libsnapshot: Integrate with snapuserd.

This integrates libsnapshot with dm-user and snapuserd. Tests progress
significantly further now. Tests involving merging still fail as
snapuserd doesn't support this yet.

Bug: 168554689
Test: vts_libsnapshot_test
Change-Id: I464b683b464fe29a646f0f2823b7f4434a878614
This commit is contained in:
David Anderson 2020-10-20 15:56:57 -07:00
parent 6a1e9ca279
commit 8e46846501
4 changed files with 111 additions and 1 deletions

View File

@ -35,9 +35,11 @@ cc_defaults {
"update_metadata-protos",
],
whole_static_libs: [
"libcutils",
"libext2_uuid",
"libext4_utils",
"libfstab",
"libsnapshot_snapuserd",
],
header_libs: [
"libchrome",

View File

@ -37,6 +37,7 @@
#include <libsnapshot/auto_device.h>
#include <libsnapshot/return.h>
#include <libsnapshot/snapshot_writer.h>
#include <libsnapshot/snapuserd_client.h>
#ifndef FRIEND_TEST
#define FRIEND_TEST(test_set_name, individual_test) \
@ -355,6 +356,9 @@ class SnapshotManager final : public ISnapshotManager {
// This is created lazily since it can connect via binder.
bool EnsureImageManager();
// Ensure we're connected to snapuserd.
bool EnsureSnapuserdConnected();
// Helper for first-stage init.
bool ForceLocalImageManager();
@ -411,6 +415,11 @@ class SnapshotManager final : public ISnapshotManager {
const std::string& cow_device, const std::chrono::milliseconds& timeout_ms,
std::string* dev_path);
// Create a dm-user device for a given snapshot.
bool MapDmUserCow(LockedFile* lock, const std::string& name, const std::string& cow_file,
const std::string& base_device, const std::chrono::milliseconds& timeout_ms,
std::string* path);
// Map a COW image that was previous created with CreateCowImage.
std::optional<std::string> MapCowImage(const std::string& name,
const std::chrono::milliseconds& timeout_ms);
@ -639,6 +648,7 @@ class SnapshotManager final : public ISnapshotManager {
std::unique_ptr<IImageManager> images_;
bool has_local_image_manager_ = false;
bool in_factory_data_reset_ = false;
std::unique_ptr<SnapuserdClient> snapuserd_client_;
};
} // namespace snapshot

View File

@ -91,7 +91,7 @@ class SnapuserdServer : public Stoppable {
bool HandleClient(android::base::borrowed_fd fd, int revents);
bool Recv(android::base::borrowed_fd fd, std::string* data);
bool Sendmsg(android::base::borrowed_fd fd, const std::string& msg);
bool Receivemsg(android::base::borrowed_fd fd, const std::string& msg);
bool Receivemsg(android::base::borrowed_fd fd, const std::string& str);
void ShutdownThreads();
bool WaitForDelete(const std::string& control_device);

View File

@ -56,6 +56,7 @@ using android::dm::DmDeviceState;
using android::dm::DmTable;
using android::dm::DmTargetLinear;
using android::dm::DmTargetSnapshot;
using android::dm::DmTargetUser;
using android::dm::kSectorSize;
using android::dm::SnapshotStorageMode;
using android::fiemap::FiemapStatus;
@ -115,6 +116,10 @@ static std::string GetCowName(const std::string& snapshot_name) {
return snapshot_name + "-cow";
}
static std::string GetDmUserCowName(const std::string& snapshot_name) {
return snapshot_name + "-user-cow";
}
static std::string GetCowImageDeviceName(const std::string& snapshot_name) {
return snapshot_name + "-cow-img";
}
@ -370,6 +375,45 @@ Return SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name
return Return(images_->CreateBackingImage(cow_image_name, status.cow_file_size(), cow_flags));
}
bool SnapshotManager::MapDmUserCow(LockedFile* lock, const std::string& name,
const std::string& cow_file, const std::string& base_device,
const std::chrono::milliseconds& timeout_ms, std::string* path) {
CHECK(lock);
auto& dm = DeviceMapper::Instance();
// Use the size of the base device for the COW device. It doesn't really
// matter, it just needs to look similar enough so the kernel doesn't complain
// about alignment or being too small.
uint64_t base_sectors = 0;
{
unique_fd fd(open(base_device.c_str(), O_RDONLY | O_CLOEXEC));
if (fd < 0) {
PLOG(ERROR) << "open failed: " << base_device;
return false;
}
auto dev_size = get_block_device_size(fd);
if (!dev_size) {
PLOG(ERROR) << "Could not determine block device size: " << base_device;
return false;
}
base_sectors = dev_size / kSectorSize;
}
DmTable table;
table.Emplace<DmTargetUser>(0, base_sectors, name);
if (!dm.CreateDevice(name, table, path, timeout_ms)) {
return false;
}
if (!EnsureSnapuserdConnected()) {
return false;
}
auto control_device = "/dev/dm-user/" + name;
return snapuserd_client_->InitializeSnapuserd(cow_file, base_device, control_device);
}
bool SnapshotManager::MapSnapshot(LockedFile* lock, const std::string& name,
const std::string& base_device, const std::string& cow_device,
const std::chrono::milliseconds& timeout_ms,
@ -1728,6 +1772,30 @@ bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock,
return true;
}
if (IsCompressionEnabled()) {
auto name = GetDmUserCowName(params.GetPartitionName());
// :TODO: need to force init to process uevents for these in first-stage.
std::string cow_path;
if (!GetMappedImageDevicePath(cow_name, &cow_path)) {
LOG(ERROR) << "Could not determine path for: " << cow_name;
return false;
}
std::string new_cow_device;
if (!MapDmUserCow(lock, name, cow_path, base_path, remaining_time, &new_cow_device)) {
LOG(ERROR) << "Could not map dm-user device for partition "
<< params.GetPartitionName();
return false;
}
created_devices.EmplaceBack<AutoUnmapDevice>(&dm, name);
remaining_time = GetRemainingTime(params.timeout_ms, begin);
if (remaining_time.count() < 0) return false;
cow_device = new_cow_device;
}
std::string path;
if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, remaining_time,
&path)) {
@ -1847,6 +1915,22 @@ bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name)
if (!EnsureImageManager()) return false;
auto& dm = DeviceMapper::Instance();
auto dm_user_name = GetDmUserCowName(name);
if (IsCompressionEnabled() && dm.GetState(dm_user_name) != DmDeviceState::INVALID) {
if (!EnsureSnapuserdConnected()) {
return false;
}
if (!dm.DeleteDevice(dm_user_name)) {
LOG(ERROR) << "Cannot unmap " << dm_user_name;
return false;
}
if (!snapuserd_client_->WaitForDeviceDelete("/dev/dm-user/" + dm_user_name)) {
LOG(ERROR) << "Failed to wait for " << dm_user_name << " control device to delete";
return false;
}
}
auto cow_name = GetCowName(name);
if (!dm.DeleteDeviceIfExists(cow_name)) {
LOG(ERROR) << "Cannot unmap " << cow_name;
@ -2117,6 +2201,20 @@ bool SnapshotManager::EnsureImageManager() {
return true;
}
bool SnapshotManager::EnsureSnapuserdConnected() {
if (!snapuserd_client_) {
if (!EnsureSnapuserdStarted()) {
return false;
}
snapuserd_client_ = SnapuserdClient::Connect(kSnapuserdSocket, 10s);
if (!snapuserd_client_) {
LOG(ERROR) << "Unable to connect to snapuserd";
return false;
}
}
return true;
}
bool SnapshotManager::ForceLocalImageManager() {
images_ = android::fiemap::ImageManager::Open(gsid_dir_);
if (!images_) {