ufs_fs.h

linux得一些常用命令,以及linux环境下的c编程

/*
 *  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
 *
 */

#ifndef __LINUX_UFS_FS_H
#define __LINUX_UFS_FS_H

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

#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 UFS_CIGAM 0x54190100 /* byteswapped MAGIC */


/* 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  ((char)0x00)
#define UFS_FSCLEAN   ((char)0x01)
#define UFS_FSSTABLE  ((char)0x02)
#define UFS_FSOSF1    ((char)0x03)	/* is this correct for DEC OSF/1? */
#define UFS_FSBAD     ((char)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
#define UFS_ST_SUNx86		0x00000400
/*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

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

/* mount options */
#define UFS_MOUNT_ONERROR		0x0000000F
#define UFS_MOUNT_ONERROR_PANIC		0x00000001
#define UFS_MOUNT_ONERROR_LOCK		0x00000002
#define UFS_MOUNT_ONERROR_UMOUNT	0x00000004
#define UFS_MOUNT_ONERROR_REPAIR	0x00000008

#define UFS_MOUNT_UFSTYPE		0x00000FF0
#define UFS_MOUNT_UFSTYPE_OLD		0x00000010
#define UFS_MOUNT_UFSTYPE_44BSD		0x00000020
#define UFS_MOUNT_UFSTYPE_SUN		0x00000040
#define UFS_MOUNT_UFSTYPE_NEXTSTEP	0x00000080
#define UFS_MOUNT_UFSTYPE_NEXTSTEP_CD	0x00000100
#define UFS_MOUNT_UFSTYPE_OPENSTEP	0x00000200
#define UFS_MOUNT_UFSTYPE_SUNx86	0x00000400
#define UFS_MOUNT_UFSTYPE_HP	        0x00000800

#define ufs_clear_opt(o,opt)	o &= ~UFS_MOUNT_##opt
#define ufs_set_opt(o,opt)	o |= UFS_MOUNT_##opt
#define ufs_test_opt(o,opt)	((o) & UFS_MOUNT_##opt)

/*
 * 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)	(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)	(ufs_cgimin(ufs_inotocg(x)) + ufs_inotocgoff(x) / uspi->s_inopf)
#define	ufs_inotofsbo(x)	((x) % uspi->s_inopf)

/*
 * Give cylinder group number for a file system block.
 * Give cylinder group block number for a file system block.
 */
#define	ufs_dtog(d)	((d) / uspi->s_fpg)
#define	ufs_dtogd(d)	((d) % uspi->s_fpg)

/*
 * 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 UFS_MAXCSBUFS 31
#define UFS_LINK_MAX 32000

/*
 * 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 {
	__s32	tv_sec;
	__s32	tv_usec;
};

struct ufs_dir_entry {
	__u32  d_ino;			/* inode number of this entry */
	__u16  d_reclen;		/* length of this entry */
	union {
		__u16	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 {
	__u32	cs_ndir;	/* number of directories */
	__u32	cs_nbfree;	/* number of free blocks */
	__u32	cs_nifree;	/* number of free inodes */
	__u32	cs_nffree;	/* number of free frags */
};

/*
 * This is the actual superblock, as it is laid out on the disk.
 */
struct ufs_super_block {
	__u32	fs_link;	/* UNUSED */
	__u32	fs_rlink;	/* UNUSED */
	__u32	fs_sblkno;	/* addr of super-block in filesys */
	__u32	fs_cblkno;	/* offset of cyl-block in filesys */
	__u32	fs_iblkno;	/* offset of inode-blocks in filesys */
	__u32	fs_dblkno;	/* offset of first data after cg */
	__u32	fs_cgoffset;	/* cylinder group offset in cylinder */
	__u32	fs_cgmask;	/* used to calc mod fs_ntrak */
	__u32	fs_time;	/* last time written -- time_t */
	__u32	fs_size;	/* number of blocks in fs */
	__u32	fs_dsize;	/* number of data blocks in fs */
	__u32	fs_ncg;		/* number of cylinder groups */
	__u32	fs_bsize;	/* size of basic blocks in fs */
	__u32	fs_fsize;	/* size of frag blocks in fs */
	__u32	fs_frag;	/* number of frags in a block in fs */
/* these are configuration parameters */
	__u32	fs_minfree;	/* minimum percentage of free blocks */
	__u32	fs_rotdelay;	/* num of ms for optimal next block */
	__u32	fs_rps;		/* disk revolutions per second */
/* these fields can be computed from the others */
	__u32	fs_bmask;	/* ``blkoff'' calc of blk offsets */
	__u32	fs_fmask;	/* ``fragoff'' calc of frag offsets */