ufs_fs.h

UnixBSD、SunOs、FreeBSD、NetBSD、OpenBSD和NeXTStep文件系统源代码

/*
 *  linux/include/linux/ufs_fs.h
 *
 * Copyright (C) 1996
 * Adrian Rodriguez ([e-mail])
 * Laboratory for Computer Science Research Computing Facility
 * Rutgers, The State University of New Jersey
 *
 * Clean swab support by Fare <[e-mail]>
 * just hope no one is using NNUUXXI on __?64 structure elements
 * 64-bit clean thanks to Maciej W. Rozycki <[e-mail]>
 *
 * 4.4BSD (FreeBSD) support added on February 1st 1998 by
 * Niels Kristian Bech Jensen <[e-mail]> partially based
 * on code by Martin von Loewis <[e-mail]>.
 *
 * NeXTstep support added on February 5th 1998 by
 * Niels Kristian Bech Jensen <[e-mail]>.
 *
 * Write support by Daniel Pirkl <[e-mail]>
 *
 * HP/UX hfs filesystem support added by
 * Martin K. Petersen <[e-mail]>, August 1999
 *
 * UFS2 (of FreeBSD 5.x) support added by
 * Niraj Kumar <[e-mail]>  , Jan 2004
 *
 */

#ifndef __LINUX_UFS_FS_H
#define __LINUX_UFS_FS_H

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/fs.h>

#include <asm/div64.h>
typedef __u64 __bitwise __fs64;
typedef __u32 __bitwise __fs32;
typedef __u16 __bitwise __fs16;

#define UFS_BBLOCK 0
#define UFS_BBSIZE 8192
#define UFS_SBLOCK 8192
#define UFS_SBSIZE 8192

#define UFS_SECTOR_SIZE 512
#define UFS_SECTOR_BITS 9
#define UFS_MAGIC  0x00011954
#define UFS2_MAGIC 0x19540119
#define UFS_CIGAM  0x54190100 /* byteswapped MAGIC */

/* Copied from FreeBSD */
/*
 * Each disk drive contains some number of filesystems.
 * A filesystem consists of a number of cylinder groups.
 * Each cylinder group has inodes and data.
 *
 * A filesystem is described by its super-block, which in turn
 * describes the cylinder groups.  The super-block is critical
 * data and is replicated in each cylinder group to protect against
 * catastrophic loss.  This is done at `newfs' time and the critical
 * super-block data does not change, so the copies need not be
 * referenced further unless disaster strikes.
 *
 * For filesystem fs, the offsets of the various blocks of interest
 * are given in the super block as:
 *      [fs->fs_sblkno]         Super-block
 *      [fs->fs_cblkno]         Cylinder group block
 *      [fs->fs_iblkno]         Inode blocks
 *      [fs->fs_dblkno]         Data blocks
 * The beginning of cylinder group cg in fs, is given by
 * the ``cgbase(fs, cg)'' macro.
 *
 * Depending on the architecture and the media, the superblock may
 * reside in any one of four places. For tiny media where every block
 * counts, it is placed at the very front of the partition. Historically,
 * UFS1 placed it 8K from the front to leave room for the disk label and
 * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
 * room for the disk label and a bigger bootstrap, and for really piggy
 * systems we check at 256K from the front if the first three fail. In
 * all cases the size of the superblock will be SBLOCKSIZE. All values are
 * given in byte-offset form, so they do not imply a sector size. The
 * SBLOCKSEARCH specifies the order in which the locations should be searched.
 */
#define SBLOCK_FLOPPY        0
#define SBLOCK_UFS1       8192
#define SBLOCK_UFS2      65536
#define SBLOCK_PIGGY    262144
#define SBLOCKSIZE        8192
#define SBLOCKSEARCH \
        { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }


/* HP specific MAGIC values */

#define UFS_MAGIC_LFN   0x00095014 /* fs supports filenames > 14 chars */
#define UFS_CIGAM_LFN   0x14500900 /* srahc 41 < semanelif stroppus sf */

#define UFS_MAGIC_SEC   0x00612195 /* B1 security fs */
#define UFS_CIGAM_SEC   0x95216100

#define UFS_MAGIC_FEA   0x00195612 /* fs_featurebits supported */
#define UFS_CIGAM_FEA   0x12561900

#define UFS_MAGIC_4GB   0x05231994 /* fs > 4 GB && fs_featurebits */
#define UFS_CIGAM_4GB   0x94192305

/* Seems somebody at HP goofed here. B1 and lfs are both 0x2 !?! */
#define UFS_FSF_LFN     0x00000001 /* long file names */
#define UFS_FSF_B1      0x00000002 /* B1 security */
#define UFS_FSF_LFS     0x00000002 /* large files */
#define UFS_FSF_LUID    0x00000004 /* large UIDs */

/* End of HP stuff */


#define UFS_BSIZE	8192
#define UFS_MINBSIZE	4096
#define UFS_FSIZE	1024
#define UFS_MAXFRAG	(UFS_BSIZE / UFS_FSIZE)

#define UFS_NDADDR 12
#define UFS_NINDIR 3

#define UFS_IND_BLOCK	(UFS_NDADDR + 0)
#define UFS_DIND_BLOCK	(UFS_NDADDR + 1)
#define UFS_TIND_BLOCK	(UFS_NDADDR + 2)

#define UFS_NDIR_FRAGMENT (UFS_NDADDR << uspi->s_fpbshift)
#define UFS_IND_FRAGMENT (UFS_IND_BLOCK << uspi->s_fpbshift)
#define UFS_DIND_FRAGMENT (UFS_DIND_BLOCK << uspi->s_fpbshift)
#define UFS_TIND_FRAGMENT (UFS_TIND_BLOCK << uspi->s_fpbshift)

#define UFS_ROOTINO 2
#define UFS_FIRST_INO (UFS_ROOTINO + 1)

#define UFS_USEEFT  ((__u16)65535)

#define UFS_FSOK      0x7c269d38
#define UFS_FSACTIVE  ((__s8)0x00)
#define UFS_FSCLEAN   ((__s8)0x01)
#define UFS_FSSTABLE  ((__s8)0x02)
#define UFS_FSOSF1    ((__s8)0x03)	/* is this correct for DEC OSF/1? */
#define UFS_FSBAD     ((__s8)0xff)

/* From here to next blank line, s_flags for ufs_sb_info */
/* directory entry encoding */
#define UFS_DE_MASK		0x00000010	/* mask for the following */
#define UFS_DE_OLD		0x00000000
#define UFS_DE_44BSD		0x00000010
/* uid encoding */
#define UFS_UID_MASK		0x00000060	/* mask for the following */
#define UFS_UID_OLD		0x00000000
#define UFS_UID_44BSD		0x00000020
#define UFS_UID_EFT		0x00000040
/* superblock state encoding */
#define UFS_ST_MASK		0x00000700	/* mask for the following */
#define UFS_ST_OLD		0x00000000
#define UFS_ST_44BSD		0x00000100
#define UFS_ST_SUN		0x00000200 /* Solaris */
#define UFS_ST_SUNOS		0x00000300
#define UFS_ST_SUNx86		0x00000400 /* Solaris x86 */
/*cylinder group encoding */
#define UFS_CG_MASK		0x00003000	/* mask for the following */
#define UFS_CG_OLD		0x00000000
#define UFS_CG_44BSD		0x00002000
#define UFS_CG_SUN		0x00001000
/* filesystem type encoding */
#define UFS_TYPE_MASK		0x00010000	/* mask for the following */
#define UFS_TYPE_UFS1		0x00000000
#define UFS_TYPE_UFS2		0x00010000


/* fs_inodefmt options */
#define UFS_42INODEFMT	-1
#define UFS_44INODEFMT	2

/*
 * MINFREE gives the minimum acceptable percentage of file system
 * blocks which may be free. If the freelist drops below this level
 * only the superuser may continue to allocate blocks. This may
 * be set to 0 if no reserve of free blocks is deemed necessary,
 * however throughput drops by fifty percent if the file system
 * is run at between 95% and 100% full; thus the minimum default
 * value of fs_minfree is 5%. However, to get good clustering
 * performance, 10% is a better choice. hence we use 10% as our
 * default value. With 10% free space, fragmentation is not a
 * problem, so we choose to optimize for time.
 */
#define UFS_MINFREE         5
#define UFS_DEFAULTOPT      UFS_OPTTIME

/*
 * Turn file system block numbers into disk block addresses.
 * This maps file system blocks to device size blocks.
 */
#define ufs_fsbtodb(uspi, b)	((b) << (uspi)->s_fsbtodb)
#define	ufs_dbtofsb(uspi, b)	((b) >> (uspi)->s_fsbtodb)

/*
 * Cylinder group macros to locate things in cylinder groups.
 * They calc file system addresses of cylinder group data structures.
 */
#define	ufs_cgbase(c)	(uspi->s_fpg * (c))
#define ufs_cgstart(c)	((uspi)->fs_magic == UFS2_MAGIC ?  ufs_cgbase(c) : \
	(ufs_cgbase(c)  + uspi->s_cgoffset * ((c) & ~uspi->s_cgmask)))
#define	ufs_cgsblock(c)	(ufs_cgstart(c) + uspi->s_sblkno)	/* super blk */
#define	ufs_cgcmin(c)	(ufs_cgstart(c) + uspi->s_cblkno)	/* cg block */
#define	ufs_cgimin(c)	(ufs_cgstart(c) + uspi->s_iblkno)	/* inode blk */
#define	ufs_cgdmin(c)	(ufs_cgstart(c) + uspi->s_dblkno)	/* 1st data */

/*
 * Macros for handling inode numbers:
 *     inode number to file system block offset.
 *     inode number to cylinder group number.
 *     inode number to file system block address.
 */
#define	ufs_inotocg(x)		((x) / uspi->s_ipg)
#define	ufs_inotocgoff(x)	((x) % uspi->s_ipg)
#define	ufs_inotofsba(x)	(((u64)ufs_cgimin(ufs_inotocg(x))) + ufs_inotocgoff(x) / uspi->s_inopf)
#define	ufs_inotofsbo(x)	((x) % uspi->s_inopf)

/*
 * Compute the cylinder and rotational position of a cyl block addr.
 */
#define ufs_cbtocylno(bno) \
	((bno) * uspi->s_nspf / uspi->s_spc)
#define ufs_cbtorpos(bno) \
	((((bno) * uspi->s_nspf % uspi->s_spc / uspi->s_nsect \
	* uspi->s_trackskew + (bno) * uspi->s_nspf % uspi->s_spc \
	% uspi->s_nsect * uspi->s_interleave) % uspi->s_nsect \
	* uspi->s_nrpos) / uspi->s_npsect)

/*
 * The following macros optimize certain frequently calculated
 * quantities by using shifts and masks in place of divisions
 * modulos and multiplications.
 */
#define ufs_blkoff(loc)		((loc) & uspi->s_qbmask)
#define ufs_fragoff(loc)	((loc) & uspi->s_qfmask)
#define ufs_lblktosize(blk)	((blk) << uspi->s_bshift)
#define ufs_lblkno(loc)		((loc) >> uspi->s_bshift)
#define ufs_numfrags(loc)	((loc) >> uspi->s_fshift)
#define ufs_blkroundup(size)	(((size) + uspi->s_qbmask) & uspi->s_bmask)
#define ufs_fragroundup(size)	(((size) + uspi->s_qfmask) & uspi->s_fmask)
#define ufs_fragstoblks(frags)	((frags) >> uspi->s_fpbshift)
#define ufs_blkstofrags(blks)	((blks) << uspi->s_fpbshift)
#define ufs_fragnum(fsb)	((fsb) & uspi->s_fpbmask)
#define ufs_blknum(fsb)		((fsb) & ~uspi->s_fpbmask)

#define	UFS_MAXNAMLEN 255
#define UFS_MAXMNTLEN 512
#define UFS2_MAXMNTLEN 468
#define UFS2_MAXVOLLEN 32
#define UFS_MAXCSBUFS 31
#define UFS_LINK_MAX 32000
/*
#define	UFS2_NOCSPTRS	((128 / sizeof(void *)) - 4)
*/
#define	UFS2_NOCSPTRS	28

/*
 * UFS_DIR_PAD defines the directory entries boundaries
 * (must be a multiple of 4)
 */
#define UFS_DIR_PAD			4
#define UFS_DIR_ROUND			(UFS_DIR_PAD - 1)
#define UFS_DIR_REC_LEN(name_len)	(((name_len) + 1 + 8 + UFS_DIR_ROUND) & ~UFS_DIR_ROUND)

struct ufs_timeval {
	__fs32	tv_sec;
	__fs32	tv_usec;
};

struct ufs_dir_entry {
	__fs32  d_ino;			/* inode number of this entry */
	__fs16  d_reclen;		/* length of this entry */
	union {
		__fs16	d_namlen;		/* actual length of d_name */
		struct {
			__u8	d_type;		/* file type */
			__u8	d_namlen;	/* length of string in d_name */
		} d_44;
	} d_u;
	__u8	d_name[UFS_MAXNAMLEN + 1];	/* file name */
};

struct ufs_csum {
	__fs32	cs_ndir;	/* number of directories */
	__fs32	cs_nbfree;	/* number of free blocks */
	__fs32	cs_nifree;	/* number of free inodes */
	__fs32	cs_nffree;	/* number of free frags */
};
struct ufs2_csum_total {
	__fs64	cs_ndir;	/* number of directories */
	__fs64	cs_nbfree;	/* number of free blocks */
	__fs64	cs_nifree;	/* number of free inodes */
	__fs64	cs_nffree;	/* number of free frags */
	__fs64   cs_numclusters;	/* number of free clusters */
	__fs64   cs_spare[3];	/* future expansion */
};

struct ufs_csum_core {
	__u64	cs_ndir;	/* number of directories */
	__u64	cs_nbfree;	/* number of free blocks */
	__u64	cs_nifree;	/* number of free inodes */
	__u64	cs_nffree;	/* number of free frags */
	__u64   cs_numclusters;	/* number of free clusters */
};

/*
 * File system flags
 */
#define UFS_UNCLEAN      0x01    /* file system not clean at mount (unused) */