sysv_fs_sb.h

LINUX1.0内核源代码,学习LINUX编程的一定要看。

#ifndef _SYSV_FS_SB
#define _SYSV_FS_SB

/*
 * SystemV/Coherent super-block data in memory
 * The SystemV/Coherent superblock contains dynamic data (it gets modified
 * while the system is running). This is in contrast to the Minix and Berkeley
 * filesystems (where the superblock is never modified). This affects the
 * sync() operation: we must keep the superblock in a disk buffer and use this
 * one as our "working copy".
 */

struct sysv_sb_info {
	int	       s_type;		/* file system type: FSTYPE_{XENIX|SYSV|COH} */
	unsigned int   s_block_size;	/* zone size, = 512 or = 1024 */
	unsigned int   s_block_size_1;	/* block_size - 1 */
	unsigned int   s_block_size_bits;	/* log2(block_size) */
	unsigned int   s_block_size_ratio;	/* BLOCK_SIZE / block_size */
	unsigned int   s_block_size_ratio_1;	/* block_size_ratio - 1 */
	unsigned int   s_block_size_ratio_bits;	/* log2(block_size_ratio) */
	char	       s_convert;	/* flag whether byte ordering requires conversion */
	char	       s_kludge_symlinks; /* flag whether symlinks have a kludgey mode */
	char	       s_truncate;	/* if 1: names > SYSV_NAMELEN chars are truncated */
					/* if 0: they are disallowed (ENAMETOOLONG) */
	nlink_t        s_link_max;	/* max number of hard links to a file */
	unsigned int   s_inodes_per_block;	/* number of inodes per block */
	unsigned int   s_inodes_per_block_1;	/* inodes_per_block - 1 */
	unsigned int   s_inodes_per_block_bits;	/* log2(inodes_per_block) */
	unsigned int   s_ind_per_block;		/* number of indirections per block */
	unsigned int   s_ind_per_block_1;	/* ind_per_block - 1 */
	unsigned int   s_ind_per_block_bits;	/* log2(ind_per_block) */
	unsigned int   s_ind_per_block_2;	/* ind_per_block ^ 2 */
	unsigned int   s_ind_per_block_2_1;	/* ind_per_block ^ 2 - 1 */
	unsigned int   s_ind_per_block_2_bits;	/* log2(ind_per_block^2) */
	unsigned int   s_ind_per_block_3;	/* ind_per_block ^ 3 */
	unsigned int   s_toobig_block;		/* 10 + ipb + ipb^2 + ipb^3 */
	unsigned int   s_block_base;	/* physical block number of block 0 */
	unsigned short s_fic_size;	/* free inode cache size, NICINOD */
	unsigned short s_flc_size;	/* free block list chunk size, NICFREE */
	/* The superblock is kept in a disk buffer: */
	struct buffer_head *s_bh;
	/* These are pointers into the disk buffer, to compensate for
	   different superblock layout. */
	char *         s_sbd;		/* entire superblock data */
	unsigned short *s_sb_fic_count;	/* pointer to s_sbd->s_ninode */
        unsigned short *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
	unsigned short *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
	unsigned short *s_sb_flc_count;	/* pointer to s_sbd->s_nfree */
	unsigned long  *s_sb_flc_blocks; /* pointer to s_sbd->s_free */
	unsigned long  *s_sb_total_free_blocks;/* pointer to s_sbd->s_tfree */
	unsigned long  *s_sb_time;	/* pointer to s_sbd->s_time */
	/* We keep those superblock entities that don't change here;
	   this saves us an indirection and perhaps a conversion. */
	unsigned long  s_firstinodezone; /* index of first inode zone */
	unsigned long  s_firstdatazone;	/* same as s_sbd->s_isize */
	unsigned long  s_ninodes;	/* total number of inodes */
	unsigned long  s_ndatazones;	/* total number of data zones */
	unsigned long  s_nzones;	/* same as s_sbd->s_fsize */
};
/* The fields s_block_size_ratio, s_toobig_block, s_sbd are currently unused. */

/* sv_ == u.sysv_sb.s_ */
#define sv_type				u.sysv_sb.s_type
#define sv_block_size			u.sysv_sb.s_block_size
#define sv_block_size_1			u.sysv_sb.s_block_size_1
#define sv_block_size_bits		u.sysv_sb.s_block_size_bits
#define sv_block_size_ratio		u.sysv_sb.s_block_size_ratio
#define sv_block_size_ratio_1		u.sysv_sb.s_block_size_ratio_1
#define sv_block_size_ratio_bits	u.sysv_sb.s_block_size_ratio_bits
#define sv_convert			u.sysv_sb.s_convert
#define sv_kludge_symlinks		u.sysv_sb.s_kludge_symlinks
#define sv_truncate			u.sysv_sb.s_truncate
#define sv_link_max			u.sysv_sb.s_link_max
#define sv_inodes_per_block		u.sysv_sb.s_inodes_per_block
#define sv_inodes_per_block_1		u.sysv_sb.s_inodes_per_block_1
#define sv_inodes_per_block_bits	u.sysv_sb.s_inodes_per_block_bits
#define sv_ind_per_block		u.sysv_sb.s_ind_per_block
#define sv_ind_per_block_1		u.sysv_sb.s_ind_per_block_1
#define sv_ind_per_block_bits		u.sysv_sb.s_ind_per_block_bits
#define sv_ind_per_block_2		u.sysv_sb.s_ind_per_block_2
#define sv_ind_per_block_2_1		u.sysv_sb.s_ind_per_block_2_1
#define sv_ind_per_block_2_bits		u.sysv_sb.s_ind_per_block_2_bits
#define sv_ind_per_block_3		u.sysv_sb.s_ind_per_block_3
#define sv_toobig_block			u.sysv_sb.s_toobig_block
#define sv_block_base			u.sysv_sb.s_block_base
#define sv_fic_size			u.sysv_sb.s_fic_size
#define sv_flc_size			u.sysv_sb.s_flc_size
#define sv_bh				u.sysv_sb.s_bh
#define sv_sbd				u.sysv_sb.s_sbd
#define sv_sb_fic_count			u.sysv_sb.s_sb_fic_count
#define sv_sb_fic_inodes		u.sysv_sb.s_sb_fic_inodes
#define sv_sb_total_free_inodes		u.sysv_sb.s_sb_total_free_inodes
#define sv_sb_flc_count			u.sysv_sb.s_sb_flc_count
#define sv_sb_flc_blocks		u.sysv_sb.s_sb_flc_blocks
#define sv_sb_total_free_blocks		u.sysv_sb.s_sb_total_free_blocks
#define sv_sb_time			u.sysv_sb.s_sb_time
#define sv_firstinodezone		u.sysv_sb.s_firstinodezone
#define sv_firstdatazone		u.sysv_sb.s_firstdatazone
#define sv_ninodes			u.sysv_sb.s_ninodes
#define sv_ndatazones			u.sysv_sb.s_ndatazones
#define sv_nzones			u.sysv_sb.s_nzones

#endif