fd: new abstraction

src/sys/syscalls/isatty.c

@@ -12,26 +12,22 @@ syscallret syscall_isatty(int ifd){
 	
 	proc_t* proc = arch_getcls()->thread->proc;
 
-        fd_t* fd = proc->fds + ifd;
+        fd_t* fd;
+	
+	int ret = fd_access(&proc->fdtable, &fd, ifd);
 
-        spinlock_acquire(&proc->fdlock);
-        
-	if(proc->fdcount <= ifd || fd->node == NULL){
-                spinlock_release(&proc->fdlock);
-                retv.errno = EBADF;
-                return retv;
-        }
+	if(ret){
+		retv.errno = ret;
+		return retv;
+	}
 
-        spinlock_acquire(&fd->lock);
-        spinlock_release(&proc->fdlock);
-
-	int ret = vfs_isatty(fd->node);
+	ret = vfs_isatty(fd->node);
 	
 	retv.errno = ret;
 
 	retv.ret = retv.errno == ENOTTY ? 0 : 1;
 
-	spinlock_release(&fd->lock);
+	fd_release(fd);
 
 	return retv;