From 356386246db1fe1fd60c304a82a9a7b0c14476dd Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Mon, 27 Aug 2018 14:02:47 -0700
Subject: [PATCH] fs_mgr: Better error messages in fs_mgr_update_verity_state.

With verity disabled, fs_mgr_update_verity_state spews some confusing
error messages from device-mapper. This change checks whether a device
exists and logs an explicit error.

Bug: N/A
Test: AVB properties are set correctly on AVB device
      Messages are logged correctly with AVB disabled

Change-Id: If490c18cfec2d63ad784972c13ceef63d9aa3e4c
---
 fs_mgr/fs_mgr.cpp               |  9 +++++++--
 fs_mgr/libdm/dm.cpp             | 13 ++++++++++---
 fs_mgr/libdm/include/libdm/dm.h |  2 +-
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 99f2df811..b0c55e339 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -79,7 +79,8 @@
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
-using DeviceMapper = android::dm::DeviceMapper;
+using android::dm::DeviceMapper;
+using android::dm::DmDeviceState;
 
 // record fs stat
 enum FsStatFlags {
@@ -1400,8 +1401,12 @@ bool fs_mgr_update_verity_state(std::function<fs_mgr_verity_state_callback> call
             mount_point = basename(fstab->recs[i].mount_point);
         }
 
-        const char* status = nullptr;
+        if (dm.GetState(mount_point) == DmDeviceState::INVALID) {
+            PERROR << "Could not find verity device for mount point: " << mount_point;
+            continue;
+        }
 
+        const char* status = nullptr;
         std::vector<DeviceMapper::TargetInfo> table;
         if (!dm.GetTableStatus(mount_point, &table) || table.empty() || table[0].data.empty()) {
             if (fstab->recs[i].fs_mgr_flags & MF_VERIFYATBOOT) {
diff --git a/fs_mgr/libdm/dm.cpp b/fs_mgr/libdm/dm.cpp
index 8bcbec2c9..2b526f65a 100644
--- a/fs_mgr/libdm/dm.cpp
+++ b/fs_mgr/libdm/dm.cpp
@@ -98,9 +98,16 @@ const std::unique_ptr<DmTable> DeviceMapper::table(const std::string& /* name */
     return nullptr;
 }
 
-DmDeviceState DeviceMapper::state(const std::string& /* name */) const {
-    // TODO(b/110035986): Return the state, as read from the kernel instead
-    return DmDeviceState::INVALID;
+DmDeviceState DeviceMapper::GetState(const std::string& name) const {
+    struct dm_ioctl io;
+    InitIo(&io, name);
+    if (ioctl(fd_, DM_DEV_STATUS, &io) < 0) {
+        return DmDeviceState::INVALID;
+    }
+    if ((io.flags & DM_ACTIVE_PRESENT_FLAG) && !(io.flags & DM_SUSPEND_FLAG)) {
+        return DmDeviceState::ACTIVE;
+    }
+    return DmDeviceState::SUSPENDED;
 }
 
 bool DeviceMapper::CreateDevice(const std::string& name, const DmTable& table) {
diff --git a/fs_mgr/libdm/include/libdm/dm.h b/fs_mgr/libdm/include/libdm/dm.h
index 9b61ddcec..91f8bb422 100644
--- a/fs_mgr/libdm/include/libdm/dm.h
+++ b/fs_mgr/libdm/include/libdm/dm.h
@@ -79,7 +79,7 @@ class DeviceMapper final {
     // Returns the current state of the underlying device mapper device
     // with given name.
     // One of INVALID, SUSPENDED or ACTIVE.
-    DmDeviceState state(const std::string& name) const;
+    DmDeviceState GetState(const std::string& name) const;
 
     // Creates a device, loads the given table, and activates it. If the device
     // is not able to be activated, it is destroyed, and false is returned.