libsnapshot: Propagate the compression bit across state changes.
This bit was getting lost because InitiateMerge() did not save the
compression bit when overwriting the update state.
Bug: N/A
Test: vts_libsnapshot_test
Test: reboot during merge phase of VABC OTA
Change-Id: I1a2219b501088de352a9c31d4b8b1a3f72d0e159
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index f0646fc..6570044 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -676,6 +676,8 @@
}
}
+ bool compression_enabled = false;
+
uint64_t total_cow_file_size = 0;
DmTargetSnapshot::Status initial_target_values = {};
for (const auto& snapshot : snapshots) {
@@ -692,6 +694,8 @@
return false;
}
total_cow_file_size += snapshot_status.cow_file_size();
+
+ compression_enabled |= snapshot_status.compression_enabled();
}
if (cow_file_size) {
@@ -703,6 +707,7 @@
initial_status.set_sectors_allocated(initial_target_values.sectors_allocated);
initial_status.set_total_sectors(initial_target_values.total_sectors);
initial_status.set_metadata_sectors(initial_target_values.metadata_sectors);
+ initial_status.set_compression_enabled(compression_enabled);
// Point of no return - mark that we're starting a merge. From now on every
// snapshot must be a merge target.
@@ -2285,9 +2290,15 @@
}
bool SnapshotManager::WriteUpdateState(LockedFile* lock, UpdateState state) {
- SnapshotUpdateStatus status = {};
+ SnapshotUpdateStatus status;
status.set_state(state);
- status.set_compression_enabled(IsCompressionEnabled());
+
+ // If we're transitioning between two valid states (eg, we're not beginning
+ // or ending an OTA), then make sure to propagate the compression bit.
+ if (!(state == UpdateState::Initiated || state == UpdateState::None)) {
+ SnapshotUpdateStatus old_status = ReadSnapshotUpdateStatus(lock);
+ status.set_compression_enabled(old_status.compression_enabled());
+ }
return WriteSnapshotUpdateStatus(lock, status);
}
@@ -2477,6 +2488,12 @@
auto lock = LockExclusive();
if (!lock) return Return::Error();
+ auto update_state = ReadUpdateState(lock.get());
+ if (update_state != UpdateState::Initiated) {
+ LOG(ERROR) << "Cannot create update snapshots in state " << update_state;
+ return Return::Error();
+ }
+
// TODO(b/134949511): remove this check. Right now, with overlayfs mounted, the scratch
// partition takes up a big chunk of space in super, causing COW images to be created on
// retrofit Virtual A/B devices.
@@ -2571,6 +2588,14 @@
return Return::Error();
}
+ SnapshotUpdateStatus status = {};
+ status.set_state(update_state);
+ status.set_compression_enabled(cow_creator.compression_enabled);
+ if (!WriteSnapshotUpdateStatus(lock.get(), status)) {
+ LOG(ERROR) << "Unable to write new update state";
+ return Return::Error();
+ }
+
created_devices.Release();
LOG(INFO) << "Successfully created all snapshots for target slot " << target_suffix;
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index ab224d2..80a6074 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -1106,6 +1106,7 @@
// Initiate the merge and wait for it to be completed.
ASSERT_TRUE(init->InitiateMerge());
+ ASSERT_EQ(init->IsSnapuserdRequired(), IsCompressionEnabled());
ASSERT_EQ(UpdateState::MergeCompleted, init->ProcessUpdateState());
// Check that the target partitions have the same content after the merge.
@@ -1130,6 +1131,7 @@
SetSize(sys_, 4_MiB); // grows
SetSize(vnd_, 2_MiB); // shrinks
// prd_b is unchanged
+ ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
ASSERT_EQ(4_MiB, GetSnapshotSize("sys_b").value_or(0));
}
@@ -1139,6 +1141,7 @@
TEST_F(SnapshotUpdateTest, CowPartitionDoNotTakeOldPartitions) {
SetSize(sys_, 2_MiB); // shrinks
// vnd_b and prd_b are unchanged.
+ ASSERT_TRUE(sm->BeginUpdate());
ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
auto tgt = MetadataBuilder::New(*opener_, "super", 1);
