Add io_uring support to fastboot (682e5b53) · Commits · e / os / android_system_core

fastboot/Android.bp

+3 −0

Original line number	Diff line number	Diff line
		@@ -154,6 +154,7 @@ cc_binary {
		"device/flashing.cpp",
		"device/main.cpp",
		"device/usb.cpp",
		"device/usb_iouring.cpp",
		"device/usb_client.cpp",
		"device/tcp_client.cpp",
		"device/utility.cpp",
		@@ -195,7 +196,9 @@ cc_binary {
		"liblz4",
		"libsnapshot_nobinder",
		"update_metadata-protos",
		"liburing",
		],
		include_dirs: ["bionic/libc/kernel"],

		header_libs: [
		"avb_headers",

fastboot/device/usb.cpp

+33 −18

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		*/

		#include "usb.h"
		#include "usb_iouring.h"

		#include <dirent.h>
		#include <errno.h>
		@@ -28,6 +29,7 @@

		#include <linux/usb/ch9.h>
		#include <linux/usb/functionfs.h>
		#include <sys/utsname.h>

		#include <algorithm>
		#include <atomic>
		@@ -38,6 +40,7 @@

		#include <android-base/logging.h>
		#include <android-base/properties.h>
		#include <liburing.h>

		using namespace std::chrono_literals;

		@@ -65,8 +68,8 @@ static void aio_block_init(aio_block* aiob, unsigned num_bufs) {
		}
		}

		static int getMaxPacketSize(int ffs_fd) {
		usb_endpoint_descriptor desc;
		int getMaxPacketSize(int ffs_fd) {
		usb_endpoint_descriptor desc{};
		if (ioctl(ffs_fd, FUNCTIONFS_ENDPOINT_DESC, reinterpret_cast<unsigned long>(&desc))) {
		D("[ could not get endpoint descriptor! (%d) ]", errno);
		return MAX_PACKET_SIZE_HS;
		@@ -128,11 +131,9 @@ static int usb_ffs_read(usb_handle* h, void* data, int len, bool allow_partial)

		static int usb_ffs_do_aio(usb_handle* h, const void* data, int len, bool read) {
		aio_block* aiob = read ? &h->read_aiob : &h->write_aiob;
		bool zero_packet = false;

		int num_bufs = len / h->io_size + (len % h->io_size == 0 ? 0 : 1);
		const char* cur_data = reinterpret_cast<const char*>(data);
		int packet_size = getMaxPacketSize(aiob->fd);

		if (posix_madvise(const_cast<void*>(data), len, POSIX_MADV_SEQUENTIAL \| POSIX_MADV_WILLNEED) <
		0) {
		@@ -145,17 +146,6 @@ static int usb_ffs_do_aio(usb_handle* h, const void* data, int len, bool read) {

		len -= buf_len;
		cur_data += buf_len;

		if (len == 0 && buf_len % packet_size == 0 && read) {
		// adb does not expect the device to send a zero packet after data transfer,
		// but the host does send a zero packet for the device to read.
		zero_packet = h->reads_zero_packets;
		}
		}
		if (zero_packet) {
		io_prep(&aiob->iocb[num_bufs], aiob->fd, reinterpret_cast<const void*>(cur_data),
		packet_size, 0, read);
		num_bufs += 1;
		}

		while (true) {
		@@ -204,21 +194,46 @@ static void usb_ffs_close(usb_handle* h) {
		h->open_new_connection = true;
		h->lock.unlock();
		h->notify.notify_one();
		if (h->aio_type == AIOType::IO_URING) {
		exit_io_uring_ffs(h);
		}
		}

		usb_handle* create_usb_handle(unsigned num_bufs, unsigned io_size) {
		usb_handle* h = new usb_handle();
		bool DoesKernelSupportIouring() {
		struct utsname uts {};
		unsigned int major = 0, minor = 0;
		if ((uname(&uts) != 0) \|\| (sscanf(uts.release, "%u.%u", &major, &minor) != 2)) {
		return false;
		}
		if (major > 5) {
		return true;
		}
		// We will only support kernels from 5.6 onwards as IOSQE_ASYNC flag and
		// IO_URING_OP_READ/WRITE opcodes were introduced only on 5.6 kernel
		return minor >= 6;
		}

		if (android::base::GetBoolProperty("sys.usb.ffs.aio_compat", false)) {
		std::unique_ptr<usb_handle> create_usb_handle(unsigned num_bufs, unsigned io_size) {
		auto h = std::make_unique<usb_handle>();
		if (DoesKernelSupportIouring() &&
		android::base::GetBoolProperty("sys.usb.ffs.io_uring_enabled", false)) {
		init_io_uring_ffs(h.get(), num_bufs);
		h->aio_type = AIOType::IO_URING;
		LOG(INFO) << "Using io_uring for usb ffs";
		} else if (android::base::GetBoolProperty("sys.usb.ffs.aio_compat", false)) {
		// Devices on older kernels (< 3.18) will not have aio support for ffs
		// unless backported. Fall back on the non-aio functions instead.
		h->write = usb_ffs_write;
		h->read = usb_ffs_read;
		h->aio_type = AIOType::SYNC_IO;
		LOG(INFO) << "Using sync io for usb ffs";
		} else {
		h->write = usb_ffs_aio_write;
		h->read = usb_ffs_aio_read;
		aio_block_init(&h->read_aiob, num_bufs);
		aio_block_init(&h->write_aiob, num_bufs);
		h->aio_type = AIOType::AIO;
		LOG(INFO) << "Using aio for usb ffs";
		}
		h->io_size = io_size;
		h->close = usb_ffs_close;

fastboot/device/usb.h

+9 −4

Original line number	Diff line number	Diff line
		@@ -18,8 +18,10 @@

		#include <linux/usb/functionfs.h>

		#include <liburing.h>
		#include <atomic>
		#include <condition_variable>
		#include <memory>
		#include <mutex>
		#include <vector>

		@@ -35,9 +37,11 @@ struct aio_block {
		int fd;
		};

		struct usb_handle {
		usb_handle() {}
		int getMaxPacketSize(int ffs_fd);

		enum class AIOType { SYNC_IO, AIO, IO_URING };

		struct usb_handle {
		std::condition_variable notify;
		std::mutex lock;
		bool open_new_connection = true;
		@@ -56,8 +60,9 @@ struct usb_handle {
		struct aio_block read_aiob;
		struct aio_block write_aiob;

		bool reads_zero_packets;
		io_uring ring;
		size_t io_size;
		AIOType aio_type;
		};

		usb_handle* create_usb_handle(unsigned num_bufs, unsigned io_size);
		std::unique_ptr<usb_handle> create_usb_handle(unsigned num_bufs, unsigned io_size);

fastboot/device/usb_client.cpp

+0 −1

Original line number	Diff line number	Diff line
		@@ -232,7 +232,6 @@ static bool InitFunctionFs(usb_handle* h) {

		h->read_aiob.fd = h->bulk_out.get();
		h->write_aiob.fd = h->bulk_in.get();
		h->reads_zero_packets = false;
		return true;

		err:

fastboot/device/usb_iouring.cpp

0 → 100644

+140 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2022 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 <android-base/logging.h>
		#include <liburing.h>
		#include "liburing/io_uring.h"
		#include "usb.h"

		static int prep_async_read(struct io_uring* ring, int fd, void* data, size_t len, int64_t offset) {
		if (io_uring_sq_space_left(ring) <= 0) {
		LOG(ERROR) << "Submission queue run out of space.";
		return -1;
		}
		auto sqe = io_uring_get_sqe(ring);
		if (sqe == nullptr) {
		return -1;
		}
		io_uring_sqe_set_flags(sqe, IOSQE_IO_LINK \| IOSQE_ASYNC);
		io_uring_prep_read(sqe, fd, data, len, offset);
		return 0;
		}

		static int prep_async_write(struct io_uring* ring, int fd, const void* data, size_t len,
		int64_t offset) {
		if (io_uring_sq_space_left(ring) <= 0) {
		LOG(ERROR) << "Submission queue run out of space.";
		return -1;
		}
		auto sqe = io_uring_get_sqe(ring);
		if (sqe == nullptr) {
		return -1;
		}
		io_uring_sqe_set_flags(sqe, IOSQE_IO_LINK \| IOSQE_ASYNC);
		io_uring_prep_write(sqe, fd, data, len, offset);
		return 0;
		}

		template <bool read, typename T>
		int prep_async_io(struct io_uring* ring, int fd, T* data, size_t len, int64_t offset) {
		if constexpr (read) {
		return prep_async_read(ring, fd, data, len, offset);
		} else {
		return prep_async_write(ring, fd, data, len, offset);
		}
		}

		template <typename T>
		static constexpr T DivRoundup(T x, T y) {
		return (x + y - 1) / y;
		}

		extern int getMaxPacketSize(int ffs_fd);

		template <bool read, typename T>
		static int usb_ffs_do_aio(usb_handle* h, T* const data, const int len) {
		const aio_block* aiob = read ? &h->read_aiob : &h->write_aiob;
		const int num_requests = DivRoundup<int>(len, h->io_size);
		auto cur_data = data;
		const auto packet_size = getMaxPacketSize(aiob->fd);

		for (int bytes_remain = len; bytes_remain > 0;) {
		const int buf_len = std::min(bytes_remain, static_cast<int>(h->io_size));
		const auto ret = prep_async_io<read>(&h->ring, aiob->fd, cur_data, buf_len, 0);
		if (ret < 0) {
		PLOG(ERROR) << "Failed to queue io_uring request";
		return -1;
		}

		bytes_remain -= buf_len;
		cur_data = reinterpret_cast<T*>(reinterpret_cast<size_t>(cur_data) + buf_len);
		}
		const int ret = io_uring_submit(&h->ring);
		if (ret <= 0 \|\| ret != num_requests) {
		PLOG(ERROR) << "io_uring: failed to submit SQE entries to kernel";
		return -1;
		}
		int res = 0;
		bool success = true;
		for (int i = 0; i < num_requests; ++i) {
		struct io_uring_cqe* cqe{};
		const auto ret = TEMP_FAILURE_RETRY(io_uring_wait_cqe(&h->ring, &cqe));
		if (ret < 0 \|\| cqe == nullptr) {
		PLOG(ERROR) << "Failed to get CQE from kernel";
		success = false;
		continue;
		}
		res += cqe->res;
		if (cqe->res < 0) {
		LOG(ERROR) << "io_uring request failed:, i = " << i
		<< ", num_requests = " << num_requests << ", res = " << cqe->res << ": "
		<< strerror(cqe->res) << (read ? " read" : " write")
		<< " request size: " << len << ", io_size: " << h->io_size
		<< " max packet size: " << packet_size << ", fd: " << aiob->fd;
		success = false;
		errno = -cqe->res;
		}
		io_uring_cqe_seen(&h->ring, cqe);
		}
		if (!success) {
		return -1;
		}
		return res;
		}

		static int usb_ffs_io_uring_read(usb_handle* h, void* data, int len, bool /* allow_partial */) {
		return usb_ffs_do_aio<true>(h, data, len);
		}

		static int usb_ffs_io_uring_write(usb_handle* h, const void* data, int len) {
		return usb_ffs_do_aio<false>(h, data, len);
		}

		void exit_io_uring_ffs(usb_handle* h) {
		io_uring_queue_exit(&h->ring);
		}

		bool init_io_uring_ffs(usb_handle* h, size_t queue_depth) {
		const auto err = io_uring_queue_init(queue_depth, &h->ring, 0);
		if (err) {
		LOG(ERROR) << "Failed to initialize io_uring of depth " << queue_depth << ": "
		<< strerror(err);
		return false;
		}
		h->write = usb_ffs_io_uring_write;
		h->read = usb_ffs_io_uring_read;
		return true;
		}