i_flags;	/* File flags */
	union {
		struct {
574
			__le32  l_i_version;
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		} linux1;
		struct {
			__u32  h_i_translator;
		} hurd1;
		struct {
			__u32  m_i_reserved1;
		} masix1;
	} osd1;				/* OS dependent 1 */
583
	__le32	i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
584
	__le32	i_generation;	/* File version (for NFS) */
585
	__le32	i_file_acl_lo;	/* File ACL */
586
	__le32	i_size_high;
587
	__le32	i_obso_faddr;	/* Obsoleted fragment address */
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	union {
		struct {
590
			__le16	l_i_blocks_high; /* were l_i_reserved1 */
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			__le16	l_i_file_acl_high;
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			__le16	l_i_uid_high;	/* these 2 fields */
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			__le16	l_i_gid_high;	/* were reserved2[0] */
			__u32	l_i_reserved2;
		} linux2;
		struct {
597
			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
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			__u16	h_i_mode_high;
			__u16	h_i_uid_high;
			__u16	h_i_gid_high;
			__u32	h_i_author;
		} hurd2;
		struct {
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			__le16	h_i_reserved1;	/* Obsoleted fragment number/size which are removed in ext4 */
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			__le16	m_i_file_acl_high;
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			__u32	m_i_reserved2[2];
		} masix2;
	} osd2;				/* OS dependent 2 */
	__le16	i_extra_isize;
	__le16	i_pad1;
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	__le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
	__le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
	__le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
	__le32  i_crtime;       /* File Creation time */
	__le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
616
	__le32  i_version_hi;	/* high 32 bits for 64-bit version */
617 618
};

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struct move_extent {
	__u32 reserved;		/* should be zero */
	__u32 donor_fd;		/* donor file descriptor */
	__u64 orig_start;	/* logical start offset in block for orig */
	__u64 donor_start;	/* logical start offset in block for donor */
	__u64 len;		/* block length to be moved */
	__u64 moved_len;	/* moved block length */
};
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#define EXT4_EPOCH_BITS 2
#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
#define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)

/*
 * Extended fields will fit into an inode if the filesystem was formatted
 * with large inodes (-I 256 or larger) and there are not currently any EAs
 * consuming all of the available space. For new inodes we always reserve
 * enough space for the kernel's known extended fields, but for inodes
 * created with an old kernel this might not have been the case. None of
 * the extended inode fields is critical for correct filesystem operation.
 * This macro checks if a certain field fits in the inode. Note that
 * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
 */
#define EXT4_FITS_IN_INODE(ext4_inode, einode, field)	\
	((offsetof(typeof(*ext4_inode), field) +	\
	  sizeof((ext4_inode)->field))			\
	<= (EXT4_GOOD_OLD_INODE_SIZE +			\
	    (einode)->i_extra_isize))			\

static inline __le32 ext4_encode_extra_time(struct timespec *time)
{
       return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
651 652
			   (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
                          ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
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}

static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
{
       if (sizeof(time->tv_sec) > 4)
	       time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
			       << 32;
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       time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
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}

#define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)			       \
do {									       \
	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	       \
	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
		(raw_inode)->xtime ## _extra =				       \
				ext4_encode_extra_time(&(inode)->xtime);       \
} while (0)

#define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
do {									       \
	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
		(raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
		(raw_inode)->xtime ## _extra =				       \
				ext4_encode_extra_time(&(einode)->xtime);      \
} while (0)

#define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)			       \
do {									       \
	(inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
		ext4_decode_extra_time(&(inode)->xtime,			       \
				       raw_inode->xtime ## _extra);	       \
} while (0)

#define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)			       \
do {									       \
	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))		       \
		(einode)->xtime.tv_sec = 				       \
			(signed)le32_to_cpu((raw_inode)->xtime);	       \
	if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))	       \
		ext4_decode_extra_time(&(einode)->xtime,		       \
				       raw_inode->xtime ## _extra);	       \
} while (0)

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#define i_disk_version osd1.linux1.l_i_version

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#if defined(__KERNEL__) || defined(__linux__)
#define i_reserved1	osd1.linux1.l_i_reserved1
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#define i_file_acl_high	osd2.linux2.l_i_file_acl_high
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#define i_blocks_high	osd2.linux2.l_i_blocks_high
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#define i_uid_low	i_uid
#define i_gid_low	i_gid
#define i_uid_high	osd2.linux2.l_i_uid_high
#define i_gid_high	osd2.linux2.l_i_gid_high
#define i_reserved2	osd2.linux2.l_i_reserved2

#elif defined(__GNU__)

#define i_translator	osd1.hurd1.h_i_translator
#define i_uid_high	osd2.hurd2.h_i_uid_high
#define i_gid_high	osd2.hurd2.h_i_gid_high
#define i_author	osd2.hurd2.h_i_author

#elif defined(__masix__)

#define i_reserved1	osd1.masix1.m_i_reserved1
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#define i_file_acl_high	osd2.masix2.m_i_file_acl_high
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#define i_reserved2	osd2.masix2.m_i_reserved2

#endif /* defined(__KERNEL__) || defined(__linux__) */

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/*
 * storage for cached extent
 */
struct ext4_ext_cache {
	ext4_fsblk_t	ec_start;
	ext4_lblk_t	ec_block;
	__u32		ec_len; /* must be 32bit to return holes */
	__u32		ec_type;
};

/*
 * fourth extended file system inode data in memory
 */
struct ext4_inode_info {
	__le32	i_data[15];	/* unconverted */
	__u32	i_dtime;
741
	ext4_fsblk_t	i_file_acl;
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	/*
	 * i_block_group is the number of the block group which contains
	 * this file's inode.  Constant across the lifetime of the inode,
	 * it is ued for making block allocation decisions - we try to
	 * place a file's data blocks near its inode block, and new inodes
	 * near to their parent directory's inode.
	 */
	ext4_group_t	i_block_group;
751
	unsigned long	i_state_flags;		/* Dynamic state flags */
752
	unsigned long	i_flags;
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	ext4_lblk_t		i_dir_start_lookup;
#ifdef CONFIG_EXT4_FS_XATTR
	/*
	 * Extended attributes can be read independently of the main file
	 * data. Taking i_mutex even when reading would cause contention
	 * between readers of EAs and writers of regular file data, so
	 * instead we synchronize on xattr_sem when reading or changing
	 * EAs.
	 */
	struct rw_semaphore xattr_sem;
#endif

	struct list_head i_orphan;	/* unlinked but open inodes */

	/*
	 * i_disksize keeps track of what the inode size is ON DISK, not
	 * in memory.  During truncate, i_size is set to the new size by
	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
	 * set i_disksize to 0 until the truncate is actually under way.
	 *
	 * The intent is that i_disksize always represents the blocks which
	 * are used by this file.  This allows recovery to restart truncate
	 * on orphans if we crash during truncate.  We actually write i_disksize
	 * into the on-disk inode when writing inodes out, instead of i_size.
	 *
	 * The only time when i_disksize and i_size may be different is when
	 * a truncate is in progress.  The only things which change i_disksize
	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
	 */
	loff_t	i_disksize;

	/*
	 * i_data_sem is for serialising ext4_truncate() against
	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
	 * data tree are chopped off during truncate. We can't do that in
	 * ext4 because whenever we perform intermediate commits during
	 * truncate, the inode and all the metadata blocks *must* be in a
	 * consistent state which allows truncation of the orphans to restart
	 * during recovery.  Hence we must fix the get_block-vs-truncate race
	 * by other means, so we have i_data_sem.
	 */
	struct rw_semaphore i_data_sem;
	struct inode vfs_inode;
	struct jbd2_inode jinode;

	struct ext4_ext_cache i_cached_extent;
	/*
	 * File creation time. Its function is same as that of
	 * struct timespec i_{a,c,m}time in the generic inode.
	 */
	struct timespec i_crtime;

	/* mballoc */
	struct list_head i_prealloc_list;
	spinlock_t i_prealloc_lock;

	/* ialloc */
	ext4_group_t	i_last_alloc_group;

	/* allocation reservation info for delalloc */
	unsigned int i_reserved_data_blocks;
	unsigned int i_reserved_meta_blocks;
	unsigned int i_allocated_meta_blocks;
	unsigned short i_delalloc_reserved_flag;
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	sector_t i_da_metadata_calc_last_lblock;
	int i_da_metadata_calc_len;
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	/* on-disk additional length */
	__u16 i_extra_isize;

	spinlock_t i_block_reservation_lock;
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#ifdef CONFIG_QUOTA
	/* quota space reservation, managed internally by quota code */
	qsize_t i_reserved_quota;
#endif
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830 831
	/* completed IOs that might need unwritten extents handling */
	struct list_head i_completed_io_list;
832
	spinlock_t i_completed_io_lock;
833 834
	/* current io_end structure for async DIO write*/
	ext4_io_end_t *cur_aio_dio;
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	/*
	 * Transactions that contain inode's metadata needed to complete
	 * fsync and fdatasync, respectively.
	 */
	tid_t i_sync_tid;
	tid_t i_datasync_tid;
842 843
};

844 845 846
/*
 * File system states
 */
847 848 849
#define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */
#define	EXT4_ERROR_FS			0x0002	/* Errors detected */
#define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
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851 852 853 854 855 856 857
/*
 * Misc. filesystem flags
 */
#define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
#define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
#define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */

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/*
 * Mount flags
 */
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#define EXT4_MOUNT_OLDALLOC		0x00002  /* Don't use the new Orlov allocator */
#define EXT4_MOUNT_GRPID		0x00004	/* Create files with directory's group */
#define EXT4_MOUNT_DEBUG		0x00008	/* Some debugging messages */
#define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
#define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
#define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
#define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
#define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
#define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */
#define EXT4_MOUNT_JOURNAL_DATA		0x00400	/* Write data to journal */
#define EXT4_MOUNT_ORDERED_DATA		0x00800	/* Flush data before commit */
#define EXT4_MOUNT_WRITEBACK_DATA	0x00C00	/* No data ordering */
#define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
#define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
#define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
#define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
877
#define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
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#define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
#define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
#define EXT4_MOUNT_USRQUOTA		0x100000 /* "old" user quota */
#define EXT4_MOUNT_GRPQUOTA		0x200000 /* "old" group quota */
882
#define EXT4_MOUNT_DIOREAD_NOLOCK	0x400000 /* Enable support for dio read nolocking */
883
#define EXT4_MOUNT_JOURNAL_CHECKSUM	0x800000 /* Journal checksums */
884
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT	0x1000000 /* Journal Async Commit */
885
#define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
886
#define EXT4_MOUNT_DELALLOC		0x8000000 /* Delalloc support */
887
#define EXT4_MOUNT_DATA_ERR_ABORT	0x10000000 /* Abort on file data write */
888
#define EXT4_MOUNT_BLOCK_VALIDITY	0x20000000 /* Block validity checking */
889
#define EXT4_MOUNT_DISCARD		0x40000000 /* Issue DISCARD requests */
890

891 892 893 894
#define clear_opt(o, opt)		o &= ~EXT4_MOUNT_##opt
#define set_opt(o, opt)			o |= EXT4_MOUNT_##opt
#define test_opt(sb, opt)		(EXT4_SB(sb)->s_mount_opt & \
					 EXT4_MOUNT_##opt)
895

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#define ext4_set_bit			ext2_set_bit
#define ext4_set_bit_atomic		ext2_set_bit_atomic
#define ext4_clear_bit			ext2_clear_bit
#define ext4_clear_bit_atomic		ext2_clear_bit_atomic
#define ext4_test_bit			ext2_test_bit
#define ext4_find_first_zero_bit	ext2_find_first_zero_bit
#define ext4_find_next_zero_bit		ext2_find_next_zero_bit
903
#define ext4_find_next_bit		ext2_find_next_bit
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/*
 * Maximal mount counts between two filesystem checks
 */
908 909
#define EXT4_DFL_MAX_MNT_COUNT		20	/* Allow 20 mounts */
#define EXT4_DFL_CHECKINTERVAL		0	/* Don't use interval check */
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/*
 * Behaviour when detecting errors
 */
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#define EXT4_ERRORS_CONTINUE		1	/* Continue execution */
#define EXT4_ERRORS_RO			2	/* Remount fs read-only */
#define EXT4_ERRORS_PANIC		3	/* Panic */
#define EXT4_ERRORS_DEFAULT		EXT4_ERRORS_CONTINUE
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/*
 * Structure of the super block
 */
922
struct ext4_super_block {
923
/*00*/	__le32	s_inodes_count;		/* Inodes count */
924
	__le32	s_blocks_count_lo;	/* Blocks count */
925 926
	__le32	s_r_blocks_count_lo;	/* Reserved blocks count */
	__le32	s_free_blocks_count_lo;	/* Free blocks count */
927 928 929
/*10*/	__le32	s_free_inodes_count;	/* Free inodes count */
	__le32	s_first_data_block;	/* First Data Block */
	__le32	s_log_block_size;	/* Block size */
930
	__le32	s_obso_log_frag_size;	/* Obsoleted fragment size */
931
/*20*/	__le32	s_blocks_per_group;	/* # Blocks per group */
932
	__le32	s_obso_frags_per_group;	/* Obsoleted fragments per group */
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	__le32	s_inodes_per_group;	/* # Inodes per group */
	__le32	s_mtime;		/* Mount time */
/*30*/	__le32	s_wtime;		/* Write time */
	__le16	s_mnt_count;		/* Mount count */
	__le16	s_max_mnt_count;	/* Maximal mount count */
	__le16	s_magic;		/* Magic signature */
	__le16	s_state;		/* File system state */
	__le16	s_errors;		/* Behaviour when detecting errors */
	__le16	s_minor_rev_level;	/* minor revision level */
/*40*/	__le32	s_lastcheck;		/* time of last check */
	__le32	s_checkinterval;	/* max. time between checks */
	__le32	s_creator_os;		/* OS */
	__le32	s_rev_level;		/* Revision level */
/*50*/	__le16	s_def_resuid;		/* Default uid for reserved blocks */
	__le16	s_def_resgid;		/* Default gid for reserved blocks */
	/*
949
	 * These fields are for EXT4_DYNAMIC_REV superblocks only.
950 951 952 953 954 955 956 957 958 959 960 961
	 *
	 * Note: the difference between the compatible feature set and
	 * the incompatible feature set is that if there is a bit set
	 * in the incompatible feature set that the kernel doesn't
	 * know about, it should refuse to mount the filesystem.
	 *
	 * e2fsck's requirements are more strict; if it doesn't know
	 * about a feature in either the compatible or incompatible
	 * feature set, it must abort and not try to meddle with
	 * things it doesn't understand...
	 */
	__le32	s_first_ino;		/* First non-reserved inode */
962
	__le16  s_inode_size;		/* size of inode structure */
963 964 965 966 967 968 969 970 971 972
	__le16	s_block_group_nr;	/* block group # of this superblock */
	__le32	s_feature_compat;	/* compatible feature set */
/*60*/	__le32	s_feature_incompat;	/* incompatible feature set */
	__le32	s_feature_ro_compat;	/* readonly-compatible feature set */
/*68*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
/*78*/	char	s_volume_name[16];	/* volume name */
/*88*/	char	s_last_mounted[64];	/* directory where last mounted */
/*C8*/	__le32	s_algorithm_usage_bitmap; /* For compression */
	/*
	 * Performance hints.  Directory preallocation should only
973
	 * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
974 975 976 977 978
	 */
	__u8	s_prealloc_blocks;	/* Nr of blocks to try to preallocate*/
	__u8	s_prealloc_dir_blocks;	/* Nr to preallocate for dirs */
	__le16	s_reserved_gdt_blocks;	/* Per group desc for online growth */
	/*
979
	 * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
980 981 982 983 984 985 986 987
	 */
/*D0*/	__u8	s_journal_uuid[16];	/* uuid of journal superblock */
/*E0*/	__le32	s_journal_inum;		/* inode number of journal file */
	__le32	s_journal_dev;		/* device number of journal file */
	__le32	s_last_orphan;		/* start of list of inodes to delete */
	__le32	s_hash_seed[4];		/* HTREE hash seed */
	__u8	s_def_hash_version;	/* Default hash version to use */
	__u8	s_reserved_char_pad;
988
	__le16  s_desc_size;		/* size of group descriptor */
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/*100*/	__le32	s_default_mount_opts;
990
	__le32	s_first_meta_bg;	/* First metablock block group */
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991 992 993 994 995 996
	__le32	s_mkfs_time;		/* When the filesystem was created */
	__le32	s_jnl_blocks[17];	/* Backup of the journal inode */
	/* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
/*150*/	__le32	s_blocks_count_hi;	/* Blocks count */
	__le32	s_r_blocks_count_hi;	/* Reserved blocks count */
	__le32	s_free_blocks_count_hi;	/* Free blocks count */
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997 998 999 1000 1001 1002 1003
	__le16	s_min_extra_isize;	/* All inodes have at least # bytes */
	__le16	s_want_extra_isize; 	/* New inodes should reserve # bytes */
	__le32	s_flags;		/* Miscellaneous flags */
	__le16  s_raid_stride;		/* RAID stride */
	__le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
	__le64  s_mmp_block;            /* Block for multi-mount protection */
	__le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1004 1005 1006
	__u8	s_log_groups_per_flex;  /* FLEX_BG group size */
	__u8	s_reserved_char_pad2;
	__le16  s_reserved_pad;
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	__le64	s_kbytes_written;	/* nr of lifetime kilobytes written */
1008 1009 1010 1011 1012 1013
	__le32	s_snapshot_inum;	/* Inode number of active snapshot */
	__le32	s_snapshot_id;		/* sequential ID of active snapshot */
	__le64	s_snapshot_r_blocks_count; /* reserved blocks for active
					      snapshot's future use */
	__le32	s_snapshot_list;	/* inode number of the head of the
					   on-disk snapshot list */
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027
#define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
	__le32	s_error_count;		/* number of fs errors */
	__le32	s_first_error_time;	/* first time an error happened */
	__le32	s_first_error_ino;	/* inode involved in first error */
	__le64	s_first_error_block;	/* block involved of first error */
	__u8	s_first_error_func[32];	/* function where the error happened */
	__le32	s_first_error_line;	/* line number where error happened */
	__le32	s_last_error_time;	/* most recent time of an error */
	__le32	s_last_error_ino;	/* inode involved in last error */
	__le32	s_last_error_line;	/* line number where error happened */
	__le64	s_last_error_block;	/* block involved of last error */
	__u8	s_last_error_func[32];	/* function where the error happened */
#define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_reserved)
	__le32   s_reserved[128];        /* Padding to the end of the block */
1028 1029
};

1030 1031
#define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)

1032
#ifdef __KERNEL__
1033 1034

/*
1035
 * run-time mount flags
1036 1037
 */
#define EXT4_MF_MNTDIR_SAMPLED	0x0001
1038
#define EXT4_MF_FS_ABORTED	0x0002	/* Fatal error detected */
1039

1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051
/*
 * fourth extended-fs super-block data in memory
 */
struct ext4_sb_info {
	unsigned long s_desc_size;	/* Size of a group descriptor in bytes */
	unsigned long s_inodes_per_block;/* Number of inodes per block */
	unsigned long s_blocks_per_group;/* Number of blocks in a group */
	unsigned long s_inodes_per_group;/* Number of inodes in a group */
	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
	ext4_group_t s_groups_count;	/* Number of groups in the fs */
1052
	ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1053 1054 1055 1056 1057 1058
	unsigned long s_overhead_last;  /* Last calculated overhead */
	unsigned long s_blocks_last;    /* Last seen block count */
	loff_t s_bitmap_maxbytes;	/* max bytes for bitmap files */
	struct buffer_head * s_sbh;	/* Buffer containing the super block */
	struct ext4_super_block *s_es;	/* Pointer to the super block in the buffer */
	struct buffer_head **s_group_desc;
1059
	unsigned int s_mount_opt;
1060
	unsigned int s_mount_flags;
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070
	ext4_fsblk_t s_sb_block;
	uid_t s_resuid;
	gid_t s_resgid;
	unsigned short s_mount_state;
	unsigned short s_pad;
	int s_addr_per_block_bits;
	int s_desc_per_block_bits;
	int s_inode_size;
	int s_first_ino;
	unsigned int s_inode_readahead_blks;
1071
	unsigned int s_inode_goal;
1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104
	spinlock_t s_next_gen_lock;
	u32 s_next_generation;
	u32 s_hash_seed[4];
	int s_def_hash_version;
	int s_hash_unsigned;	/* 3 if hash should be signed, 0 if not */
	struct percpu_counter s_freeblocks_counter;
	struct percpu_counter s_freeinodes_counter;
	struct percpu_counter s_dirs_counter;
	struct percpu_counter s_dirtyblocks_counter;
	struct blockgroup_lock *s_blockgroup_lock;
	struct proc_dir_entry *s_proc;
	struct kobject s_kobj;
	struct completion s_kobj_unregister;

	/* Journaling */
	struct inode *s_journal_inode;
	struct journal_s *s_journal;
	struct list_head s_orphan;
	struct mutex s_orphan_lock;
	struct mutex s_resize_lock;
	unsigned long s_commit_interval;
	u32 s_max_batch_time;
	u32 s_min_batch_time;
	struct block_device *journal_bdev;
#ifdef CONFIG_JBD2_DEBUG
	struct timer_list turn_ro_timer;	/* For turning read-only (crash simulation) */
	wait_queue_head_t ro_wait_queue;	/* For people waiting for the fs to go read-only */
#endif
#ifdef CONFIG_QUOTA
	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
	int s_jquota_fmt;			/* Format of quota to use */
#endif
	unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1105
	struct rb_root system_blks;
1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134

#ifdef EXTENTS_STATS
	/* ext4 extents stats */
	unsigned long s_ext_min;
	unsigned long s_ext_max;
	unsigned long s_depth_max;
	spinlock_t s_ext_stats_lock;
	unsigned long s_ext_blocks;
	unsigned long s_ext_extents;
#endif

	/* for buddy allocator */
	struct ext4_group_info ***s_group_info;
	struct inode *s_buddy_cache;
	long s_blocks_reserved;
	spinlock_t s_reserve_lock;
	spinlock_t s_md_lock;
	tid_t s_last_transaction;
	unsigned short *s_mb_offsets;
	unsigned int *s_mb_maxs;

	/* tunables */
	unsigned long s_stripe;
	unsigned int s_mb_stream_request;
	unsigned int s_mb_max_to_scan;
	unsigned int s_mb_min_to_scan;
	unsigned int s_mb_stats;
	unsigned int s_mb_order2_reqs;
	unsigned int s_mb_group_prealloc;
1135
	unsigned int s_max_writeback_mb_bump;
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
	/* where last allocation was done - for stream allocation */
	unsigned long s_mb_last_group;
	unsigned long s_mb_last_start;

	/* stats for buddy allocator */
	spinlock_t s_mb_pa_lock;
	atomic_t s_bal_reqs;	/* number of reqs with len > 1 */
	atomic_t s_bal_success;	/* we found long enough chunks */
	atomic_t s_bal_allocated;	/* in blocks */
	atomic_t s_bal_ex_scanned;	/* total extents scanned */
	atomic_t s_bal_goals;	/* goal hits */
	atomic_t s_bal_breaks;	/* too long searches */
	atomic_t s_bal_2orders;	/* 2^order hits */
	spinlock_t s_bal_lock;
	unsigned long s_mb_buddies_generated;
	unsigned long long s_mb_generation_time;
	atomic_t s_mb_lost_chunks;
	atomic_t s_mb_preallocated;
	atomic_t s_mb_discarded;
1155
	atomic_t s_lock_busy;
1156 1157

	/* locality groups */
1158
	struct ext4_locality_group __percpu *s_locality_groups;
1159 1160 1161 1162 1163 1164 1165

	/* for write statistics */
	unsigned long s_sectors_written_start;
	u64 s_kbytes_written;

	unsigned int s_log_groups_per_flex;
	struct flex_groups *s_flex_groups;
1166 1167 1168

	/* workqueue for dio unwritten */
	struct workqueue_struct *dio_unwritten_wq;
1169 1170
};

1171
static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1172 1173 1174
{
	return sb->s_fs_info;
}
1175
static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1176
{
1177
	return container_of(inode, struct ext4_inode_info, vfs_inode);
1178 1179
}

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1180 1181 1182 1183 1184 1185
static inline struct timespec ext4_current_time(struct inode *inode)
{
	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
}

1186
static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1187
{
1188 1189 1190 1191 1192
	return ino == EXT4_ROOT_INO ||
		ino == EXT4_JOURNAL_INO ||
		ino == EXT4_RESIZE_INO ||
		(ino >= EXT4_FIRST_INO(sb) &&
		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1193
}
1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205

/*
 * Inode dynamic state flags
 */
enum {
	EXT4_STATE_JDATA,		/* journaled data exists */
	EXT4_STATE_NEW,			/* inode is newly created */
	EXT4_STATE_XATTR,		/* has in-inode xattrs */
	EXT4_STATE_NO_EXPAND,		/* No space for expansion */
	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */
	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */
	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/
1206
	EXT4_STATE_NEWENTRY,		/* File just added to dir */
1207 1208
};

1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220
#define EXT4_INODE_BIT_FNS(name, field)					\
static inline int ext4_test_inode_##name(struct inode *inode, int bit)	\
{									\
	return test_bit(bit, &EXT4_I(inode)->i_##field);		\
}									\
static inline void ext4_set_inode_##name(struct inode *inode, int bit)	\
{									\
	set_bit(bit, &EXT4_I(inode)->i_##field);			\
}									\
static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
{									\
	clear_bit(bit, &EXT4_I(inode)->i_##field);			\
1221 1222
}

1223 1224
EXT4_INODE_BIT_FNS(flag, flags)
EXT4_INODE_BIT_FNS(state, state_flags)
1225
#else
1226
/* Assume that user mode programs are passing in an ext4fs superblock, not
1227 1228
 * a kernel struct super_block.  This will allow us to call the feature-test
 * macros from user land. */
1229
#define EXT4_SB(sb)	(sb)
1230 1231
#endif

1232
#define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1233 1234 1235 1236

/*
 * Codes for operating systems
 */
1237 1238 1239 1240 1241
#define EXT4_OS_LINUX		0
#define EXT4_OS_HURD		1
#define EXT4_OS_MASIX		2
#define EXT4_OS_FREEBSD		3
#define EXT4_OS_LITES		4
1242 1243 1244 1245

/*
 * Revision levels
 */
1246 1247
#define EXT4_GOOD_OLD_REV	0	/* The good old (original) format */
#define EXT4_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
1248

1249 1250
#define EXT4_CURRENT_REV	EXT4_GOOD_OLD_REV
#define EXT4_MAX_SUPP_REV	EXT4_DYNAMIC_REV
1251

1252
#define EXT4_GOOD_OLD_INODE_SIZE 128
1253 1254 1255 1256 1257

/*
 * Feature set definitions
 */

1258
#define EXT4_HAS_COMPAT_FEATURE(sb,mask)			\
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1259
	((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1260
#define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)			\
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1261
	((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1262
#define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)			\
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1263
	((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
#define EXT4_SET_COMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
#define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
#define EXT4_SET_INCOMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
#define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
#define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
#define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)			\
	EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)

#define EXT4_FEATURE_COMPAT_DIR_PREALLOC	0x0001
#define EXT4_FEATURE_COMPAT_IMAGIC_INODES	0x0002
#define EXT4_FEATURE_COMPAT_HAS_JOURNAL		0x0004
#define EXT4_FEATURE_COMPAT_EXT_ATTR		0x0008
#define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
#define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020

#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
#define EXT4_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
1287
#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
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#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
1289
#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
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1290
#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
1291 1292 1293 1294 1295 1296

#define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
#define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
#define EXT4_FEATURE_INCOMPAT_RECOVER		0x0004 /* Needs recovery */
#define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008 /* Journal device */
#define EXT4_FEATURE_INCOMPAT_META_BG		0x0010
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#define EXT4_FEATURE_INCOMPAT_EXTENTS		0x0040 /* extents support */
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1298
#define EXT4_FEATURE_INCOMPAT_64BIT		0x0080
1299
#define EXT4_FEATURE_INCOMPAT_MMP               0x0100
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1300
#define EXT4_FEATURE_INCOMPAT_FLEX_BG		0x0200
1301 1302
#define EXT4_FEATURE_INCOMPAT_EA_INODE		0x0400 /* EA in inode */
#define EXT4_FEATURE_INCOMPAT_DIRDATA		0x1000 /* data in dirent */
1303 1304 1305 1306

#define EXT4_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
#define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
					 EXT4_FEATURE_INCOMPAT_RECOVER| \
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					 EXT4_FEATURE_INCOMPAT_META_BG| \
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					 EXT4_FEATURE_INCOMPAT_EXTENTS| \
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1309 1310
					 EXT4_FEATURE_INCOMPAT_64BIT| \
					 EXT4_FEATURE_INCOMPAT_FLEX_BG)
1311 1312
#define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
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1313
					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1314
					 EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
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1315
					 EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1316 1317
					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1318 1319 1320 1321

/*
 * Default values for user and/or group using reserved blocks
 */
1322 1323
#define	EXT4_DEF_RESUID		0
#define	EXT4_DEF_RESGID		0
1324

1325 1326
#define EXT4_DEF_INODE_READAHEAD_BLKS	32

1327 1328 1329
/*
 * Default mount options
 */
1330 1331 1332 1333 1334 1335 1336 1337 1338
#define EXT4_DEFM_DEBUG		0x0001
#define EXT4_DEFM_BSDGROUPS	0x0002
#define EXT4_DEFM_XATTR_USER	0x0004
#define EXT4_DEFM_ACL		0x0008
#define EXT4_DEFM_UID16		0x0010
#define EXT4_DEFM_JMODE		0x0060
#define EXT4_DEFM_JMODE_DATA	0x0020
#define EXT4_DEFM_JMODE_ORDERED	0x0040
#define EXT4_DEFM_JMODE_WBACK	0x0060
1339

1340 1341 1342 1343 1344 1345
/*
 * Default journal batch times
 */
#define EXT4_DEF_MIN_BATCH_TIME	0
#define EXT4_DEF_MAX_BATCH_TIME	15000 /* 15ms */

1346 1347 1348 1349 1350 1351
/*
 * Minimum number of groups in a flexgroup before we separate out
 * directories into the first block group of a flexgroup
 */
#define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME	4

1352 1353 1354
/*
 * Structure of a directory entry
 */
1355
#define EXT4_NAME_LEN 255
1356

1357
struct ext4_dir_entry {
1358 1359 1360
	__le32	inode;			/* Inode number */
	__le16	rec_len;		/* Directory entry length */
	__le16	name_len;		/* Name length */
1361
	char	name[EXT4_NAME_LEN];	/* File name */
1362 1363 1364
};

/*
1365
 * The new version of the directory entry.  Since EXT4 structures are
1366 1367 1368 1369
 * stored in intel byte order, and the name_len field could never be
 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 * file_type field.
 */
1370
struct ext4_dir_entry_2 {
1371 1372 1373 1374
	__le32	inode;			/* Inode number */
	__le16	rec_len;		/* Directory entry length */
	__u8	name_len;		/* Name length */
	__u8	file_type;
1375
	char	name[EXT4_NAME_LEN];	/* File name */
1376 1377 1378
};

/*
1379
 * Ext4 directory file types.  Only the low 3 bits are used.  The
1380 1381
 * other bits are reserved for now.
 */
1382 1383 1384 1385 1386 1387 1388 1389
#define EXT4_FT_UNKNOWN		0
#define EXT4_FT_REG_FILE	1
#define EXT4_FT_DIR		2
#define EXT4_FT_CHRDEV		3
#define EXT4_FT_BLKDEV		4
#define EXT4_FT_FIFO		5
#define EXT4_FT_SOCK		6
#define EXT4_FT_SYMLINK		7
1390

1391
#define EXT4_FT_MAX		8
1392 1393

/*
1394
 * EXT4_DIR_PAD defines the directory entries boundaries
1395 1396 1397
 *
 * NOTE: It must be a multiple of 4
 */
1398 1399 1400 1401
#define EXT4_DIR_PAD			4
#define EXT4_DIR_ROUND			(EXT4_DIR_PAD - 1)
#define EXT4_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT4_DIR_ROUND) & \
					 ~EXT4_DIR_ROUND)
1402 1403
#define EXT4_MAX_REC_LEN		((1<<16)-1)

1404 1405 1406 1407 1408
/*
 * Hash Tree Directory indexing
 * (c) Daniel Phillips, 2001
 */

1409 1410
#define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
				      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1411
		    ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1412 1413
#define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
#define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1414 1415 1416 1417 1418 1419

/* Legal values for the dx_root hash_version field: */

#define DX_HASH_LEGACY		0
#define DX_HASH_HALF_MD4	1
#define DX_HASH_TEA		2
1420 1421 1422
#define DX_HASH_LEGACY_UNSIGNED	3
#define DX_HASH_HALF_MD4_UNSIGNED	4
#define DX_HASH_TEA_UNSIGNED		5
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434

#ifdef __KERNEL__

/* hash info structure used by the directory hash */
struct dx_hash_info
{
	u32		hash;
	u32		minor_hash;
	int		hash_version;
	u32		*seed;
};

1435
#define EXT4_HTREE_EOF	0x7fffffff
1436 1437

/*
1438
 * Control parameters used by ext4_htree_next_block
1439 1440 1441 1442 1443 1444 1445
 */
#define HASH_NB_ALWAYS		1


/*
 * Describe an inode's exact location on disk and in memory
 */
1446
struct ext4_iloc
1447 1448 1449
{
	struct buffer_head *bh;
	unsigned long offset;
1450
	ext4_group_t block_group;
1451 1452
};

1453
static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1454
{
1455
	return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473
}

/*
 * This structure is stuffed into the struct file's private_data field
 * for directories.  It is where we put information so that we can do
 * readdir operations in hash tree order.
 */
struct dir_private_info {
	struct rb_root	root;
	struct rb_node	*curr_node;
	struct fname	*extra_fname;
	loff_t		last_pos;
	__u32		curr_hash;
	__u32		curr_minor_hash;
	__u32		next_hash;
};

/* calculate the first block number of the group */
1474
static inline ext4_fsblk_t
1475
ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1476
{
1477 1478
	return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
		le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1479 1480 1481 1482 1483 1484 1485
}

/*
 * Special error return code only used by dx_probe() and its callers.
 */
#define ERR_BAD_DX_DIR	-75000

1486
void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1487
			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1488

1489 1490
extern struct proc_dir_entry *ext4_proc_root;

1491 1492 1493 1494 1495 1496
/*
 * Function prototypes
 */

/*
 * Ok, these declarations are also in <linux/kernel.h> but none of the
1497
 * ext4 source programs needs to include it so they are duplicated here.
1498
 */
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Dave Kleikamp 已提交
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# define NORET_TYPE	/**/
# define ATTRIB_NORET	__attribute__((noreturn))
# define NORET_AND	noreturn,
1502

1503 1504 1505
/* bitmap.c */
extern unsigned int ext4_count_free(struct buffer_head *, unsigned);

1506
/* balloc.c */
1507 1508 1509 1510
extern unsigned int ext4_block_group(struct super_block *sb,
			ext4_fsblk_t blocknr);
extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
			ext4_fsblk_t blocknr);
1511 1512 1513
extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
			ext4_group_t group);
1514
extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1515
			ext4_fsblk_t goal, unsigned long *count, int *errp);
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Aneesh Kumar K.V 已提交
1516
extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1517
extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1518 1519
extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
				ext4_fsblk_t block, unsigned long count);
1520 1521
extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
extern void ext4_check_blocks_bitmap(struct super_block *);
1522
extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1523
						    ext4_group_t block_group,
1524
						    struct buffer_head ** bh);
1525
extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1526 1527 1528 1529 1530 1531 1532 1533
struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
				      ext4_group_t block_group);
extern unsigned ext4_init_block_bitmap(struct super_block *sb,
				       struct buffer_head *bh,
				       ext4_group_t group,
				       struct ext4_group_desc *desc);
#define ext4_free_blocks_after_init(sb, group, desc)			\
		ext4_init_block_bitmap(sb, NULL, group, desc)
1534 1535

/* dir.c */
1536 1537 1538 1539 1540
extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
				  struct ext4_dir_entry_2 *,
				  struct buffer_head *, unsigned int);
#define ext4_check_dir_entry(dir, de, bh, offset) \
	__ext4_check_dir_entry(__func__, __LINE__, (dir), (de), (bh), (offset))
1541
extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1542
				    __u32 minor_hash,
1543 1544
				    struct ext4_dir_entry_2 *dirent);
extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1545 1546

/* fsync.c */
1547
extern int ext4_sync_file(struct file *, int);
1548 1549

/* hash.c */
1550
extern int ext4fs_dirhash(const char *name, int len, struct
1551 1552 1553
			  dx_hash_info *hinfo);

/* ialloc.c */
1554
extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1555
				    const struct qstr *qstr, __u32 goal);
1556 1557 1558 1559 1560
extern void ext4_free_inode(handle_t *, struct inode *);
extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
extern unsigned long ext4_count_free_inodes(struct super_block *);
extern unsigned long ext4_count_dirs(struct super_block *);
extern void ext4_check_inodes_bitmap(struct super_block *);
1561 1562 1563 1564 1565
extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
				       struct buffer_head *bh,
				       ext4_group_t group,
				       struct ext4_group_desc *desc);
extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1566

1567 1568 1569 1570 1571 1572 1573 1574
/* mballoc.c */
extern long ext4_mb_stats;
extern long ext4_mb_max_to_scan;
extern int ext4_mb_init(struct super_block *, int);
extern int ext4_mb_release(struct super_block *);
extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
				struct ext4_allocation_request *, int *);
extern int ext4_mb_reserve_blocks(struct super_block *, int);
1575
extern void ext4_discard_preallocations(struct inode *);
1576 1577
extern int __init init_ext4_mballoc(void);
extern void exit_ext4_mballoc(void);
1578
extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1579 1580
			     struct buffer_head *bh, ext4_fsblk_t block,
			     unsigned long count, int flags);
1581
extern int ext4_mb_add_groupinfo(struct super_block *sb,
1582
		ext4_group_t i, struct ext4_group_desc *desc);
1583 1584 1585
extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
						ext4_group_t, int);
1586
/* inode.c */
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Aneesh Kumar K.V 已提交
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struct buffer_head *ext4_getblk(handle_t *, struct inode *,
						ext4_lblk_t, int, int *);
struct buffer_head *ext4_bread(handle_t *, struct inode *,
						ext4_lblk_t, int, int *);
1591 1592
int ext4_get_block(struct inode *inode, sector_t iblock,
				struct buffer_head *bh_result, int create);
1593

1594
extern struct inode *ext4_iget(struct super_block *, unsigned long);
1595
extern int  ext4_write_inode(struct inode *, struct writeback_control *);
1596
extern int  ext4_setattr(struct dentry *, struct iattr *);
1597 1598
extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
				struct kstat *stat);
1599 1600
extern void ext4_delete_inode(struct inode *);
extern int  ext4_sync_inode(handle_t *, struct inode *);
1601 1602 1603
extern void ext4_dirty_inode(struct inode *);
extern int ext4_change_inode_journal_flag(struct inode *, int);
extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1604
extern int ext4_can_truncate(struct inode *inode);
1605
extern void ext4_truncate(struct inode *);
1606
extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
1607
extern void ext4_set_inode_flags(struct inode *);
1608
extern void ext4_get_inode_flags(struct ext4_inode_info *);
1609
extern int ext4_alloc_da_blocks(struct inode *inode);
1610
extern void ext4_set_aops(struct inode *inode);
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Alex Tomas 已提交
1611
extern int ext4_writepage_trans_blocks(struct inode *);
1612
extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1613
extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1614
extern int ext4_block_truncate_page(handle_t *handle,
A
Alex Tomas 已提交
1615
		struct address_space *mapping, loff_t from);
1616
extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1617
extern qsize_t *ext4_get_reserved_space(struct inode *inode);
1618
extern int flush_completed_IO(struct inode *inode);
1619 1620
extern void ext4_da_update_reserve_space(struct inode *inode,
					int used, int quota_claim);
1621
/* ioctl.c */
A
Andi Kleen 已提交
1622
extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1623
extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1624

1625
/* migrate.c */
1626
extern int ext4_ext_migrate(struct inode *);
1627

1628
/* namei.c */
1629 1630
extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1631 1632 1633
extern int ext4_orphan_add(handle_t *, struct inode *);
extern int ext4_orphan_del(handle_t *, struct inode *);
extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1634 1635 1636
				__u32 start_minor_hash, __u32 *next_hash);

/* resize.c */
1637 1638 1639 1640 1641
extern int ext4_group_add(struct super_block *sb,
				struct ext4_new_group_data *input);
extern int ext4_group_extend(struct super_block *sb,
				struct ext4_super_block *es,
				ext4_fsblk_t n_blocks_count);
1642 1643

/* super.c */
1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
extern void __ext4_error(struct super_block *, const char *, unsigned int,
			 const char *, ...)
	__attribute__ ((format (printf, 4, 5)));
#define ext4_error(sb, message...)	__ext4_error(sb, __func__,	\
						     __LINE__, ## message)
extern void ext4_error_inode(struct inode *, const char *, unsigned int,
			     ext4_fsblk_t, const char *, ...)
	__attribute__ ((format (printf, 5, 6)));
extern void ext4_error_file(struct file *, const char *, unsigned int,
			    const char *, ...)
	__attribute__ ((format (printf, 4, 5)));
extern void __ext4_std_error(struct super_block *, const char *,
			     unsigned int, int);
extern void __ext4_abort(struct super_block *, const char *, unsigned int,
		       const char *, ...)
	__attribute__ ((format (printf, 4, 5)));
1660
#define ext4_abort(sb, message...)	__ext4_abort(sb, __func__, \
1661 1662
						       __LINE__, ## message)
extern void __ext4_warning(struct super_block *, const char *, unsigned int,
1663
			  const char *, ...)
1664 1665 1666
	__attribute__ ((format (printf, 4, 5)));
#define ext4_warning(sb, message...)	__ext4_warning(sb, __func__, \
						       __LINE__, ## message)
1667 1668
extern void ext4_msg(struct super_block *, const char *, const char *, ...)
	__attribute__ ((format (printf, 3, 4)));
1669 1670 1671 1672 1673 1674 1675
extern void __ext4_grp_locked_error(const char *, unsigned int, \
				    struct super_block *, ext4_group_t, \
				    unsigned long, ext4_fsblk_t, \
				    const char *, ...)
	__attribute__ ((format (printf, 7, 8)));
#define ext4_grp_locked_error(sb, grp, message...) \
	__ext4_grp_locked_error(__func__, __LINE__, (sb), (grp), ## message)
1676
extern void ext4_update_dynamic_rev(struct super_block *sb);
1677 1678 1679 1680 1681 1682
extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
					__u32 compat);
extern int ext4_update_rocompat_feature(handle_t *handle,
					struct super_block *sb,	__u32 rocompat);
extern int ext4_update_incompat_feature(handle_t *handle,
					struct super_block *sb,	__u32 incompat);
1683 1684 1685 1686 1687 1688
extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
				      struct ext4_group_desc *bg);
extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
				      struct ext4_group_desc *bg);
extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
				     struct ext4_group_desc *bg);
1689 1690 1691 1692 1693 1694 1695 1696
extern __u32 ext4_free_blks_count(struct super_block *sb,
				struct ext4_group_desc *bg);
extern __u32 ext4_free_inodes_count(struct super_block *sb,
				 struct ext4_group_desc *bg);
extern __u32 ext4_used_dirs_count(struct super_block *sb,
				struct ext4_group_desc *bg);
extern __u32 ext4_itable_unused_count(struct super_block *sb,
				   struct ext4_group_desc *bg);
1697 1698 1699 1700 1701 1702
extern void ext4_block_bitmap_set(struct super_block *sb,
				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
extern void ext4_inode_bitmap_set(struct super_block *sb,
				  struct ext4_group_desc *bg, ext4_fsblk_t blk);
extern void ext4_inode_table_set(struct super_block *sb,
				 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1703 1704 1705 1706 1707 1708 1709 1710
extern void ext4_free_blks_set(struct super_block *sb,
			       struct ext4_group_desc *bg, __u32 count);
extern void ext4_free_inodes_set(struct super_block *sb,
				struct ext4_group_desc *bg, __u32 count);
extern void ext4_used_dirs_set(struct super_block *sb,
				struct ext4_group_desc *bg, __u32 count);
extern void ext4_itable_unused_set(struct super_block *sb,
				   struct ext4_group_desc *bg, __u32 count);
1711 1712 1713 1714
extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
				   struct ext4_group_desc *gdp);
extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
				       struct ext4_group_desc *gdp);
L
Laurent Vivier 已提交
1715 1716 1717 1718

static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
{
	return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1719
		le32_to_cpu(es->s_blocks_count_lo);
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Laurent Vivier 已提交
1720 1721 1722 1723 1724
}

static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
{
	return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1725
		le32_to_cpu(es->s_r_blocks_count_lo);
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Laurent Vivier 已提交
1726 1727 1728 1729 1730
}

static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
{
	return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1731
		le32_to_cpu(es->s_free_blocks_count_lo);
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Laurent Vivier 已提交
1732 1733 1734 1735 1736
}

static inline void ext4_blocks_count_set(struct ext4_super_block *es,
					 ext4_fsblk_t blk)
{
1737
	es->s_blocks_count_lo = cpu_to_le32((u32)blk);
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Laurent Vivier 已提交
1738 1739 1740 1741 1742 1743
	es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
}

static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
					      ext4_fsblk_t blk)
{
1744
	es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
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Laurent Vivier 已提交
1745 1746 1747 1748 1749 1750
	es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
}

static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
					   ext4_fsblk_t blk)
{
1751
	es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
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Laurent Vivier 已提交
1752 1753 1754
	es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
}

1755 1756
static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
{
1757 1758 1759 1760 1761
	if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
		return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
			le32_to_cpu(raw_inode->i_size_lo);
	else
		return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1762
}
L
Laurent Vivier 已提交
1763

1764 1765 1766 1767 1768
static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
{
	raw_inode->i_size_lo = cpu_to_le32(i_size);
	raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
}
1769

1770 1771
static inline
struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1772
					    ext4_group_t group)
1773 1774 1775 1776 1777 1778 1779 1780 1781
{
	 struct ext4_group_info ***grp_info;
	 long indexv, indexh;
	 grp_info = EXT4_SB(sb)->s_group_info;
	 indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
	 indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
	 return grp_info[indexv][indexh];
}

1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793
/*
 * Reading s_groups_count requires using smp_rmb() afterwards.  See
 * the locking protocol documented in the comments of ext4_group_add()
 * in resize.c
 */
static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
{
	ext4_group_t	ngroups = EXT4_SB(sb)->s_groups_count;

	smp_rmb();
	return ngroups;
}
1794

1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805
static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
					     ext4_group_t block_group)
{
	return block_group >> sbi->s_log_groups_per_flex;
}

static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
{
	return 1 << sbi->s_log_groups_per_flex;
}

1806
#define ext4_std_error(sb, errno)				\
1807 1808
do {								\
	if ((errno))						\
1809
		__ext4_std_error((sb), __func__, __LINE__, (errno));	\
1810 1811
} while (0)

1812
#ifdef CONFIG_SMP
1813
/* Each CPU can accumulate percpu_counter_batch blocks in their local
1814
 * counters. So we need to make sure we have free blocks more
1815
 * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
1816
 */
1817
#define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1818 1819 1820 1821
#else
#define EXT4_FREEBLOCKS_WATERMARK 0
#endif

1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832
static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
{
	/*
	 * XXX: replace with spinlock if seen contended -bzzz
	 */
	down_write(&EXT4_I(inode)->i_data_sem);
	if (newsize > EXT4_I(inode)->i_disksize)
		EXT4_I(inode)->i_disksize = newsize;
	up_write(&EXT4_I(inode)->i_data_sem);
	return ;
}
1833

1834 1835 1836
struct ext4_group_info {
	unsigned long   bb_state;
	struct rb_root  bb_free_root;
1837 1838 1839
	ext4_grpblk_t	bb_first_free;	/* first free block */
	ext4_grpblk_t	bb_free;	/* total free blocks */
	ext4_grpblk_t	bb_fragments;	/* nr of freespace fragments */
1840
	ext4_grpblk_t	bb_largest_free_order;/* order of largest frag in BG */
1841 1842 1843 1844 1845
	struct          list_head bb_prealloc_list;
#ifdef DOUBLE_CHECK
	void            *bb_bitmap;
#endif
	struct rw_semaphore alloc_sem;
1846 1847 1848 1849
	ext4_grpblk_t	bb_counters[];	/* Nr of free power-of-two-block
					 * regions, index is order.
					 * bb_counters[3] = 5 means
					 * 5 free 8-block regions. */
1850 1851 1852 1853 1854 1855 1856
};

#define EXT4_GROUP_INFO_NEED_INIT_BIT	0

#define EXT4_MB_GRP_NEED_INIT(grp)	\
	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))

1857 1858 1859
#define EXT4_MAX_CONTENTION		8
#define EXT4_CONTENTION_THRESHOLD	2

1860 1861
static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
					      ext4_group_t group)
1862
{
1863 1864
	return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
}
1865

1866 1867 1868 1869 1870 1871 1872 1873 1874
/*
 * Returns true if the filesystem is busy enough that attempts to
 * access the block group locks has run into contention.
 */
static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
{
	return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
}

1875 1876
static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
{
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892
	spinlock_t *lock = ext4_group_lock_ptr(sb, group);
	if (spin_trylock(lock))
		/*
		 * We're able to grab the lock right away, so drop the
		 * lock contention counter.
		 */
		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
	else {
		/*
		 * The lock is busy, so bump the contention counter,
		 * and then wait on the spin lock.
		 */
		atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
				  EXT4_MAX_CONTENTION);
		spin_lock(lock);
	}
1893 1894 1895 1896 1897
}

static inline void ext4_unlock_group(struct super_block *sb,
					ext4_group_t group)
{
1898
	spin_unlock(ext4_group_lock_ptr(sb, group));
1899 1900
}

T
Theodore Ts'o 已提交
1901 1902 1903 1904 1905 1906
static inline void ext4_mark_super_dirty(struct super_block *sb)
{
	if (EXT4_SB(sb)->s_journal == NULL)
		sb->s_dirt =1;
}

1907 1908 1909 1910 1911
/*
 * Inodes and files operations
 */

/* dir.c */
1912
extern const struct file_operations ext4_dir_operations;
1913 1914

/* file.c */
1915
extern const struct inode_operations ext4_file_inode_operations;
1916
extern const struct file_operations ext4_file_operations;
1917 1918

/* namei.c */
1919 1920
extern const struct inode_operations ext4_dir_inode_operations;
extern const struct inode_operations ext4_special_inode_operations;
1921
extern struct dentry *ext4_get_parent(struct dentry *child);
1922 1923

/* symlink.c */
1924 1925
extern const struct inode_operations ext4_symlink_inode_operations;
extern const struct inode_operations ext4_fast_symlink_inode_operations;
1926

1927 1928 1929 1930 1931 1932 1933 1934 1935
/* block_validity */
extern void ext4_release_system_zone(struct super_block *sb);
extern int ext4_setup_system_zone(struct super_block *sb);
extern int __init init_ext4_system_zone(void);
extern void exit_ext4_system_zone(void);
extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
				 ext4_fsblk_t start_blk,
				 unsigned int count);

A
Alex Tomas 已提交
1936 1937 1938
/* extents.c */
extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1939 1940
extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
				       int chunk);
1941 1942
extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
			       struct ext4_map_blocks *map, int flags);
1943
extern void ext4_ext_truncate(struct inode *);
A
Alex Tomas 已提交
1944 1945
extern void ext4_ext_init(struct super_block *);
extern void ext4_ext_release(struct super_block *);
A
Amit Arora 已提交
1946 1947
extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
			  loff_t len);
1948
extern int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
1949
			  ssize_t len);
1950 1951
extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
			   struct ext4_map_blocks *map, int flags);
1952 1953
extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
			   sector_t block, unsigned int max_blocks,
1954
			   struct buffer_head *bh, int flags);
A
Aneesh Kumar K.V 已提交
1955 1956
extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
			__u64 start, __u64 len);
1957 1958 1959 1960 1961
/* move_extent.c */
extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
			     __u64 start_orig, __u64 start_donor,
			     __u64 len, __u64 *moved_len);

A
Aneesh Kumar K.V 已提交
1962

1963 1964 1965 1966 1967 1968 1969 1970 1971
/* BH_Uninit flag: blocks are allocated but uninitialized on disk */
enum ext4_state_bits {
	BH_Uninit	/* blocks are allocated but uninitialized on disk */
	  = BH_JBDPrivateStart,
};

BUFFER_FNS(Uninit, uninit)
TAS_BUFFER_FNS(Uninit, uninit)

1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988
/*
 * Add new method to test wether block and inode bitmaps are properly
 * initialized. With uninit_bg reading the block from disk is not enough
 * to mark the bitmap uptodate. We need to also zero-out the bitmap
 */
#define BH_BITMAP_UPTODATE BH_JBDPrivateStart

static inline int bitmap_uptodate(struct buffer_head *bh)
{
	return (buffer_uptodate(bh) &&
			test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
}
static inline void set_bitmap_uptodate(struct buffer_head *bh)
{
	set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
}

1989 1990
#define in_range(b, first, len)	((b) >= (first) && (b) <= (first) + (len) - 1)

1991 1992
#endif	/* __KERNEL__ */

1993
#endif	/* _EXT4_H */