Checkpoint of better dynamic device support.
This is the first in a series of changes that are designed to
introduce better support for dynamic block devices.
It starts by defining a new Volume object which represents a storage
endpoint that knows how to mount, unmount, and format itself. This
could be a filesystem directly on a partition, or it could be an
emulated FUSE filesystem, an ASEC, or an OBB.
These new volumes can be "stacked" so that unmounting a volume will
also unmount any volumes stacked above it. Volumes that provide
shared storage can also be asked to present themselves (through bind
mounts) into user-specific mount areas.
This change also adds a Disk class which is created based on block
kernel netlink events. Instead of waiting for partition events from
the kernel, it uses gptfdisk to read partition details and creates
the relevant Volume objects.
Change-Id: I0e8bc1f8f9dcb24405f5e795c0658998e22ae2f7
diff --git a/PublicVolume.h b/PublicVolume.h
new file mode 100644
index 0000000..3da0995
--- /dev/null
+++ b/PublicVolume.h
@@ -0,0 +1,89 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_VOLD_PUBLIC_VOLUME_H
+#define ANDROID_VOLD_PUBLIC_VOLUME_H
+
+#include "VolumeBase.h"
+
+#include <cutils/multiuser.h>
+
+namespace android {
+namespace vold {
+
+/*
+ * Shared storage provided by public (vfat) partition.
+ *
+ * Knows how to mount itself and then spawn a FUSE daemon to synthesize
+ * permissions. AsecVolume and ObbVolume can be stacked above it.
+ *
+ * This volume is not inherently multi-user aware, so it has two possible
+ * modes of operation:
+ * 1. If primary storage for the device, it only binds itself to the
+ * owner user.
+ * 2. If secondary storage, it binds itself for all users, but masks
+ * away the Android directory for secondary users.
+ */
+class PublicVolume : public VolumeBase {
+public:
+ explicit PublicVolume(dev_t device);
+ virtual ~PublicVolume();
+
+ status_t readMetadata();
+ status_t initAsecStage();
+
+ void setPrimary(bool primary);
+ bool getPrimary() { return mPrimary; }
+
+ const std::string& getFsUuid() { return mFsUuid; }
+ const std::string& getFsLabel() { return mFsLabel; }
+
+ status_t bindUser(userid_t user);
+ status_t unbindUser(userid_t user);
+
+protected:
+ status_t doMount();
+ status_t doUnmount();
+ status_t doFormat();
+
+ status_t bindUserInternal(userid_t user, bool bind);
+
+private:
+ /* Kernel device representing partition */
+ dev_t mDevice;
+ /* Block device path */
+ std::string mDevPath;
+ /* Mount point of raw partition */
+ std::string mRawPath;
+ /* Mount point of FUSE wrapper */
+ std::string mFusePath;
+ /* PID of FUSE wrapper */
+ pid_t mFusePid;
+ /* Flag indicating this is primary storage */
+ bool mPrimary;
+
+ /* Parsed UUID from filesystem */
+ std::string mFsUuid;
+ /* User-visible label from filesystem */
+ std::string mFsLabel;
+
+ DISALLOW_COPY_AND_ASSIGN(PublicVolume);
+};
+
+} // namespace vold
+} // namespace android
+
+#endif