Add NTFS support in vold
This CR, when paired with a functional NTFS implementation and the
corresponding SEPolicy updates, will allow NTFS USB drives to be mounted
on Android.
Bug: 254407246
Test: Extensive testing with an ADT-4 and NTFS USB drives.
Merged-In: If4197c4c588866c611cd6ba3483707d3cb0e0cf8
Change-Id: If4197c4c588866c611cd6ba3483707d3cb0e0cf8
diff --git a/fs/Ntfs.cpp b/fs/Ntfs.cpp
new file mode 100644
index 0000000..6f57693
--- /dev/null
+++ b/fs/Ntfs.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2022 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 <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <linux/kdev_t.h>
+
+#define LOG_TAG "Vold"
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <cutils/log.h>
+#include <cutils/properties.h>
+#include <selinux/selinux.h>
+
+#include <logwrap/logwrap.h>
+
+#include "Ntfs.h"
+#include "Utils.h"
+#include "VoldUtil.h"
+
+using android::base::StringPrintf;
+
+namespace android {
+namespace vold {
+namespace ntfs {
+
+static const char* kFsckPath = "/system/bin/ntfsfix";
+static const char* kMkfsPath = "/system/bin/mkntfs";
+
+static const char* fsName = "ntfs3";
+
+bool IsSupported() {
+ return access(kFsckPath, X_OK) == 0 && access(kMkfsPath, X_OK) == 0 &&
+ IsFilesystemSupported(fsName);
+}
+
+status_t Check(const std::string& source) {
+ std::vector<std::string> cmd;
+ cmd.push_back(kFsckPath);
+
+ // ntfsfix sets the dirty bit by default, which prevents mounting the drive.
+ // -d tells it to instead reset the dirty bit. Technically, this could be dangerous,
+ // but since ntfsfix should report any errors with the drive and separately return
+ // a failed check, this should be relatively safe.
+ cmd.push_back("-d");
+
+ cmd.push_back(source);
+
+ int rc = ForkExecvpTimeout(cmd, kUntrustedFsckSleepTime, sFsckUntrustedContext);
+ if (rc == 0) {
+ LOG(INFO) << "Check NTFS OK";
+ return 0;
+ } else {
+ LOG(ERROR) << "Check NTFS failed (code " << rc << ")";
+ errno = EIO;
+ return -1;
+ }
+}
+
+status_t Mount(const std::string& source, const std::string& target, bool ro, bool remount,
+ bool executable, int ownerUid, int ownerGid, int permMask) {
+ unsigned long flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC | MS_NOATIME;
+
+ flags |= (executable ? 0 : MS_NOEXEC);
+ flags |= (ro ? MS_RDONLY : 0);
+ flags |= (remount ? MS_REMOUNT : 0);
+
+ // Android mount does not support "utf8" as an option. We use the deprecated iocharset instead.
+ auto mountData = android::base::StringPrintf("uid=%d,gid=%d,fmask=%o,dmask=%o,iocharset=%s",
+ ownerUid, ownerGid, permMask, permMask, "utf8");
+
+ int rc = mount(source.c_str(), target.c_str(), fsName, flags, mountData.c_str());
+
+ if (rc && errno == EROFS) {
+ LOG(ERROR) << source << " appears to be a read only filesystem - retrying mount RO";
+ flags |= MS_RDONLY;
+ rc = mount(source.c_str(), target.c_str(), fsName, flags, mountData.c_str());
+ }
+
+ return rc;
+}
+
+status_t Format(const std::string& source, unsigned int numSectors) {
+ std::vector<std::string> cmd;
+ cmd.push_back(kMkfsPath);
+ cmd.push_back(source);
+
+ if (numSectors) {
+ cmd.push_back(StringPrintf("%u", numSectors));
+ }
+
+ int rc = ForkExecvp(cmd);
+ if (rc == 0) {
+ LOG(INFO) << "Filesystem formatted OK";
+ return 0;
+ } else {
+ LOG(ERROR) << "Format failed with error code: " << rc;
+ errno = EIO;
+ return -1;
+ }
+ return 0;
+}
+
+} // namespace ntfs
+} // namespace vold
+} // namespace android
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