From 71ab9dbebaa19a800b6fd64ea34432db900d570c Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Thu, 21 Jan 2021 20:13:35 -0800
Subject: [PATCH 1/2] libsnapshot: Do not attempt compression features in
 recovery.

Test: adb sideload
Change-Id: Ic69fc2f5c37a5d4fc0fcd0819ebf58e0249f7773
---
 fs_mgr/libsnapshot/snapshot.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index b55d9a0b1..34c684c8b 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -2130,10 +2130,6 @@ bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name)
 bool SnapshotManager::UnmapDmUserDevice(const std::string& snapshot_name) {
     auto& dm = DeviceMapper::Instance();
 
-    if (!EnsureSnapuserdConnected()) {
-        return false;
-    }
-
     auto dm_user_name = GetDmUserCowName(snapshot_name);
     if (dm.GetState(dm_user_name) == DmDeviceState::INVALID) {
         return true;
@@ -2144,6 +2140,9 @@ bool SnapshotManager::UnmapDmUserDevice(const std::string& snapshot_name) {
         return false;
     }
 
+    if (!EnsureSnapuserdConnected()) {
+        return false;
+    }
     if (!snapuserd_client_->WaitForDeviceDelete(dm_user_name)) {
         LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete";
         return false;
@@ -2585,8 +2584,9 @@ Return SnapshotManager::CreateUpdateSnapshots(const DeltaArchiveManifest& manife
     // these devices.
     AutoDeviceList created_devices;
 
-    bool use_compression =
-            IsCompressionEnabled() && manifest.dynamic_partition_metadata().vabc_enabled();
+    bool use_compression = IsCompressionEnabled() &&
+                           manifest.dynamic_partition_metadata().vabc_enabled() &&
+                           !device_->IsRecovery();
 
     PartitionCowCreator cow_creator{
             .target_metadata = target_metadata.get(),

From 5283ae4a86f003c029d020501473021c17f3b0ae Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Mon, 25 Jan 2021 13:52:16 -0800
Subject: [PATCH 2/2] libsnapshot: Only mount snapshots in MapAllSnapshots().

By accident, this was mounting partitions as well, which caused
conflicts in partial updates where some partitions don't have snapshots.

Test: update_device.py with partial OTA
Change-Id: I2db0e6269f0a02cbe8164fa2a72b887c352f56d8
---
 fs_mgr/libsnapshot/snapshot.cpp | 38 ++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 34c684c8b..932972576 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -2172,12 +2172,44 @@ bool SnapshotManager::MapAllSnapshots(const std::chrono::milliseconds& timeout_m
         return false;
     }
 
-    if (!UnmapAllSnapshots(lock.get())) {
+    std::vector<std::string> snapshots;
+    if (!ListSnapshots(lock.get(), &snapshots)) {
         return false;
     }
 
-    uint32_t slot = SlotNumberForSlotSuffix(device_->GetOtherSlotSuffix());
-    return MapAllPartitions(lock.get(), device_->GetSuperDevice(slot), slot, timeout_ms);
+    const auto& opener = device_->GetPartitionOpener();
+    auto slot_suffix = device_->GetOtherSlotSuffix();
+    auto slot_number = SlotNumberForSlotSuffix(slot_suffix);
+    auto super_device = device_->GetSuperDevice(slot_number);
+    auto metadata = android::fs_mgr::ReadMetadata(opener, super_device, slot_number);
+    if (!metadata) {
+        LOG(ERROR) << "MapAllSnapshots could not read dynamic partition metadata for device: "
+                   << super_device;
+        return false;
+    }
+
+    for (const auto& snapshot : snapshots) {
+        if (!UnmapPartitionWithSnapshot(lock.get(), snapshot)) {
+            LOG(ERROR) << "MapAllSnapshots could not unmap snapshot: " << snapshot;
+            return false;
+        }
+
+        CreateLogicalPartitionParams params = {
+                .block_device = super_device,
+                .metadata = metadata.get(),
+                .partition_name = snapshot,
+                .partition_opener = &opener,
+                .timeout_ms = timeout_ms,
+        };
+        if (!MapPartitionWithSnapshot(lock.get(), std::move(params), SnapshotContext::Mount,
+                                      nullptr)) {
+            LOG(ERROR) << "MapAllSnapshots failed to map: " << snapshot;
+            return false;
+        }
+    }
+
+    LOG(INFO) << "MapAllSnapshots succeeded.";
+    return true;
 }
 
 bool SnapshotManager::UnmapAllSnapshots() {