liblp: Allow specifying a custom block size when building sparse images.
liblp currently creates sparse files with a block size of 512 bytes.
Unfortunately devices can reject sparse files that don't have a specific
block size. To accomodate this, SparseBuilder now requires that
partition metadata be built with an explicit block size, and the device
alignment must be a multiple of that block size.
This change also modifies SerializeGeometry to automatically include
0-padding to 4096 bytes.
Bug: 79173901
Test: lpmake -S can be flashed with fastboot to walleye
Change-Id: Iab04f6f55bb373e21767963335c85ad1119a65a7
diff --git a/fs_mgr/liblp/images.cpp b/fs_mgr/liblp/images.cpp
index 93c5618..aeb339b 100644
--- a/fs_mgr/liblp/images.cpp
+++ b/fs_mgr/liblp/images.cpp
@@ -57,10 +57,9 @@
bool WriteToImageFile(int fd, const LpMetadata& input) {
std::string geometry = SerializeGeometry(input.geometry);
- std::string padding(LP_METADATA_GEOMETRY_SIZE - geometry.size(), '\0');
std::string metadata = SerializeMetadata(input);
- std::string everything = geometry + padding + metadata;
+ std::string everything = geometry + metadata;
if (!android::base::WriteFully(fd, everything.data(), everything.size())) {
PERROR << __PRETTY_FUNCTION__ << "write " << everything.size() << " bytes failed";
@@ -83,26 +82,29 @@
// to do this when the data pointers are all in one place.
class SparseBuilder {
public:
- explicit SparseBuilder(const LpMetadata& metadata);
+ SparseBuilder(const LpMetadata& metadata, uint32_t block_size);
bool Build();
bool Export(const char* file);
bool IsValid() const { return file_ != nullptr; }
private:
- bool AddData(const std::string& blob, uint32_t block);
+ bool AddData(const std::string& blob, uint64_t sector);
+ bool SectorToBlock(uint64_t sector, uint32_t* block);
const LpMetadata& metadata_;
const LpMetadataGeometry& geometry_;
+ uint32_t block_size_;
std::unique_ptr<sparse_file, decltype(&sparse_file_destroy)> file_;
- std::string geometry_blob_;
- std::string metadata_blob_;
+ std::string primary_blob_;
+ std::string backup_blob_;
};
-SparseBuilder::SparseBuilder(const LpMetadata& metadata)
+SparseBuilder::SparseBuilder(const LpMetadata& metadata, uint32_t block_size)
: metadata_(metadata),
geometry_(metadata.geometry),
- file_(sparse_file_new(LP_SECTOR_SIZE, geometry_.block_device_size), sparse_file_destroy) {}
+ block_size_(block_size),
+ file_(sparse_file_new(block_size_, geometry_.block_device_size), sparse_file_destroy) {}
bool SparseBuilder::Export(const char* file) {
android::base::unique_fd fd(open(file, O_CREAT | O_RDWR | O_TRUNC, 0644));
@@ -119,7 +121,11 @@
return true;
}
-bool SparseBuilder::AddData(const std::string& blob, uint32_t block) {
+bool SparseBuilder::AddData(const std::string& blob, uint64_t sector) {
+ uint32_t block;
+ if (!SectorToBlock(sector, &block)) {
+ return false;
+ }
void* data = const_cast<char*>(blob.data());
int ret = sparse_file_add_data(file_.get(), data, blob.size(), block);
if (ret != 0) {
@@ -129,22 +135,37 @@
return true;
}
-bool SparseBuilder::Build() {
- geometry_blob_ = SerializeGeometry(geometry_);
- geometry_blob_.resize(LP_METADATA_GEOMETRY_SIZE);
- if (!AddData(geometry_blob_, 0)) {
+bool SparseBuilder::SectorToBlock(uint64_t sector, uint32_t* block) {
+ // The caller must ensure that the metadata has an alignment that is a
+ // multiple of the block size. liblp will take care of the rest, ensuring
+ // that all partitions are on an aligned boundary. Therefore all writes
+ // should be block-aligned, and if they are not, the table was misconfigured.
+ // Note that the default alignment is 1MiB, which is a multiple of the
+ // default block size (4096).
+ if ((sector * LP_SECTOR_SIZE) % block_size_ != 0) {
+ LERROR << "sector " << sector << " is not aligned to block size " << block_size_;
return false;
}
+ *block = (sector * LP_SECTOR_SIZE) / block_size_;
+ return true;
+}
+
+bool SparseBuilder::Build() {
+ std::string geometry_blob = SerializeGeometry(geometry_);
+ std::string metadata_blob = SerializeMetadata(metadata_);
+ metadata_blob.resize(geometry_.metadata_max_size);
+
+ std::string all_metadata;
+ for (size_t i = 0; i < geometry_.metadata_slot_count; i++) {
+ all_metadata += metadata_blob;
+ }
// Metadata immediately follows geometry, and we write the same metadata
- // to all slots.
- uint32_t metadata_block = LP_METADATA_GEOMETRY_SIZE / LP_SECTOR_SIZE;
- metadata_blob_ = SerializeMetadata(metadata_);
- for (size_t i = 0; i < geometry_.metadata_slot_count; i++) {
- if (!AddData(metadata_blob_, metadata_block)) {
- return false;
- }
- metadata_block += geometry_.metadata_max_size / LP_SECTOR_SIZE;
+ // to all slots. Note that we don't bother trying to write skip chunks
+ // here since it's a small amount of data.
+ primary_blob_ = geometry_blob + all_metadata;
+ if (!AddData(primary_blob_, 0)) {
+ return false;
}
// The backup area contains all metadata slots, and then geometry. Similar
@@ -152,31 +173,32 @@
int64_t backup_offset = GetBackupMetadataOffset(geometry_, 0);
uint64_t backups_start = geometry_.block_device_size + backup_offset;
uint64_t backup_sector = backups_start / LP_SECTOR_SIZE;
- for (size_t i = 0; i < geometry_.metadata_slot_count; i++) {
- if (!AddData(metadata_blob_, backup_sector)) {
- return false;
- }
- backup_sector += geometry_.metadata_max_size / LP_SECTOR_SIZE;
- }
- if (!AddData(geometry_blob_, backup_sector)) {
+
+ backup_blob_ = all_metadata + geometry_blob;
+ if (!AddData(backup_blob_, backup_sector)) {
return false;
}
return true;
}
-bool WriteToSparseFile(const char* file, const LpMetadata& metadata) {
- uint64_t num_blocks =
- AlignTo(metadata.geometry.block_device_size, LP_SECTOR_SIZE) / LP_SECTOR_SIZE;
+bool WriteToSparseFile(const char* file, const LpMetadata& metadata, uint32_t block_size) {
+ if (block_size % LP_SECTOR_SIZE != 0) {
+ LERROR << "Block size must be a multiple of the sector size, " << LP_SECTOR_SIZE;
+ return false;
+ }
+ if (metadata.geometry.block_device_size % block_size != 0) {
+ LERROR << "Device size must be a multiple of the block size, " << block_size;
+ return false;
+ }
+ uint64_t num_blocks = metadata.geometry.block_device_size % block_size;
if (num_blocks >= UINT_MAX) {
- // libsparse counts blocks in unsigned 32-bit integers, but our block
- // size is rather low (512 bytes), since we operate in sectors.
- // Therefore the maximum block device size we can represent with a
- // sparse file is 2TB for now.
+ // libsparse counts blocks in unsigned 32-bit integers, so we check to
+ // make sure we're not going to overflow.
LERROR << "Block device is too large to encode with libsparse.";
return false;
}
- SparseBuilder builder(metadata);
+ SparseBuilder builder(metadata, block_size);
if (!builder.IsValid()) {
LERROR << "Could not allocate sparse file of size " << metadata.geometry.block_device_size;
return false;
diff --git a/fs_mgr/liblp/include/liblp/liblp.h b/fs_mgr/liblp/include/liblp/liblp.h
index c8d34d9..a9f01c6 100644
--- a/fs_mgr/liblp/include/liblp/liblp.h
+++ b/fs_mgr/liblp/include/liblp/liblp.h
@@ -59,7 +59,7 @@
// Read/Write logical partition metadata to an image file, for diagnostics or
// flashing.
-bool WriteToSparseFile(const char* file, const LpMetadata& metadata);
+bool WriteToSparseFile(const char* file, const LpMetadata& metadata, uint32_t block_size);
bool WriteToImageFile(const char* file, const LpMetadata& metadata);
std::unique_ptr<LpMetadata> ReadFromImageFile(const char* file);
diff --git a/fs_mgr/liblp/writer.cpp b/fs_mgr/liblp/writer.cpp
index 74c03bf..156319b 100644
--- a/fs_mgr/liblp/writer.cpp
+++ b/fs_mgr/liblp/writer.cpp
@@ -34,7 +34,10 @@
LpMetadataGeometry geometry = input;
memset(geometry.checksum, 0, sizeof(geometry.checksum));
SHA256(&geometry, sizeof(geometry), geometry.checksum);
- return std::string(reinterpret_cast<const char*>(&geometry), sizeof(geometry));
+
+ std::string blob(reinterpret_cast<const char*>(&geometry), sizeof(geometry));
+ blob.resize(LP_METADATA_GEOMETRY_SIZE);
+ return blob;
}
static bool CompareGeometry(const LpMetadataGeometry& g1, const LpMetadataGeometry& g2) {