windows-nt/Source/XPSP1/NT/drivers/storage/mpath/hpdsm/hpdsm.c
2020-09-26 16:20:57 +08:00

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/*++
Copyright (C) 2000-2001 Microsoft Corporation
Module Name:
hpdsm.c
Abstract:
This driver is the DSM for HP XP-256/512
Author:
Environment:
kernel mode only
Notes:
Revision History:
--*/
#include <ntddk.h>
#include <stdio.h>
#include <stdarg.h>
#include "dsm.h"
#include "hpdsm.h"
NTSTATUS
DriverEntry(
IN PDRIVER_OBJECT DriverObject,
IN PUNICODE_STRING RegistryPath
)
/*++
Routine Description:
This routine is called when the driver loads loads.
Arguments:
DriverObject - Supplies the driver object.
RegistryPath - Supplies the registry path.
Return Value:
NTSTATUS
--*/
{
DSM_INIT_DATA initData;
WCHAR dosDeviceName[40];
UNICODE_STRING mpUnicodeName;
PDEVICE_OBJECT deviceObject;
PFILE_OBJECT fileObject;
NTSTATUS status;
PDSM_CONTEXT dsmContext;
PDSM_MPIO_CONTEXT mpctlContext;
PVOID buffer;
//
// Build the init data structure.
//
dsmContext = ExAllocatePool(NonPagedPool, sizeof(DSM_CONTEXT));
if (dsmContext == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(dsmContext, sizeof(DSM_CONTEXT));
buffer = &initData;
//
// Set-up the init data
//
initData.DsmContext = (PVOID)dsmContext;
initData.InitDataSize = sizeof(DSM_INIT_DATA);
initData.DsmInquireDriver = HPInquire;
initData.DsmCompareDevices = HPCompareDevices;
initData.DsmSetDeviceInfo = HPSetDeviceInfo;
initData.DsmGetControllerInfo = HPGetControllerInfo;
initData.DsmIsPathActive = HPIsPathActive;
initData.DsmPathVerify = HPPathVerify;
initData.DsmInvalidatePath = HPInvalidatePath;
initData.DsmRemoveDevice = HPRemoveDevice;
initData.DsmRemovePath = HPRemovePath;
initData.DsmReenablePath = HPBringPathOnLine;
initData.DsmCategorizeRequest = HPCategorizeRequest;
initData.DsmBroadcastSrb = HPBroadcastRequest;
initData.DsmSrbDeviceControl = HPSrbDeviceControl;
initData.DsmSetCompletion = HPSetCompletion;
initData.DsmLBGetPath = HPLBGetPath;
initData.DsmInterpretError = HPInterpretError;
initData.DsmUnload = HPUnload;
//
// Need to also set-up the WMI info. TODO
//
//
// Set the DriverObject. Used by MPIO for Unloading.
//
initData.DriverObject = DriverObject;
RtlInitUnicodeString(&initData.DisplayName, L"HP FC-12 Device-Specific Module");
//
// Initialize the context objects.
//
KeInitializeSpinLock(&dsmContext->SpinLock);
InitializeListHead(&dsmContext->GroupList);
InitializeListHead(&dsmContext->DeviceList);
InitializeListHead(&dsmContext->FailGroupList);
ExInitializeNPagedLookasideList(&dsmContext->ContextList,
NULL,
NULL,
0,
sizeof(COMPLETION_CONTEXT),
'MSDG',
0);
//
// Build the mpctl name.
//
swprintf(dosDeviceName, L"\\DosDevices\\MPathControl");
RtlInitUnicodeString(&mpUnicodeName, dosDeviceName);
//
// Get mpctl's deviceObject.
//
status = IoGetDeviceObjectPointer(&mpUnicodeName,
FILE_READ_ATTRIBUTES,
&fileObject,
&deviceObject);
if (NT_SUCCESS(status)) {
KEVENT event;
PIRP irp;
IO_STATUS_BLOCK ioStatus;
//
// Send the IOCTL to mpctl.sys to register ourselves.
//
DsmSendDeviceIoControlSynchronous(IOCTL_MPDSM_REGISTER,
deviceObject,
&initData,
&initData,
sizeof(DSM_INIT_DATA),
sizeof(DSM_MPIO_CONTEXT),
TRUE,
&ioStatus);
status = ioStatus.Status;
ObDereferenceObject(fileObject);
}
if (status == STATUS_SUCCESS) {
//
// Grab the context value passed back by mpctl.
//
mpctlContext = buffer;
dsmContext->MPIOContext = mpctlContext->MPIOContext;
} else {
DebugPrint((0,
"HPDsm: Failed to register (%x)\n",
status));
//
// Stay loaded, perhaps mpctl will come up later.
// Will need to implement a mechanism to poll for mpio to arrive.
//
status = STATUS_SUCCESS;
}
return status;
}
NTSTATUS
HPInquire (
IN PVOID DsmContext,
IN PDEVICE_OBJECT TargetDevice,
IN PDEVICE_OBJECT PortObject,
IN PSTORAGE_DEVICE_DESCRIPTOR Descriptor,
IN PSTORAGE_DEVICE_ID_DESCRIPTOR DeviceIdList,
OUT PVOID *DsmIdentifier
)
{
PDEVICE_INFO deviceInfo;
PGROUP_ENTRY group;
NTSTATUS status;
ULONG deviceState;
ULONG allocationLength;
PHP_ENQUIRY enquiry;
PHP_DAC_STATUS dacStatus;
UCHAR majorRev;
UCHAR minorRev;
ULONG loadBal;
PUCHAR vendorIndex;
PUCHAR productIndex;
BOOLEAN needInquiry = FALSE;
UCHAR nativeSlot;
UCHAR portNumber;
UCHAR logicalPort;
PUCHAR vendorId = "HP ";
PUCHAR productId = "FCArray";
//
// Ensure that the device's serial number is present. If not, can't claim
// support for this drive.
//
if ((Descriptor->SerialNumberOffset == (ULONG)-1) ||
(Descriptor->SerialNumberOffset == 0)) {
// TODO : remove after FW update...
//
//return STATUS_NOT_SUPPORTED;
needInquiry = TRUE;
}
vendorIndex = (PUCHAR)Descriptor;
productIndex = (PUCHAR)Descriptor;
(ULONG_PTR)vendorIndex += Descriptor->VendorIdOffset;
(ULONG_PTR)productIndex += Descriptor->ProductIdOffset;
//
// Determine if the device is supported.
//
if ((!RtlEqualMemory(vendorId, vendorIndex, 8)) ||
(!RtlEqualMemory(productId, productIndex, 7))) {
return STATUS_NOT_SUPPORTED;
}
//
// Allocate the descriptor. This is also used as DsmId.
//
allocationLength = sizeof(DEVICE_INFO);
allocationLength += Descriptor->Size - sizeof(STORAGE_DEVICE_DESCRIPTOR);
deviceInfo = ExAllocatePool(NonPagedPool, allocationLength);
if (deviceInfo == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(deviceInfo, allocationLength);
//
// Copy over the StorageDescriptor.
//
RtlCopyMemory(&deviceInfo->Descriptor,
Descriptor,
Descriptor->Size);
//
// Save the PortPdo Object.
//
deviceInfo->PortPdo = TargetDevice;
//
// Send the enquire command to get the FW revs. Based on the revision
// we can either do fail-over only or active lb.
//
enquiry = ExAllocatePool(NonPagedPoolCacheAligned, sizeof(HP_ENQUIRY));
if (enquiry == NULL) {
ExFreePool(deviceInfo);
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(enquiry, sizeof(HP_ENQUIRY));
status = HPSendDirectCommand(TargetDevice,
(PUCHAR)enquiry,
sizeof(HP_ENQUIRY),
DCMD_ENQUIRY);
if (NT_SUCCESS(status)) {
majorRev = enquiry->FwMajorRev;
minorRev = enquiry->FwMinorRev;
DebugPrint((0,
"HPDSM: FirmWare Major (%u) Minor (%u)\n",
majorRev,
minorRev));
//
// Free the buffer.
//
ExFreePool(enquiry);
if (majorRev > 5 || (majorRev == 5 && minorRev >= 46)) {
//
// Supports dual active/active.
//
loadBal = LB_MIN_QUEUE;
} else if (majorRev == 5 && minorRev >= 41) {
//
// Fail-over only.
//
loadBal = LB_ACTIVE_PASSIVE;
} else {
//
// Not supported. LOG.
//
ExFreePool(deviceInfo);
return STATUS_NOT_SUPPORTED;
}
} else {
ExFreePool(enquiry);
ExFreePool(deviceInfo);
return status;
}
//
// Send the Get Controller Status command so that the port
// on which this device lives can be determined.
//
dacStatus = ExAllocatePool(NonPagedPoolCacheAligned, sizeof(HP_DAC_STATUS));
if (dacStatus == NULL) {
ExFreePool(deviceInfo);
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(dacStatus, sizeof(HP_DAC_STATUS));
status = HPSendDirectCommand(TargetDevice,
(PUCHAR)dacStatus,
sizeof(HP_DAC_STATUS),
DCMD_GET_DAC_STATUS);
if (NT_SUCCESS(status)) {
//
// Build a logical port value (1-4) based on the NativeSlot and PortNumber
// values. NativeSlot 0 or 1, and portNumber 0 or 1 for 4 possibilities.
// NativeSlot refers to the controller and portNumber to the port.
//
nativeSlot = dacStatus->DACInfo[0] >> 4;
portNumber = (dacStatus->DACInfo[1] >> 5) & 0x01;
logicalPort = ((nativeSlot & 1) << 1) + (portNumber + 1);
//
// Set the port number for this device.
// Used to help create the FOGroups and as the index into
// the path array.
//
deviceInfo->Controller = logicalPort;
} else {
ExFreePool(deviceInfo);
return status;
}
//
// Build the controller serial number.
// Bytes 40-47 of the inquiry data have the Node Name of Controller 0.
// Use this as a 64-bit identifier.
//
if (needInquiry) {
CDB cdb;
PINQUIRYDATA inquiryBuffer;
RtlZeroMemory(&cdb, sizeof(CDB));
cdb.START_STOP.OperationCode = SCSIOP_START_STOP_UNIT;
cdb.START_STOP.Start = 1;
status = HPSendScsiCommand(TargetDevice,
NULL,
0,
6,
&cdb,
1);
RtlZeroMemory(&cdb, sizeof(CDB));
cdb.CDB6INQUIRY.OperationCode = SCSIOP_INQUIRY;
cdb.CDB6INQUIRY.AllocationLength = 56;
inquiryBuffer = ExAllocatePool(NonPagedPoolCacheAligned, 56);
status = HPSendScsiCommand(TargetDevice,
(PUCHAR)inquiryBuffer,
56,
6,
&cdb,
1);
if (NT_SUCCESS(status)) {
UCHAR controllerSerialNumber[9];
UCHAR driveNumber[11];
RtlZeroMemory(controllerSerialNumber, 9);
RtlZeroMemory(driveNumber, 11);
//
// Copy the serial number over into the deviceInfo.
// SerialNumber is built from the Node Name of the Controller +
// the SystemDrive Number.
//
RtlCopyMemory(controllerSerialNumber,
&inquiryBuffer->VendorSpecific[4],
8);
//
// Get the drive Number.
//
driveNumber[0] = inquiryBuffer->VendorSpecific[0];
driveNumber[1] = inquiryBuffer->VendorSpecific[1];
//
// cat the driveNumber & controller serial number into 10-byte binary value.
//
RtlCopyMemory(&driveNumber[2],
controllerSerialNumber,
8);
//
// Convert to ascii.
//
HPConvertHexToAscii(driveNumber,
deviceInfo->SerialNumber,
10);
DebugPrint((0,
"HPInquiry: SerialNumber: %s\n", deviceInfo->SerialNumber));
}
}
//
// See if there is an existing Muli-path group to which this belongs.
// (same serial number).
//
group = FindDevice(DsmContext,
deviceInfo);
if (group == NULL) {
//
// Build a multi-path group entry.
//
group = BuildGroupEntry(DsmContext,
deviceInfo);
if (group == NULL) {
ExFreePool(deviceInfo);
return STATUS_INSUFFICIENT_RESOURCES;
}
//
// This is the first in the group, so make it the active
// device. The actual active/passive devices will be set-up
// later when the first call to LBGetPath is made.
//
deviceState = DEV_ACTIVE;
} else {
//
// Already something active, this will be the fail-over
// device until the load-balance groups are set-up.
//
deviceState = DEV_PASSIVE;
}
//
// Add it to the list.
//
status = AddDeviceEntry(DsmContext,
group,
deviceInfo,
deviceState);
*DsmIdentifier = deviceInfo;
return status;
}
VOID
HPConvertHexToAscii(
IN PUCHAR HexString,
IN OUT PUCHAR AsciiString,
IN ULONG Count
)
{
ULONG i;
ULONG j;
UCHAR value;
DebugPrint((0,
"ConvertHexToAscii: "));
for (i = 0, j = 0; i < Count; i++, j++) {
value = HexString[i];
DebugPrint((0,
"%x ", value));
if (value <= 9) {
AsciiString[j] = value + '0';
} else {
AsciiString[j] = value - 10 + 'A';
}
}
DebugPrint((0,"\n"));
}
BOOLEAN
HPCompareDevices(
IN PVOID DsmContext,
IN PVOID DsmId1,
IN PVOID DsmId2
)
{
PDEVICE_INFO deviceInfo = DsmId1;
PDEVICE_INFO comparedDevice = DsmId2;
ULONG length;
PUCHAR serialNumber;
PUCHAR comparedSerialNumber;
//
// If this is an RS12, then no serial number in the device descriptor.
//
if (deviceInfo->Descriptor.SerialNumberOffset == (ULONG)-1) {
//
// Use the one's built from inquiry Data.
//
serialNumber = deviceInfo->SerialNumber;
comparedSerialNumber = comparedDevice->SerialNumber;
} else {
//
// Get the two serial numbers.
// They reside at SNOffset from the front of the
// descriptor buffer.
//
serialNumber = (PUCHAR)&deviceInfo->Descriptor;
serialNumber += deviceInfo->Descriptor.SerialNumberOffset;
comparedSerialNumber = (PUCHAR)&comparedDevice->Descriptor;
comparedSerialNumber += comparedDevice->Descriptor.SerialNumberOffset;
}
//
// Get the length of the base-device Serial Number.
//
length = strlen(serialNumber);
//
// If the lengths match, compare the contents.
//
if (length == strlen(comparedSerialNumber)) {
if (RtlEqualMemory(serialNumber,
comparedSerialNumber,
length)) {
return TRUE;
}
}
return FALSE;
}
NTSTATUS
HPSetDeviceInfo(
IN PVOID DsmContext,
IN PDEVICE_OBJECT TargetObject,
IN PVOID DsmId,
IN OUT PVOID *PathId
)
{
PDEVICE_INFO deviceInfo = DsmId;
PGROUP_ENTRY group = deviceInfo->Group;
PFAILOVER_GROUP failGroup;
NTSTATUS status;
//
// TargetObject is the destination for any requests created by this driver.
// Save this for future reference.
//
deviceInfo->TargetObject = TargetObject;
//
// PathId indicates the path on which this device resides. Meaning
// that when a Fail-Over occurs all device's on the same path fail together.
// Search for a matching F.O. Group
//
failGroup = FindFOGroup(DsmContext,
*PathId);
//
// if not found, create a new f.o. group
//
if (failGroup == NULL) {
failGroup = BuildFOGroup(DsmContext,
DsmId,
*PathId);
if (failGroup == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
}
//
// add this deviceInfo to the f.o. group.
//
status = UpdateFOGroup(DsmContext,
failGroup,
deviceInfo);
return status;
}
NTSTATUS
HPGetControllerInfo(
IN PVOID DsmContext,
IN PVOID DsmId,
IN ULONG Flags,
IN OUT PCONTROLLER_INFO *ControllerInfo
)
{
PCONTROLLER_INFO controllerInfo;
if (Flags & DSM_CNTRL_FLAGS_ALLOCATE) {
controllerInfo = ExAllocatePool(NonPagedPool, sizeof(CONTROLLER_INFO));
if (controllerInfo == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(controllerInfo, sizeof(CONTROLLER_INFO));
//
// TODO Get the ID etc.
//
controllerInfo->State = DSM_CONTROLLER_NO_CNTRL;
*ControllerInfo = controllerInfo;
} else {
controllerInfo = *ControllerInfo;
//
// TODO Get the state.
//
controllerInfo->State = DSM_CONTROLLER_NO_CNTRL;
}
return STATUS_SUCCESS;
}
BOOLEAN
HPIsPathActive(
IN PVOID DsmContext,
IN PVOID PathId
)
{
PFAILOVER_GROUP group;
//
// NOTE: Internal callers of this assume certain behaviours. If it's changed,
// those functions need to be updated appropriately.
//
//
// Get the F.O. Group information.
//
group = FindFOGroup(DsmContext,
PathId);
//
// If there are any devices on this path, and
// it's not in a failed state: it's capable of handling requests
// so it's active.
//
if ((group->Count >= 1) && (group->State == FG_NORMAL)) {
return TRUE;
}
return FALSE;
}
NTSTATUS
HPPathVerify(
IN PVOID DsmContext,
IN PVOID DsmId,
IN PVOID PathId
)
{
PDEVICE_INFO deviceInfo = DsmId;
PFAILOVER_GROUP group;
NTSTATUS status;
ULONG i;
//
// Get the F.O. group
//
group = FindFOGroup(DsmContext,
PathId);
if (group == NULL) {
return STATUS_DEVICE_NOT_CONNECTED;
}
//
// Check the Path state to ensure all is normal.
// Should be in FAILBACK state. This indicates that either
// an admin utility told us we are O.K. or the AutoRecovery detected
// the error was transitory.
// BUGBUG: Need to implement both of the above assumptions.
//
if ((group->Count >= 1) && group->State == FG_FAILBACK) {
//
// Ensure that the device is still there
//
for (i = 0; i < group->Count; i++) {
if (group->DeviceList[i] == deviceInfo) {
//
// Send it a TUR.
//
status = DsmSendTUR(deviceInfo->TargetObject);
}
}
} else {
//
// What really has to happen:
// Ensure the device is in our structs
// Send it a TUR.
// Depending upon prior state - update to the new, appropriate state.
// return status.
//
status = STATUS_UNSUCCESSFUL;
for (i = 0; i < group->Count; i++) {
if (group->DeviceList[i] == deviceInfo) {
status = DsmSendTUR(deviceInfo->TargetObject);
}
}
if (!NT_SUCCESS(status)) {
//
// Either the device is not in the group, or the TUR was not successful.
// TODO - Something.
//
}
}
//
// Update the group State, depending upon the outcome.
// TODO
//
ASSERT(status == STATUS_SUCCESS);
if (status == STATUS_SUCCESS) {
//
// This lets the LBInit run to properly set-up this device.
//
deviceInfo->NeedsVerification = FALSE;
}
return status;
}
NTSTATUS
HPInvalidatePath(
IN PVOID DsmContext,
IN ULONG ErrorMask,
IN PVOID PathId,
IN OUT PVOID *NewPathId
)
{
PFAILOVER_GROUP failGroup;
PFAILOVER_GROUP hintPath;
PGROUP_ENTRY group;
PDEVICE_INFO deviceInfo;
NTSTATUS status;
ULONG i;
ASSERT((ErrorMask & DSM_FATAL_ERROR) || (ErrorMask & DSM_ADMIN_FO));
failGroup = FindFOGroup(DsmContext,
PathId);
//
// Mark the path as failed.
//
failGroup->State = FG_FAILED;
//
// First interation, the hint will be NULL. This allows the
// GetNewPath routine the opportunity to select the best new path
// Subsequent calls will be fed the updated value.
//
hintPath = NULL;
//
// Process each device in the fail-over group
//
for (i = 0; i < failGroup->Count; i++) {
//
// Get the deviceInfo.
//
deviceInfo = failGroup->DeviceList[i];
//
// Set the state of the Failing Devicea
//
deviceInfo->State = DEV_FAILED;
//
// Get it's Multi-Path Group entry.
//
group = deviceInfo->Group;
//
// Get a new path for this failed device.
//
hintPath = SetNewPath(DsmContext,
group,
deviceInfo,
hintPath);
}
if (hintPath == NULL) {
//
// This indicates that no acceptable paths
// were found. Return the error to mpctl.
//
status = STATUS_NO_SUCH_DEVICE;
*NewPathId = NULL;
} else {
//
// return the new path.
//
*NewPathId = hintPath->PathId;
status = STATUS_SUCCESS;
}
return status;
}
NTSTATUS
HPRemoveDevice(
IN PVOID DsmContext,
IN PVOID DsmId,
IN PVOID PathId
)
{
PDSM_CONTEXT dsmContext = DsmContext;
PDEVICE_INFO deviceInfo;
PFAILOVER_GROUP failGroup;
PGROUP_ENTRY group;
ULONG state;
WCHAR buffer[64];
//
// DsmId is our deviceInfo structure.
//
deviceInfo = DsmId;
//
// Get it's Multi-Path Group entry.
//
group = deviceInfo->Group;
//
// Get the Fail-over group.
//
failGroup = deviceInfo->FailGroup;
//
// If it's active, need to 'Fail-Over' to another device in
// the group.
//
state = deviceInfo->State;
//
// Set the state of the Failing Devicea
//
deviceInfo->State = DEV_FAILED;
if (state == DEV_ACTIVE) {
//
// Find the next available device.
// This is basically a fail-over for just
// this device.
//
SetNewPath(DsmContext,
group,
deviceInfo,
NULL);
}
//
// Remove it's entry from the Fail-Over Group.
//
RemoveDeviceFailGroup(DsmContext,
failGroup,
deviceInfo);
//
// Remove it from it's multi-path group. This has the side-effect
// of cleaning up the Group if the number of devices goes to zero.
//
RemoveDeviceEntry(DsmContext,
group,
deviceInfo);
swprintf(buffer, L"Removing Device");
DsmWriteEvent(dsmContext->MPIOContext,
L"HpDsm",
buffer,
2);
return STATUS_SUCCESS;
}
NTSTATUS
HPRemovePath(
IN PDSM_CONTEXT DsmContext,
IN PVOID PathId
)
{
PFAILOVER_GROUP failGroup;
KIRQL irql;
failGroup = FindFOGroup(DsmContext,
PathId);
if (failGroup == NULL) {
//
// It's already been removed.
// LOG though.
//
return STATUS_SUCCESS;
}
//
// The claim is that a path won't be removed, until all
// the devices on it are.
//
ASSERT(failGroup->Count == 0);
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
//
// Yank it from the list.
//
RemoveEntryList(&failGroup->ListEntry);
DsmContext->NumberFOGroups--;
//
// Zero the entry.
//
RtlZeroMemory(failGroup, sizeof(FAILOVER_GROUP));
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
//
// Free the allocation.
//
ExFreePool(failGroup);
return STATUS_SUCCESS;
}
NTSTATUS
HPBringPathOnLine(
IN PVOID DsmContext,
IN PVOID PathId,
OUT PULONG DSMError
)
{
PFAILOVER_GROUP failGroup;
//
// PathVerify has been called already, so if
// it came back successfully, then this is O.K.
//
failGroup = FindFOGroup(DsmContext,
PathId);
if (failGroup == NULL) {
//
// LOG
//
*DSMError = 0;
return STATUS_DEVICE_NOT_CONNECTED;
}
//
// Should be in FG_PENDING
//
ASSERT(failGroup->State == FG_PENDING);
//
// Indicate that it's ready to go.
//
failGroup->State = FG_NORMAL;
return STATUS_SUCCESS;
}
PVOID
HPLBGetPath(
IN PVOID DsmContext,
IN PSCSI_REQUEST_BLOCK Srb,
IN PDSM_IDS DsmList,
IN PVOID CurrentPath,
OUT NTSTATUS *Status
)
{
PDEVICE_INFO deviceInfo;
PGROUP_ENTRY group;
PFAILOVER_GROUP failGroup = NULL;
ULONG i;
//
// Up-front checking to minimally validate
// the list of DsmId's being passed in.
//
ASSERT(DsmList->Count);
ASSERT(DsmList->IdList[0]);
//
// Grab the first device from the list.
//
deviceInfo = DsmList->IdList[0];
//
// Get the multi-path group.
//
group = deviceInfo->Group;
//
// See if Load-Balancing has been initialized.
//
if (group->LoadBalanceInit == FALSE) {
PDEVICE_INFO lbDevice;
BOOLEAN doInit = TRUE;
//
// Check to see whether we are really ready to run
// the LBInit. If any of the list aren't verified, then
// we will hold off.
//
for (i = 0; i < DsmList->Count; i++) {
lbDevice = DsmList->IdList[i];
if (lbDevice->NeedsVerification) {
DebugPrint((0,
"LBGetPath: (%x) needs verify\n",
lbDevice));
doInit = FALSE;
break;
}
}
if (doInit) {
//
// Set-up the load-balancing. This routine
// builds a static assignment of multi-path group to
// a particular path.
//
LBInit(DsmContext,
group);
}
}
//
// Ensure that mpctl and this dsm are in sync.
//
ASSERT(DsmList->Count == group->NumberDevices);
//
// Find the active device.
//
for (i = 0; i < DsmList->Count; i++) {
//
// Get each of the DsmId's, in reality the deviceInfo.
//
deviceInfo = DsmList->IdList[i];
//
// Ensure that the device is in our list.
//
ASSERT(FindDevice(DsmContext, deviceInfo));
//
// NOTE: This assumes 'static' Load-Balancing. Once others
// are implemented, this section will have to be updated.
//
// Return the path on which the ACTIVE device resides.
//
if (deviceInfo->State == DEV_ACTIVE) {
//
// Get the F.O.Group, as it contains the
// correct PathId for this device.
//
failGroup = deviceInfo->FailGroup;
*Status = STATUS_SUCCESS;
return failGroup->PathId;
}
}
//
// Should never have gotten here.
//
DebugPrint((0,
"LBGetPath: Returning STATUS_DEVICE_NOT_CONNECTED\n"));
DbgBreakPoint();
ASSERT(failGroup);
*Status = STATUS_DEVICE_NOT_CONNECTED;
return NULL;
}
ULONG
HPCategorizeRequest(
IN PVOID DsmContext,
IN PDSM_IDS DsmIds,
IN PIRP Irp,
IN PSCSI_REQUEST_BLOCK Srb,
IN PVOID CurrentPath,
OUT PVOID *PathId,
OUT NTSTATUS *Status
)
{
ULONG dsmStatus;
NTSTATUS status;
//
// Requests to broadcast
// Reset
// Reserve
// Release
//
// Requests to Handle
// None for now.
//
//
// For all other requests, punt it back to the bus-driver.
// Need to get a path for the request first, so call the Load-Balance
// function.
//
*PathId = HPLBGetPath(DsmContext,
Srb,
DsmIds,
CurrentPath,
&status);
if (NT_SUCCESS(status)) {
//
// Indicate that the path is updated, and mpctl should handle the request.
//
dsmStatus = DSM_PATH_SET;
} else {
//
// Indicate the error back to mpctl.
//
dsmStatus = DSM_ERROR;
//
// Mark-up the Srb to show that a failure has occurred.
// This value is really only for this DSM to know what to do
// in the InterpretError routine - Fatal Error.
// It could be something more meaningful.
//
Srb->SrbStatus = SRB_STATUS_NO_DEVICE;
}
//
// Pass back status info to mpctl.
//
*Status = status;
return dsmStatus;
}
NTSTATUS
HPBroadcastRequest(
IN PVOID DsmContext,
IN PDSM_IDS DsmIds,
IN PIRP Irp,
IN PSCSI_REQUEST_BLOCK Srb,
IN PKEVENT Event
)
{
//
// BUGBUG: Need to handle Reset, Reserve, and Release.
//
return STATUS_INVALID_DEVICE_REQUEST;
}
NTSTATUS
HPSrbDeviceControl(
IN PVOID DsmContext,
IN PDSM_IDS DsmIds,
IN PIRP Irp,
IN PSCSI_REQUEST_BLOCK Srb,
IN PKEVENT Event
)
{
//
// BUGBUG: Need to handle ??
//
return STATUS_INVALID_DEVICE_REQUEST;
}
VOID
HPCompletion(
IN PVOID DsmId,
IN PIRP Irp,
IN PSCSI_REQUEST_BLOCK Srb,
IN PVOID DsmContext
)
{
PCOMPLETION_CONTEXT completionContext = DsmContext;
PDEVICE_INFO deviceInfo;
PDSM_CONTEXT dsmContext;
UCHAR opCode;
//
// If it's read or write, save stats.
// Categorize set-up the Context to have path, target info.
// TODO
//
ASSERT(DsmContext);
dsmContext = completionContext->DsmContext;
deviceInfo = completionContext->DeviceInfo;
opCode = Srb->Cdb[0];
//
// Indicate one less request on this device.
//
InterlockedDecrement(&deviceInfo->Requests);
//
// TODO: Use the timestamp.
// Path/Device up-time, ave. time/request...
//
//
// If it's a read or a write, update the stats.
//
if (opCode == SCSIOP_READ) {
deviceInfo->Stats.NumberReads++;
deviceInfo->Stats.BytesRead.QuadPart += Srb->DataTransferLength;
} else if (opCode == SCSIOP_WRITE) {
deviceInfo->Stats.NumberWrites++;
deviceInfo->Stats.BytesWritten.QuadPart += Srb->DataTransferLength;
}
//
// Release the allocation.
//
ExFreeToNPagedLookasideList(&dsmContext->ContextList,
DsmContext);
}
VOID
HPSetCompletion(
IN PVOID DsmContext,
IN PVOID DsmId,
IN PIRP Irp,
IN PSCSI_REQUEST_BLOCK Srb,
IN OUT PDSM_COMPLETION_INFO DsmCompletion
)
{
PCOMPLETION_CONTEXT completionContext;
PDSM_CONTEXT dsmContext = DsmContext;
PDEVICE_INFO deviceInfo = DsmId;
//
// Save the DeviceInfo as being the target for this request.
// Get a timestamp
// TODO Determine other data.
//
completionContext = ExAllocateFromNPagedLookasideList(&dsmContext->ContextList);
if (completionContext == NULL) {
//
// LOG
//
}
//
// Time stamp this.
//
KeQueryTickCount(&completionContext->TickCount);
//
// Indicate the target for this request.
//
completionContext->DeviceInfo = deviceInfo;
completionContext->DsmContext = DsmContext;
//
// Indicate one more request on this device.
// LB may use this.
//
InterlockedIncrement(&deviceInfo->Requests);
DsmCompletion->DsmCompletionRoutine = HPCompletion;
DsmCompletion->DsmContext = completionContext;
return;
}
ULONG
HPInterpretError(
IN PVOID DsmContext,
IN PVOID DsmId,
IN PSCSI_REQUEST_BLOCK Srb,
IN OUT NTSTATUS *Status,
OUT PBOOLEAN Retry
)
{
ULONG errorMask = 0;
BOOLEAN failover = FALSE;
BOOLEAN retry = FALSE;
BOOLEAN handled = FALSE;
//
// Check the NT Status first.
// Several are clearly failover conditions.
//
switch (*Status) {
case STATUS_DEVICE_NOT_CONNECTED:
case STATUS_DEVICE_DOES_NOT_EXIST:
case STATUS_NO_SUCH_DEVICE:
//
// The port pdo has either been removed or is
// very broken. A fail-over is necessary.
//
handled = TRUE;
failover = TRUE;
break;
default:
break;
}
if (handled == FALSE) {
if (Srb) {
//
// The ntstatus didn't indicate a fail-over condition, but
// check various srb status for failover-class error.
//
switch (Srb->SrbStatus) {
case SRB_STATUS_SELECTION_TIMEOUT:
case SRB_STATUS_INVALID_LUN:
case SRB_STATUS_INVALID_TARGET_ID:
case SRB_STATUS_NO_DEVICE:
case SRB_STATUS_NO_HBA:
case SRB_STATUS_INVALID_PATH_ID:
//
// All of these are fatal.
//
failover = TRUE;
break;
default:
break;
}
}
}
if (failover) {
DebugPrint((0,
"InterpretError: Marking Fatal. Srb (%x). *Status (%x)\n",
Srb,
*Status));
errorMask = DSM_FATAL_ERROR;
}
//
// TODO: Gather a list of status that indicate a retry is necessary.
// Look at InterpretSenseInfo.
//
*Retry = retry;
return errorMask;
}
NTSTATUS
HPUnload(
IN PVOID DsmContext
)
{
//
// It's the responsibility of the mpio bus driver to have already
// destroyed all devices and paths.
// As those functions free allocations for the objects, the only thing
// needed here is to free the DsmContext.
//
ExFreePool(DsmContext);
return STATUS_SUCCESS;
}
//
// Utility functions.
//
NTSTATUS
HPSendDirectCommand(
IN PDEVICE_OBJECT DeviceObject,
IN PUCHAR Buffer,
IN ULONG BufferSize,
IN UCHAR Opcode
)
{
PSCSI_PASS_THROUGH_DIRECT passThrough;
ULONG length;
NTSTATUS status;
PCDB cdb;
IO_STATUS_BLOCK ioStatus;
DsmSendTUR(DeviceObject);
//
// Allocate the pass through plus sense info buffer.
//
length = sizeof(SCSI_PASS_THROUGH_DIRECT) + sizeof(SENSE_DATA);
passThrough = ExAllocatePool(NonPagedPool,
length);
if (passThrough == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(passThrough, length);
//
// These are always 10-byte CDB, guess on the timeout.
// Buffer is allocated by the caller and is it's responsibility to be correctly
// sized and aligned.
//
passThrough->Length = sizeof(SCSI_PASS_THROUGH_DIRECT);
passThrough->CdbLength = 10;
passThrough->SenseInfoLength = sizeof(SENSE_DATA);
passThrough->DataIn = 1;
passThrough->DataTransferLength = BufferSize;
passThrough->TimeOutValue = 20;
passThrough->DataBuffer = Buffer;
passThrough->SenseInfoOffset = sizeof(SCSI_PASS_THROUGH_DIRECT);
cdb = (PCDB)passThrough->Cdb;
//
// These are always 0x20.
//
cdb->CDB10.OperationCode = 0x20;
//
// The sub-code (DCMD OpCode)
//
cdb->CDB10.LogicalBlockByte0 = Opcode;
//
// Allocation length.
//
cdb->CDB10.TransferBlocksLsb = (UCHAR)(BufferSize & 0xFF);
cdb->CDB10.TransferBlocksMsb = (UCHAR)(BufferSize >> 8);
//
// Submit the command.
//
DsmSendDeviceIoControlSynchronous(IOCTL_SCSI_PASS_THROUGH_DIRECT,
DeviceObject,
passThrough,
passThrough,
length,
length,
FALSE,
&ioStatus);
status = ioStatus.Status;
// status = DsmSendPassThroughDirect(DeviceObject,
// passThrough,
// length,
// BufferSize);
if (!NT_SUCCESS(status)) {
//
// The call above has already 'interpreted' the senseInfo, but check
// to see if it is correct.
//
if (Opcode == 0x5) {
//
// No error conditions reported with this command, so trust the interpretation.
//
//
}
}
if (passThrough->ScsiStatus) {
DebugPrint((0,
"SendDirect: ScsiStatus (%x)\n",
passThrough->ScsiStatus));
}
ExFreePool(passThrough);
return status;
}
NTSTATUS
HPSendScsiCommand(
IN PDEVICE_OBJECT DeviceObject,
IN PUCHAR Buffer,
IN ULONG BufferSize,
IN ULONG CdbLength,
IN PCDB Cdb,
IN BOOLEAN DataIn
)
{
PSCSI_PASS_THROUGH_DIRECT passThrough;
ULONG length;
NTSTATUS status;
IO_STATUS_BLOCK ioStatus;
//
// Allocate the pass through plus sense info buffer.
//
length = sizeof(SCSI_PASS_THROUGH_DIRECT) + sizeof(SENSE_DATA);
passThrough = ExAllocatePool(NonPagedPool,
length);
if (passThrough == NULL) {
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(passThrough, length);
//
// These are always 10-byte CDB, guess on the timeout.
// Buffer is allocated by the caller and is it's responsibility to be correctly
// sized and aligned.
//
passThrough->Length = sizeof(SCSI_PASS_THROUGH_DIRECT);
passThrough->CdbLength = (UCHAR)CdbLength;
passThrough->SenseInfoLength = sizeof(SENSE_DATA);
passThrough->DataIn = DataIn;
passThrough->DataTransferLength = BufferSize;
passThrough->TimeOutValue = 20;
passThrough->DataBuffer = Buffer;
passThrough->SenseInfoOffset = sizeof(SCSI_PASS_THROUGH_DIRECT);
RtlCopyMemory(passThrough->Cdb,
Cdb,
CdbLength);
//
// Submit the command.
//
DsmSendDeviceIoControlSynchronous(IOCTL_SCSI_PASS_THROUGH_DIRECT,
DeviceObject,
passThrough,
passThrough,
length,
length,
FALSE,
&ioStatus);
status = ioStatus.Status;
// status = DsmSendPassThroughDirect(DeviceObject,
// passThrough,
// length,
// BufferSize);
return status;
}
PGROUP_ENTRY
FindDevice(
IN PDSM_CONTEXT DsmContext,
IN PDEVICE_INFO DeviceInfo
)
{
PDEVICE_INFO deviceInfo;
PLIST_ENTRY entry;
ULONG i;
//
// Run through the DeviceInfo List
//
entry = DsmContext->DeviceList.Flink;
for (i = 0; i < DsmContext->NumberDevices; i++, entry = entry->Flink) {
//
// Extract the deviceInfo structure.
//
deviceInfo = CONTAINING_RECORD(entry, DEVICE_INFO, ListEntry);
ASSERT(deviceInfo);
//
// Call the Serial Number compare routine.
//
if (HPCompareDevices(DsmContext,
DeviceInfo,
deviceInfo)) {
return deviceInfo->Group;
}
}
DebugPrint((0,
"DsmFindDevice: DsmContext (%x), DeviceInfo (%x)\n",
DsmContext,
DeviceInfo));
return NULL;
}
PGROUP_ENTRY
BuildGroupEntry(
IN PDSM_CONTEXT DsmContext,
IN PDEVICE_INFO DeviceInfo
)
{
PGROUP_ENTRY group;
//
// Allocate the memory for the multi-path group.
//
group = ExAllocatePool(NonPagedPool, sizeof(GROUP_ENTRY));
if (group == NULL) {
return NULL;
}
RtlZeroMemory(group, sizeof(GROUP_ENTRY));
//
// Add it to the list of multi-path groups.
//
ExInterlockedInsertTailList(&DsmContext->GroupList,
&group->ListEntry,
&DsmContext->SpinLock);
group->GroupNumber = InterlockedIncrement(&DsmContext->NumberGroups);
ASSERT(group->GroupNumber >= 1);
return group;
}
NTSTATUS
AddDeviceEntry(
IN PDSM_CONTEXT DsmContext,
IN PGROUP_ENTRY Group,
IN PDEVICE_INFO DeviceInfo,
IN ULONG DeviceState
)
{
ULONG numberDevices;
ULONG i;
KIRQL irql;
//
// Ensure that this is a valid config - namely, it hasn't
// exceeded the number of paths supported.
//
numberDevices = Group->NumberDevices;
if (numberDevices >= MAX_PATHS) {
return STATUS_UNSUCCESSFUL;
}
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
#if DBG
//
// Ensure that this isn't a second copy of the same pdo.
//
for (i = 0; i < numberDevices; i++) {
if (Group->DeviceList[i]->PortPdo == DeviceInfo->PortPdo) {
DebugPrint((0,
"DsmAddDeviceEntry: Received same PDO twice\n"));
DbgBreakPoint();
}
}
#endif
//
// Indicate one device is present in
// this group.
//
Group->DeviceList[numberDevices] = DeviceInfo;
//
// Indicate one more in the list.
//
Group->NumberDevices++;
//
// Set-up this device's group id.
//
DeviceInfo->Group = Group;
//
// Set-up whether this is an active/passive member of the
// group.
//
DeviceInfo->State = DeviceState;
//
// One more deviceInfo entry.
//
DsmContext->NumberDevices++;
//
// Finally, add it to the global list of devices.
//
InsertTailList(&DsmContext->DeviceList,
&DeviceInfo->ListEntry);
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
return STATUS_SUCCESS;
}
VOID
RemoveDeviceEntry(
IN PDSM_CONTEXT DsmContext,
IN PGROUP_ENTRY Group,
IN PDEVICE_INFO DeviceInfo
)
{
KIRQL irql;
NTSTATUS status;
ULONG i;
ULONG j;
BOOLEAN freeGroup = FALSE;
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
//
// Find it's offset in the array of devices.
//
for (i = 0; i < Group->NumberDevices; i++) {
if (Group->DeviceList[i] == DeviceInfo) {
//
// Zero out it's entry.
//
Group->DeviceList[i] = NULL;
//
// Reduce the number in the group.
//
Group->NumberDevices--;
//
// Collapse the array.
//
// BUGBUG: If any requests come in during this time, it's
// possible to either bugcheck or get an incorrect deviceInfo
// structure.
//
for (j = i; j < Group->NumberDevices; j++) {
//
// Shuffle all entries down to fill the hole.
//
Group->DeviceList[j] = Group->DeviceList[j + 1];
}
//
// Zero out the last one.
//
Group->DeviceList[j] = NULL;
break;
}
}
//
// See if anything is left in the Group.
//
if (Group->NumberDevices == 0) {
//
// Yank it from the Group list.
//
RemoveEntryList(&Group->ListEntry);
DsmContext->NumberGroups--;
//
// Zero it.
//
RtlZeroMemory(Group,
sizeof(GROUP_ENTRY));
freeGroup = TRUE;
}
//
// Yank the device out of the Global list.
//
RemoveEntryList(&DeviceInfo->ListEntry);
DsmContext->NumberDevices--;
//
// Zero it.
//
RtlZeroMemory(DeviceInfo,
sizeof(DEVICE_INFO));
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
//
// Free the allocation.
//
ExFreePool(DeviceInfo);
if (freeGroup) {
//
// Free the allocation.
//
ExFreePool(Group);
}
}
PFAILOVER_GROUP
FindFOGroup(
IN PDSM_CONTEXT DsmContext,
IN PVOID PathId
)
{
PFAILOVER_GROUP failOverGroup;
PLIST_ENTRY entry;
ULONG i;
//
// Run through the list of Fail-Over Groups
//
entry = DsmContext->FailGroupList.Flink;
for (i = 0; i < DsmContext->NumberFOGroups; i++, entry = entry->Flink) {
//
// Extract the fail-over group structure.
//
failOverGroup = CONTAINING_RECORD(entry, FAILOVER_GROUP, ListEntry);
ASSERT(failOverGroup);
//
// Check for a match of the PathId.
//
if (failOverGroup->PathId == PathId) {
return failOverGroup;
}
}
return NULL;
}
PFAILOVER_GROUP
BuildFOGroup(
IN PDSM_CONTEXT DsmContext,
IN PDEVICE_INFO DeviceInfo,
IN PVOID PathId
)
{
PFAILOVER_GROUP failOverGroup;
KIRQL irql;
ULONG numberGroups;
//
// Allocate an entry.
//
failOverGroup = ExAllocatePool(NonPagedPool, sizeof(FAILOVER_GROUP));
if (failOverGroup == NULL) {
return NULL;
}
RtlZeroMemory(failOverGroup, sizeof(FAILOVER_GROUP));
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
//
// Get the current number of groups, and add the one that's
// being created.
//
numberGroups = DsmContext->NumberFOGroups++;
//
// Set the PathId - All devices on the same PathId will
// failover together.
//
failOverGroup->PathId = PathId;
//
// Set the initial state to NORMAL.
//
failOverGroup->State = FG_NORMAL;
//
// Add it to the global list.
//
InsertTailList(&DsmContext->FailGroupList,
&failOverGroup->ListEntry);
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
return failOverGroup;
}
NTSTATUS
UpdateFOGroup(
IN PDSM_CONTEXT DsmContext,
IN PFAILOVER_GROUP FailGroup,
IN PDEVICE_INFO DeviceInfo
)
{
PGROUP_ENTRY group;
ULONG count;
KIRQL irql;
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
//
// Add the device to the list of devices that are on this path.
//
count = FailGroup->Count++;
FailGroup->DeviceList[count] = DeviceInfo;
//
// Get the MultiPath group for this device.
//
group = DeviceInfo->Group;
//
// Indicate that the L.B. policy needs to be updated.
// The next call to LBGetPath will cause the re-shuffle to
// take place.
//
group->LoadBalanceInit = FALSE;
DeviceInfo->NeedsVerification = TRUE;
//
// Set the device's F.O. Group.
//
DeviceInfo->FailGroup = FailGroup;
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
return STATUS_SUCCESS;
}
VOID
RemoveDeviceFailGroup(
IN PDSM_CONTEXT DsmContext,
IN PFAILOVER_GROUP FailGroup,
IN PDEVICE_INFO DeviceInfo
)
{
ULONG count;
KIRQL irql;
ULONG i;
ULONG j;
KeAcquireSpinLock(&DsmContext->SpinLock, &irql);
//
// Find it's offset in the array of devices.
//
for (i = 0; i < FailGroup->Count; i++) {
if (FailGroup->DeviceList[i] == DeviceInfo) {
//
// Zero out it's entry.
//
FailGroup->DeviceList[i] = NULL;
//
// Reduce the number in the group.
//
FailGroup->Count--;
//
// Collapse the array.
//
for (j = i; j < FailGroup->Count; j++) {
//
// Shuffle all entries down to fill the hole.
//
FailGroup->DeviceList[j] = FailGroup->DeviceList[j + 1];
}
//
// Zero out the last one.
//
FailGroup->DeviceList[j] = NULL;
break;
}
}
KeReleaseSpinLock(&DsmContext->SpinLock, irql);
return;
}
PFAILOVER_GROUP
SetNewPath(
IN PDSM_CONTEXT DsmContext,
IN PGROUP_ENTRY Group,
IN PDEVICE_INFO FailingDevice,
IN PFAILOVER_GROUP SelectedPath
)
{
PFAILOVER_GROUP failGroup;
PGROUP_ENTRY group;
PDEVICE_INFO device;
ULONG i;
NTSTATUS status;
BOOLEAN matched = FALSE;
if (SelectedPath) {
//
// This indicates that a new path has already been selected
// for at least one device in the Fail-Over Group.
// Run the list of new devices and find the matching
// multi-path group.
//
for (i = 0; i < SelectedPath->Count; i++) {
//
// Get the device from the newly selected Path.
//
device = SelectedPath->DeviceList[i];
//
// Determine if the device's group matches the failing
// device's group.
//
if (device->Group == Group) {
//
// The new device should be either ACTIVE or PASSIVE
//
if ((device->State == DEV_ACTIVE) ||
(device->State == DEV_PASSIVE)) {
//
// Set it to ACTIVE.
//
device->State = DEV_ACTIVE;
//
// Ensure that it's ready.
//
status = DsmSendTUR(device->TargetObject);
ASSERT(status == STATUS_SUCCESS);
matched = TRUE;
break;
}
}
}
//
// When the first call was made and a path selected, all devices
// on the path were checked for validity.
//
ASSERT(matched == TRUE);
//
// Just return the SelectedPath
//
failGroup = SelectedPath;
} else {
//
// Go through Group, looking for an available device.
//
for (i = 0; i < Group->NumberDevices; i++) {
//
// Look for any that are Passive. They are the best
// choice. This would indicate either an ActiveN/PassiveN arrangement.
//
device = Group->DeviceList[i];
if (device->State == DEV_PASSIVE) {
matched = TRUE;
break;
}
}
if (matched) {
//
// Mark the device as active.
//
device->State = DEV_ACTIVE;
//
// Ensure that it's ready.
//
status = DsmSendTUR(device->TargetObject);
ASSERT(status == STATUS_SUCCESS);
//
// Get the Fail-Over group from the selected device.
//
failGroup = device->FailGroup;
} else {
//
// No passive devices. This indicates either an Active/Active arrangement,
// or everything is failed.
// Look for active devices.
//
for (i = 0; i < Group->NumberDevices; i++) {
device = Group->DeviceList[i];
if (device->State == DEV_ACTIVE) {
matched = TRUE;
break;
}
}
if (matched) {
//
// The device is already active, just return the
// new path info.
//
failGroup = device->FailGroup;
} else {
//
// Everything has failed. Should try to do something?? TODO
//
failGroup = NULL;
}
}
if (failGroup) {
//
// Run through all the devices to ensure that they are
// in a reasonable state.
//
for (i = 0; i < failGroup->Count; i++) {
device = failGroup->DeviceList[i];
if ((device->State != DEV_ACTIVE) &&
(device->State != DEV_PASSIVE)) {
//
// Really need to find a new fail-over group.
// TODO.
// This isn't necessarily a valid assert. If static lb is in
// effect and this is one of the first to fail-over, others
// could be considered bad.
//
ASSERT(device->State == DEV_ACTIVE);
}
}
}
}
return failGroup;
}
VOID
LBInit(
IN PDSM_CONTEXT DsmContext,
IN PGROUP_ENTRY Group
)
{
PFAILOVER_GROUP failGroup;
PDEVICE_INFO device;
PLIST_ENTRY entry;
ULONG numberPaths;
ULONG assignedPath;
ULONG i;
BOOLEAN found;
//
// TODO: Once the Wmi support is here, this will be configurable
// Need to add code to handle each of the different policies.
//
//
// Doing 'static' LB. Out of each Multi-Path Group, one
// device will be active and assigned to a particular path.
// The assignment is based on the group ordinal modulus the total
// number of paths.
//
numberPaths = DsmContext->NumberFOGroups;
assignedPath = Group->GroupNumber % numberPaths;
DebugPrint((0,
"DsmLBInit: NumberFOGs (%x), Group Number (%x), assignedPath (%x)\n",
DsmContext->NumberFOGroups,
Group->GroupNumber,
assignedPath));
//
// Get the Fail-Over Group with the correct path.
//
i = 0;
found = FALSE;
//
// Get the first entry.
//
entry = DsmContext->FailGroupList.Flink;
do {
//
// Extract the F.O. Group entry.
//
failGroup = CONTAINING_RECORD(entry, FAILOVER_GROUP, ListEntry);
ASSERT(failGroup);
DebugPrint((0,
"DsmLBInit: Trying %x. at (%x) of (%x)\n",
failGroup,
i,
assignedPath));
if (i == assignedPath) {
//
// This is the one.
//
found = TRUE;
} else {
//
// Advance to the next entry.
//
entry = entry->Flink;
i++;
}
//
// BUGBUG: Need to terminate this loop based on #of FG's.
//
} while (found == FALSE);
DebugPrint((0,
"DsmLBInit: Using FOG (%x)\n",
failGroup));
//
// It may occur that though there are multiple paths/groups, not
// all devices have been put into the DeviceList.
// If there is only 1, special case this. It will get fixed up
// when the second device arrives.
//
if (Group->NumberDevices == 1) {
//
// LOG. Indicates something "might" be wrong - definitely
// not multi-pathing this device, so could lead to disaster
//
//
// Grab device 0 and set it active.
//
device = Group->DeviceList[0];
device->State = DEV_ACTIVE;
//
// Go ahead state that this is init'ed. If/when another
// device shows up, we will re-do this.
//
Group->LoadBalanceInit = TRUE;
Group->LoadBalanceType = LB_STATIC;
DebugPrint((0,
"DsmLBInit: Only One Device (%x) currently in group. Setting it Active\n",
device));
return;
}
//
// Find the device with the same F.O. Group
// in the mulit-path group.
//
for (i = 0; i < Group->NumberDevices; i++) {
//
// Get the device info.
//
device = Group->DeviceList[i];
//
// See if there is a match.
//
if (device->FailGroup == failGroup) {
//
// Set the device to active.
//
device->State = DEV_ACTIVE;
DebugPrint((0,
"DsmLBInit: Marking (%x) as active device\n",
device));
//
// Done setting up this multi-path group.
// Indicate that it's so, and that we are using
// STATIC Load-Balancing.
//
Group->LoadBalanceInit = TRUE;
Group->LoadBalanceType = LB_STATIC;
return;
} else {
DebugPrint((0,
"DsmLBInit: Marking (%x) as stand-by device\n",
device));
device->State = DEV_PASSIVE;
}
}
}
VOID
DsmDebugPrint(
ULONG DebugPrintLevel,
PCCHAR DebugMessage,
...
)
/*++
Routine Description:
Debug print for the DSM
Arguments:
Return Value:
None
--*/
{
va_list ap;
va_start(ap, DebugMessage);
if (DebugPrintLevel <= HPDSMDebug) {
_vsnprintf(DebugBuffer, DEBUG_BUFFER_LENGTH, DebugMessage, ap);
DbgPrint(DebugBuffer);
}
va_end(ap);
}