1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_VOLD_PUBLIC_VOLUME_H
18 #define ANDROID_VOLD_PUBLIC_VOLUME_H
19 
20 #include "VolumeBase.h"
21 
22 #include <cutils/multiuser.h>
23 
24 namespace android {
25 namespace vold {
26 
27 /*
28  * Shared storage provided by public (vfat) partition.
29  *
30  * Knows how to mount itself and then spawn a FUSE daemon to synthesize
31  * permissions.  AsecVolume and ObbVolume can be stacked above it.
32  *
33  * This volume is not inherently multi-user aware, so it has two possible
34  * modes of operation:
35  * 1. If primary storage for the device, it only binds itself to the
36  * owner user.
37  * 2. If secondary storage, it binds itself for all users, but masks
38  * away the Android directory for secondary users.
39  */
40 class PublicVolume : public VolumeBase {
41   public:
42     explicit PublicVolume(dev_t device);
43     virtual ~PublicVolume();
44 
45   protected:
46     status_t doCreate() override;
47     status_t doDestroy() override;
48     status_t doMount() override;
49     status_t doUnmount() override;
50     status_t doFormat(const std::string& fsType) override;
51 
52     status_t readMetadata();
53     status_t initAsecStage();
54 
55   private:
56     /* Kernel device representing partition */
57     dev_t mDevice;
58     /* Block device path */
59     std::string mDevPath;
60     /* Mount point of raw partition */
61     std::string mRawPath;
62 
63     std::string mFuseDefault;
64     std::string mFuseRead;
65     std::string mFuseWrite;
66     std::string mFuseFull;
67 
68     /* PID of FUSE wrapper */
69     pid_t mFusePid;
70 
71     /* Filesystem type */
72     std::string mFsType;
73     /* Filesystem UUID */
74     std::string mFsUuid;
75     /* User-visible filesystem label */
76     std::string mFsLabel;
77 
78     DISALLOW_COPY_AND_ASSIGN(PublicVolume);
79 };
80 
81 }  // namespace vold
82 }  // namespace android
83 
84 #endif
85