Hi all, This patch series develops more fully the e2croncheck contrib script. We start with a 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. Next we create an e2scrub_all command that finds all ext4 filesystems living in LVM volumes and iteratively calls e2scrub on each of them. The third 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. The fourth patch teaches the build system to build with LTO enabled, and enables it for the debian package. This reduces the size of the static e2fsck binary by 30%, though the static libraries are now significantly larger because we ship the LTO information. Missing from this is a boot-time service to remove stale fsck snapshots. --D
