Re: [Qemu-devel] [PATCH v4 0/6] dirty-bitmaps: fix QMP command permissions

[Eric Blake]

On 10/2/18 6:02 PM, John Snow wrote:
> based on: jsnow/bitmaps staging branch
>
> This series builds on a previous standalone patch and adjusts
> the permission for all (or most) of the QMP bitmap commands.
>
> V4:
>   - Replace "in-use" with "in use"
>   - Replace "user_modifiable" version with "user_locked"
>   - Remove more usages of frozen-and-or-locked in NBD.
>
> John Snow (6):
>    block/dirty-bitmaps: add user_locked status checker
>    block/dirty-bitmaps: fix merge permissions
>    block/dirty-bitmaps: allow clear on disabled bitmaps
>    block/dirty-bitmaps: prohibit enable/disable on locked/frozen bitmaps
>    block/backup: prohibit backup from using in use bitmaps
>    nbd: forbid use of frozen bitmaps

Just now noticing that our docs are slightly out of sync with these changes:

# @DirtyBitmapStatus:
#
# An enumeration of possible states that a dirty bitmap can report to 
the user.
#
# @frozen: The bitmap is currently in-use by a backup operation or block 
job,
#          and is immutable.
#
# @disabled: The bitmap is currently in-use by an internal operation and is
#            read-only. It can still be deleted.

This state is also reachable when using x-block-dirty-bitmap-disable, 
which is not an internal operation.  We probably also ought to document 
that this state is a prereq to x-nbd-server-add-bitmap, since...

#
# @active: The bitmap is actively monitoring for new writes, and can be 
cleared,
#          deleted, or used for backup operations.

...active is not valid for that usage.

#
# @locked: The bitmap is currently in-use by some operation and can not be
#          cleared, deleted, or used for backup operations. (Since 2.12)


--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org