Merge "snapuserd: remove implicit assumption about dm-user in BufferSink" into main (2007e0cc) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/snapuserd/dm_user_block_server.cpp

+5 −3

Original line number	Diff line number	Diff line
		@@ -27,11 +27,12 @@ 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(buffer_size);
		buffer_.Initialize(sizeof(struct dm_user_header), buffer_size);
		}

		bool DmUserBlockServer::ProcessRequests() {
		struct dm_user_header* header = buffer_.GetHeaderPtr();
		struct dm_user_header* header =
		reinterpret_cast<struct dm_user_header*>(buffer_.GetHeaderPtr());
		if (!android::base::ReadFully(ctrl_fd_, header, sizeof(*header))) {
		if (errno != ENOTBLK) {
		SNAP_PLOG(ERROR) << "Control-read failed";
		@@ -90,7 +91,8 @@ bool DmUserBlockServer::SendBufferedIo() {
		}

		void DmUserBlockServer::SendError() {
		struct dm_user_header* header = buffer_.GetHeaderPtr();
		struct dm_user_header* header =
		reinterpret_cast<struct dm_user_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

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

+1 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@

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

		namespace android {
		namespace snapshot {

fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_buffer.h

+7 −2

Original line number	Diff line number	Diff line
		@@ -27,13 +27,17 @@ namespace snapshot {

		class BufferSink final {
		public:
		void Initialize(size_t size);
		// Do not reserve any space of header by default
		void Initialize(size_t size) { return Initialize(0, size); };
		// This allows to set const header_size_ to be used if caller needs it
		// for example, while working with dm_user
		void Initialize(size_t header_size, size_t size);
		void* GetBufPtr() { return buffer_.get(); }
		void Clear() { memset(GetBufPtr(), 0, buffer_size_); }
		void* GetPayloadBuffer(size_t size);
		void* GetBuffer(size_t requested, size_t* actual);
		void UpdateBufferOffset(size_t size) { buffer_offset_ += size; }
		struct dm_user_header* GetHeaderPtr();
		void* GetHeaderPtr();
		void ResetBufferOffset() { buffer_offset_ = 0; }
		void* GetPayloadBufPtr();
		loff_t GetPayloadBytesWritten() { return buffer_offset_; }
		@@ -56,6 +60,7 @@ class BufferSink final {
		std::unique_ptr<uint8_t[]> buffer_;
		loff_t buffer_offset_;
		size_t buffer_size_;
		size_t header_size_;
		};

		} // namespace snapshot

fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_kernel.h

+0 −10

Original line number	Diff line number	Diff line
		@@ -92,15 +92,5 @@ struct dm_user_header {
		__u64 len;
		} __attribute__((packed));

		struct dm_user_payload {
		__u8 buf[];
		};

		// Message comprising both header and payload
		struct dm_user_message {
		struct dm_user_header header;
		struct dm_user_payload payload;
		};

		} // namespace snapshot
		} // namespace android

fs_mgr/libsnapshot/snapuserd/snapuserd_buffer.cpp

+11 −11

Original line number	Diff line number	Diff line
		@@ -22,8 +22,9 @@
		namespace android {
		namespace snapshot {

		void BufferSink::Initialize(size_t size) {
		buffer_size_ = size + sizeof(struct dm_user_header);
		void BufferSink::Initialize(size_t header_size, size_t size) {
		header_size_ = header_size;
		buffer_size_ = size + header_size;
		buffer_offset_ = 0;
		buffer_ = std::make_unique<uint8_t[]>(buffer_size_);
		}
		@@ -41,11 +42,11 @@ void* BufferSink::AcquireBuffer(size_t size, size_t to_write) {

		void* BufferSink::GetPayloadBuffer(size_t size) {
		char* buffer = reinterpret_cast<char*>(GetBufPtr());
		struct dm_user_message* msg = (struct dm_user_message*)(&(buffer[0]));
		if ((buffer_size_ - buffer_offset_ - sizeof(msg->header)) < size) {

		if ((buffer_size_ - buffer_offset_ - header_size_) < size) {
		return nullptr;
		}
		return (char*)msg->payload.buf + buffer_offset_;
		return (char*)(&buffer[0] + header_size_ + buffer_offset_);
		}

		void* BufferSink::GetBuffer(size_t requested, size_t* actual) {
		@@ -58,19 +59,18 @@ void* BufferSink::GetBuffer(size_t requested, size_t* actual) {
		return buf;
		}

		struct dm_user_header* BufferSink::GetHeaderPtr() {
		if (!(sizeof(struct dm_user_header) <= buffer_size_)) {
		void* BufferSink::GetHeaderPtr() {
		// If no sufficient space or header not reserved
		if (!(header_size_ <= buffer_size_) \|\| !header_size_) {
		return nullptr;
		}
		char* buf = reinterpret_cast<char*>(GetBufPtr());
		struct dm_user_header* header = (struct dm_user_header*)(&(buf[0]));
		return header;
		return (void*)(&(buf[0]));
		}

		void* BufferSink::GetPayloadBufPtr() {
		char* buffer = reinterpret_cast<char*>(GetBufPtr());
		struct dm_user_message* msg = reinterpret_cast<struct dm_user_message*>(&(buffer[0]));
		return msg->payload.buf;
		return &buffer[header_size_];
		}

		} // namespace snapshot