ext2-inode.c

用于汇编领域的,运用于OS的MAIN函数.基于硬件基础的源代码

#include "fs.h"
//member functions for Ext2Inode 

/* ATTENTION:ext2 inode table stores inode n in inode_table[n-1]!!! */

void Ext2Inode_init(struct Ext2Inode *in){
   in->i_blocks=0; // 0 blocks assigned yet
}
void Ext2Inode_alloc_block(struct Ext2Inode *in, int blk_no){
// assign a block (whose block number is blk_no) to this inode
   int nblk = in->i_blocks;
   if (nblk <= 12) { // we can still use direct block
      in->i_block[nblk] = blk_no;
	  in->i_blocks++;
   }
   else panic("we can't handle more than 13 blocks yet\n");
}

struct Ext2Inode * Ext2Inode_make_inode(int ino, int blkno){
// make ext2 inode with inode num=ino and 1 block whose block num is blkno
   int q, r,blk_loc;
   struct Ext2Inode * iblock; int adj_ino;
   adj_ino = ino-1; // inode table starts with ino 1, not ino 0
   q = adj_ino / EXT2_INODES_PER_BLOCK; //block num in which this ino belongs to
   r = adj_ino % EXT2_INODES_PER_BLOCK; // offset
   blk_loc = EXT2_INODE_TABLE_LOCATION + q; // block location
   iblock = (struct Ext2Inode *)FBTable_get_block(blk_loc);
   Ext2Inode_alloc_block(&iblock[r], blkno);
   return &iblock[r];
}

struct Ext2Inode * Ext2Inode_get_inode(int ino){
// get ext2 inode with inode num=ino
   int q, r,blk_loc;
   struct Ext2Inode * iblock;
   int adj_ino;
   printk("ext2 inode %d is goint to be retrieved\n",ino);
   printk("EXT2_INODES_PER_BLOCK is %d\n",EXT2_INODES_PER_BLOCK);
   adj_ino = ino-1; // inode table starts with ino 1 not ino 0
   q = adj_ino / EXT2_INODES_PER_BLOCK; //block num in which this ino belongs to
   r = adj_ino % EXT2_INODES_PER_BLOCK; // offset
   blk_loc = EXT2_INODE_TABLE_LOCATION + q; // block location
   iblock = (struct Ext2Inode *)FBTable_get_block(blk_loc);
   printk("now it is: bnum:%d off:%d i_blocks:%d, i_block[0]:%d\n", q,r,iblock[r].i_blocks, iblock[r].i_block[0]);
   return &iblock[r];
}