Merge changes Ie9a781e4,I060788c9,Ie75e9440 into main (a49b8d22) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/snapuserd/Android.bp

+3 −2

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		@@ -60,13 +60,14 @@ cc_library_static {
		local_include_dirs: ["include/"],
		srcs: [
		"dm-snapshot-merge/snapuserd.cpp",
		"dm-snapshot-merge/snapuserd_worker.cpp",
		"dm-snapshot-merge/snapuserd_readahead.cpp",
		"dm-snapshot-merge/snapuserd_worker.cpp",
		"dm_user_block_server.cpp",
		"snapuserd_buffer.cpp",
		"user-space-merge/handler_manager.cpp",
		"user-space-merge/merge_worker.cpp",
		"user-space-merge/read_worker.cpp",
		"user-space-merge/snapuserd_core.cpp",
		"user-space-merge/snapuserd_merge.cpp",
		"user-space-merge/snapuserd_readahead.cpp",
		"user-space-merge/snapuserd_transitions.cpp",
		"user-space-merge/snapuserd_verify.cpp",

fs_mgr/libsnapshot/snapuserd/dm_user_block_server.cpp

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+146 −0

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		// Copyright (C) 2023 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 <snapuserd/dm_user_block_server.h>

		#include <android-base/file.h>
		#include <android-base/logging.h>
		#include <snapuserd/snapuserd_kernel.h>
		#include "snapuserd_logging.h"

		namespace android {
		namespace snapshot {

		using android::base::unique_fd;

		DmUserBlockServer::DmUserBlockServer(const std::string& misc_name, unique_fd&& ctrl_fd,
		Delegate* delegate, size_t buffer_size)
		: misc_name_(misc_name), ctrl_fd_(std::move(ctrl_fd)), delegate_(delegate) {
		buffer_.Initialize(sizeof(struct dm_user_header) + buffer_size);
		}

		bool DmUserBlockServer::ProcessRequests() {
		struct dm_user_header* header = buffer_.GetHeaderPtr();
		if (!android::base::ReadFully(ctrl_fd_, header, sizeof(*header))) {
		if (errno != ENOTBLK) {
		SNAP_PLOG(ERROR) << "Control-read failed";
		}

		SNAP_PLOG(DEBUG) << "ReadDmUserHeader failed....";
		return false;
		}

		SNAP_LOG(DEBUG) << "Daemon: msg->seq: " << std::dec << header->seq;
		SNAP_LOG(DEBUG) << "Daemon: msg->len: " << std::dec << header->len;
		SNAP_LOG(DEBUG) << "Daemon: msg->sector: " << std::dec << header->sector;
		SNAP_LOG(DEBUG) << "Daemon: msg->type: " << std::dec << header->type;
		SNAP_LOG(DEBUG) << "Daemon: msg->flags: " << std::dec << header->flags;

		if (!ProcessRequest(header)) {
		if (header->type != DM_USER_RESP_ERROR) {
		SendError();
		}
		return false;
		}
		return true;
		}

		bool DmUserBlockServer::ProcessRequest(dm_user_header* header) {
		// Use the same header buffer as the response header.
		int request_type = header->type;
		header->type = DM_USER_RESP_SUCCESS;
		header_response_ = true;

		// Reset the output buffer.
		buffer_.ResetBufferOffset();

		switch (request_type) {
		case DM_USER_REQ_MAP_READ:
		return delegate_->RequestSectors(header->sector, header->len);

		case DM_USER_REQ_MAP_WRITE:
		// We should not get any write request to dm-user as we mount all
		// partitions as read-only.
		SNAP_LOG(ERROR) << "Unexpected write request from dm-user";
		return false;

		default:
		SNAP_LOG(ERROR) << "Unexpected request from dm-user: " << request_type;
		return false;
		}
		}

		void* DmUserBlockServer::GetResponseBuffer(size_t size, size_t to_write) {
		return buffer_.AcquireBuffer(size, to_write);
		}

		bool DmUserBlockServer::SendBufferedIo() {
		return WriteDmUserPayload(buffer_.GetPayloadBytesWritten());
		}

		void DmUserBlockServer::SendError() {
		struct dm_user_header* header = buffer_.GetHeaderPtr();
		header->type = DM_USER_RESP_ERROR;
		// This is an issue with the dm-user interface. There
		// is no way to propagate the I/O error back to dm-user
		// if we have already communicated the header back. Header
		// is responded once at the beginning; however I/O can
		// be processed in chunks. If we encounter an I/O error
		// somewhere in the middle of the processing, we can't communicate
		// this back to dm-user.
		//
		// TODO: Fix the interface
		CHECK(header_response_);

		WriteDmUserPayload(0);
		}

		bool DmUserBlockServer::WriteDmUserPayload(size_t size) {
		size_t payload_size = size;
		void* buf = buffer_.GetPayloadBufPtr();
		if (header_response_) {
		payload_size += sizeof(struct dm_user_header);
		buf = buffer_.GetBufPtr();
		}

		if (!android::base::WriteFully(ctrl_fd_, buf, payload_size)) {
		SNAP_PLOG(ERROR) << "Write to dm-user failed size: " << payload_size;
		return false;
		}

		// After the first header is sent in response to a request, we cannot
		// send any additional headers.
		header_response_ = false;

		// Reset the buffer for use by the next request.
		buffer_.ResetBufferOffset();
		return true;
		}

		DmUserBlockServerOpener::DmUserBlockServerOpener(const std::string& misc_name,
		const std::string& dm_user_path)
		: misc_name_(misc_name), dm_user_path_(dm_user_path) {}

		std::unique_ptr<IBlockServer> DmUserBlockServerOpener::Open(IBlockServer::Delegate* delegate,
		size_t buffer_size) {
		unique_fd fd(open(dm_user_path_.c_str(), O_RDWR \| O_CLOEXEC));
		if (fd < 0) {
		SNAP_PLOG(ERROR) << "Could not open dm-user path: " << dm_user_path_;
		return nullptr;
		}
		return std::make_unique<DmUserBlockServer>(misc_name_, std::move(fd), delegate, buffer_size);
		}

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapuserd/include/snapuserd/block_server.h

0 → 100644

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		// Copyright (C) 2023 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.

		#pragma once

		#include <stddef.h>
		#include <stdint.h>

		#include <memory>

		namespace android {
		namespace snapshot {

		// These interfaces model the block device driver component of snapuserd (eg,
		// dm-user).

		// An open connection to a userspace block device control
		class IBlockServer {
		public:
		class Delegate {
		public:
		virtual ~Delegate() {}

		// Respond to a request for reading a contiguous run of sectors. This
		// call should be followed by calls to GetResponseBuffer/CommitBuffer
		// until the \|size\| is fulfilled.
		//
		// If false is returned, an error will be automatically reported unless
		// SendError was called.
		virtual bool RequestSectors(uint64_t sector, uint64_t size) = 0;
		};

		virtual ~IBlockServer() {}

		// Process I/O requests. This can block the worker thread until either a
		// request is available or the underlying connection has been destroyed.
		//
		// True indicates that one or more requests was processed. False indicates
		// an unrecoverable condition and processing should stop.
		virtual bool ProcessRequests() = 0;

		// Return a buffer for fulfilling a RequestSectors request. This buffer
		// is valid until calling SendBufferedIo. This cannot be called outside
		// of RequestSectors().
		//
		// "to_write" must be <= "size". If it is < size, the excess bytes are
		// available for writing, but will not be send via SendBufferedIo, and
		// may be reallocated in the next call to GetResponseBuffer.
		//
		// All buffers returned are invalidated after SendBufferedIo or returning
		// control from RequestSectors.
		virtual void* GetResponseBuffer(size_t size, size_t to_write) = 0;

		// Send all outstanding buffers to the driver, in order. This should
		// be called at least once in response to RequestSectors. This returns
		// ownership of any buffers returned by GetResponseBuffer.
		//
		// If false is returned, an error is automatically reported to the driver.
		virtual bool SendBufferedIo() = 0;

		void* GetResponseBuffer(size_t size) { return GetResponseBuffer(size, size); }
		};

		class IBlockServerOpener {
		public:
		virtual ~IBlockServerOpener() = default;

		// Open a connection to the service. This is called on the daemon thread.
		//
		// buffer_size is the maximum amount of buffered I/O to use.
		virtual std::unique_ptr<IBlockServer> Open(IBlockServer::Delegate* delegate,
		size_t buffer_size) = 0;
		};

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapuserd/include/snapuserd/dm_user_block_server.h

0 → 100644

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		// Copyright (C) 2023 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.

		#pragma once

		#include <android-base/unique_fd.h>

		#include <string>

		#include <snapuserd/block_server.h>
		#include <snapuserd/snapuserd_buffer.h>

		namespace android {
		namespace snapshot {

		class DmUserBlockServer : public IBlockServer {
		public:
		DmUserBlockServer(const std::string& misc_name, android::base::unique_fd&& ctrl_fd,
		Delegate* delegate, size_t buffer_size);

		bool ProcessRequests() override;
		void* GetResponseBuffer(size_t size, size_t to_write) override;
		bool SendBufferedIo() override;
		void SendError();

		private:
		bool ProcessRequest(dm_user_header* header);
		bool WriteDmUserPayload(size_t size);

		std::string misc_name_;
		android::base::unique_fd ctrl_fd_;
		Delegate* delegate_;

		// Per-request state.
		BufferSink buffer_;
		bool header_response_ = false;
		};

		class DmUserBlockServerOpener : public IBlockServerOpener {
		public:
		DmUserBlockServerOpener(const std::string& misc_name, const std::string& dm_user_path);

		std::unique_ptr<IBlockServer> Open(IBlockServer::Delegate* delegate,
		size_t buffer_size) override;

		private:
		std::string misc_name_;
		std::string dm_user_path_;
		};

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapuserd/snapuserd_logging.h

0 → 100644

+20 −0

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		// Copyright (C) 2023 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.

		#pragma once

		#include <android-base/logging.h>

		#define SNAP_LOG(level) LOG(level) << misc_name_ << ": "
		#define SNAP_PLOG(level) PLOG(level) << misc_name_ << ": "