xemu/include/block
Vladimir Sementsov-Ogievskiy 9c98f145df dirty-bitmaps: clean-up bitmaps loading and migration logic
This patch aims to bring the following behavior:

1. We don't load bitmaps, when started in inactive mode. It's the case
of incoming migration. In this case we wait for bitmaps migration
through migration channel (if 'dirty-bitmaps' capability is enabled) or
for invalidation (to load bitmaps from the image).

2. We don't remove persistent bitmaps on inactivation. Instead, we only
remove bitmaps after storing. This is the only way to restore bitmaps,
if we decided to resume source after [failed] migration with
'dirty-bitmaps' capability enabled (which means, that bitmaps were not
stored).

3. We load bitmaps on open and any invalidation, it's ok for all cases:
  - normal open
  - migration target invalidation with dirty-bitmaps capability
    (bitmaps are migrating through migration channel, the are not
     stored, so they should have IN_USE flag set and will be skipped
     when loading. However, it would fail if bitmaps are read-only[1])
  - migration target invalidation without dirty-bitmaps capability
    (normal load of the bitmaps, if migrated with shared storage)
  - source invalidation with dirty-bitmaps capability
    (skip because IN_USE)
  - source invalidation without dirty-bitmaps capability
    (bitmaps were dropped, reload them)

[1]: to accurately handle this, migration of read-only bitmaps is
     explicitly forbidden in this patch.

New mechanism for not storing bitmaps when migrate with dirty-bitmaps
capability is introduced: migration filed in BdrvDirtyBitmap.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:17 -04:00
..
accounting.h block/accounting: introduce latency histogram 2018-03-19 14:58:37 -05:00
aio-wait.h block: Use a single global AioWait 2018-09-25 15:50:15 +02:00
aio.h qemu-timer: introduce timer attributes 2018-10-19 13:44:03 +02:00
block_backup.h backup: Switch block_backup.h to byte-based 2017-07-10 13:18:06 +02:00
block_int.h dirty-bitmap: rename bdrv_undo_clear_dirty_bitmap 2018-10-29 16:23:14 -04:00
block.h block: Allow changing 'detect-zeroes' on reopen 2018-10-01 12:51:12 +02:00
blockjob_int.h block: Really pause block jobs on drain 2018-06-18 15:03:25 +02:00
blockjob.h block: Use a single global AioWait 2018-09-25 15:50:15 +02:00
dirty-bitmap.h dirty-bitmaps: clean-up bitmaps loading and migration logic 2018-10-29 16:23:17 -04:00
nbd.h nbd: fix NBD_FLAG_SEND_CACHE value 2018-10-04 09:08:56 -05:00
nvme.h block: Move NVMe constants to a separate header 2018-02-08 09:22:03 +08:00
qapi.h Drop superfluous includes of qapi-types.h and test-qapi-types.h 2018-02-09 05:05:11 +01:00
qdict.h block: Factor out qobject_input_visitor_new_flat_confused() 2018-06-15 14:49:44 +02:00
raw-aio.h file-posix: Make .bdrv_co_truncate asynchronous 2018-06-29 14:20:56 +02:00
snapshot.h Move include qemu/option.h from qemu-common.h to actual users 2018-02-09 13:52:16 +01:00
thread-pool.h Clean up decorations and whitespace around header guards 2016-07-12 16:20:46 +02:00
throttle-groups.h block: add throttle block filter driver 2017-09-06 10:12:02 +02:00
write-threshold.h Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00