Merge changes I49495684,I0db2e0f4,I07bb811b am: 67665a4571 am: f6016177f2 am:... (cfe6ac39) · Commits · e / os / android_system_core

fs_mgr/libdm/Android.bp

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -42,6 +42,7 @@ cc_library_static {
	enabled: false,		enabled: false,
	},		},
	},		},
			ramdisk_available: true,
	}		}

	filegroup {		filegroup {

fs_mgr/libsnapshot/Android.bp

+33 −0

Original line number	Original line	Diff line number	Diff line
	@@ -310,3 +310,36 @@ cc_test {
	auto_gen_config: true,		auto_gen_config: true,
	require_root: true,		require_root: true,
	}		}

			cc_defaults {
			name: "snapuserd_defaults",
			srcs: [
			"snapuserd.cpp",
			],

			cflags: [
			"-Wall",
			"-Werror"
			],

			static_libs: [
			"libbase",
			"liblog",
			"libdm",
			],
			}

			cc_binary {
			name: "snapuserd",
			defaults: ["snapuserd_defaults"],
			}

			cc_binary {
			name: "snapuserd_ramdisk",
			stem: "snapuserd",
			defaults: ["snapuserd_defaults"],

			ramdisk: true,
			static_executable: true,
			system_shared_libs: [],
			}

fs_mgr/libsnapshot/snapuserd.cpp

0 → 100644

+126 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Copyright (C) 2020 The Android Open Source Project
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			#include <linux/types.h>

			#include <android-base/file.h>
			#include <android-base/logging.h>
			#include <android-base/stringprintf.h>
			#include <android-base/unique_fd.h>
			#include <libdm/dm.h>

			using android::base::unique_fd;

			#define DM_USER_MAP_READ 0
			#define DM_USER_MAP_WRITE 1

			struct dm_user_message {
			__u64 seq;
			__u64 type;
			__u64 flags;
			__u64 sector;
			__u64 len;
			__u8 buf[];
			};

			using namespace android::dm;

			static int daemon_main(const std::string& device) {
			unique_fd block_fd(open(device.c_str(), O_RDWR));
			if (block_fd < 0) {
			PLOG(ERROR) << "Unable to open " << device;
			return 1;
			}

			unique_fd ctrl_fd(open("/dev/dm-user", O_RDWR));
			if (ctrl_fd < 0) {
			PLOG(ERROR) << "Unable to open /dev/dm-user";
			return 1;
			}

			size_t buf_size = 1UL << 16;
			auto buf = std::make_unique<char>(buf_size);

			/* Just keeps pumping messages between userspace and the kernel. We won't
			* actually be doing anything, but the sequence numbers line up so it'll at
			* least make forward progress. */
			while (true) {
			struct dm_user_message* msg = (struct dm_user_message*)buf.get();

			memset(buf.get(), 0, buf_size);

			ssize_t readed = read(ctrl_fd.get(), buf.get(), buf_size);
			if (readed < 0) {
			PLOG(ERROR) << "Control read failed, trying with more space";
			buf_size *= 2;
			buf = std::make_unique<char>(buf_size);
			continue;
			}

			LOG(DEBUG) << android::base::StringPrintf("read() from dm-user returned %d bytes:",
			(int)readed);
			LOG(DEBUG) << android::base::StringPrintf(" msg->seq: 0x%016llx", msg->seq);
			LOG(DEBUG) << android::base::StringPrintf(" msg->type: 0x%016llx", msg->type);
			LOG(DEBUG) << android::base::StringPrintf(" msg->flags: 0x%016llx", msg->flags);
			LOG(DEBUG) << android::base::StringPrintf(" msg->sector: 0x%016llx", msg->sector);
			LOG(DEBUG) << android::base::StringPrintf(" msg->len: 0x%016llx", msg->len);

			switch (msg->type) {
			case DM_USER_MAP_READ: {
			LOG(DEBUG) << android::base::StringPrintf(
			"Responding to read of sector %lld with %lld bytes data", msg->sector,
			msg->len);

			if ((sizeof(*msg) + msg->len) > buf_size) {
			auto old_buf = std::move(buf);
			buf_size = sizeof(*msg) + msg->len;
			buf = std::make_unique<char>(buf_size);
			memcpy(buf.get(), old_buf.get(), sizeof(*msg));
			msg = (struct dm_user_message*)buf.get();
			}

			if (lseek(block_fd.get(), msg->sector * 512, SEEK_SET) < 0) {
			PLOG(ERROR) << "lseek failed: " << device;
			return 7;
			}
			if (!android::base::ReadFully(block_fd.get(), msg->buf, msg->len)) {
			PLOG(ERROR) << "read failed: " << device;
			return 7;
			}

			if (!android::base::WriteFully(ctrl_fd.get(), buf.get(), sizeof(*msg) + msg->len)) {
			PLOG(ERROR) << "write control failed";
			return 3;
			}
			break;
			}

			case DM_USER_MAP_WRITE:
			abort();
			break;
			}

			LOG(DEBUG) << "read() finished, next message";
			}

			return 0;
			}

			int main([[maybe_unused]] int argc, char** argv) {
			android::base::InitLogging(argv, &android::base::KernelLogger);
			daemon_main(argv[1]);
			return 0;
			}

init/block_dev_initializer.cpp

+12 −4

Original line number	Original line	Diff line number	Diff line
	@@ -37,7 +37,15 @@ BlockDevInitializer::BlockDevInitializer() : uevent_listener_(16 * 1024 * 1024)
	}		}

	bool BlockDevInitializer::InitDeviceMapper() {		bool BlockDevInitializer::InitDeviceMapper() {
	const std::string dm_path = "/devices/virtual/misc/device-mapper";		return InitMiscDevice("device-mapper");
			}

			bool BlockDevInitializer::InitDmUser() {
			return InitMiscDevice("dm-user");
			}

			bool BlockDevInitializer::InitMiscDevice(const std::string& name) {
			const std::string dm_path = "/devices/virtual/misc/" + name;
	bool found = false;		bool found = false;
	auto dm_callback = [this, &dm_path, &found](const Uevent& uevent) {		auto dm_callback = [this, &dm_path, &found](const Uevent& uevent) {
	if (uevent.path == dm_path) {		if (uevent.path == dm_path) {
	@@ -49,13 +57,13 @@ bool BlockDevInitializer::InitDeviceMapper() {
	};		};
	uevent_listener_.RegenerateUeventsForPath("/sys" + dm_path, dm_callback);		uevent_listener_.RegenerateUeventsForPath("/sys" + dm_path, dm_callback);
	if (!found) {		if (!found) {
	LOG(INFO) << "device-mapper device not found in /sys, waiting for its uevent";		LOG(INFO) << name << " device not found in /sys, waiting for its uevent";
	Timer t;		Timer t;
	uevent_listener_.Poll(dm_callback, 10s);		uevent_listener_.Poll(dm_callback, 10s);
	LOG(INFO) << "Wait for device-mapper returned after " << t;		LOG(INFO) << "Wait for " << name << " returned after " << t;
	}		}
	if (!found) {		if (!found) {
	LOG(ERROR) << "device-mapper device not found after polling timeout";		LOG(ERROR) << name << " device not found after polling timeout";
	return false;		return false;
	}		}
	return true;		return true;

init/block_dev_initializer.h

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -27,12 +27,15 @@ class BlockDevInitializer final {
	BlockDevInitializer();		BlockDevInitializer();

	bool InitDeviceMapper();		bool InitDeviceMapper();
			bool InitDmUser();
	bool InitDevices(std::set<std::string> devices);		bool InitDevices(std::set<std::string> devices);
	bool InitDmDevice(const std::string& device);		bool InitDmDevice(const std::string& device);

	private:		private:
	ListenerAction HandleUevent(const Uevent& uevent, std::set<std::string>* devices);		ListenerAction HandleUevent(const Uevent& uevent, std::set<std::string>* devices);

			bool InitMiscDevice(const std::string& name);

	std::unique_ptr<DeviceHandler> device_handler_;		std::unique_ptr<DeviceHandler> device_handler_;
	UeventListener uevent_listener_;		UeventListener uevent_listener_;
	};		};