commit 5ff75452ff71f65e4c01c9156b02080976630e46
author David Anderson <dvander@google.com> Wed Aug 15 14:42:07 2018 -0700
committer David Anderson <dvander@google.com> Wed Aug 22 10:03:09 2018 -0700
tree f78706ed465a76a360c9a5cf35a73b81dca9ee42
parent 960f6758dcdfe85b2cdedb4222ce8f15ac1c79e8

liblp: Always copy geometry to LpMetadata.

Callers of ParseMetadata must manually copy geometry to the final
LpMetadata structure, which is error-prone. Instead, force callers to
pass geometry to ParseMetadata to ensure it is always propagated.

Bug: N/A
Test: liblp_test gtest

Change-Id: I5b24b9d94ab1857db600c40bf6d3c9d8aaa47368

fs_mgr/liblp/images.cpp

diff --git a/fs_mgr/liblp/images.cpp b/fs_mgr/liblp/images.cpp
index a361a5d..98d57f6 100644
--- a/fs_mgr/liblp/images.cpp
+++ b/fs_mgr/liblp/images.cpp
@@ -38,12 +38,7 @@
         PERROR << __PRETTY_FUNCTION__ << "lseek failed: offset " << LP_METADATA_GEOMETRY_SIZE;
         return nullptr;
     }
-    std::unique_ptr<LpMetadata> metadata = ParseMetadata(fd);
-    if (!metadata) {
-        return nullptr;
-    }
-    metadata->geometry = geometry;
-    return metadata;
+    return ParseMetadata(geometry, fd);
 }
 
 std::unique_ptr<LpMetadata> ReadFromImageFile(const char* file) {

fs_mgr/liblp/reader.cpp

diff --git a/fs_mgr/liblp/reader.cpp b/fs_mgr/liblp/reader.cpp
index 117da59..b7074d8 100644
--- a/fs_mgr/liblp/reader.cpp
+++ b/fs_mgr/liblp/reader.cpp
@@ -171,7 +171,7 @@
 
 // Parse and validate all metadata at the current position in the given file
 // descriptor.
-std::unique_ptr<LpMetadata> ParseMetadata(int fd) {
+std::unique_ptr<LpMetadata> ParseMetadata(const LpMetadataGeometry& geometry, int fd) {
     // First read and validate the header.
     std::unique_ptr<LpMetadata> metadata = std::make_unique<LpMetadata>();
     if (!android::base::ReadFully(fd, &metadata->header, sizeof(metadata->header))) {
@@ -181,6 +181,7 @@
     if (!ValidateMetadataHeader(metadata->header)) {
         return nullptr;
     }
+    metadata->geometry = geometry;
 
     LpMetadataHeader& header = metadata->header;
 
@@ -231,7 +232,6 @@
 
         metadata->extents.push_back(extent);
     }
-
     return metadata;
 }
 
@@ -242,7 +242,7 @@
         PERROR << __PRETTY_FUNCTION__ << "lseek failed: offset " << offset;
         return nullptr;
     }
-    return ParseMetadata(fd);
+    return ParseMetadata(geometry, fd);
 }
 
 std::unique_ptr<LpMetadata> ReadBackupMetadata(int fd, const LpMetadataGeometry& geometry,
@@ -252,7 +252,7 @@
         PERROR << __PRETTY_FUNCTION__ << "lseek failed: offset " << offset;
         return nullptr;
     }
-    return ParseMetadata(fd);
+    return ParseMetadata(geometry, fd);
 }
 
 std::unique_ptr<LpMetadata> ReadMetadata(int fd, uint32_t slot_number) {
@@ -268,13 +268,10 @@
 
     // Read the priamry copy, and if that fails, try the backup.
     std::unique_ptr<LpMetadata> metadata = ReadPrimaryMetadata(fd, geometry, slot_number);
-    if (!metadata) {
-        metadata = ReadBackupMetadata(fd, geometry, slot_number);
-    }
     if (metadata) {
-        metadata->geometry = geometry;
+        return metadata;
     }
-    return metadata;
+    return ReadBackupMetadata(fd, geometry, slot_number);
 }
 
 std::unique_ptr<LpMetadata> ReadMetadata(const char* block_device, uint32_t slot_number) {

fs_mgr/liblp/reader.h

diff --git a/fs_mgr/liblp/reader.h b/fs_mgr/liblp/reader.h
index 843b2f2..ae0875b 100644
--- a/fs_mgr/liblp/reader.h
+++ b/fs_mgr/liblp/reader.h
@@ -30,7 +30,7 @@
 
 // Helper functions for manually reading geometry and metadata.
 bool ReadLogicalPartitionGeometry(int fd, LpMetadataGeometry* geometry);
-std::unique_ptr<LpMetadata> ParseMetadata(int fd);
+std::unique_ptr<LpMetadata> ParseMetadata(const LpMetadataGeometry& geometry, int fd);
 
 // These functions assume a valid geometry and slot number.
 std::unique_ptr<LpMetadata> ReadPrimaryMetadata(int fd, const LpMetadataGeometry& geometry,