From e4c93da49297f70c8f0fc11fbc5c21efeedc5e98 Mon Sep 17 00:00:00 2001
From: Paul Crowley <paulcrowley@google.com>
Date: Fri, 16 Jun 2017 09:21:18 -0700
Subject: [PATCH] Abolish AutoCloseFD.h in favour of unique_fd

Android has a standard way to do what AutoCloseFD.h does, so use that
instead. Refactor before work on the bug.

Bug: 36029169
Test: Deleted a user and checked that secdiscard logs looked good.
Change-Id: I5d8bedfb3fa1f032fd2bced88b1b561e4a8c2ff4
---
 AutoCloseFD.h     | 50 -----------------------------------------------
 MetadataCrypt.cpp | 12 +++++++-----
 secdiscard.cpp    | 13 ++++++------
 3 files changed, 14 insertions(+), 61 deletions(-)
 delete mode 100644 AutoCloseFD.h

diff --git a/AutoCloseFD.h b/AutoCloseFD.h
deleted file mode 100644
index 9b68469..0000000
--- a/AutoCloseFD.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <string>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-
-#include <android-base/logging.h>
-
-// File descriptor which is automatically closed when this object is destroyed.
-// Cannot be copied, since that would cause double-closes.
-class AutoCloseFD {
-public:
-    AutoCloseFD(const char *path, int flags = O_RDONLY, int mode = 0):
-        fd{TEMP_FAILURE_RETRY(open(path, flags | O_CLOEXEC, mode))} {}
-    AutoCloseFD(const std::string &path, int flags = O_RDONLY, int mode = 0):
-        AutoCloseFD(path.c_str(), flags, mode) {}
-    ~AutoCloseFD() {
-        if (fd != -1) {
-            int preserve_errno = errno;
-            if (close(fd) == -1) {
-                PLOG(ERROR) << "close(2) failed";
-            };
-            errno = preserve_errno;
-        }
-    }
-    AutoCloseFD(const AutoCloseFD&) = delete;
-    AutoCloseFD& operator=(const AutoCloseFD&) = delete;
-    explicit operator bool() {return fd != -1;}
-    int get() const {return fd;}
-private:
-    const int fd;
-};
-
diff --git a/MetadataCrypt.cpp b/MetadataCrypt.cpp
index b707549..743e08c 100644
--- a/MetadataCrypt.cpp
+++ b/MetadataCrypt.cpp
@@ -29,10 +29,10 @@
 #include <linux/dm-ioctl.h>
 
 #include <android-base/logging.h>
+#include <android-base/unique_fd.h>
 #include <cutils/properties.h>
 #include <fs_mgr.h>
 
-#include "AutoCloseFD.h"
 #include "EncryptInplace.h"
 #include "KeyStorage.h"
 #include "KeyUtil.h"
@@ -105,8 +105,9 @@ static std::string default_key_params(const std::string& real_blkdev, const std:
 }
 
 static bool get_number_of_sectors(const std::string& real_blkdev, uint64_t *nr_sec) {
-    AutoCloseFD dev_fd(real_blkdev, O_RDONLY);
-    if (!dev_fd) {
+    android::base::unique_fd dev_fd(TEMP_FAILURE_RETRY(open(
+        real_blkdev.c_str(), O_RDONLY | O_CLOEXEC, 0)));
+    if (dev_fd == -1) {
         PLOG(ERROR) << "Unable to open " << real_blkdev << " to measure size";
         return false;
     }
@@ -143,8 +144,9 @@ static struct dm_ioctl* dm_ioctl_init(char *buffer, size_t buffer_size,
 static bool create_crypto_blk_dev(const std::string& dm_name, uint64_t nr_sec,
                                   const std::string& target_type, const std::string& crypt_params,
                                   std::string* crypto_blkdev) {
-    AutoCloseFD dm_fd("/dev/device-mapper", O_RDWR);
-    if (!dm_fd) {
+    android::base::unique_fd dm_fd(TEMP_FAILURE_RETRY(open(
+        "/dev/device-mapper", O_RDWR | O_CLOEXEC, 0)));
+    if (dm_fd == -1) {
         PLOG(ERROR) << "Cannot open device-mapper";
         return false;
     }
diff --git a/secdiscard.cpp b/secdiscard.cpp
index fe51990..a335ab6 100644
--- a/secdiscard.cpp
+++ b/secdiscard.cpp
@@ -29,8 +29,7 @@
 #include <mntent.h>
 
 #include <android-base/logging.h>
-
-#include <AutoCloseFD.h>
+#include <android-base/unique_fd.h>
 
 namespace {
 
@@ -107,8 +106,9 @@ bool secdiscard_path(const std::string &path) {
     if (block_device.empty()) {
         return false;
     }
-    AutoCloseFD fs_fd(block_device, O_RDWR | O_LARGEFILE);
-    if (!fs_fd) {
+    android::base::unique_fd fs_fd(TEMP_FAILURE_RETRY(open(
+        block_device.c_str(), O_RDWR | O_LARGEFILE | O_CLOEXEC, 0)));
+    if (fs_fd == -1) {
         PLOG(ERROR) << "Failed to open device " << block_device;
         return false;
     }
@@ -128,8 +128,9 @@ bool secdiscard_path(const std::string &path) {
 // Read the file's FIEMAP
 std::unique_ptr<struct fiemap> path_fiemap(const std::string &path, uint32_t extent_count)
 {
-    AutoCloseFD fd(path);
-    if (!fd) {
+    android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(
+        path.c_str(), O_RDONLY | O_CLOEXEC, 0)));
+    if (fd == -1) {
         if (errno == ENOENT) {
             PLOG(DEBUG) << "Unable to open " << path;
         } else {