[Qemu-commits] [qemu/qemu] 9a5992: docs/block-replication: use blockdev-backup

[Richard Henderson]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: 9a599217a44d98ac2ccdd22f8c75a07c03ad45c9
      
https://github.com/qemu/qemu/commit/9a599217a44d98ac2ccdd22f8c75a07c03ad45c9
  Author: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  Date:   2021-11-09 (Tue, 09 Nov 2021)

  Changed paths:
    M docs/block-replication.txt

  Log Message:
  -----------
  docs/block-replication: use blockdev-backup

We are going to deprecate drive-backup, so don't mention it here.
Moreover, blockdev-backup seems more correct in the context.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>


  Commit: 24d6cc1fa17745228694a3b2c94e8a5cbd4fc4d9
      
https://github.com/qemu/qemu/commit/24d6cc1fa17745228694a3b2c94e8a5cbd4fc4d9
  Author: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  Date:   2021-11-09 (Tue, 09 Nov 2021)

  Changed paths:
    M docs/interop/bitmaps.rst

  Log Message:
  -----------
  docs/interop/bitmaps: use blockdev-backup

We are going to deprecate drive-backup, so use modern interface here.
In examples where target image creation is shown, show blockdev-add as
well. If target creation omitted, omit blockdev-add as well.

Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>


  Commit: 1084159b31015e003946d199cbfecaec282e0eb2
      
https://github.com/qemu/qemu/commit/1084159b31015e003946d199cbfecaec282e0eb2
  Author: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  Date:   2021-11-09 (Tue, 09 Nov 2021)

  Changed paths:
    M docs/about/deprecated.rst
    M docs/interop/live-block-operations.rst
    M qapi/block-core.json
    M qapi/transaction.json

  Log Message:
  -----------
  qapi: deprecate drive-backup

Modern way is using blockdev-add + blockdev-backup, which provides a
lot more control on how target is opened.

As example of drive-backup problems consider the following:

User of drive-backup expects that target will be opened in the same
cache and aio mode as source. Corresponding logic is in
drive_backup_prepare(), where we take bs->open_flags of source.

It works rather bad if source was added by blockdev-add. Assume source
is qcow2 image. On blockdev-add we should specify aio and cache options
for file child of qcow2 node. What happens next:

drive_backup_prepare() looks at bs->open_flags of qcow2 source node.
But there no BDRV_O_NOCAHE neither BDRV_O_NATIVE_AIO: BDRV_O_NOCAHE is
places in bs->file->bs->open_flags, and BDRV_O_NATIVE_AIO is nowhere,
as file-posix parse options and simply set s->use_linux_aio.

The documentation is updated in a minimal way, so that drive-backup is
noted only as a deprecated command, and blockdev-backup used in most of
places.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>


  Commit: 856f9fa9a2c528dc29693d3b3a64a9b93bf866a2
      
https://github.com/qemu/qemu/commit/856f9fa9a2c528dc29693d3b3a64a9b93bf866a2
  Author: Richard Henderson <richard.henderson@linaro.org>
  Date:   2021-11-09 (Tue, 09 Nov 2021)

  Changed paths:
    M docs/about/deprecated.rst
    M docs/block-replication.txt
    M docs/interop/bitmaps.rst
    M docs/interop/live-block-operations.rst
    M qapi/block-core.json
    M qapi/transaction.json

  Log Message:
  -----------
  Merge tag 'pull-jobs-2021-11-09' of 
https://src.openvz.org/scm/~vsementsov/qemu into staging

qmp: deprecate drive-backup (use blockdev-backup instead)

# gpg: Signature made Tue 09 Nov 2021 06:43:31 PM CET
# gpg:                using RSA key 8B9C26CDB2FD147C880E86A1561F24C1F19F79FB
# gpg: Good signature from "Vladimir Sementsov-Ogievskiy 
<vsementsov@virtuozzo.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8B9C 26CD B2FD 147C 880E  86A1 561F 24C1 F19F 79FB

* tag 'pull-jobs-2021-11-09' of https://src.openvz.org/scm/~vsementsov/qemu:
  qapi: deprecate drive-backup
  docs/interop/bitmaps: use blockdev-backup
  docs/block-replication: use blockdev-backup

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Compare: https://github.com/qemu/qemu/compare/0a70bcf18caf...856f9fa9a2c5