[Qemu-devel] [PATCH v2 0/4] block: more read-only changes, related to backing files

[Naphtali Sprei]

This is version 2. The change between previous patch (only 3/4) is the order of 
closing/re-opening the image.

The read-only changes broke qemu-img create with read-only base image
These changes fix it.
It also make things a little safer, opening the backing file for read-only,
upgrading to read-write only for commit, and back to read-only when done.

Naphtali Sprei (4):
  Add open_flags to BlockDriverState Will be used later
  qemu-img: Fix qemu-img can't create qcow image based on read-only
    image
  Block: readonly changes
  Open backing file read-only also for snapshot mode