This series adds a mechanism that allows the user or management tool to
manually activate and inactivate block nodes instead of fully relying on
the automatic management in the migration code.
One case where this is needed is for migration with shared storage and
devices backed by qemu-storage-daemon, which as an external process is
not involved in the VM migration. Management tools can manually
orchestrate the handover in this scenario. The new qemu-iotests case
qsd-migrate demonstrates this.
There are other cases without qemu-storage-daemon where manual
management is necessary. For example, after migration, the destination
VM only activates images on 'cont', but after migrating a paused VM, the
user may want to perform operations on a block node while the VM is
still paused.
This series adds support for block exports on an inactive node (needed
for shared storage migration with qemu-storage-daemon) only to NBD.
Adding it to other export types will be done in a future series.
v3:
- Moved bdrv_is_inactive() to patch 1 to fix the build [Fabiano]
- Patch 5 ('block: Allow inactivating already inactive nodes') has
become patch 2 to fix the logical ordering [Eric]
- Patch 8: Fixed typo in the documentation [Eric]
- Patch 10: Fixed typo in the commit message [Stefan]
- Added Patch 11: Drain nodes for setting inactive flag [Stefan]
- Patch 14: Test reading inactive images from both sides [Eric]
- Patch 16: Fix typo in a comment [Eric]
v2:
- Added a comprehensive test case that tests how inactive nodes
interoperate with many operations
- Added a couple of fixes for bugs uncovered by the tests (that would
usually lead to crashes when an unsupported operation is performed on
inactive nodes)
- Added 'active' status to query-block information
Kevin Wolf (16):
block: Add 'active' field to BlockDeviceInfo
block: Allow inactivating already inactive nodes
block: Inactivate external snapshot overlays when necessary
migration/block-active: Remove global active flag
block: Don't attach inactive child to active node
block: Fix crash on block_resize on inactive node
block: Add option to create inactive nodes
block: Add blockdev-set-active QMP command
block: Support inactive nodes in blk_insert_bs()
block/export: Don't ignore image activation error in blk_exp_add()
block: Drain nodes before inactivating them
block/export: Add option to allow export of inactive nodes
nbd/server: Support inactive nodes
iotests: Add filter_qtest()
iotests: Add qsd-migrate case
iotests: Add (NBD-based) tests for inactive nodes
qapi/block-core.json | 44 ++-
qapi/block-export.json | 10 +-
include/block/block-common.h | 1 +
include/block/block-global-state.h | 6 +
include/block/export.h | 3 +
migration/migration.h | 3 -
block.c | 64 +++-
block/block-backend.c | 16 +-
block/export/export.c | 29 +-
block/monitor/block-hmp-cmds.c | 5 +-
block/qapi.c | 1 +
blockdev.c | 48 +++
migration/block-active.c | 46 ---
migration/migration.c | 8 -
nbd/server.c | 17 +
tests/qemu-iotests/iotests.py | 8 +
tests/qemu-iotests/041 | 4 +-
tests/qemu-iotests/165 | 4 +-
tests/qemu-iotests/184.out | 2 +
tests/qemu-iotests/191.out | 16 +
tests/qemu-iotests/273.out | 5 +
tests/qemu-iotests/tests/copy-before-write | 3 +-
tests/qemu-iotests/tests/inactive-node-nbd | 303 ++++++++++++++++++
.../qemu-iotests/tests/inactive-node-nbd.out | 239 ++++++++++++++
tests/qemu-iotests/tests/migrate-bitmaps-test | 7 +-
tests/qemu-iotests/tests/qsd-migrate | 140 ++++++++
tests/qemu-iotests/tests/qsd-migrate.out | 59 ++++
27 files changed, 1004 insertions(+), 87 deletions(-)
create mode 100755 tests/qemu-iotests/tests/inactive-node-nbd
create mode 100644 tests/qemu-iotests/tests/inactive-node-nbd.out
create mode 100755 tests/qemu-iotests/tests/qsd-migrate
create mode 100644 tests/qemu-iotests/tests/qsd-migrate.out
--
2.48.1
