Merge remote-tracking branch 'stefanha/block' into staging

# By Kevin Wolf (22) and Fam Zheng (1)
# Via Stefan Hajnoczi
* stefanha/block: (23 commits)
  vmdk: refuse to open higher version than supported
  block: Always enable discard on the protocol level
  qcow2: Batch discards
  qcow2: Options to enable discard for freed clusters
  qcow2: Add refcount update reason to all callers
  Revert "block: Disable driver-specific options for 1.5"
  ide: Clean up ide_exec_cmd()
  ide: Convert SMART commands to ide_cmd_table handler
  ide: Convert CF-ATA commands to ide_cmd_table handler
  ide: Convert ATAPI commands to ide_cmd_table handler
  ide: Convert SEEK to ide_cmd_table handler
  ide: Convert FLUSH CACHE to ide_cmd_table handler
  ide: Convert SET FEATURES to ide_cmd_table handler
  ide: Convert CHECK POWER MDOE to ide_cmd_table handler
  ide: Convert READ NATIVE MAX ADDRESS to ide_cmd_table handler
  ide: Convert DMA read/write commands to ide_cmd_table handler
  ide: Convert PIO read/write commands to ide_cmd_table handler
  ide: Convert read/write multiple commands to ide_cmd_table handler
  ide: Convert verify commands to ide_cmd_table handler
  ide: Convert cmd_nop commands to ide_cmd_table handler
  ...

Message-id: 1372065035-19601-1-git-send-email-stefanha@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>