RASCSI/cpp/devices/storage_device.cpp

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//---------------------------------------------------------------------------
//
// SCSI Target Emulator PiSCSI
// for Raspberry Pi
//
// Copyright (C) 2022-2023 Uwe Seimet
//
//---------------------------------------------------------------------------
#include "shared/piscsi_exceptions.h"
#include "storage_device.h"
#include <unistd.h>
using namespace std;
using namespace filesystem;
StorageDevice::StorageDevice(PbDeviceType type, int lun) : ModePageDevice(type, lun)
{
SupportsFile(true);
SetStoppable(true);
}
void StorageDevice::CleanUp()
{
UnreserveFile();
ModePageDevice::CleanUp();
}
void StorageDevice::SetFilename(string_view f)
{
filename = filesystem::path(f);
// Permanently write-protected
SetReadOnly(IsReadOnlyFile());
SetProtectable(!IsReadOnlyFile());
if (IsReadOnlyFile()) {
SetProtected(false);
}
}
void StorageDevice::ValidateFile()
{
if (blocks == 0) {
throw io_exception(string(GetTypeString()) + " device has 0 blocks");
}
if (!exists(filename)) {
throw file_not_found_exception("Image file '" + filename.string() + "' for " + GetTypeString() + " device does not exist");
}
if (GetFileSize() > 2LL * 1024 * 1024 * 1024 * 1024) {
throw io_exception("Image files > 2 TiB are not supported");
}
// TODO Check for duplicate handling of these properties (-> piscsi_executor.cpp)
if (IsReadOnlyFile()) {
// Permanently write-protected
SetReadOnly(true);
SetProtectable(false);
SetProtected(false);
}
SetStopped(false);
SetRemoved(false);
SetLocked(false);
SetReady(true);
}
void StorageDevice::ReserveFile() const
{
assert(!filename.empty());
assert(!reserved_files.contains(filename.string()));
reserved_files[filename.string()] = { GetId(), GetLun() };
}
void StorageDevice::UnreserveFile()
{
reserved_files.erase(filename.string());
filename.clear();
}
id_set StorageDevice::GetIdsForReservedFile(const string& file)
{
if (const auto& it = reserved_files.find(file); it != reserved_files.end()) {
return { it->second.first, it->second.second };
}
return { -1, -1 };
}
void StorageDevice::UnreserveAll()
{
reserved_files.clear();
}
bool StorageDevice::FileExists(string_view file)
{
return exists(path(file));
}
bool StorageDevice::IsReadOnlyFile() const
{
return access(filename.c_str(), W_OK);
}
off_t StorageDevice::GetFileSize() const
{
try {
return file_size(filename);
}
catch (const filesystem_error& e) {
throw io_exception("Can't get size of '" + filename.string() + "': " + e.what());
}
}