From 67cd9f09ca2dcc31c1cd2772bc66ac920ea50a29 Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Wed, 8 Jul 2020 13:46:50 -0700
Subject: [PATCH] init: Initiate other misc devices from BlockDevInitializer.

This allows init to easily ensure misc devices other than device-mapper
are present.

Bug: 154536437
Test: manual test
Change-Id: I49495684edee322f9787ce7ab7f79d0e8060171d
---
 init/block_dev_initializer.cpp | 16 ++++++++++++----
 init/block_dev_initializer.h   |  3 +++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/init/block_dev_initializer.cpp b/init/block_dev_initializer.cpp
index b423f864e..8db9793f5 100644
--- a/init/block_dev_initializer.cpp
+++ b/init/block_dev_initializer.cpp
@@ -37,7 +37,15 @@ BlockDevInitializer::BlockDevInitializer() : uevent_listener_(16 * 1024 * 1024)
 }
 
 bool BlockDevInitializer::InitDeviceMapper() {
-    const std::string dm_path = "/devices/virtual/misc/device-mapper";
+    return InitMiscDevice("device-mapper");
+}
+
+bool BlockDevInitializer::InitDmUser() {
+    return InitMiscDevice("dm-user");
+}
+
+bool BlockDevInitializer::InitMiscDevice(const std::string& name) {
+    const std::string dm_path = "/devices/virtual/misc/" + name;
     bool found = false;
     auto dm_callback = [this, &dm_path, &found](const Uevent& uevent) {
         if (uevent.path == dm_path) {
@@ -49,13 +57,13 @@ bool BlockDevInitializer::InitDeviceMapper() {
     };
     uevent_listener_.RegenerateUeventsForPath("/sys" + dm_path, dm_callback);
     if (!found) {
-        LOG(INFO) << "device-mapper device not found in /sys, waiting for its uevent";
+        LOG(INFO) << name << " device not found in /sys, waiting for its uevent";
         Timer t;
         uevent_listener_.Poll(dm_callback, 10s);
-        LOG(INFO) << "Wait for device-mapper returned after " << t;
+        LOG(INFO) << "Wait for " << name << " returned after " << t;
     }
     if (!found) {
-        LOG(ERROR) << "device-mapper device not found after polling timeout";
+        LOG(ERROR) << name << " device not found after polling timeout";
         return false;
     }
     return true;
diff --git a/init/block_dev_initializer.h b/init/block_dev_initializer.h
index 0d4c6e9fc..b8dd3f172 100644
--- a/init/block_dev_initializer.h
+++ b/init/block_dev_initializer.h
@@ -27,12 +27,15 @@ class BlockDevInitializer final {
     BlockDevInitializer();
 
     bool InitDeviceMapper();
+    bool InitDmUser();
     bool InitDevices(std::set<std::string> devices);
     bool InitDmDevice(const std::string& device);
 
   private:
     ListenerAction HandleUevent(const Uevent& uevent, std::set<std::string>* devices);
 
+    bool InitMiscDevice(const std::string& name);
+
     std::unique_ptr<DeviceHandler> device_handler_;
     UeventListener uevent_listener_;
 };