/*
?*??linux/fs/bitmap.c
?*
?*??（C）?1991??Linus?Torvalds
?*/

/*?bitmap.c?contains?the?code?that?handles?the?inode?and?block?bitmaps?*/
#include?

#include?
#include?

#define?clear_block（addr）?\
__asm__（“cld\n\t“?\
	“rep\n\t“?\
	“stosl“?\
	::“a“?（0）“c“?（BLOCK_SIZE/4）“D“?（（long）?（addr））:“cx““di“）

#define?set_bit（nraddr）?（{\
register?int?res?__asm__（“ax“）;?\
__asm__?__volatile__（“btsl?%2%3\n\tsetb?%%al“:?\
“=a“?（res）:“0“?（0）“r“?（nr）“m“?（*（addr）））;?\
res;}）

#define?clear_bit（nraddr）?（{\
register?int?res?__asm__（“ax“）;?\
__asm__?__volatile__（“btrl?%2%3\n\tsetnb?%%al“:?\
“=a“?（res）:“0“?（0）“r“?（nr）“m“?（*（addr）））;?\
res;}）

#define?find_first_zero（addr）?（{?\
int?__res;?\
__asm__（“cld\n“?\
	“1:\tlodsl\n\t“?\
	“notl?%%eax\n\t“?\
	“bsfl?%%eax%%edx\n\t“?\
	“je?2f\n\t“?\
	“addl?%%edx%%ecx\n\t“?\
	“jmp?3f\n“?\
	“2:\taddl?$32%%ecx\n\t“?\
	“cmpl?$8192%%ecx\n\t“?\
	“jl?1b\n“?\
	“3:“?\
	:“=c“?（__res）:“c“?（0）“S“?（addr）:“ax““dx““si“）;?\
__res;}）

void?free_block（int?dev?int?block）
{
	struct?super_block?*?sb;
	struct?buffer_head?*?bh;

	if?（!（sb?=?get_super（dev）））
		panic（“trying?to?free?block?on?nonexistent?device“）;
	if?（block?s_firstdatazone?||?block?>=?sb->s_nzones）
		panic（“trying?to?free?block?not?in?datazone“）;
	bh?=?get_hash_table（devblock）;
	if?（bh）?{
		if?（bh->b_count?!=?1）?{
			printk（“trying?to?free?block?（%04x:%d）?count=%d\n“
				devblockbh->b_count）;
			return;
		}
		bh->b_dirt=0;
		bh->b_uptodate=0;
		brelse（bh）;
	}
	block?-=?sb->s_firstdatazone?-?1?;
	if?（clear_bit（block&8191sb->s_zmap[block/8192]->b_data））?{
		printk（“block?（%04x:%d）?“devblock+sb->s_firstdatazone-1）;
		panic（“free_block:?bit?already?cleared“）;
	}
	sb->s_zmap[block/8192]->b_dirt?=?1;
}

int?new_block（int?dev）
{
	struct?buffer_head?*?bh;
	struct?super_block?*?sb;
	int?ij;

	if?（!（sb?=?get_super（dev）））
		panic（“trying?to?get?new?block?from?nonexistant?device“）;
	j?=?8192;
	for?（i=0?;?i<8?;?i++）
		if?（bh=sb->s_zmap[i]）
			if?（（j=find_first_zero（bh->b_data））<8192）
				break;
	if?（i>=8?||?!bh?||?j>=8192）
		return?0;
	if?（set_bit（jbh->b_data））
		panic（“new_block:?bit?already?set“）;
	bh->b_dirt?=?1;
	j?+=?i*8192?+?sb->s_firstdatazone-1;
	if?（j?>=?sb->s_nzones）
		return?0;
	if?（!（bh=getblk（devj）））
		panic（“new_block:?cannot?get?block“）;
	if?（bh->b_count?!=?1）
		panic（“new?block:?count?is?!=?1“）;
	clear_block（bh->b_data）;
	bh->b_uptodate?=?1;
	bh->b_dirt?=?1;
	brelse（bh）;
	return?j;
}

void?free_inode（struct?m_inode?*?inode）
{
	struct?super_block?*?sb;
	struct?buffer_head?*?bh;

	if?（!inode）
		return;
	if?（!inode->i_dev）?{
		memset（inode0sizeof（*inode））;
		return;
	}
	if?（inode->i_count>1）?{
		printk（“trying?to?free?inode?with?count=%d\n“inode->i_count）;
		panic（“free_inode“）;
	}
	if?（inode->i_nlinks）
		panic（“trying?to?free?inode?with?links“）;
	if?（!（sb?=?get_super（inode->i_dev）））
		panic（“trying?to?free?inode?on?nonexistent?device“）;
	if?（inode->i_num?i_num?>?sb->s_ninodes）
		panic（“trying?to?fr

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??1991-12-08?21:38??linux-0.11\
?????目錄???????????0??1991-12-04?13:11??linux-0.11\tools\
?????目錄???????????0??1991-12-08?14:08??linux-0.11\mm\
?????目錄???????????0??1991-12-08?14:10??linux-0.11\lib\
?????目錄???????????0??1991-12-08?14:08??linux-0.11\kernel\
?????目錄???????????0??1991-12-05?19:59??linux-0.11\init\
?????目錄???????????0??1991-09-22?19:58??linux-0.11\include\
?????目錄???????????0??1991-12-08?14:08??linux-0.11\fs\
?????目錄???????????0??1991-12-05?22:48??linux-0.11\boot\
?????目錄???????????0??1991-12-08?14:09??linux-0.11\kernel\blk_drv\
?????目錄???????????0??1991-12-08?14:09??linux-0.11\kernel\math\
?????目錄???????????0??1991-12-08?18:36??linux-0.11\kernel\chr_drv\
?????目錄???????????0??1991-09-17?13:08??linux-0.11\include\asm\
?????目錄???????????0??1991-11-02?13:35??linux-0.11\include\linux\
?????目錄???????????0??1991-09-17?15:06??linux-0.11\include\sys\
?????目錄???????????0??2010-05-26?05:12??linux中文注釋\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\tools\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\mm\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\lib\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\kernel\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\init\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\include\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\fs\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\boot\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\kernel\math\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\kernel\chr_drv\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\kernel\blk_drv\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\include\sys\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\include\linux\
?????目錄???????????0??2007-03-16?03:39??linux中文注釋\include\asm\
?????文件????????2887??1991-12-06?03:12??linux-0.11\Makefile
............此處省略197個文件信息