1 /*
2  * Copyright (C) 2019 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 #include "partition_installer.h"
18 
19 #include <sys/statvfs.h>
20 
21 #include <android-base/file.h>
22 #include <android-base/logging.h>
23 #include <android-base/unique_fd.h>
24 #include <ext4_utils/ext4_utils.h>
25 #include <fs_mgr_dm_linear.h>
26 #include <libdm/dm.h>
27 #include <libgsi/libgsi.h>
28 
29 #include "file_paths.h"
30 #include "gsi_service.h"
31 #include "libgsi_private.h"
32 
33 namespace android {
34 namespace gsi {
35 
36 using namespace std::literals;
37 using namespace android::dm;
38 using namespace android::fiemap;
39 using namespace android::fs_mgr;
40 using android::base::unique_fd;
41 
PartitionInstaller(GsiService * service,const std::string & install_dir,const std::string & name,const std::string & active_dsu,int64_t size,bool read_only)42 PartitionInstaller::PartitionInstaller(GsiService* service, const std::string& install_dir,
43                                        const std::string& name, const std::string& active_dsu,
44                                        int64_t size, bool read_only)
45     : service_(service),
46       install_dir_(install_dir),
47       name_(name),
48       active_dsu_(active_dsu),
49       size_(size),
50       readOnly_(read_only) {
51     images_ = ImageManager::Open(MetadataDir(active_dsu), install_dir_);
52 }
53 
~PartitionInstaller()54 PartitionInstaller::~PartitionInstaller() {
55     if (FinishInstall() != IGsiService::INSTALL_OK) {
56         LOG(ERROR) << "Installation failed: install_dir=" << install_dir_
57                    << ", dsu_slot=" << active_dsu_ << ", partition_name=" << name_;
58     }
59     if (IsAshmemMapped()) {
60         UnmapAshmem();
61     }
62 }
63 
FinishInstall()64 int PartitionInstaller::FinishInstall() {
65     if (finished_) {
66         return finished_status_;
67     }
68     finished_ = true;
69     finished_status_ = CheckInstallState();
70     system_device_ = nullptr;
71     if (finished_status_ != IGsiService::INSTALL_OK) {
72         auto file = GetBackingFile(name_);
73         LOG(ERROR) << "Installation failed, clean up: " << file;
74         if (images_->IsImageMapped(file)) {
75             LOG(ERROR) << "unmap " << file;
76             images_->UnmapImageDevice(file);
77         }
78         images_->DeleteBackingImage(file);
79     }
80     return finished_status_;
81 }
82 
StartInstall()83 int PartitionInstaller::StartInstall() {
84     if (int status = PerformSanityChecks()) {
85         return status;
86     }
87     if (int status = Preallocate()) {
88         return status;
89     }
90     if (!readOnly_) {
91         if (!Format()) {
92             return IGsiService::INSTALL_ERROR_GENERIC;
93         }
94     } else {
95         // Map ${name}_gsi so we can write to it.
96         system_device_ = OpenPartition(GetBackingFile(name_));
97         if (!system_device_) {
98             return IGsiService::INSTALL_ERROR_GENERIC;
99         }
100 
101         // Clear the progress indicator.
102         service_->UpdateProgress(IGsiService::STATUS_NO_OPERATION, 0);
103     }
104     return IGsiService::INSTALL_OK;
105 }
106 
PerformSanityChecks()107 int PartitionInstaller::PerformSanityChecks() {
108     if (!images_) {
109         LOG(ERROR) << "unable to create image manager";
110         return IGsiService::INSTALL_ERROR_GENERIC;
111     }
112     if (size_ < 0) {
113         LOG(ERROR) << "image size " << size_ << " is negative";
114         return IGsiService::INSTALL_ERROR_GENERIC;
115     }
116     if (android::gsi::IsGsiRunning()) {
117         LOG(ERROR) << "cannot install gsi inside a live gsi";
118         return IGsiService::INSTALL_ERROR_GENERIC;
119     }
120 
121     struct statvfs sb;
122     if (statvfs(install_dir_.c_str(), &sb)) {
123         PLOG(ERROR) << "failed to read file system stats";
124         return IGsiService::INSTALL_ERROR_GENERIC;
125     }
126 
127     // This is the same as android::vold::GetFreebytes() but we also
128     // need the total file system size so we open code it here.
129     uint64_t free_space = static_cast<uint64_t>(sb.f_bavail) * sb.f_frsize;
130     uint64_t fs_size = static_cast<uint64_t>(sb.f_blocks) * sb.f_frsize;
131     if (free_space <= (size_)) {
132         LOG(ERROR) << "not enough free space (only " << free_space << " bytes available)";
133         return IGsiService::INSTALL_ERROR_NO_SPACE;
134     }
135     // We are asking for 40% of the /data to be empty.
136     // TODO: may be not hard code it like this
137     double free_space_percent = ((1.0 * free_space) / fs_size) * 100;
138     if (free_space_percent < kMinimumFreeSpaceThreshold) {
139         LOG(ERROR) << "free space " << static_cast<uint64_t>(free_space_percent)
140                    << "% is below the minimum threshold of " << kMinimumFreeSpaceThreshold << "%";
141         return IGsiService::INSTALL_ERROR_FILE_SYSTEM_CLUTTERED;
142     }
143     return IGsiService::INSTALL_OK;
144 }
145 
Preallocate()146 int PartitionInstaller::Preallocate() {
147     std::string file = GetBackingFile(name_);
148     if (!images_->UnmapImageIfExists(file)) {
149         LOG(ERROR) << "failed to UnmapImageIfExists " << file;
150         return IGsiService::INSTALL_ERROR_GENERIC;
151     }
152     // always delete the old one when it presents in case there might a partition
153     // with same name but different size.
154     if (images_->BackingImageExists(file)) {
155         if (!images_->DeleteBackingImage(file)) {
156             LOG(ERROR) << "failed to DeleteBackingImage " << file;
157             return IGsiService::INSTALL_ERROR_GENERIC;
158         }
159     }
160     service_->StartAsyncOperation("create " + name_, size_);
161     if (!CreateImage(file, size_)) {
162         LOG(ERROR) << "Could not create userdata image";
163         return IGsiService::INSTALL_ERROR_GENERIC;
164     }
165     service_->UpdateProgress(IGsiService::STATUS_COMPLETE, 0);
166     return IGsiService::INSTALL_OK;
167 }
168 
CreateImage(const std::string & name,uint64_t size)169 bool PartitionInstaller::CreateImage(const std::string& name, uint64_t size) {
170     auto progress = [this](uint64_t bytes, uint64_t /* total */) -> bool {
171         service_->UpdateProgress(IGsiService::STATUS_WORKING, bytes);
172         if (service_->should_abort()) return false;
173         return true;
174     };
175     int flags = ImageManager::CREATE_IMAGE_DEFAULT;
176     if (readOnly_) {
177         flags |= ImageManager::CREATE_IMAGE_READONLY;
178     }
179     return images_->CreateBackingImage(name, size, flags, std::move(progress));
180 }
181 
OpenPartition(const std::string & name)182 std::unique_ptr<MappedDevice> PartitionInstaller::OpenPartition(const std::string& name) {
183     return MappedDevice::Open(images_.get(), 10s, name);
184 }
185 
CommitGsiChunk(int stream_fd,int64_t bytes)186 bool PartitionInstaller::CommitGsiChunk(int stream_fd, int64_t bytes) {
187     service_->StartAsyncOperation("write " + name_, size_);
188 
189     if (bytes < 0) {
190         LOG(ERROR) << "chunk size " << bytes << " is negative";
191         return false;
192     }
193 
194     static const size_t kBlockSize = 4096;
195     auto buffer = std::make_unique<char[]>(kBlockSize);
196 
197     int progress = -1;
198     uint64_t remaining = bytes;
199     while (remaining) {
200         size_t max_to_read = std::min(static_cast<uint64_t>(kBlockSize), remaining);
201         ssize_t rv = TEMP_FAILURE_RETRY(read(stream_fd, buffer.get(), max_to_read));
202         if (rv < 0) {
203             PLOG(ERROR) << "read gsi chunk";
204             return false;
205         }
206         if (rv == 0) {
207             LOG(ERROR) << "no bytes left in stream";
208             return false;
209         }
210         if (!CommitGsiChunk(buffer.get(), rv)) {
211             return false;
212         }
213         CHECK(static_cast<uint64_t>(rv) <= remaining);
214         remaining -= rv;
215 
216         // Only update the progress when the % (or permille, in this case)
217         // significantly changes.
218         int new_progress = ((size_ - remaining) * 1000) / size_;
219         if (new_progress != progress) {
220             service_->UpdateProgress(IGsiService::STATUS_WORKING, size_ - remaining);
221         }
222     }
223 
224     service_->UpdateProgress(IGsiService::STATUS_COMPLETE, size_);
225     return true;
226 }
227 
IsFinishedWriting()228 bool PartitionInstaller::IsFinishedWriting() {
229     return gsi_bytes_written_ == size_;
230 }
231 
IsAshmemMapped()232 bool PartitionInstaller::IsAshmemMapped() {
233     return ashmem_data_ != MAP_FAILED;
234 }
235 
CommitGsiChunk(const void * data,size_t bytes)236 bool PartitionInstaller::CommitGsiChunk(const void* data, size_t bytes) {
237     if (static_cast<uint64_t>(bytes) > size_ - gsi_bytes_written_) {
238         // We cannot write past the end of the image file.
239         LOG(ERROR) << "chunk size " << bytes << " exceeds remaining image size (" << size_
240                    << " expected, " << gsi_bytes_written_ << " written)";
241         return false;
242     }
243     if (service_->should_abort()) {
244         return false;
245     }
246     if (!android::base::WriteFully(system_device_->fd(), data, bytes)) {
247         PLOG(ERROR) << "write failed";
248         return false;
249     }
250     gsi_bytes_written_ += bytes;
251     return true;
252 }
253 
GetPartitionFd()254 int PartitionInstaller::GetPartitionFd() {
255     return system_device_->fd();
256 }
257 
MapAshmem(int fd,size_t size)258 bool PartitionInstaller::MapAshmem(int fd, size_t size) {
259     ashmem_size_ = size;
260     ashmem_data_ = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
261     return ashmem_data_ != MAP_FAILED;
262 }
263 
UnmapAshmem()264 void PartitionInstaller::UnmapAshmem() {
265     if (munmap(ashmem_data_, ashmem_size_) != 0) {
266         PLOG(ERROR) << "cannot munmap";
267         return;
268     }
269     ashmem_data_ = MAP_FAILED;
270     ashmem_size_ = -1;
271 }
272 
CommitGsiChunk(size_t bytes)273 bool PartitionInstaller::CommitGsiChunk(size_t bytes) {
274     if (!IsAshmemMapped()) {
275         PLOG(ERROR) << "ashmem is not mapped";
276         return false;
277     }
278     bool success = CommitGsiChunk(ashmem_data_, bytes);
279     if (success && IsFinishedWriting()) {
280         UnmapAshmem();
281     }
282     return success;
283 }
284 
GetBackingFile(std::string name)285 const std::string PartitionInstaller::GetBackingFile(std::string name) {
286     return name + "_gsi";
287 }
288 
Format()289 bool PartitionInstaller::Format() {
290     auto file = GetBackingFile(name_);
291     auto device = OpenPartition(file);
292     if (!device) {
293         return false;
294     }
295 
296     // libcutils checks the first 4K, no matter the block size.
297     std::string zeroes(4096, 0);
298     if (!android::base::WriteFully(device->fd(), zeroes.data(), zeroes.size())) {
299         PLOG(ERROR) << "write " << file;
300         return false;
301     }
302     return true;
303 }
304 
CheckInstallState()305 int PartitionInstaller::CheckInstallState() {
306     if (readOnly_ && !IsFinishedWriting()) {
307         // We cannot boot if the image is incomplete.
308         LOG(ERROR) << "image incomplete; expected " << size_ << " bytes, waiting for "
309                    << (size_ - gsi_bytes_written_) << " bytes";
310         return IGsiService::INSTALL_ERROR_GENERIC;
311     }
312     if (system_device_ != nullptr && fsync(GetPartitionFd())) {
313         PLOG(ERROR) << "fsync failed for " << GetBackingFile(name_);
314         return IGsiService::INSTALL_ERROR_GENERIC;
315     }
316     // If files moved (are no longer pinned), the metadata file will be invalid.
317     // This check can be removed once b/133967059 is fixed.
318     if (!images_->Validate()) {
319         return IGsiService::INSTALL_ERROR_GENERIC;
320     }
321     return IGsiService::INSTALL_OK;
322 }
323 
WipeWritable(const std::string & active_dsu,const std::string & install_dir,const std::string & name)324 int PartitionInstaller::WipeWritable(const std::string& active_dsu, const std::string& install_dir,
325                                      const std::string& name) {
326     auto image = ImageManager::Open(MetadataDir(active_dsu), install_dir);
327     // The device object has to be destroyed before the image object
328     auto device = MappedDevice::Open(image.get(), 10s, name);
329     if (!device) {
330         return IGsiService::INSTALL_ERROR_GENERIC;
331     }
332 
333     // Wipe the first 1MiB of the device, ensuring both the first block and
334     // the superblock are destroyed.
335     static constexpr uint64_t kEraseSize = 1024 * 1024;
336 
337     std::string zeroes(4096, 0);
338     uint64_t erase_size = std::min(kEraseSize, get_block_device_size(device->fd()));
339     for (uint64_t i = 0; i < erase_size; i += zeroes.size()) {
340         if (!android::base::WriteFully(device->fd(), zeroes.data(), zeroes.size())) {
341             PLOG(ERROR) << "write " << name;
342             return IGsiService::INSTALL_ERROR_GENERIC;
343         }
344     }
345     return IGsiService::INSTALL_OK;
346 }
347 
348 }  // namespace gsi
349 }  // namespace android
350