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
diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index 84c93b1..d7a0b7e 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -35,9 +35,11 @@
"update_metadata-protos",
],
whole_static_libs: [
+ "libcutils",
"libext2_uuid",
"libext4_utils",
"libfstab",
+ "libsnapshot_snapuserd",
],
header_libs: [
"libchrome",
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 4bbdca3..bf57ce9 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -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 @@
// 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 @@
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 @@
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
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_server.h b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_server.h
index 6bcd666..181ee33 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_server.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapuserd_server.h
@@ -91,7 +91,7 @@
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);
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 6574457..c88c01a 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -56,6 +56,7 @@
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 @@
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 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 @@
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 @@
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 @@
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_) {