# Patched-kernel (#1, fix.diff) results:
#   whang:  pwrite(1 @ 0) = 1  -- returns immediately (baseline: livelock, RUN_EXIT=124, load 11.99)
#   wprobe: 13/13 pwrite(1 @ off) = 1 -- normal in-bounds writes (baseline: 13/13 EFAULT)
#   readback of offsets 199-202/510 = 0x41 confirms data landed in the file's own block
#   DF-3101 fix (same kernel): ftruncate returns EINVAL, 'hpfs_truncatealblk: alsec
#   tree too deep' on console, no double fault (see ../DF-3101/fix_run.log)