From d4db07e9bbf7c606d20e88c1d8d4f36697718ce7 Mon Sep 17 00:00:00 2001
From: Yifan Hong <elsk@google.com>
Date: Thu, 18 Oct 2018 17:46:27 -0700
Subject: Support updateable groups.

Adds updateable group support to OTA.

* DeltaPerformer combines partition sizes with
  dynamic_partition_metadata to
  BootControlInterface::PartitionMetadata.

* BootControlAndroid::InitPartitionMetadata:
    * Copy all groups / partitions from source metadata slot
    * Remove all groups / partitions mentioned in the manifest (of the
    target slot)
    * Re-add all groups / partitions mentioned in the manifest.

* BootControlAndroid::InitPartitionMetadata can check
  the incoming PartitionMetadata to see if a partition is dynamic
  or not. The guessing logic is completely removed.

* Because a partition is removed then re-added, there is no need
  for preserving the entry with size 0 to indicate that a partition
  is removed. When update_engine sees a partition in a group "foo" on
  the device, but manifest contains group "foo" without the partition,
  it removes the partition.

* Hence, Removing a partition does NOT require keeping the entry (i.e.
  RemovePartition is used instead of ShrinkPartition(0) ). This makes
  retrofitting dynamic partitions on older devices easier.

The following is now allowed:
- Adding / removing / resizing partitions
- Adding / resizing groups

It is not allowed to remove a group, but a group can always be resized
to zero to deprecate it.

Test: update_engine_unittests
Bug: 117182932

Change-Id: I39d77f1d1d1fc52fc245f3de699635e6a429015e
---
 common/boot_control_interface.h | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

(limited to 'common/boot_control_interface.h')

diff --git a/common/boot_control_interface.h b/common/boot_control_interface.h
index 1b76939a..43517ce2 100644
--- a/common/boot_control_interface.h
+++ b/common/boot_control_interface.h
@@ -20,6 +20,7 @@
 #include <climits>
 #include <map>
 #include <string>
+#include <vector>
 
 #include <base/callback.h>
 #include <base/macros.h>
@@ -33,7 +34,19 @@ namespace chromeos_update_engine {
 class BootControlInterface {
  public:
   using Slot = unsigned int;
-  using PartitionMetadata = std::map<std::string, uint64_t>;
+
+  struct PartitionMetadata {
+    struct Partition {
+      std::string name;
+      uint64_t size;
+    };
+    struct Group {
+      std::string name;
+      uint64_t size;
+      std::vector<Partition> partitions;
+    };
+    std::vector<Group> groups;
+  };
 
   static const Slot kInvalidSlot = UINT_MAX;
 
@@ -80,10 +93,11 @@ class BootControlInterface {
   virtual bool MarkBootSuccessfulAsync(base::Callback<void(bool)> callback) = 0;
 
   // Initialize metadata of underlying partitions for a given |slot|.
-  // Ensure that partitions at the specified |slot| has a given size, as
-  // specified by |partition_metadata|. |partition_metadata| has the format:
-  // {"vendor": 524288000, "system": 2097152000, ...}; values must be
-  // aligned to the logical block size of the super partition.
+  // Ensure that all updateable groups with the suffix GetSuffix(|slot|) exactly
+  // matches the layout specified in |partition_metadata|. Ensure that
+  // partitions at the specified |slot| has a given size and updateable group,
+  // as specified by |partition_metadata|. Sizes must be aligned to the logical
+  // block size of the super partition.
   virtual bool InitPartitionMetadata(
       Slot slot, const PartitionMetadata& partition_metadata) = 0;
 
-- 
cgit v1.2.3