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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Memory.h>
#include <AK/StringView.h>
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Storage/StorageDevice.h>
#include <Kernel/Storage/StorageManagement.h>
#include <LibC/sys/ioctl_numbers.h>
namespace Kernel {
StorageDevice::StorageDevice(MajorNumber major, MinorNumber minor, size_t sector_size, u64 max_addressable_block, NonnullOwnPtr<KString> device_name)
: BlockDevice(major, minor, sector_size)
, m_early_storage_device_name(move(device_name))
, m_max_addressable_block(max_addressable_block)
{
}
StringView StorageDevice::class_name() const
{
return "StorageDevice"sv;
}
ErrorOr<size_t> StorageDevice::read(OpenFileDescription&, u64 offset, UserOrKernelBuffer& outbuf, size_t len)
{
unsigned index = offset / block_size();
u16 whole_blocks = len / block_size();
size_t remaining = len % block_size();
unsigned blocks_per_page = PAGE_SIZE / block_size();
// PATAChannel will chuck a wobbly if we try to read more than PAGE_SIZE
// at a time, because it uses a single page for its DMA buffer.
if (whole_blocks >= blocks_per_page) {
whole_blocks = blocks_per_page;
remaining = 0;
}
dbgln_if(STORAGE_DEVICE_DEBUG, "StorageDevice::read() index={}, whole_blocks={}, remaining={}", index, whole_blocks, remaining);
if (whole_blocks > 0) {
auto read_request = TRY(try_make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index, whole_blocks, outbuf, whole_blocks * block_size()));
auto result = read_request->wait();
if (result.wait_result().was_interrupted())
return EINTR;
switch (result.request_result()) {
case AsyncDeviceRequest::Failure:
case AsyncDeviceRequest::Cancelled:
return EIO;
case AsyncDeviceRequest::MemoryFault:
return EFAULT;
default:
break;
}
}
off_t pos = whole_blocks * block_size();
if (remaining > 0) {
auto data_result = ByteBuffer::create_uninitialized(block_size());
if (!data_result.has_value())
return ENOMEM;
auto data = data_result.release_value();
auto data_buffer = UserOrKernelBuffer::for_kernel_buffer(data.data());
auto read_request = TRY(try_make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index + whole_blocks, 1, data_buffer, block_size()));
auto result = read_request->wait();
if (result.wait_result().was_interrupted())
return EINTR;
switch (result.request_result()) {
case AsyncDeviceRequest::Failure:
return pos;
case AsyncDeviceRequest::Cancelled:
return EIO;
case AsyncDeviceRequest::MemoryFault:
// This should never happen, we're writing to a kernel buffer!
VERIFY_NOT_REACHED();
default:
break;
}
TRY(outbuf.write(data.data(), pos, remaining));
}
return pos + remaining;
}
bool StorageDevice::can_read(const OpenFileDescription&, size_t offset) const
{
return offset < (max_addressable_block() * block_size());
}
ErrorOr<size_t> StorageDevice::write(OpenFileDescription&, u64 offset, const UserOrKernelBuffer& inbuf, size_t len)
{
unsigned index = offset / block_size();
u16 whole_blocks = len / block_size();
size_t remaining = len % block_size();
unsigned blocks_per_page = PAGE_SIZE / block_size();
// PATAChannel will chuck a wobbly if we try to write more than PAGE_SIZE
// at a time, because it uses a single page for its DMA buffer.
if (whole_blocks >= blocks_per_page) {
whole_blocks = blocks_per_page;
remaining = 0;
}
dbgln_if(STORAGE_DEVICE_DEBUG, "StorageDevice::write() index={}, whole_blocks={}, remaining={}", index, whole_blocks, remaining);
if (whole_blocks > 0) {
auto write_request = TRY(try_make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Write, index, whole_blocks, inbuf, whole_blocks * block_size()));
auto result = write_request->wait();
if (result.wait_result().was_interrupted())
return EINTR;
switch (result.request_result()) {
case AsyncDeviceRequest::Failure:
case AsyncDeviceRequest::Cancelled:
return EIO;
case AsyncDeviceRequest::MemoryFault:
return EFAULT;
default:
break;
}
}
off_t pos = whole_blocks * block_size();
// since we can only write in block_size() increments, if we want to do a
// partial write, we have to read the block's content first, modify it,
// then write the whole block back to the disk.
if (remaining > 0) {
// FIXME: Do something sensible with this OOM scenario.
auto data = ByteBuffer::create_zeroed(block_size()).release_value();
auto data_buffer = UserOrKernelBuffer::for_kernel_buffer(data.data());
{
auto read_request = TRY(try_make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index + whole_blocks, 1, data_buffer, block_size()));
auto result = read_request->wait();
if (result.wait_result().was_interrupted())
return EINTR;
switch (result.request_result()) {
case AsyncDeviceRequest::Failure:
return pos;
case AsyncDeviceRequest::Cancelled:
return EIO;
case AsyncDeviceRequest::MemoryFault:
// This should never happen, we're writing to a kernel buffer!
VERIFY_NOT_REACHED();
default:
break;
}
}
TRY(inbuf.read(data.data(), pos, remaining));
{
auto write_request = TRY(try_make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Write, index + whole_blocks, 1, data_buffer, block_size()));
auto result = write_request->wait();
if (result.wait_result().was_interrupted())
return EINTR;
switch (result.request_result()) {
case AsyncDeviceRequest::Failure:
return pos;
case AsyncDeviceRequest::Cancelled:
return EIO;
case AsyncDeviceRequest::MemoryFault:
// This should never happen, we're writing to a kernel buffer!
VERIFY_NOT_REACHED();
default:
break;
}
}
}
return pos + remaining;
}
StringView StorageDevice::early_storage_name() const
{
return m_early_storage_device_name->view();
}
bool StorageDevice::can_write(const OpenFileDescription&, size_t offset) const
{
return offset < (max_addressable_block() * block_size());
}
ErrorOr<void> StorageDevice::ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg)
{
switch (request) {
case STORAGE_DEVICE_GET_SIZE: {
size_t disk_size = m_max_addressable_block * block_size();
return copy_to_user(static_ptr_cast<size_t*>(arg), &disk_size);
break;
}
case STORAGE_DEVICE_GET_BLOCK_SIZE: {
size_t size = block_size();
return copy_to_user(static_ptr_cast<size_t*>(arg), &size);
break;
}
default:
return EINVAL;
}
}
}
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