mirror of
https://github.com/RGBCube/serenity
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1570e67881
This change ensures that we don't return a zero value blindly from DiskPartition write/read methods. Fixes #1719.
102 lines
3.9 KiB
C++
102 lines
3.9 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <Kernel/Devices/DiskPartition.h>
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#include <Kernel/FileSystem/FileDescription.h>
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// #define OFFD_DEBUG
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namespace Kernel {
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NonnullRefPtr<DiskPartition> DiskPartition::create(BlockDevice& device, unsigned block_offset, unsigned block_limit)
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{
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return adopt(*new DiskPartition(device, block_offset, block_limit));
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}
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DiskPartition::DiskPartition(BlockDevice& device, unsigned block_offset, unsigned block_limit)
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: BlockDevice(100, 0, device.block_size())
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, m_device(device)
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, m_block_offset(block_offset)
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, m_block_limit(block_limit)
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{
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}
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DiskPartition::~DiskPartition()
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{
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}
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ssize_t DiskPartition::read(FileDescription& file_description, u8* buffer, ssize_t length)
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{
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// FIXME: This is a hacky solution, but works fine for now...
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off_t current_offset = file_description.seek(0, SEEK_CUR);
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auto new_offset = current_offset + (m_block_offset * m_device->block_size());
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if ((new_offset / m_device->block_size()) > m_block_limit || ((new_offset + length) / m_device->block_size()) > m_block_limit) {
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return 0;
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}
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file_description.seek(new_offset, SEEK_SET);
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auto result = m_device->read(file_description, buffer, length);
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file_description.seek(current_offset, SEEK_SET);
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return result;
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}
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ssize_t DiskPartition::write(FileDescription& file_description, const u8* buffer, ssize_t length)
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{
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// FIXME: This is a hacky solution, but works fine for now...
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off_t current_offset = file_description.seek(0, SEEK_CUR);
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auto new_offset = current_offset + (m_block_offset * m_device->block_size());
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if ((new_offset / m_device->block_size()) > m_block_limit || ((new_offset + length) / m_device->block_size()) > m_block_limit) {
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return 0;
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}
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file_description.seek(new_offset, SEEK_SET);
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auto result = m_device->write(file_description, buffer, length);
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file_description.seek(current_offset, SEEK_SET);
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return result;
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}
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bool DiskPartition::read_blocks(unsigned index, u16 count, u8* out)
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{
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#ifdef OFFD_DEBUG
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klog() << "DiskPartition::read_blocks " << index << " (really: " << (m_block_offset + index) << ") count=" << count;
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#endif
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return m_device->read_blocks(m_block_offset + index, count, out);
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}
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bool DiskPartition::write_blocks(unsigned index, u16 count, const u8* data)
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{
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#ifdef OFFD_DEBUG
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klog() << "DiskPartition::write_blocks " << index << " (really: " << (m_block_offset + index) << ") count=" << count;
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#endif
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return m_device->write_blocks(m_block_offset + index, count, data);
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}
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const char* DiskPartition::class_name() const
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{
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return "DiskPartition";
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}
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}
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