commit 2a3b4a22eb6925326e439f820fa91a3976afac10
author Alessio Balsini <balsini@google.com> Mon Nov 25 16:46:51 2019 +0000
committer Yifan Hong <elsk@google.com> Wed Dec 04 04:02:20 2019 +0000
tree 895d9d338377f0b8700c8d8352c16f397f9a3f85
parent 36e2289b82af548128191e7e8a0d94f0ce6bbe30

Skip identical SOURCE_COPY operations

When Virtual A/B devices are updated, SOURCE_COPY operations that are
copying data from source to destination at the same locations:
- are useless;
- introduce an overhead for overwritingin identical data;
- increase the COW device size when using dm-snapshot.
This patch analyzes SOURCE_COPY operations and skips them if applied to
Virtual A/B devices and source and destination addresses are identical.

Bug: 141207436
Test: DynamicPartitionControlAndroidTest:ShouldSkipOperationTest
Depends-On: I146aeba1c8ede35f21cfef8e21d4af62274bda84
Change-Id: Ifec33abaf81b1d4cbd61533293735de68578c9c4
Signed-off-by: Alessio Balsini <balsini@google.com>