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Commit 81ca5ade authored by Daichi Hirono's avatar Daichi Hirono
Browse files

Read whole data from MTP device even on writing error. 

Once the object bytes is requested on the MTP client device, the device tries to
send whole data of object. We need to read the complete data from the device
even when we have errors at the destination file descriptor. Otherwise the
object data will be received as a response of next request unintentionally.

BUG=23264575

Change-Id: I3369786370022f65aa760dd6b75204a946f712af
parent 2b355c20

media/mtp/MtpDevice.cpp

+18 −22
Original line number Diff line number Diff line
@@ -683,7 +683,6 @@ fail: 
    return result;

}





// reads the object's data and writes it to the specified file path

bool MtpDevice::readObject(MtpObjectHandle handle, const char* destPath, int group, int perm) {

    ALOGD("readObject: %s", destPath);
@@ -708,25 +707,26 @@ bool MtpDevice::readObject(MtpObjectHandle handle, int fd) { 
    ALOGD("readObject: %d", fd);



    Mutex::Autolock autoLock(mMutex);

    bool result = false;



    mRequest.reset();

    mRequest.setParameter(1, handle);

    if (sendRequest(MTP_OPERATION_GET_OBJECT)

            && mData.readDataHeader(mRequestIn1)) {

    if (sendRequest(MTP_OPERATION_GET_OBJECT) && mData.readDataHeader(mRequestIn1)) {

        uint32_t length = mData.getContainerLength();

        if (length < MTP_CONTAINER_HEADER_SIZE)

            goto fail;

        if (length < MTP_CONTAINER_HEADER_SIZE) {

            ALOGE("Invalid container length.");

            return false;

        }

        length -= MTP_CONTAINER_HEADER_SIZE;

        uint32_t remaining = length;



        bool writingError = false;

        int initialDataLength = 0;

        void* initialData = mData.getData(initialDataLength);

        if (initialData) {

            if (initialDataLength > 0) {

                if (write(fd, initialData, initialDataLength) != initialDataLength) {

                    free(initialData);

                    goto fail;

                    ALOGE("Failed to write initial data.");

                    writingError = true;

                }

                remaining -= initialDataLength;

            }
@@ -747,29 +747,27 @@ bool MtpDevice::readObject(MtpObjectHandle handle, int fd) { 
                req->buffer_length = (remaining > sizeof(buffer1) ? sizeof(buffer1) : remaining);

                if (mData.readDataAsync(req)) {

                    ALOGE("readDataAsync failed");

                    goto fail;

                    return false;

                }

            } else {

                req = NULL;

            }



            if (writeBuffer) {

            if (writeBuffer && !writingError) {

                // write previous buffer

                if (write(fd, writeBuffer, writeLength) != writeLength) {

                    ALOGE("write failed");

                    // wait for pending read before failing

                    if (req)

                        mData.readDataWait(mDevice);

                    goto fail;

                    writingError = true;

                }

                writeBuffer = NULL;

            }

            writeBuffer = NULL;



            // wait for read to complete

            if (req) {

                int read = mData.readDataWait(mDevice);

                if (read < 0)

                    goto fail;

                if (read < 0) {

                    ALOGE("readDataWait failed.");

                    return false;

                }



                if (read > 0) {

                    writeBuffer = req->buffer;
@@ -783,12 +781,10 @@ bool MtpDevice::readObject(MtpObjectHandle handle, int fd) { 
        }



        MtpResponseCode response = readResponse();

        if (response == MTP_RESPONSE_OK)

            result = true;

        return response == MTP_RESPONSE_OK && !writingError;

    }



fail:

    return result;

    return false;

}



bool MtpDevice::sendRequest(MtpOperationCode operation) {