--- run.log (DF-3064 baseline, stock kernel #0 Jul 2 2026) ---
$ sh /root/trigger3064.sh
attached /root/df3064.img size=0
MOUNT-RC=0
touch: /mnt/e4/x: File exists        <- ext2_valloc returned EEXIST
TOUCH-RC=1
BEFORE-HANG-MARKER
lost+found
AFTER-LS (never reached: root vnode lock leaked by ext2_valloc EEXIST path)

--- console (serial) ---
ext2_valloc: vp 0xfffff80118106c00 exists for inode 2

--- aftermath (later ssh session) ---
$ ps ax | grep -E "ls /mnt|umount"
 981 ??  I5  timeout 15 ls /mnt/e4
 982 ??  D2  ls /mnt/e4          <- uninterruptible
 1001 ??  D5  ls /mnt/e4          <- uninterruptible
 1022 ??  D1  umount /mnt/e4      <- uninterruptible; mount un-unmountable
(backgrounded ls with cached path still listed entries; foreground
 lock acquires block forever)