/*
?*??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;}）

int?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）?{
			brelse（bh）;
			return?0;
		}
		bh->b_dirt=0;
		bh->b_uptodate=0;
		if?（bh->b_count）
			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）;
		printk（“free_block:?bit?already?cleared\n“）;
	}
	sb->s_zmap[block/8192]->b_dirt?=?1;
	return?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?free?inode?0?or?nonexistant?inode“）;

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----

?????文件???????7574??1992-01-14?23:45??linux-0.12\linux-0.12\boot\bootsect.S

?????文件???????5938??1992-01-11?12:50??linux-0.12\linux-0.12\boot\head.s

?????文件??????12144??1992-01-12?02:10??linux-0.12\linux-0.12\boot\setup.S

?????文件???????4007??1992-01-12?03:57??linux-0.12\linux-0.12\fs\bitmap.c

?????文件???????1763??1991-12-10?05:11??linux-0.12\linux-0.12\fs\block_dev.c

?????文件???????9072??1991-12-07?04:21??linux-0.12\linux-0.12\fs\buffer.c

?????文件???????2103??1991-11-19?17:10??linux-0.12\linux-0.12\fs\char_dev.c

?????文件???????9908??1992-01-14?07:36??linux-0.12\linux-0.12\fs\exec.c

?????文件???????1455??1991-10-02?22:16??linux-0.12\linux-0.12\fs\fcntl.c

?????文件???????1852??1991-12-02?03:02??linux-0.12\linux-0.12\fs\file_dev.c

?????文件????????122??1991-10-02?22:16??linux-0.12\linux-0.12\fs\file_table.c

?????文件???????7166??1992-01-11?06:27??linux-0.12\linux-0.12\fs\inode.c

?????文件???????1136??1991-12-21?09:58??linux-0.12\linux-0.12\fs\ioctl.c

?????文件???????7176??1992-01-13?03:49??linux-0.12\linux-0.12\fs\Makefile.c

?????文件??????18958??1992-01-12?12:09??linux-0.12\linux-0.12\fs\namei.c

?????文件???????4862??1992-01-09?04:01??linux-0.12\linux-0.12\fs\open.c

?????文件???????2834??1992-01-11?06:18??linux-0.12\linux-0.12\fs\pipe.c

?????文件???????2802??1991-11-25?23:47??linux-0.12\linux-0.12\fs\read_write.c

?????文件???????6381??1992-01-14?06:25??linux-0.12\linux-0.12\fs\select.c

?????文件???????1875??1992-01-12?04:39??linux-0.12\linux-0.12\fs\stat.c

?????文件???????5603??1991-12-10?05:11??linux-0.12\linux-0.12\fs\super.c

?????文件???????1692??1992-01-12?03:47??linux-0.12\linux-0.12\fs\truncate.c

?????文件???????6047??1991-09-17?23:10??linux-0.12\linux-0.12\include\a.out.h

?????文件????????477??1991-08-07?18:17??linux-0.12\linux-0.12\include\asm\io.h

?????文件????????507??1991-06-16?04:54??linux-0.12\linux-0.12\include\asm\memory.h

?????文件???????1366??1991-11-26?02:48??linux-0.12\linux-0.12\include\asm\segment.h

?????文件???????1707??1992-01-13?21:02??linux-0.12\linux-0.12\include\asm\system.h

?????文件????????321??1991-09-17?23:12??linux-0.12\linux-0.12\include\const.h

?????文件???????1049??1991-11-08?01:30??linux-0.12\linux-0.12\include\ctype.h

?????文件???????1364??1992-01-04?02:52??linux-0.12\linux-0.12\include\errno.h

............此處省略117個(gè)文件信息