::panic: hammer left edge case 0000000000004000 16384

    I've committed 60G which should hopefully deal with both bugs
    revealed by this panic and crash dump.

    Also, please continue to test filesystem out-of-space issues.  It
    should no longer create empty files after write() failures are
    reported.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>