Added support for ext4fs marked filesystems in disklabel and added an fsck_ext4fs and a mount_ext4fs command to mount ext4fs filesystems in IABSD. The patch was rejected by OpenBSD and now we have IABSD that supports it.
Added journal replay support in mount_ext4fs and fsck_ext4fs.
Added journal write support for metadata backup before transaction commit on read/write ext4fs mounted filesystems.
Added 200+ tests in regress/sys/ext4fs*. Tests cover the corner cases and use vmm/vmd to spawn vms and abort writes after a countdown. Both ext4fs and its journal filesystem were tested thouroughly through the development process.
After 4 rounds of optimization refactors we achieved rsync to ext4fs performances that are three times slower than FFSv2.
vmm/vmd/vmctl
added options in vmd and vmctl to virtually fail disk writes to simulate IO error and hard machine shutdown, after a number of fsync calls. This allows for testing filesystem failure in a controlled way.
msdosfs
newfs_msdos: speed up filesystem creation by 3600x. Formatting a 500GB USB disk used to take 5 hours and now it takes 5 seconds. Following Microsoft recommendations and batching writes and zeros was the trick.
found regressions in makefs -t msdos and msdosfs.
cp
correctly report when destination file fails to be truncated.