From 27c5047313deab5e268103759fdeb02c09ea11b1 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@google.com>
Date: Thu, 7 Mar 2019 12:53:19 -0800
Subject: [PATCH] fs_mgr: overlay: preserve errno android::gsi::IsGsiRunning()

Resulted in remount reporting an mount_all failure.

Test: adb-remount-test.sh
Bug: 126256072
Change-Id: Ib9567748e5c12b047e38869c07755eb741308df4
---
 fs_mgr/fs_mgr_overlayfs.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 40da36d87..e61f58838 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -769,9 +769,10 @@ bool fs_mgr_overlayfs_invalid() {
 
     // in recovery, fastbootd, or gsi mode, not allowed!
     if (fs_mgr_access("/system/bin/recovery")) return true;
-    if (android::gsi::IsGsiRunning()) return true;
-
-    return false;
+    auto save_errno = errno;
+    auto ret = android::gsi::IsGsiRunning();
+    errno = save_errno;
+    return ret;
 }
 
 }  // namespace