Use sfdisk to get GPT partition by name as partition names are not
known by the kernel if added via partx.
Make sure physical volume names are unique, if possible correlate
with the disks serial number and/or card's cid.
mkf2fs apparently returns 134 even in case format succeeded, so don't
fail in that case (this fixes rw volumes large enough for F2FS to be
selected by the lvm scripts of uvol).

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Emmit ubus events when volumes come up/down.
Make sure volume state is always well defined by introducing
additional state 'write-prepare' (wp) during mkfs.
Add init scripts to bring up volumes at boot.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

Make sure filesystem is ready when volume becomes available.
Use 'write-once' as initial state for read-only volumes, only allow
writing to volumes in that state and transision to 'read-only' once
write has completed.
Also fix a typo which prevented 'list' command from working with LVM.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

* use lvm --reportformat json
 * add 'list' and 'align' commands
 * add help output

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

uvol is a wrapper-script which allows automated handling of storage
volumes. uvol currently comes with backend support for LVM2 and UBI,
covering practically all options for storage large enough to be
managed (NAND, SPI-NAND, eMMC, SATA, NVME, virtio-blk, ...).

Signed-off-by: Daniel Golle <daniel@makrotopia.org>