guest (QEMU/KVM, dfbsd-qemu/vm.sh, 4GB RAM, 6 vCPUs): DragonFly dfbsd 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026 root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC x86_64 (stock) KERNCONF=X86_64_GENERIC, options INVARIANTS (KKASSERT active) kernel A (baseline): stock + inject.diff (#1) kernel B (fix): stock + fix.diff + inject.diff (#2) / on hammer2 (vbd0s1d); test media: vn(4) over /root/h2661.img, vnconfig -c -S 512m -T; newfs_hammer2 -L DATA; mounted /mnt/h2661 fault injector: sysctl vfs.hammer2.df2661_fail_inode_read (int) — forces EIO on INODE-type DIO reads after bp instantiation, gated to volu_size == 0x20000000 (512MB test volume only; guest root fs untouched) build: make -j6 nativekernel KERNCONF=X86_64_GENERIC (~14 min)