磁盘驱动相关高级API之辅助函数之得到一个磁盘块
static struct buf*
bget(uint dev, uint blockno)
{
struct buf *b;
for (bcache.head.next; b!=&bcache.head; b=b->next){
if (b->dev == dev && b->blockno == blockno) {
b->refcnt++;
return b;
}
}
}