diff options
| author | David Anderson <dvander@google.com> | 2021-01-19 22:13:37 -0800 |
|---|---|---|
| committer | David Anderson <dvander@google.com> | 2021-01-20 18:17:08 -0800 |
| commit | 86ba14be168cc50fb46bf130c53cfd9ee8f38a39 (patch) | |
| tree | 26a95f0c900ada44e87e77b5223af428df791f50 /debuggerd/handler/debuggerd_handler.cpp | |
| parent | 91c9f56d30a164fafc07db62b2016e8a40c77bcb (diff) | |
libsnapshot: Use a two-phase merge for VABC.
If a partition shrinks in an update, it must be merged before any other
partitions. Otherwise, a copy operation may source from the tail of the
shrunk partition, which could be overwritten by a merge operation in
another partition.
This patch adds a "MergePhase" indicator to the update status that is
valid only when the state is MERGING. Partitions that shrink are merged
first, and the phase will be FIRST_PHASE. Once ProcessUpdateState() has
determined that all first-phase snapshots are merged, it will switch to
SECOND_PHASE and remaining snapshots can start merging.
Otherwise, there is no change to the merge algorithm. The phase split is
an implementation detail and not exposed to update_engine.
Bug: 177935716
Test: vts_libsnapshot_test
Change-Id: I06043f8e3b81bdecefb6a4b5944a97b7086eeb49
Diffstat (limited to 'debuggerd/handler/debuggerd_handler.cpp')
0 files changed, 0 insertions, 0 deletions