mirror of
https://github.com/RGBCube/serenity
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aee4786d8e
This singleton simplifies many aspects that we struggled with before: 1. There's no need to make derived classes of Device expose the constructor as public anymore. The singleton is a friend of them, so he can call the constructor. This solves the issue with try_create_device helper neatly, hopefully for good. 2. Getting a reference of the NullDevice is now being done from this singleton, which means that NullDevice no longer needs to use its own singleton, and we can apply the try_create_device helper on it too :) 3. We can now defer registration completely after the Device constructor which means the Device constructor is merely assigning the major and minor numbers of the Device, and the try_create_device helper ensures it calls the after_inserting method immediately after construction. This creates a great opportunity to make registration more OOM-safe.
69 lines
2.2 KiB
C++
69 lines
2.2 KiB
C++
/*
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* Copyright (c) 2021, the SerenityOS developers.
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/Memory.h>
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#include <AK/StringView.h>
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#include <Kernel/Devices/DeviceManagement.h>
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#include <Kernel/FileSystem/OpenFileDescription.h>
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#include <Kernel/Storage/RamdiskController.h>
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#include <Kernel/Storage/RamdiskDevice.h>
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namespace Kernel {
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NonnullRefPtr<RamdiskDevice> RamdiskDevice::create(const RamdiskController& controller, NonnullOwnPtr<Memory::Region>&& region, int major, int minor)
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{
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auto device_or_error = DeviceManagement::try_create_device<RamdiskDevice>(controller, move(region), major, minor);
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// FIXME: Find a way to propagate errors
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VERIFY(!device_or_error.is_error());
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return device_or_error.release_value();
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}
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RamdiskDevice::RamdiskDevice(const RamdiskController& controller, NonnullOwnPtr<Memory::Region>&& region, int major, int minor)
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: StorageDevice(controller, major, minor, 512, region->size() / 512)
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, m_region(move(region))
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{
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dmesgln("Ramdisk: Device #{} @ {}, Capacity={}", minor, m_region->vaddr(), max_addressable_block() * 512);
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}
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RamdiskDevice::~RamdiskDevice()
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{
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}
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StringView RamdiskDevice::class_name() const
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{
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return "RamdiskDevice";
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}
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void RamdiskDevice::start_request(AsyncBlockDeviceRequest& request)
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{
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MutexLocker locker(m_lock);
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u8* base = m_region->vaddr().as_ptr();
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size_t size = m_region->size();
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u8* offset = base + request.block_index() * 512;
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size_t length = request.block_count() * 512;
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if ((offset + length > base + size) || (offset + length < base)) {
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request.complete(AsyncDeviceRequest::Failure);
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} else {
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auto result = KResult(KSuccess);
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if (request.request_type() == AsyncBlockDeviceRequest::Read) {
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result = request.buffer().write(offset, length);
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} else {
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result = request.buffer().read(offset, length);
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}
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request.complete(result.is_success() ? AsyncDeviceRequest::Success : AsyncDeviceRequest::MemoryFault);
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}
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}
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String RamdiskDevice::storage_name() const
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{
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// FIXME: Try to not hardcode a maximum of 16 partitions per drive!
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size_t drive_index = minor() / 16;
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return String::formatted("ramdisk{}", drive_index);
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}
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}
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