wprotect does not work

[seekstar]

I remove nova_memunlock_inode(sb, pi, &irq_flags) and nova_memlock_inode(sb, pi, &irq_flags) around nova_update_inode(sb, inode, pi, &update, 1) in function do_nova_inplace_file_write, and run fio with wprotect enabled, expecting a kernel panic or something else:

mount -t NOVA -o init -o wprotect /dev/pmem0 /mnt/pmem
fio -filename=/mnt/pmem/test1 -fallocate=none -direct=1 -iodepth 1 -rw=write -ioengine=sync -bs=4K -thread -numjobs=1 -size=3G -name=randrw -group_reporting

But nothing happens, the command simply finishes successfully. Is there something I miss?