static struct buffer * find_entry(struct inode *dir_inode, char *filename,
struct dir_entry **res_de)
{
struct buffer *buf;
struct dir_entry *de;
for (int i = 0; i < 7 + 512; i++) {
buf = bread(dir_inode->i_dev, minix1_rbmap(dir_inode, i));
if (!buf)
panic("add_entry:can not read buf");
de = (struct dir_entry *) buf->b_data;
for (int j = 0; j < 1024 / sizeof(struct dir_entry); j++) {
if (i * 1024 + j * sizeof(struct dir_entry)
> dir_inode->i_size) {
brelse(buf);
*res_de = NULL;
return NULL;
}
if (!strncmp(de->name, filename, NAME_LEN)) {
*res_de = de;
return buf;
}
de++;
}
brelse(buf);
}
*res_de = NULL;
return NULL;
}
int count_entry(struct inode *inode)
{
struct buffer *buf;
struct dir_entry *de;
int count=0;
for (int i = 0; i < 7 + 512; i++) {
buf = bread(inode->i_dev, minix1_rbmap(inode, i));
if (!buf)
panic("add_entry:can not read buf");
de = (struct dir_entry *) buf->b_data;
for (int j = 0; j < 1024 / sizeof(struct dir_entry); j++) {
if (i * 1024 + j * sizeof(struct dir_entry)
> inode->i_size) {
brelse(buf);
return count;
}
if(!de->ino){
de++;
continue;
}
count++;
de++;
}
brelse(buf);
}
return count;
}
int minix1_file_read(struct inode *inode, char * buf, size_t size, off_t off,
int rw_flag)
{
struct buffer *bh;
int block, chars, left;
if (off >= inode->i_size)
return 0;
if (off + size >= inode->i_size)
size = inode->i_size - off;
left = size;
while (left > 0) {
bh = bread(inode->i_dev, minix1_rbmap(inode, off / 1024));
if (!bh) {
panic("read file error");
}
chars = min(left, 1024 - off % 1024);
memcpy(buf, bh->b_data + off % 1024, chars);
brelse(bh);
buf += chars;
off += chars;
left -= chars;
}
return size - left;
}
