===== DF-3115 pattern A: unprivileged ls loop vs kernel msgbuf (live run)
mount_msdos -o ro /dev/vn0 /mnt/df3115 (image: craft_lfn.py pattern A)
BEFORE=$(dmesg | grep -c non-decreasing)   -> 0
su nobody: 100 x (ls /mnt/df3115; stat /mnt/df3115/LONGN000.TXT)
AFTER -> 1212
RESULT-A: non-decreasing lines before=0 after=1212 delta=1212
last msgbuf lines:
msdosfs: non-decreasing id: id 0, last id 0
msdosfs: non-decreasing id: id 0, last id 0

===== DF-3115 pattern B: 130-byte LFN reassembly (live run)
mount_msdos -o ro /dev/vn0 /mnt/df3115 (image: craft_lfn.py pattern B)
su nobody: 100 x ls
RESULT-B: too-large lines before=0 after=100 delta=100
msdosfs: file name length 130 too large

Serial console echo during the runs: 1312 msdosfs lines captured in the
QEMU serial log (console_flood_excerpt.log) -- every kprintf also hits
the logging console, unthrottled.