upload android base code part6

android/system/vold/EmulatedVolume.cpp

@@ -0,0 +1,141 @@
+/*
+ * 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 "EmulatedVolume.h"
+#include "Utils.h"
+
+#include <android-base/stringprintf.h>
+#include <android-base/logging.h>
+#include <cutils/fs.h>
+#include <private/android_filesystem_config.h>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/sysmacros.h>
+#include <sys/wait.h>
+
+using android::base::StringPrintf;
+
+namespace android {
+namespace vold {
+
+static const char* kFusePath = "/system/bin/sdcard";
+
+EmulatedVolume::EmulatedVolume(const std::string& rawPath) :
+        VolumeBase(Type::kEmulated), mFusePid(0) {
+    setId("emulated");
+    mRawPath = rawPath;
+    mLabel = "emulated";
+}
+
+EmulatedVolume::EmulatedVolume(const std::string& rawPath, dev_t device,
+        const std::string& fsUuid) : VolumeBase(Type::kEmulated), mFusePid(0) {
+    setId(StringPrintf("emulated:%u,%u", major(device), minor(device)));
+    mRawPath = rawPath;
+    mLabel = fsUuid;
+}
+
+EmulatedVolume::~EmulatedVolume() {
+}
+
+status_t EmulatedVolume::doMount() {
+    // We could have migrated storage to an adopted private volume, so always
+    // call primary storage "emulated" to avoid media rescans.
+    std::string label = mLabel;
+    if (getMountFlags() & MountFlags::kPrimary) {
+        label = "emulated";
+    }
+
+    mFuseDefault = StringPrintf("/mnt/runtime/default/%s", label.c_str());
+    mFuseRead = StringPrintf("/mnt/runtime/read/%s", label.c_str());
+    mFuseWrite = StringPrintf("/mnt/runtime/write/%s", label.c_str());
+
+    setInternalPath(mRawPath);
+    setPath(StringPrintf("/storage/%s", label.c_str()));
+
+    if (fs_prepare_dir(mFuseDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
+            fs_prepare_dir(mFuseRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
+            fs_prepare_dir(mFuseWrite.c_str(), 0700, AID_ROOT, AID_ROOT)) {
+        PLOG(ERROR) << getId() << " failed to create mount points";
+        return -errno;
+    }
+
+    dev_t before = GetDevice(mFuseWrite);
+
+    if (!(mFusePid = fork())) {
+        if (execl(kFusePath, kFusePath,
+                "-u", "1023", // AID_MEDIA_RW
+                "-g", "1023", // AID_MEDIA_RW
+                "-m",
+                "-w",
+                "-G",
+                mRawPath.c_str(),
+                label.c_str(),
+                NULL)) {
+            PLOG(ERROR) << "Failed to exec";
+        }
+
+        LOG(ERROR) << "FUSE exiting";
+        _exit(1);
+    }
+
+    if (mFusePid == -1) {
+        PLOG(ERROR) << getId() << " failed to fork";
+        return -errno;
+    }
+
+    while (before == GetDevice(mFuseWrite)) {
+        LOG(VERBOSE) << "Waiting for FUSE to spin up...";
+        usleep(50000); // 50ms
+    }
+    /* sdcardfs will have exited already. FUSE will still be running */
+    TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, WNOHANG));
+
+    return OK;
+}
+
+status_t EmulatedVolume::doUnmount() {
+    // Unmount the storage before we kill the FUSE process. If we kill
+    // the FUSE process first, most file system operations will return
+    // ENOTCONN until the unmount completes. This is an exotic and unusual
+    // error code and might cause broken behaviour in applications.
+    KillProcessesUsingPath(getPath());
+    ForceUnmount(mFuseDefault);
+    ForceUnmount(mFuseRead);
+    ForceUnmount(mFuseWrite);
+
+    if (mFusePid > 0) {
+        kill(mFusePid, SIGTERM);
+        TEMP_FAILURE_RETRY(waitpid(mFusePid, nullptr, 0));
+        mFusePid = 0;
+    }
+
+    rmdir(mFuseDefault.c_str());
+    rmdir(mFuseRead.c_str());
+    rmdir(mFuseWrite.c_str());
+
+    mFuseDefault.clear();
+    mFuseRead.clear();
+    mFuseWrite.clear();
+
+    return OK;
+}
+
+}  // namespace vold
+}  // namespace android