From 2ffc31b090dc2af7d833a4eea9e31337e3308648 Mon Sep 17 00:00:00 2001
From: David Anderson <dvander@google.com>
Date: Mon, 23 Mar 2020 23:43:45 -0700
Subject: [PATCH] fastbootd: Unmount /cache before flashing.

Bug: 150112538
Test: fastboot flash cache on non-A/B device
Change-Id: I8a86bc4d12e4b3be020bbe47e02262a5aaa913a7
---
 fastboot/device/commands.cpp        |  1 +
 fastboot/device/fastboot_device.cpp | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/fastboot/device/commands.cpp b/fastboot/device/commands.cpp
index ca120c62a..b8eee4ac1 100644
--- a/fastboot/device/commands.cpp
+++ b/fastboot/device/commands.cpp
@@ -31,6 +31,7 @@
 #include <cutils/android_reboot.h>
 #include <ext4_utils/wipe.h>
 #include <fs_mgr.h>
+#include <fs_mgr/roots.h>
 #include <libgsi/libgsi.h>
 #include <liblp/builder.h>
 #include <liblp/liblp.h>
diff --git a/fastboot/device/fastboot_device.cpp b/fastboot/device/fastboot_device.cpp
index 31fc35937..bb085c536 100644
--- a/fastboot/device/fastboot_device.cpp
+++ b/fastboot/device/fastboot_device.cpp
@@ -16,18 +16,22 @@
 
 #include "fastboot_device.h"
 
+#include <algorithm>
+
 #include <android-base/logging.h>
 #include <android-base/strings.h>
 #include <android/hardware/boot/1.0/IBootControl.h>
 #include <android/hardware/fastboot/1.0/IFastboot.h>
+#include <fs_mgr.h>
+#include <fs_mgr/roots.h>
 #include <healthhalutils/HealthHalUtils.h>
 
-#include <algorithm>
-
 #include "constants.h"
 #include "flashing.h"
 #include "usb_client.h"
 
+using android::fs_mgr::EnsurePathUnmounted;
+using android::fs_mgr::Fstab;
 using ::android::hardware::hidl_string;
 using ::android::hardware::boot::V1_0::IBootControl;
 using ::android::hardware::boot::V1_0::Slot;
@@ -64,6 +68,13 @@ FastbootDevice::FastbootDevice()
     if (boot_control_hal_) {
         boot1_1_ = android::hardware::boot::V1_1::IBootControl::castFrom(boot_control_hal_);
     }
+
+    // Make sure cache is unmounted, since recovery will have mounted it for
+    // logging.
+    Fstab fstab;
+    if (ReadDefaultFstab(&fstab)) {
+        EnsurePathUnmounted(&fstab, "/cache");
+    }
 }
 
 FastbootDevice::~FastbootDevice() {