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libsnapshot: Propagate the compression bit across state changes.

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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
This commit is contained in:
David Anderson 2021-01-14 23:27:58 -08:00
parent cf41cb7a8c
commit 116be4e2bd
2 changed files with 30 additions and 2 deletions
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29
fs_mgr/libsnapshot/snapshot.cpp
View file

@ -676,6 +676,8 @@ bool SnapshotManager::InitiateMerge(uint64_t* cow_file_size) {
}
}
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 @@ bool SnapshotManager::InitiateMerge(uint64_t* cow_file_size) {
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 @@ bool SnapshotManager::InitiateMerge(uint64_t* cow_file_size) {
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 @@ SnapshotUpdateStatus SnapshotManager::ReadSnapshotUpdateStatus(LockedFile* lock)
}
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 @@ Return SnapshotManager::CreateUpdateSnapshots(const DeltaArchiveManifest& manife
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 SnapshotManager::CreateUpdateSnapshots(const DeltaArchiveManifest& manife
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;

3
fs_mgr/libsnapshot/snapshot_test.cpp
View file

@ -1106,6 +1106,7 @@ TEST_F(SnapshotUpdateTest, FullUpdateFlow) {
// 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 @@ TEST_F(SnapshotUpdateTest, SnapshotOldPartitions) {
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, SnapshotOldPartitions) {
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);