1 //
2 // Copyright (C) 2012 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 "update_engine/payload_generator/full_update_generator.h"
18
19 #include <fcntl.h>
20 #include <inttypes.h>
21
22 #include <algorithm>
23 #include <deque>
24 #include <memory>
25
26 #include <base/format_macros.h>
27 #include <base/strings/string_util.h>
28 #include <base/strings/stringprintf.h>
29 #include <base/synchronization/lock.h>
30 #include <base/threading/simple_thread.h>
31 #include <brillo/secure_blob.h>
32
33 #include "update_engine/common/utils.h"
34 #include "update_engine/payload_generator/delta_diff_utils.h"
35
36 using std::vector;
37
38 namespace chromeos_update_engine {
39
40 namespace {
41
42 const size_t kDefaultFullChunkSize = 1024 * 1024; // 1 MiB
43
44 // This class encapsulates a full update chunk processing thread work. The
45 // processor reads a chunk of data from the input file descriptor and compresses
46 // it. The processor will destroy itself when the work is done.
47 class ChunkProcessor : public base::DelegateSimpleThread::Delegate {
48 public:
49 // Read a chunk of |size| bytes from |fd| starting at offset |offset|.
ChunkProcessor(const PayloadVersion & version,int fd,off_t offset,size_t size,BlobFileWriter * blob_file,AnnotatedOperation * aop)50 ChunkProcessor(const PayloadVersion& version,
51 int fd,
52 off_t offset,
53 size_t size,
54 BlobFileWriter* blob_file,
55 AnnotatedOperation* aop)
56 : version_(version),
57 fd_(fd),
58 offset_(offset),
59 size_(size),
60 blob_file_(blob_file),
61 aop_(aop) {}
62 // We use a default move constructor since all the data members are POD types.
63 ChunkProcessor(ChunkProcessor&&) = default;
64 ~ChunkProcessor() override = default;
65
66 // Overrides DelegateSimpleThread::Delegate.
67 // Run() handles the read from |fd| in a thread-safe way, and stores the
68 // new operation to generate the region starting at |offset| of size |size|
69 // in the output operation |aop|. The associated blob data is stored in
70 // |blob_fd| and |blob_file_size| is updated.
71 void Run() override;
72
73 private:
74 bool ProcessChunk();
75
76 // Work parameters.
77 const PayloadVersion& version_;
78 int fd_;
79 off_t offset_;
80 size_t size_;
81 BlobFileWriter* blob_file_;
82 AnnotatedOperation* aop_;
83
84 DISALLOW_COPY_AND_ASSIGN(ChunkProcessor);
85 };
86
Run()87 void ChunkProcessor::Run() {
88 if (!ProcessChunk()) {
89 LOG(ERROR) << "Error processing region at " << offset_ << " of size "
90 << size_;
91 }
92 }
93
ProcessChunk()94 bool ChunkProcessor::ProcessChunk() {
95 brillo::Blob buffer_in_(size_);
96 brillo::Blob op_blob;
97 ssize_t bytes_read = -1;
98 TEST_AND_RETURN_FALSE(utils::PReadAll(
99 fd_, buffer_in_.data(), buffer_in_.size(), offset_, &bytes_read));
100 TEST_AND_RETURN_FALSE(bytes_read == static_cast<ssize_t>(size_));
101
102 InstallOperation::Type op_type;
103 TEST_AND_RETURN_FALSE(diff_utils::GenerateBestFullOperation(
104 buffer_in_, version_, &op_blob, &op_type));
105
106 aop_->op.set_type(op_type);
107 TEST_AND_RETURN_FALSE(aop_->SetOperationBlob(op_blob, blob_file_));
108 return true;
109 }
110
111 } // namespace
112
GenerateOperations(const PayloadGenerationConfig & config,const PartitionConfig & old_part,const PartitionConfig & new_part,BlobFileWriter * blob_file,vector<AnnotatedOperation> * aops)113 bool FullUpdateGenerator::GenerateOperations(
114 const PayloadGenerationConfig& config,
115 const PartitionConfig& old_part,
116 const PartitionConfig& new_part,
117 BlobFileWriter* blob_file,
118 vector<AnnotatedOperation>* aops) {
119 TEST_AND_RETURN_FALSE(new_part.ValidateExists());
120
121 // FullUpdateGenerator requires a positive chunk_size, otherwise there will
122 // be only one operation with the whole partition which should not be allowed.
123 // For performance reasons, we force a small default hard limit of 1 MiB. This
124 // limit can be changed in the config, and we will use the smaller of the two
125 // soft/hard limits.
126 size_t full_chunk_size;
127 if (config.hard_chunk_size >= 0) {
128 full_chunk_size = std::min(static_cast<size_t>(config.hard_chunk_size),
129 config.soft_chunk_size);
130 } else {
131 full_chunk_size = std::min(kDefaultFullChunkSize, config.soft_chunk_size);
132 LOG(INFO) << "No chunk_size provided, using the default chunk_size for the "
133 << "full operations: " << full_chunk_size << " bytes.";
134 }
135 TEST_AND_RETURN_FALSE(full_chunk_size > 0);
136 TEST_AND_RETURN_FALSE(full_chunk_size % config.block_size == 0);
137
138 size_t chunk_blocks = full_chunk_size / config.block_size;
139 size_t max_threads = diff_utils::GetMaxThreads();
140 LOG(INFO) << "Compressing partition " << new_part.name << " from "
141 << new_part.path << " splitting in chunks of " << chunk_blocks
142 << " blocks (" << config.block_size << " bytes each) using "
143 << max_threads << " threads";
144
145 int in_fd = open(new_part.path.c_str(), O_RDONLY, 0);
146 TEST_AND_RETURN_FALSE(in_fd >= 0);
147 ScopedFdCloser in_fd_closer(&in_fd);
148
149 // We potentially have all the ChunkProcessors in memory but only
150 // |max_threads| will actually hold a block in memory while we process.
151 size_t partition_blocks = new_part.size / config.block_size;
152 size_t num_chunks = utils::DivRoundUp(partition_blocks, chunk_blocks);
153 aops->resize(num_chunks);
154 vector<ChunkProcessor> chunk_processors;
155 chunk_processors.reserve(num_chunks);
156 blob_file->SetTotalBlobs(num_chunks);
157
158 for (size_t i = 0; i < num_chunks; ++i) {
159 size_t start_block = i * chunk_blocks;
160 // The last chunk could be smaller.
161 size_t num_blocks =
162 std::min(chunk_blocks, partition_blocks - i * chunk_blocks);
163
164 // Preset all the static information about the operations. The
165 // ChunkProcessor will set the rest.
166 AnnotatedOperation* aop = aops->data() + i;
167 aop->name = base::StringPrintf(
168 "<%s-operation-%" PRIuS ">", new_part.name.c_str(), i);
169 Extent* dst_extent = aop->op.add_dst_extents();
170 dst_extent->set_start_block(start_block);
171 dst_extent->set_num_blocks(num_blocks);
172
173 chunk_processors.emplace_back(
174 config.version,
175 in_fd,
176 static_cast<off_t>(start_block) * config.block_size,
177 num_blocks * config.block_size,
178 blob_file,
179 aop);
180 }
181
182 // Thread pool used for worker threads.
183 base::DelegateSimpleThreadPool thread_pool("full-update-generator",
184 max_threads);
185 thread_pool.Start();
186 for (ChunkProcessor& processor : chunk_processors)
187 thread_pool.AddWork(&processor);
188 thread_pool.JoinAll();
189
190 // All the work done, disable logging.
191 blob_file->SetTotalBlobs(0);
192
193 // All the operations must have a type set at this point. Otherwise, a
194 // ChunkProcessor failed to complete.
195 for (const AnnotatedOperation& aop : *aops) {
196 if (!aop.op.has_type())
197 return false;
198 }
199 return true;
200 }
201
202 } // namespace chromeos_update_engine
203