Switch MtpFfsHandle to aio, add control functions.
MtpFfsHandle now uses kaio to handle usb data.
This achieves better performance without using
the endpoint alloc ioctl.
This also allows ep0 events to be handled without
race conditions. Events will also include control
requests, which will allow both host and device
initiated cancellation.
Bug: 37916658
Bug: 36802721
Test: Transfer various size files, run MtpFfsHandleTest
Test: Cancel transfer on Windows
Test: Allow device to cancel transfer on Windows
Change-Id: Ib3ce996f00782ce7f68f29b2510dbc17f09fdf14
diff --git a/media/mtp/MtpFfsCompatHandle.cpp b/media/mtp/MtpFfsCompatHandle.cpp
new file mode 100644
index 0000000..3dd73f3
--- /dev/null
+++ b/media/mtp/MtpFfsCompatHandle.cpp
@@ -0,0 +1,342 @@
+/*
+ * Copyright (C) 2017 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 <android-base/properties.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/functionfs.h>
+#include <mutex>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/endian.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "PosixAsyncIO.h"
+#include "MtpFfsCompatHandle.h"
+#include "mtp.h"
+
+#define FUNCTIONFS_ENDPOINT_ALLOC _IOR('g', 231, __u32)
+
+namespace {
+
+// Must be divisible by all max packet size values
+constexpr int MAX_FILE_CHUNK_SIZE = 3145728;
+
+// Safe values since some devices cannot handle large DMAs
+// To get good performance, override these with
+// higher values per device using the properties
+// sys.usb.ffs.max_read and sys.usb.ffs.max_write
+constexpr int USB_FFS_MAX_WRITE = MTP_BUFFER_SIZE;
+constexpr int USB_FFS_MAX_READ = MTP_BUFFER_SIZE;
+
+static_assert(USB_FFS_MAX_WRITE > 0, "Max r/w values must be > 0!");
+static_assert(USB_FFS_MAX_READ > 0, "Max r/w values must be > 0!");
+
+constexpr unsigned int MAX_MTP_FILE_SIZE = 0xFFFFFFFF;
+
+constexpr size_t ENDPOINT_ALLOC_RETRIES = 10;
+
+} // anonymous namespace
+
+namespace android {
+
+MtpFfsCompatHandle::MtpFfsCompatHandle() :
+ mMaxWrite(USB_FFS_MAX_WRITE),
+ mMaxRead(USB_FFS_MAX_READ) {}
+
+MtpFfsCompatHandle::~MtpFfsCompatHandle() {}
+
+int MtpFfsCompatHandle::writeHandle(int fd, const void* data, size_t len) {
+ int ret = 0;
+ const char* buf = static_cast<const char*>(data);
+ while (len > 0) {
+ int write_len = std::min(mMaxWrite, len);
+ int n = TEMP_FAILURE_RETRY(::write(fd, buf, write_len));
+
+ if (n < 0) {
+ PLOG(ERROR) << "write ERROR: fd = " << fd << ", n = " << n;
+ return -1;
+ } else if (n < write_len) {
+ errno = EIO;
+ PLOG(ERROR) << "less written than expected";
+ return -1;
+ }
+ buf += n;
+ len -= n;
+ ret += n;
+ }
+ return ret;
+}
+
+int MtpFfsCompatHandle::readHandle(int fd, void* data, size_t len) {
+ int ret = 0;
+ char* buf = static_cast<char*>(data);
+ while (len > 0) {
+ int read_len = std::min(mMaxRead, len);
+ int n = TEMP_FAILURE_RETRY(::read(fd, buf, read_len));
+ if (n < 0) {
+ PLOG(ERROR) << "read ERROR: fd = " << fd << ", n = " << n;
+ return -1;
+ }
+ ret += n;
+ if (n < read_len) // done reading early
+ break;
+ buf += n;
+ len -= n;
+ }
+ return ret;
+}
+
+int MtpFfsCompatHandle::start() {
+ mLock.lock();
+
+ if (!openEndpoints())
+ return -1;
+
+ for (unsigned i = 0; i < NUM_IO_BUFS; i++) {
+ mIobuf[i].bufs.resize(MAX_FILE_CHUNK_SIZE);
+ posix_madvise(mIobuf[i].bufs.data(), MAX_FILE_CHUNK_SIZE,
+ POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED);
+ }
+
+ // Get device specific r/w size
+ mMaxWrite = android::base::GetIntProperty("sys.usb.ffs.max_write", USB_FFS_MAX_WRITE);
+ mMaxRead = android::base::GetIntProperty("sys.usb.ffs.max_read", USB_FFS_MAX_READ);
+
+ size_t attempts = 0;
+ while (mMaxWrite >= USB_FFS_MAX_WRITE && mMaxRead >= USB_FFS_MAX_READ &&
+ attempts < ENDPOINT_ALLOC_RETRIES) {
+ // If larger contiguous chunks of memory aren't available, attempt to try
+ // smaller allocations.
+ if (ioctl(mBulkIn, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(mMaxWrite)) ||
+ ioctl(mBulkOut, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(mMaxRead))) {
+ if (errno == ENODEV) {
+ // Driver hasn't enabled endpoints yet.
+ std::this_thread::sleep_for(std::chrono::milliseconds(100));
+ attempts += 1;
+ continue;
+ }
+ mMaxWrite /= 2;
+ mMaxRead /=2;
+ } else {
+ return 0;
+ }
+ }
+ // Try to start MtpServer anyway, with the smallest max r/w values
+ mMaxWrite = USB_FFS_MAX_WRITE;
+ mMaxRead = USB_FFS_MAX_READ;
+ PLOG(ERROR) << "Functionfs could not allocate any memory!";
+ return 0;
+}
+
+int MtpFfsCompatHandle::read(void* data, size_t len) {
+ return readHandle(mBulkOut, data, len);
+}
+
+int MtpFfsCompatHandle::write(const void* data, size_t len) {
+ return writeHandle(mBulkIn, data, len);
+}
+
+int MtpFfsCompatHandle::receiveFile(mtp_file_range mfr, bool zero_packet) {
+ // When receiving files, the incoming length is given in 32 bits.
+ // A >4G file is given as 0xFFFFFFFF
+ uint32_t file_length = mfr.length;
+ uint64_t offset = mfr.offset;
+ int packet_size = getPacketSize(mBulkOut);
+
+ unsigned char *data = mIobuf[0].bufs.data();
+ unsigned char *data2 = mIobuf[1].bufs.data();
+
+ struct aiocb aio;
+ aio.aio_fildes = mfr.fd;
+ aio.aio_buf = nullptr;
+ struct aiocb *aiol[] = {&aio};
+ int ret = -1;
+ size_t length;
+ bool read = false;
+ bool write = false;
+
+ posix_fadvise(mfr.fd, 0, 0, POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE);
+
+ // Break down the file into pieces that fit in buffers
+ while (file_length > 0 || write) {
+ if (file_length > 0) {
+ length = std::min(static_cast<uint32_t>(MAX_FILE_CHUNK_SIZE), file_length);
+
+ // Read data from USB, handle errors after waiting for write thread.
+ ret = readHandle(mBulkOut, data, length);
+
+ if (file_length != MAX_MTP_FILE_SIZE && ret < static_cast<int>(length)) {
+ ret = -1;
+ errno = EIO;
+ }
+ read = true;
+ }
+
+ if (write) {
+ // get the return status of the last write request
+ aio_suspend(aiol, 1, nullptr);
+
+ int written = aio_return(&aio);
+ if (written == -1) {
+ errno = aio_error(&aio);
+ return -1;
+ }
+ if (static_cast<size_t>(written) < aio.aio_nbytes) {
+ errno = EIO;
+ return -1;
+ }
+ write = false;
+ }
+
+ // If there was an error reading above
+ if (ret == -1) {
+ return -1;
+ }
+
+ if (read) {
+ if (file_length == MAX_MTP_FILE_SIZE) {
+ // For larger files, receive until a short packet is received.
+ if (static_cast<size_t>(ret) < length) {
+ file_length = 0;
+ }
+ } else {
+ file_length -= ret;
+ }
+ // Enqueue a new write request
+ aio_prepare(&aio, data, length, offset);
+ aio_write(&aio);
+
+ offset += ret;
+ std::swap(data, data2);
+
+ write = true;
+ read = false;
+ }
+ }
+ // Receive an empty packet if size is a multiple of the endpoint size.
+ if (ret % packet_size == 0 || zero_packet) {
+ if (TEMP_FAILURE_RETRY(::read(mBulkOut, data, packet_size)) != 0) {
+ return -1;
+ }
+ }
+ return 0;
+}
+
+int MtpFfsCompatHandle::sendFile(mtp_file_range mfr) {
+ uint64_t file_length = mfr.length;
+ uint32_t given_length = std::min(static_cast<uint64_t>(MAX_MTP_FILE_SIZE),
+ file_length + sizeof(mtp_data_header));
+ uint64_t offset = mfr.offset;
+ int packet_size = getPacketSize(mBulkIn);
+
+ // If file_length is larger than a size_t, truncating would produce the wrong comparison.
+ // Instead, promote the left side to 64 bits, then truncate the small result.
+ int init_read_len = std::min(
+ static_cast<uint64_t>(packet_size - sizeof(mtp_data_header)), file_length);
+
+ unsigned char *data = mIobuf[0].bufs.data();
+ unsigned char *data2 = mIobuf[1].bufs.data();
+
+ posix_fadvise(mfr.fd, 0, 0, POSIX_FADV_SEQUENTIAL | POSIX_FADV_NOREUSE);
+
+ struct aiocb aio;
+ aio.aio_fildes = mfr.fd;
+ struct aiocb *aiol[] = {&aio};
+ int ret, length;
+ int error = 0;
+ bool read = false;
+ bool write = false;
+
+ // Send the header data
+ mtp_data_header *header = reinterpret_cast<mtp_data_header*>(data);
+ header->length = htole32(given_length);
+ header->type = htole16(2); /* data packet */
+ header->command = htole16(mfr.command);
+ header->transaction_id = htole32(mfr.transaction_id);
+
+ // Some hosts don't support header/data separation even though MTP allows it
+ // Handle by filling first packet with initial file data
+ if (TEMP_FAILURE_RETRY(pread(mfr.fd, reinterpret_cast<char*>(data) +
+ sizeof(mtp_data_header), init_read_len, offset))
+ != init_read_len) return -1;
+ if (writeHandle(mBulkIn, data, sizeof(mtp_data_header) + init_read_len) == -1) return -1;
+ file_length -= init_read_len;
+ offset += init_read_len;
+ ret = init_read_len + sizeof(mtp_data_header);
+
+ // Break down the file into pieces that fit in buffers
+ while (file_length > 0) {
+ if (read) {
+ // Wait for the previous read to finish
+ aio_suspend(aiol, 1, nullptr);
+ ret = aio_return(&aio);
+ if (ret == -1) {
+ errno = aio_error(&aio);
+ return -1;
+ }
+ if (static_cast<size_t>(ret) < aio.aio_nbytes) {
+ errno = EIO;
+ return -1;
+ }
+
+ file_length -= ret;
+ offset += ret;
+ std::swap(data, data2);
+ read = false;
+ write = true;
+ }
+
+ if (error == -1) {
+ return -1;
+ }
+
+ if (file_length > 0) {
+ length = std::min(static_cast<uint64_t>(MAX_FILE_CHUNK_SIZE), file_length);
+ // Queue up another read
+ aio_prepare(&aio, data, length, offset);
+ aio_read(&aio);
+ read = true;
+ }
+
+ if (write) {
+ if (writeHandle(mBulkIn, data2, ret) == -1) {
+ error = -1;
+ }
+ write = false;
+ }
+ }
+
+ if (ret % packet_size == 0) {
+ // If the last packet wasn't short, send a final empty packet
+ if (TEMP_FAILURE_RETRY(::write(mBulkIn, data, 0)) != 0) {
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+} // namespace android
+