# DF-2874 fix check on fix kernel (#1 Sep 18 18:43:16 2026):
$ /tmp/dfpeer openwr /dev/vbd0 3              # device opened O_RDONLY
peer: ioctl(DIOCRECLUSTER fd=4)...
ioctl(DIOCRECLUSTER): Operation not permitted     <- explicit EPERM (FWRITE gate)
$ DFOPEN_RDWR=1 /tmp/dfpeer openwr /dev/vbd0 3    # root, O_RDWR
BLK_OPEN modes=3 -> reply cmd=a80fff01 error=0    <- still works for privileged
FIXED (gate now explicit in diskioctl instead of incidental).