Invoke the transaction drivers' .clean() methods only after all
.commit() or .abort() handlers are done.
This makes it easier to have nested transactions where the top-level
transactions pass objects to lower transactions that the latter can
still use throughout their commit/abort phases, while the top-level
transaction keeps a reference that is released in its .clean() method.
(Before this commit, that is also possible, but the top-level
transaction would need to take care to invoke tran_add() before the
lower-level transaction does. This commit makes the ordering
irrelevant, which is just a bit nicer.)
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20211111120829.81329-8-hreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211115145409.176785-8-kwolf@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Add simple transaction API to use in further update of block graph
operations.
Supposed usage is:
- "prepare" is main function of the action and it should make the main
effect of the action to be visible for the following actions, keeping
possibility of roll-back, saving necessary things in action state,
which is prepended to the action list (to do that, prepare func
should call tran_add()). So, driver struct doesn't include "prepare"
field, as it is supposed to be called directly.
- commit/rollback is supposed to be called for the list of action
states, to commit/rollback all the actions in reverse order
- When possible "commit" should not make visible effect for other
actions, which make possible transparent logical interaction between
actions.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-9-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
