From 543a9283592a99aa279e8df2516da31a7a04d6f1 Mon Sep 17 00:00:00 2001
From: bigbiff <bigbiff@teamw.in>
Date: Sat, 2 Oct 2021 09:50:58 -0400
Subject: [PATCH] default fstab: only read the fstab if it hasn't been read yet

Change-Id: I0d8d5cdda4da5486f51a80772f9d581bf549138c
---
 crypto/fscrypt/FsCrypt.cpp       | 24 +++++++++++++++---------
 crypto/fscrypt/MetadataCrypt.cpp | 17 ++++++++++-------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/crypto/fscrypt/FsCrypt.cpp b/crypto/fscrypt/FsCrypt.cpp
index aa31fe1e..6284fa86 100755
--- a/crypto/fscrypt/FsCrypt.cpp
+++ b/crypto/fscrypt/FsCrypt.cpp
@@ -233,9 +233,11 @@ static bool IsEmmcStorage(const std::string& blk_device) {
 
 // Retrieve the options to use for encryption policies on the /data filesystem.
 static bool get_data_file_encryption_options(EncryptionOptions* options) {
-    if (!ReadDefaultFstab(&fstab_default)) {
-        PLOG(ERROR) << "Failed to open default fstab";
-        return false;
+    if (fstab_default.empty()) {
+        if (!ReadDefaultFstab(&fstab_default)) {
+            PLOG(ERROR) << "Failed to open default fstab";
+            return false;
+        }
     }
     auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
     if (entry == nullptr) {
@@ -299,9 +301,11 @@ static bool get_volume_file_encryption_options(EncryptionOptions* options) {
 }
 
 bool is_metadata_wrapped_key_supported() {
-    if (!ReadDefaultFstab(&fstab_default)) {
-        PLOG(ERROR) << "Failed to open default fstab";
-        return false;
+    if (fstab_default.empty()) {
+        if (!ReadDefaultFstab(&fstab_default)) {
+            PLOG(ERROR) << "Failed to open default fstab";
+            return false;
+        }
     }
     return GetEntryForMountPoint(&fstab_default, METADATA_MNT_POINT)->fs_mgr_flags.wrapped_key;
 }
@@ -491,9 +495,11 @@ bool fscrypt_initialize_systemwide_keys() {
 }
 
 bool fscrypt_init_user0() {
-    if (!ReadDefaultFstab(&fstab_default)) {
-        PLOG(ERROR) << "Failed to open default fstab";
-        return -1;
+    if (fstab_default.empty()) {
+        if (!ReadDefaultFstab(&fstab_default)) {
+            PLOG(ERROR) << "Failed to open default fstab";
+            return -1;
+        }
     }
     LOG(INFO) << "fscrypt_init_user0";
     if (fscrypt_is_native()) {
diff --git a/crypto/fscrypt/MetadataCrypt.cpp b/crypto/fscrypt/MetadataCrypt.cpp
index b53ecd41..853e81eb 100755
--- a/crypto/fscrypt/MetadataCrypt.cpp
+++ b/crypto/fscrypt/MetadataCrypt.cpp
@@ -97,9 +97,11 @@ static bool mount_via_fs_mgr(const char* mount_point, const char* blk_device) {
         return false;
     }
 
-    if (!ReadDefaultFstab(&fstab_default)) {
-        PLOG(ERROR) << "Failed to open default fstab";
-        return -1;
+    if (fstab_default.empty()) {
+        if (!ReadDefaultFstab(&fstab_default)) {
+            PLOG(ERROR) << "Failed to open default fstab";
+            return -1;
+        }
     }
     auto mount_rc = fs_mgr_do_mount(&fstab_default, const_cast<char*>(mount_point),
                                     const_cast<char*>(blk_device), nullptr,
@@ -284,9 +286,11 @@ bool fscrypt_mount_metadata_encrypted(const std::string& blk_device, const std::
         LOG(ERROR) << "fscrypt_enable_crypto got unexpected starting state: " << encrypted_state;
         return false;
     }
-    if (!ReadDefaultFstab(&fstab_default)) {
-        PLOG(ERROR) << "Failed to open default fstab";
-        return -1;
+    if (fstab_default.empty()) {
+        if (!ReadDefaultFstab(&fstab_default)) {
+            PLOG(ERROR) << "Failed to open default fstab";
+            return -1;
+        }
     }
     auto data_rec = GetEntryForMountPoint(&fstab_default, mount_point);
     if (!data_rec) {
@@ -323,7 +327,6 @@ bool fscrypt_mount_metadata_encrypted(const std::string& blk_device, const std::
         LOG(ERROR) << "Unknown options_format_version: " << options_format_version;
         return false;
     }
-
     auto gen = needs_encrypt ? makeGen(options) : neverGen();
     KeyBuffer key;
     if (!read_key(data_rec->metadata_key_dir, gen, &key)) return false;