Merge "libsnapshot: Check for valid snapshots based on current slot" into main
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 86ff5f7..51389a0 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -729,6 +729,14 @@
         LOG(ERROR) << "Failed to remove status file " << file_path << ": " << error;
         return false;
     }
+
+    // This path may never exist. If it is present, then it's a stale
+    // snapshot status file. Just remove the file and log the message.
+    const std::string tmp_path = file_path + ".tmp";
+    if (!android::base::RemoveFileIfExists(tmp_path, &error)) {
+        LOG(ERROR) << "Failed to remove stale snapshot file " << tmp_path;
+    }
+
     return true;
 }
 
@@ -754,10 +762,10 @@
         return false;
     }
 
-    auto other_suffix = device_->GetOtherSlotSuffix();
+    auto current_slot_suffix = device_->GetSlotSuffix();
 
     for (const auto& snapshot : snapshots) {
-        if (android::base::EndsWith(snapshot, other_suffix)) {
+        if (!android::base::EndsWith(snapshot, current_slot_suffix)) {
             // Allow the merge to continue, but log this unexpected case.
             LOG(ERROR) << "Unexpected snapshot found during merge: " << snapshot;
             continue;
@@ -1123,7 +1131,7 @@
         return MergeResult(UpdateState::MergeFailed, MergeFailureCode::ListSnapshots);
     }
 
-    auto other_suffix = device_->GetOtherSlotSuffix();
+    auto current_slot_suffix = device_->GetSlotSuffix();
 
     bool cancelled = false;
     bool merging = false;
@@ -1131,9 +1139,9 @@
     bool wrong_phase = false;
     MergeFailureCode failure_code = MergeFailureCode::Ok;
     for (const auto& snapshot : snapshots) {
-        if (android::base::EndsWith(snapshot, other_suffix)) {
+        if (!android::base::EndsWith(snapshot, current_slot_suffix)) {
             // This will have triggered an error message in InitiateMerge already.
-            LOG(INFO) << "Skipping merge validation of unexpected snapshot: " << snapshot;
+            LOG(ERROR) << "Skipping merge validation of unexpected snapshot: " << snapshot;
             continue;
         }
 
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 0a85489..3b6d26a 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -685,6 +685,17 @@
     }
     ASSERT_TRUE(sm->InitiateMerge());
 
+    // Create stale files in snapshot directory. Merge should skip these files
+    // as the suffix doesn't match the current slot.
+    auto tmp_path = test_device->GetMetadataDir() + "/snapshots/test_partition_b.tmp";
+    auto other_slot = test_device->GetMetadataDir() + "/snapshots/test_partition_a";
+
+    unique_fd fd(open(tmp_path.c_str(), O_RDWR | O_CLOEXEC | O_CREAT, 0644));
+    ASSERT_GE(fd, 0);
+
+    fd.reset(open(other_slot.c_str(), O_RDWR | O_CLOEXEC | O_CREAT, 0644));
+    ASSERT_GE(fd, 0);
+
     // The device should have been switched to a snapshot-merge target.
     DeviceMapper::TargetInfo target;
     ASSERT_TRUE(sm->IsSnapshotDevice("test_partition_b", &target));
@@ -700,13 +711,23 @@
     ASSERT_EQ(sm->ProcessUpdateState(), UpdateState::MergeCompleted);
     ASSERT_EQ(sm->GetUpdateState(), UpdateState::None);
 
+    // Make sure that snapshot states are cleared and all stale files
+    // are deleted
+    {
+        ASSERT_TRUE(AcquireLock());
+        auto local_lock = std::move(lock_);
+        std::vector<std::string> snapshots;
+        ASSERT_TRUE(sm->ListSnapshots(local_lock.get(), &snapshots));
+        ASSERT_TRUE(snapshots.empty());
+    }
+
     // The device should no longer be a snapshot or snapshot-merge.
     ASSERT_FALSE(sm->IsSnapshotDevice("test_partition_b"));
 
     // Test that we can read back the string we wrote to the snapshot. Note
     // that the base device is gone now. |snap_device| contains the correct
     // partition.
-    unique_fd fd(open("/dev/block/mapper/test_partition_b", O_RDONLY | O_CLOEXEC));
+    fd.reset(open("/dev/block/mapper/test_partition_b", O_RDONLY | O_CLOEXEC));
     ASSERT_GE(fd, 0);
 
     std::string buffer(test_string.size(), '\0');