dir.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 furnctions for DirEnt, DirBlock class
void DirEntInit(struct DirEnt *de){
   de->ino=-1;
}

void DirBlk_init(struct DirBlock *db){
//  init db
   int i;
   for(i=0;i<MAX_DIR_ENT;i++)
      db->entries[i].ino=-1;
}

int DirBlk_get_free_dir_ent(struct DirBlock *db){
// get free entry in directory block d
   int i;
   for(i=0;i<MAX_DIR_ENT;i++)
      if (db->entries[i].ino==-1)
	      return i;
      else printk("ino at %d-th entry is %d ",i,db->entries[i].ino);
   panic("no more entry in dir_ent");
}

void DirBlk_report_new_entry(struct DirBlock *dir, int ino, char *fname){
// fname is a new file with inode num ino. report it in dir
   int x;
   printk("DirBlk_report_new_entry for %s\n",fname);
   x=DirBlk_get_free_dir_ent(dir);
   printk("In DirBlk_report_new_entry. %d\n",x);
   dir->entries[x].ino = ino;
   strcpy(dir->entries[x].fname, fname);
}

void DirBlk_set_empty(struct DirBlock *db,int me, int parent){
// make empty dir block. me is this dir's inode; parent its parent inode
   DirBlk_init(db);
   strcpy(db->entries[0].fname, ".");
   db->entries[0].ino=me;
   strcpy(db->entries[1].fname, "..");
   db->entries[1].ino=parent;
}

int find_ino_for_file_in_dir(char *f, struct DirBlock *blk){
   int i;
   for(i=0;i<MAX_DIR_ENT;i++)
      if (!strcmp(f, blk->entries[i].fname)) // found mathcing file name
	       return (blk->entries[i].ino);
   return -1; // no such file name
}