#include <u.h>#include <libc.h>#include <auth.h>#include <fcall.h> longdirread(int f, Dir *dbuf, long count){	char buf[DIRLEN*50];	int c, n, i, r; 	n = 0;	count = (count/sizeof(Dir)) * DIRLEN;	while(n < count) {		c = count - n;		if(c > sizeof(buf))			c = sizeof(buf);		r = read(f, buf, c);		if(r == 0)			break;		if(r < 0 || r % DIRLEN)			return -1;		for(i=0; i<r; i+=DIRLEN) {			convM2D(buf+i, dbuf);			dbuf++;		}		n += r;		if(r != c)			break;	}	return (n/DIRLEN) * sizeof(Dir);}