fs_mgr: set "partition.system.verified" when AVB is used in a A/B device

In a A/B device, system partition is mounted by kernel as root.
In vboot 1.0, the dm device name of system partition is "system" with
the following configuration in kernel command line:
    - dm="system none ro,0 1 android-verity /dev/sda34"

In AVB, the dm device name is switched to vroot as:
    - dm="1 vroot none ro 1,0 5201456 verity 1 ..."

When sending ioctl DM_TABLE_STATUS to query status, we should use "vroot" as the
dm device name for AVB. But still pass "system" for the callback function to set
property [partition.system.verified] instead of [partition.vroot.verified].

Bug: 36900078
Test: Use AVB to mount system in a A/B device, checks the property exists
      [partition.system.verified]
Test: Use vboot 1.0 to mount system in a A/B device, checks the property exists
      [partition.system.verified]
Test: Checks 'adb remount' will output warning message:
        - dm_verity is enabled on the system and vendor partitions.
        - Use "adb disable-verity" to disable verity.

Change-Id: Iaee7eb2b00b03729bc07fa24f1b449488716d2ea

1 files changed, 6 insertions, 1 deletions

diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index e3d4f870c..247768aeb 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -1367,7 +1367,8 @@ bool fs_mgr_update_verity_state(fs_mgr_verity_state_callback callback) {
 
         std::string mount_point;
         if (system_root && !strcmp(fstab->recs[i].mount_point, "/")) {
-            mount_point = "system";
+            // In AVB, the dm device name is vroot instead of system.
+            mount_point = fs_mgr_is_avb(&fstab->recs[i]) ? "vroot" : "system";
         } else {
             mount_point = basename(fstab->recs[i].mount_point);
         }
@@ -1386,6 +1387,10 @@ bool fs_mgr_update_verity_state(fs_mgr_verity_state_callback callback) {
 
         status = &buffer[io->data_start + sizeof(struct dm_target_spec)];
 
+        // To be consistent in vboot 1.0 and vboot 2.0 (AVB), change the mount_point
+        // back to 'system' for the callback. So it has property [partition.system.verified]
+        // instead of [partition.vroot.verified].
+        if (mount_point == "vroot") mount_point = "system";
         if (*status == 'C' || *status == 'V') {
             callback(&fstab->recs[i], mount_point.c_str(), mode, *status);
         }