util.h

讲述linux的初始化过程

/*
 *  linux/fs/ufs/util.h
 *
 * Copyright (C) 1998 
 * Daniel Pirkl <[e-mail]>
 * Charles University, Faculty of Mathematics and Physics
 */

#include <linux/fs.h>
#include "swab.h"


/*
 * some useful macros
 */
#define in_range(b,first,len)	((b)>=(first)&&(b)<(first)+(len))
#define min(x,y)		((x)<(y)?(x):(y))
#define max(x,y)		((x)>(y)?(x):(y))



/*
 * macros used for retyping
 */
#define UCPI_UBH ((struct ufs_buffer_head *)ucpi)
#define USPI_UBH ((struct ufs_buffer_head *)uspi)



/*
 * macros used for accesing structures
 */
#define ufs_get_fs_state(usb1,usb3) _ufs_get_fs_state_(usb1,usb3,flags,swab)
static inline __s32 _ufs_get_fs_state_(struct ufs_super_block_first * usb1,
	struct ufs_super_block_third * usb3, unsigned flags, unsigned swab)
{
	switch (flags & UFS_ST_MASK) {
		case UFS_ST_SUN:
			return SWAB32((usb3)->fs_u2.fs_sun.fs_state);
		case UFS_ST_SUNx86:
			return SWAB32((usb1)->fs_u1.fs_sunx86.fs_state);
		case UFS_ST_44BSD:
		default:
			return SWAB32((usb3)->fs_u2.fs_44.fs_state);
	}
}

#define ufs_set_fs_state(usb1,usb3,value) _ufs_set_fs_state_(usb1,usb3,value,flags,swab)
static inline void _ufs_set_fs_state_(struct ufs_super_block_first * usb1,
	struct ufs_super_block_third * usb3, __s32 value, unsigned flags, unsigned swab)
{
	switch (flags & UFS_ST_MASK) {
		case UFS_ST_SUN:
			(usb3)->fs_u2.fs_sun.fs_state = SWAB32(value);
			break;
		case UFS_ST_SUNx86:
			(usb1)->fs_u1.fs_sunx86.fs_state = SWAB32(value);
			break;
		case UFS_ST_44BSD:
			(usb3)->fs_u2.fs_44.fs_state = SWAB32(value);
			break;
	}
}

#define ufs_get_fs_npsect(usb1,usb3) _ufs_get_fs_npsect_(usb1,usb3,flags,swab)
static inline __u32 _ufs_get_fs_npsect_(struct ufs_super_block_first * usb1,
	struct ufs_super_block_third * usb3, unsigned flags, unsigned swab)
{
	if ((flags & UFS_ST_MASK) == UFS_ST_SUNx86)
		return SWAB32((usb3)->fs_u2.fs_sunx86.fs_npsect);
	else
		return SWAB32((usb1)->fs_u1.fs_sun.fs_npsect);
}

#define ufs_get_fs_qbmask(usb3) _ufs_get_fs_qbmask_(usb3,flags,swab)
static inline __u64 _ufs_get_fs_qbmask_(struct ufs_super_block_third * usb3,
	unsigned flags, unsigned swab)
{
	__u64 tmp;
	switch (flags & UFS_ST_MASK) {
		case UFS_ST_SUN:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_sun.fs_qbmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_sun.fs_qbmask[1];
			break;
		case UFS_ST_SUNx86:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_sunx86.fs_qbmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_sunx86.fs_qbmask[1];
			break;
		case UFS_ST_44BSD:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_44.fs_qbmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_44.fs_qbmask[1];
			break;
	}
	return SWAB64(tmp);
}

#define ufs_get_fs_qfmask(usb3) _ufs_get_fs_qfmask_(usb3,flags,swab)
static inline __u64 _ufs_get_fs_qfmask_(struct ufs_super_block_third * usb3,
	unsigned flags, unsigned swab)
{
	__u64 tmp;
	switch (flags & UFS_ST_MASK) {
		case UFS_ST_SUN:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_sun.fs_qfmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_sun.fs_qfmask[1];
			break;
		case UFS_ST_SUNx86:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_sunx86.fs_qfmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_sunx86.fs_qfmask[1];
			break;
		case UFS_ST_44BSD:
			((u32 *)&tmp)[0] = usb3->fs_u2.fs_44.fs_qfmask[0];
			((u32 *)&tmp)[1] = usb3->fs_u2.fs_44.fs_qfmask[1];
			break;
	}
	return SWAB64(tmp);
}

#define ufs_get_de_namlen(de) \
	(((flags & UFS_DE_MASK) == UFS_DE_OLD) \
	? SWAB16(de->d_u.d_namlen) \
	: de->d_u.d_44.d_namlen)

#define ufs_set_de_namlen(de,value) \
	(((flags & UFS_DE_MASK) == UFS_DE_OLD) \
	? (de->d_u.d_namlen = SWAB16(value)) \
	: (de->d_u.d_44.d_namlen = value))

#define ufs_set_de_type(de,mode) _ufs_set_de_type_(de,mode,flags,swab)
static inline void _ufs_set_de_type_(struct ufs_dir_entry * de, int mode, 
	unsigned flags, unsigned swab)
{
	if ((flags & UFS_DE_MASK) == UFS_DE_44BSD) {
		switch (mode & S_IFMT) {
			case S_IFSOCK: de->d_u.d_44.d_type = DT_SOCK; break;
			case S_IFLNK: de->d_u.d_44.d_type = DT_LNK; break;
			case S_IFREG: de->d_u.d_44.d_type = DT_REG; break;
			case S_IFBLK: de->d_u.d_44.d_type = DT_BLK; break;
			case S_IFDIR: de->d_u.d_44.d_type = DT_DIR; break;
			case S_IFCHR: de->d_u.d_44.d_type = DT_CHR; break;
			case S_IFIFO: de->d_u.d_44.d_type = DT_FIFO; break;
			default: de->d_u.d_44.d_type = DT_UNKNOWN;
		}
	}
}

#define ufs_get_inode_uid(inode) _ufs_get_inode_uid_(inode,flags,swab)
static inline __u32 _ufs_get_inode_uid_(struct ufs_inode * inode,
	unsigned flags, unsigned swab)
{
	switch (flags & UFS_UID_MASK) {
		case UFS_UID_EFT:
			return SWAB32(inode->ui_u3.ui_sun.ui_uid);
		case UFS_UID_44BSD:
			return SWAB32(inode->ui_u3.ui_44.ui_uid);
		default:
			return SWAB16(inode->ui_u1.oldids.ui_suid);
	}
}

#define ufs_set_inode_uid(inode,value) _ufs_set_inode_uid_(inode,value,flags,swab)
static inline void _ufs_set_inode_uid_(struct ufs_inode * inode, __u32 value,
	unsigned flags, unsigned swab)
{
	inode->ui_u1.oldids.ui_suid = SWAB16(value); 
	switch (flags & UFS_UID_MASK) {
		case UFS_UID_EFT:
			inode->ui_u3.ui_sun.ui_uid = SWAB32(value);
			break;
		case UFS_UID_44BSD:
			inode->ui_u3.ui_44.ui_uid = SWAB32(value);
			break;
	}
}

#define ufs_get_inode_gid(inode) _ufs_get_inode_gid_(inode,flags,swab)
static inline __u32 _ufs_get_inode_gid_(struct ufs_inode * inode, 
	unsigned flags, unsigned swab)
{
	switch (flags & UFS_UID_MASK) {
		case UFS_UID_EFT:
			return SWAB32(inode->ui_u3.ui_sun.ui_gid);
		case UFS_UID_44BSD:
			return SWAB32(inode->ui_u3.ui_44.ui_gid);
		default:
			return SWAB16(inode->ui_u1.oldids.ui_sgid);
	}
}

#define ufs_set_inode_gid(inode,value) _ufs_set_inode_gid_(inode,value,flags,swab)
static inline void _ufs_set_inode_gid_(struct ufs_inode * inode, __u32 value, 
	unsigned flags, unsigned swab)
{
	inode->ui_u1.oldids.ui_sgid =  SWAB16(value);
	switch (flags & UFS_UID_MASK) {
		case UFS_UID_EFT:
			inode->ui_u3.ui_sun.ui_gid = SWAB32(value);
			break;
		case UFS_UID_44BSD:
			inode->ui_u3.ui_44.ui_gid = SWAB32(value);
			break;
	}
}



/*
 * These functions manipulate ufs buffers
 */
#define ubh_bread(dev,fragment,size) _ubh_bread_(uspi,dev,fragment,size)  
extern struct ufs_buffer_head * _ubh_bread_(struct ufs_sb_private_info *, kdev_t, unsigned, unsigned);
extern struct ufs_buffer_head * ubh_bread_uspi(struct ufs_sb_private_info *, kdev_t, unsigned, unsigned);
extern void ubh_brelse (struct ufs_buffer_head *);
extern void ubh_brelse_uspi (struct ufs_sb_private_info *);
extern void ubh_mark_buffer_dirty (struct ufs_buffer_head *);
extern void ubh_mark_buffer_uptodate (struct ufs_buffer_head *, int);
extern void ubh_ll_rw_block (int, unsigned, struct ufs_buffer_head **);
extern void ubh_wait_on_buffer (struct ufs_buffer_head *);
extern unsigned ubh_max_bcount (struct ufs_buffer_head *);
extern void ubh_bforget (struct ufs_buffer_head *);
extern int  ubh_buffer_dirty (struct ufs_buffer_head *);
#define ubh_ubhcpymem(mem,ubh,size) _ubh_ubhcpymem_(uspi,mem,ubh,size)
extern void _ubh_ubhcpymem_(struct ufs_sb_private_info *, unsigned char *, struct ufs_buffer_head *, unsigned);
#define ubh_memcpyubh(ubh,mem,size) _ubh_memcpyubh_(uspi,ubh,mem,size)
extern void _ubh_memcpyubh_(struct ufs_sb_private_info *, struct ufs_buffer_head *, unsigned char *, unsigned);



/*
 * macros to get important structures from ufs_buffer_head
 */
#define ubh_get_usb_first(ubh) \
	((struct ufs_super_block_first *)((ubh)->bh[0]->b_data))

#define ubh_get_usb_second(ubh) \
	((struct ufs_super_block_second *)(ubh)-> \
	bh[UFS_SECTOR_SIZE >> uspi->s_fshift]->b_data + (UFS_SECTOR_SIZE & ~uspi->s_fmask))

#define ubh_get_usb_third(ubh) \
	((struct ufs_super_block_third *)((ubh)-> \
	bh[UFS_SECTOR_SIZE*2 >> uspi->s_fshift]->b_data + (UFS_SECTOR_SIZE*2 & ~uspi->s_fmask)))

#define ubh_get_ucg(ubh) \
	((struct ufs_cylinder_group *)((ubh)->bh[0]->b_data))


/*
 * Extract byte from ufs_buffer_head
 * Extract the bits for a block from a map inside ufs_buffer_head
 */
#define ubh_get_addr8(ubh,begin) \
	((u8*)(ubh)->bh[(begin) >> uspi->s_fshift]->b_data + \
	((begin) & ~uspi->s_fmask))