Hi all, This patch series develops the old e2croncheck contrib script into a more robust online filesystem checker for ext4. The first patch enables tune2fs to set the error state bit so that we can force a fsck at next mount time. Patch 2 creates an e2scrub command that, given an ext4 filesystem on a LVM volume, creates a snapshot if there's more than 256M free in the LVM group, runs e2fsck on the snapshot, and deletes the snapshot. If the fsck ran cleanly, the fs last-check timestamp is updated and fstrim is run. If corruption is found we mark the fs as needing a fsck and advise a reboot. A udev rule file is used to prevent the creation of /dev/disk symlinks to the snapshot. Patch 3 introduces the e2scrub_all command that finds all ext4 filesystems living in LVM volumes and iteratively calls e2scrub on each of them. The fourth patch creates a weekly cron job for automatic invocation as well as systemd service files so that we can (try to) sandbox the scrub process and run it with idle priority to reduce latency spikes in the main filesystem. It also contains a scrub snapshot reaping service that will tear down old e2scrub snapshots during boot. Questions? Comments? This series targets e2fsprogs 1.45. --D