Merge "liblp: Add an attribute to indicate that a partition has been updated."
am: 74a6f4cf57

Change-Id: I0f3038c4537e38ce4d09c030bec1079dd941d973
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 77c9c28..8a74745 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -232,7 +232,7 @@
     memset(&header_, 0, sizeof(header_));
     header_.magic = LP_METADATA_HEADER_MAGIC;
     header_.major_version = LP_METADATA_MAJOR_VERSION;
-    header_.minor_version = LP_METADATA_MINOR_VERSION;
+    header_.minor_version = LP_METADATA_MINOR_VERSION_MIN;
     header_.header_size = sizeof(header_);
     header_.partitions.entry_size = sizeof(LpMetadataPartition);
     header_.extents.entry_size = sizeof(LpMetadataExtent);
@@ -796,6 +796,11 @@
             return nullptr;
         }
 
+        if (partition->attributes() & LP_PARTITION_ATTR_UPDATED) {
+            static const uint16_t kMinVersion = LP_METADATA_VERSION_FOR_UPDATED_ATTR;
+            metadata->header.minor_version = std::max(metadata->header.minor_version, kMinVersion);
+        }
+
         strncpy(part.name, partition->name().c_str(), sizeof(part.name));
         part.first_extent_index = static_cast<uint32_t>(metadata->extents.size());
         part.num_extents = static_cast<uint32_t>(partition->extents().size());
diff --git a/fs_mgr/liblp/builder_test.cpp b/fs_mgr/liblp/builder_test.cpp
index dde6d07..c5b4047 100644
--- a/fs_mgr/liblp/builder_test.cpp
+++ b/fs_mgr/liblp/builder_test.cpp
@@ -349,7 +349,7 @@
     const LpMetadataHeader& header = exported->header;
     EXPECT_EQ(header.magic, LP_METADATA_HEADER_MAGIC);
     EXPECT_EQ(header.major_version, LP_METADATA_MAJOR_VERSION);
-    EXPECT_EQ(header.minor_version, LP_METADATA_MINOR_VERSION);
+    EXPECT_EQ(header.minor_version, LP_METADATA_MINOR_VERSION_MIN);
 
     ASSERT_EQ(exported->partitions.size(), 2);
     ASSERT_EQ(exported->extents.size(), 3);
diff --git a/fs_mgr/liblp/include/liblp/metadata_format.h b/fs_mgr/liblp/include/liblp/metadata_format.h
index 8934aaf..6e928b4 100644
--- a/fs_mgr/liblp/include/liblp/metadata_format.h
+++ b/fs_mgr/liblp/include/liblp/metadata_format.h
@@ -39,7 +39,11 @@
 
 /* Current metadata version. */
 #define LP_METADATA_MAJOR_VERSION 10
-#define LP_METADATA_MINOR_VERSION 0
+#define LP_METADATA_MINOR_VERSION_MIN 0
+#define LP_METADATA_MINOR_VERSION_MAX 1
+
+/* Metadata version needed to use the UPDATED partition attribute. */
+#define LP_METADATA_VERSION_FOR_UPDATED_ATTR 1
 
 /* Attributes for the LpMetadataPartition::attributes field.
  *
@@ -58,8 +62,20 @@
  */
 #define LP_PARTITION_ATTR_SLOT_SUFFIXED (1 << 1)
 
-/* Mask that defines all valid attributes. */
-#define LP_PARTITION_ATTRIBUTE_MASK (LP_PARTITION_ATTR_READONLY | LP_PARTITION_ATTR_SLOT_SUFFIXED)
+/* This flag is applied automatically when using MetadataBuilder::NewForUpdate.
+ * It signals that the partition was created (or modified) for a snapshot-based
+ * update. If this flag is not present, the partition was likely flashed via
+ * fastboot.
+ */
+#define LP_PARTITION_ATTR_UPDATED (1 << 2)
+
+/* Mask that defines all valid attributes. When changing this, make sure to
+ * update ParseMetadata().
+ */
+#define LP_PARTITION_ATTRIBUTE_MASK_V0 \
+    (LP_PARTITION_ATTR_READONLY | LP_PARTITION_ATTR_SLOT_SUFFIXED)
+#define LP_PARTITION_ATTRIBUTE_MASK_V1 (LP_PARTITION_ATTRIBUTE_MASK_V0 | LP_PARTITION_ATTR_UPDATED)
+#define LP_PARTITION_ATTRIBUTE_MASK LP_PARTITION_ATTRIBUTE_MASK_V1
 
 /* Default name of the physical partition that holds logical partition entries.
  * The layout of this partition will look like:
diff --git a/fs_mgr/liblp/io_test.cpp b/fs_mgr/liblp/io_test.cpp
index df89e9c..22f6746 100644
--- a/fs_mgr/liblp/io_test.cpp
+++ b/fs_mgr/liblp/io_test.cpp
@@ -713,3 +713,32 @@
     ASSERT_EQ(updated->block_devices.size(), static_cast<size_t>(1));
     EXPECT_EQ(GetBlockDevicePartitionName(updated->block_devices[0]), "super");
 }
+
+TEST_F(LiblpTest, UpdateVirtualAB) {
+    ON_CALL(*GetMockedPropertyFetcher(), GetBoolProperty("ro.virtual_ab.enabled", _))
+            .WillByDefault(Return(true));
+
+    unique_fd fd = CreateFlashedDisk();
+    ASSERT_GE(fd, 0);
+
+    DefaultPartitionOpener opener(fd);
+    auto builder = MetadataBuilder::NewForUpdate(opener, "super", 0, 1);
+    ASSERT_NE(builder, nullptr);
+    auto updated = builder->Export();
+    ASSERT_NE(updated, nullptr);
+    ASSERT_TRUE(UpdatePartitionTable(opener, "super", *updated.get(), 1));
+
+    // Validate old slot.
+    auto metadata = ReadMetadata(opener, "super", 0);
+    ASSERT_NE(metadata, nullptr);
+    ASSERT_EQ(metadata->header.minor_version, 0);
+    ASSERT_GE(metadata->partitions.size(), 1);
+    ASSERT_EQ(metadata->partitions[0].attributes & LP_PARTITION_ATTR_UPDATED, 0);
+
+    // Validate new slot.
+    metadata = ReadMetadata(opener, "super", 1);
+    ASSERT_NE(metadata, nullptr);
+    ASSERT_EQ(metadata->header.minor_version, 1);
+    ASSERT_GE(metadata->partitions.size(), 1);
+    ASSERT_NE(metadata->partitions[0].attributes & LP_PARTITION_ATTR_UPDATED, 0);
+}
diff --git a/fs_mgr/liblp/reader.cpp b/fs_mgr/liblp/reader.cpp
index 8dbe955..aecf685 100644
--- a/fs_mgr/liblp/reader.cpp
+++ b/fs_mgr/liblp/reader.cpp
@@ -181,7 +181,7 @@
     }
     // Check that the version is compatible.
     if (header.major_version != LP_METADATA_MAJOR_VERSION ||
-        header.minor_version > LP_METADATA_MINOR_VERSION) {
+        header.minor_version > LP_METADATA_MINOR_VERSION_MAX) {
         LERROR << "Logical partition metadata has incompatible version.";
         return false;
     }
@@ -245,6 +245,13 @@
         return nullptr;
     }
 
+    uint32_t valid_attributes = 0;
+    if (metadata->header.minor_version >= LP_METADATA_VERSION_FOR_UPDATED_ATTR) {
+        valid_attributes = LP_PARTITION_ATTRIBUTE_MASK_V1;
+    } else {
+        valid_attributes = LP_PARTITION_ATTRIBUTE_MASK_V0;
+    }
+
     // ValidateTableSize ensured that |cursor| is valid for the number of
     // entries in the table.
     uint8_t* cursor = buffer.get() + header.partitions.offset;
@@ -253,7 +260,7 @@
         memcpy(&partition, cursor, sizeof(partition));
         cursor += header.partitions.entry_size;
 
-        if (partition.attributes & ~LP_PARTITION_ATTRIBUTE_MASK) {
+        if (partition.attributes & ~valid_attributes) {
             LERROR << "Logical partition has invalid attribute set.";
             return nullptr;
         }
diff --git a/fs_mgr/liblp/utility.cpp b/fs_mgr/liblp/utility.cpp
index 17f05aa..afcce8f 100644
--- a/fs_mgr/liblp/utility.cpp
+++ b/fs_mgr/liblp/utility.cpp
@@ -269,6 +269,7 @@
                   << "; this partition should not belong to this group!";
             continue;  // not adding to new_partition_ptrs
         }
+        partition.attributes |= LP_PARTITION_ATTR_UPDATED;
         partition.group_index = std::distance(new_group_ptrs.begin(), it);
         new_partition_ptrs.push_back(&partition);
     }