Merge commit 'c9b62a7ee14f51c9fa473a5bbefe264c904613ee' into upstream-merge

Merge commit 'c9b62a7ee14f51c9fa473a5bbefe264c904613ee' into upstream-merge

* commit 'c9b62a7ee14f51c9fa473a5bbefe264c904613ee':
  blockdev: Give drives internal linkage
  block: Decouple savevm from DriveInfo
  block: New bdrv_next()
  monitor: Make "commit FOO" complain when FOO doesn't exist
  block: Decouple block device "commit all" from DriveInfo
  block: Move error actions from DriveInfo to BlockDriverState
  cow: use qemu block API
  cow: stop using mmap
  cow: use pread/pwrite
  qcow2: Restore L1 entry on l2_allocate failure
  Fix regression for "-drive file="
  savevm: Really verify if a drive supports snapshots
  qcow2: Return real error code in load_refcount_block
  qcow2: Allow alloc_clusters_noref to return errors
  qcow2: Allow get_refcount to return errors
  vpc: Read/write multiple sectors at once

Conflicts:
	blockdev.c

Signed-off-by: Avi Kivity <avi@redhat.com>