// file.c
struct file* filealloc(void);
void fileclose(struct file*);
-void fileincref(struct file*);
+struct file* filedup(struct file*);
void fileinit(void);
int fileread(struct file*, char*, int n);
int filestat(struct file*, struct stat*);
}
// Increment ref count for file f.
-void
-fileincref(struct file *f)
+struct file*
+filedup(struct file *f)
{
acquire(&file_table_lock);
if(f->ref < 1 || f->type == FD_CLOSED)
- panic("fileincref");
+ panic("filedup");
f->ref++;
release(&file_table_lock);
+ return f;
}
// Read from file f. Addr is kernel address.
}
memmove(np->mem, p->mem, np->sz);
- for(i = 0; i < NOFILE; i++){
- if((np->ofile[i] = p->ofile[i]) != 0)
- fileincref(np->ofile[i]);
- }
+ for(i = 0; i < NOFILE; i++)
+ if(p->ofile[i])
+ np->ofile[i] = filedup(p->ofile[i]);
np->cwd = idup(p->cwd);
}
return -1;
if((fd=fdalloc(f)) < 0)
return -1;
- fileincref(f);
+ filedup(f);
return fd;
}