//读文件
int general_file_read(struct m_inode *inode,struct file *filp,char *buf,int count)
{
int i,c,m = 0;
char *p;
// char *ptr = buf;
struct buffer_head *bh;
struct dir_entry *de;
int block_nr = 0;
if(!inode || !filp)
return -EINVAL;
if(!buf || count <= 0)
return 0;
int nr_start_sect = get_first_block(inode);
printk("read num = %d.start_sect = %d.",inode->i_num, nr_start_sect);
// printk("inode->i_dev = %d inode->i_num = %d inode->i_start_sect = %d\n",inode->i_dev,inode->i_num,inode->i_start_sect);
//文件所占的磁盘块总数
off_t pos = filp->f_pos;
//开始读取的磁盘块
nr_start_sect += pos/SECTOR_SIZE;
// nr_sects = (inode->i_size + SECTOR_SIZE -1)/SECTOR_SIZE;
while(i < count)
{
block_nr = get_pos_block(inode, pos);
c = pos % SECTOR_SIZE;
c = SECTOR_SIZE -c ;
if(c > count)
{
c = count - i;
}
// printk("file_read : inode->i_dev = %d nr_start_sect = %d count = %d\n",inode->i_dev,nr_start_sect + pos/SECTOR_SIZE,count);
bh = getblk(inode->i_dev,block_nr);
hd_rw(inode->i_dev,block_nr,1,ATA_READ,bh);
p = bh->b_data + pos;
de = (struct dir_entry*)bh->b_data;
// printk("de->file_name = %s\n",(++de)->file_name);
filp->f_pos += c;
pos += c;
i += c;
m++;
// printk("c = %d\n",c);
while(c-- > 0)
{
if(*p == 0)
{
p++;
continue;
}
else
{
*buf = *p;
// printk("%d %c %c\t",512 - c,*p,*buf);
buf++;
p++;
}
}
brelse(bh);
}
return 0;
}
int general_file_write(struct m_inode *inode,struct file *filp,char *buf,int count)
{
int i = 0,block_nr,c;
off_t pos = 0;
char *p = NULL;
struct buffer_head *bh = NULL;
int nr_start_sect = 0;
printk("write 5");
if(!inode || !filp || !buf || count < 0)
{
printk("write parameters error.");
return -EINVAL;
}
/*int nr_start_sect = inode->i_start_sect;*/
if((nr_start_sect = get_first_block(inode)) == 0)
{
set_block_nums(inode->i_dev ,(struct d_inode *)inode, NR_DEFAULT_SECTS);
if((nr_start_sect = get_first_block(inode)) == 0)
return -3;
}
printk("write num = %d.start_sect = %d.",inode->i_num, nr_start_sect);
if(filp->f_flag & O_APPEND)
pos = inode->i_size;
else
pos = filp->f_pos;
while(i < count)
{
/*block = nr_start_sect + pos/SECTOR_SIZE;*/
block_nr = get_pos_block(inode, pos);
bh = getblk(inode->i_dev,block_nr);
c = pos % SECTOR_SIZE;
p = bh->b_data + c;
c = SECTOR_SIZE -c;
if(c > count)
c = count - i;
pos += c;
i += c;
if(pos > inode->i_size)
{
inode->i_size = pos;
}
while(c-- > 0)
*(p++) = *(buf++);
hd_rw(inode->i_dev,block_nr,1,ATA_WRITE,bh);
brelse(bh);
}
inode->i_dirty = 1;
return 0;
}
static void buf_ll_rw(struct buf *bp)
{
if(MAJOR(bp->dev) == MEM_MAJOR){
memhd_rw(bp);
} else if(MAJOR(bp->dev) == HD_MAJOR){
hd_rw(bp);
} else {
printk("buf_ll_rw: unknown dev %d\n", MAJOR(bp->dev));
panic("buf_ll_rw");
}
}
struct buffer_head *bread(int dev,int block_nr)
{
struct buffer_head *bh;
if(!(bh = getblk(dev,block_nr)))
panic("bread:getblk returned NULL\n");
if(bh->b_uptodate)
return bh;
hd_rw(dev,block_nr,1,ATA_READ,bh);
wait_on_buffer(bh);
if(bh->b_uptodate)
return bh;
brelse(bh);
return NULL;
}
void
verify_fs(void) {
unsigned int *q = (unsigned int *)(HD0_ADDR);
unsigned char sect[512] = {0};
struct SUPER_BLOCK sb;
unsigned int i = 0, j = 0, m = 0, n = 0;
/* get the fs sb */
sb.sb_start = q[0];
hd_rw(ABS_SUPER_BLK(sb), HD_READ, 1, &sb);
/* the first partition must be FST_FS type */
if (sb.sb_magic != FST_FS) {
kprintf(KPL_DUMP, "Partition 1 does not have a valid file system\n");
kprintf(KPL_DUMP, "Creating file system\t\t\t\t\t\t\t ");
sb.sb_magic = FST_FS;
sb.sb_start = q[0];
sb.sb_blocks = q[1];
sb.sb_dmap_blks = (sb.sb_blocks+0xfff)>>12;
sb.sb_imap_blks = INODE_BIT_BLKS;
sb.sb_inode_blks = INODE_BLKS;
hd_rw(ABS_SUPER_BLK(sb), HD_WRITE, 1, &sb);
/* initial data bitmap */
n = ABS_DMAP_BLK(sb);
j = sb.sb_dmap_blks+sb.sb_imap_blks+sb.sb_inode_blks+2;
memset(sect, 0xff, sizeof sect/sizeof sect[0]);
for (i=j/(512*8); i>0; --i) {
hd_rw(n++, HD_WRITE, 1, sect);
m += 4096;
}
m += 4096;
for (i=j%(512*8); i<512*8; ++i) {
clrb(sect, i);
--m;
}
hd_rw(n++, HD_WRITE, 1, sect);
memset(sect, 0, sizeof sect/sizeof sect[0]);
for (i=sb.sb_imap_blks-(n-ABS_DMAP_BLK(sb)); i>0; --i)
hd_rw(n++, HD_WRITE, 1, sect);
/* initail inode bitmap */
for (i=sb.sb_imap_blks; i>0; --i)
hd_rw(ABS_IMAP_BLK(sb)+i-1, HD_WRITE, 1, sect);
/* initial inode blocks */
for (i=sb.sb_inode_blks; i>0; --i)
hd_rw(ABS_INODE_BLK(sb)+i-1, HD_WRITE, 1, sect);
kprintf(KPL_DUMP, "[DONE]");
}
