VOID DestroyAllTransferPackets(PDEVICE_OBJECT Fdo)
{
PFUNCTIONAL_DEVICE_EXTENSION fdoExt = Fdo->DeviceExtension;
PCLASS_PRIVATE_FDO_DATA fdoData = fdoExt->PrivateFdoData;
TRANSFER_PACKET *pkt;
PAGED_CODE();
ASSERT(IsListEmpty(&fdoData->DeferredClientIrpList));
while (pkt = DequeueFreeTransferPacket(Fdo, FALSE)){
DestroyTransferPacket(pkt);
InterlockedDecrement(&fdoData->NumTotalTransferPackets);
}
ASSERT(fdoData->NumTotalTransferPackets == 0);
}
VOID EnqueueFreeTransferPacket(PDEVICE_OBJECT Fdo, PTRANSFER_PACKET Pkt)
{
PFUNCTIONAL_DEVICE_EXTENSION fdoExt = Fdo->DeviceExtension;
PCLASS_PRIVATE_FDO_DATA fdoData = fdoExt->PrivateFdoData;
KIRQL oldIrql;
ULONG newNumPkts;
ASSERT(!Pkt->SlistEntry.Next);
InterlockedPushEntrySList(&fdoData->FreeTransferPacketsList, &Pkt->SlistEntry);
newNumPkts = InterlockedIncrement(&fdoData->NumFreeTransferPackets);
ASSERT(newNumPkts <= fdoData->NumTotalTransferPackets);
/*
* If the total number of packets is larger than MinWorkingSetTransferPackets,
* that means that we've been in stress. If all those packets are now
* free, then we are now out of stress and can free the extra packets.
* Free down to MaxWorkingSetTransferPackets immediately, and
* down to MinWorkingSetTransferPackets lazily (one at a time).
*/
if (fdoData->NumFreeTransferPackets >= fdoData->NumTotalTransferPackets){
/*
* 1. Immediately snap down to our UPPER threshold.
*/
if (fdoData->NumTotalTransferPackets > MaxWorkingSetTransferPackets){
SINGLE_LIST_ENTRY pktList;
PSINGLE_LIST_ENTRY slistEntry;
PTRANSFER_PACKET pktToDelete;
DBGTRACE(ClassDebugTrace, ("Exiting stress, block freeing (%d-%d) packets.", fdoData->NumTotalTransferPackets, MaxWorkingSetTransferPackets));
/*
* Check the counter again with lock held. This eliminates a race condition
* while still allowing us to not grab the spinlock in the common codepath.
*
* Note that the spinlock does not synchronize with threads dequeuing free
* packets to send (DequeueFreeTransferPacket does that with a lightweight
* interlocked exchange); the spinlock prevents multiple threads in this function
* from deciding to free too many extra packets at once.
*/
SimpleInitSlistHdr(&pktList);
KeAcquireSpinLock(&fdoData->SpinLock, &oldIrql);
while ((fdoData->NumFreeTransferPackets >= fdoData->NumTotalTransferPackets) &&
(fdoData->NumTotalTransferPackets > MaxWorkingSetTransferPackets)){
pktToDelete = DequeueFreeTransferPacket(Fdo, FALSE);
if (pktToDelete){
SimplePushSlist(&pktList, &pktToDelete->SlistEntry);
InterlockedDecrement(&fdoData->NumTotalTransferPackets);
}
else {
DBGTRACE(ClassDebugTrace, ("Extremely unlikely condition (non-fatal): %d packets dequeued at once for Fdo %p. NumTotalTransferPackets=%d (1).", MaxWorkingSetTransferPackets, Fdo, fdoData->NumTotalTransferPackets));
break;
}
}
KeReleaseSpinLock(&fdoData->SpinLock, oldIrql);
while (slistEntry = SimplePopSlist(&pktList)){
pktToDelete = CONTAINING_RECORD(slistEntry, TRANSFER_PACKET, SlistEntry);
DestroyTransferPacket(pktToDelete);
}
}
/*
* 2. Lazily work down to our LOWER threshold (by only freeing one packet at a time).
*/
if (fdoData->NumTotalTransferPackets > MinWorkingSetTransferPackets){
/*
* Check the counter again with lock held. This eliminates a race condition
* while still allowing us to not grab the spinlock in the common codepath.
*
* Note that the spinlock does not synchronize with threads dequeuing free
* packets to send (DequeueFreeTransferPacket does that with a lightweight
* interlocked exchange); the spinlock prevents multiple threads in this function
* from deciding to free too many extra packets at once.
*/
PTRANSFER_PACKET pktToDelete = NULL;
DBGTRACE(ClassDebugTrace, ("Exiting stress, lazily freeing one of %d/%d packets.", fdoData->NumTotalTransferPackets, MinWorkingSetTransferPackets));
KeAcquireSpinLock(&fdoData->SpinLock, &oldIrql);
if ((fdoData->NumFreeTransferPackets >= fdoData->NumTotalTransferPackets) &&
(fdoData->NumTotalTransferPackets > MinWorkingSetTransferPackets)){
pktToDelete = DequeueFreeTransferPacket(Fdo, FALSE);
if (pktToDelete){
InterlockedDecrement(&fdoData->NumTotalTransferPackets);
}
else {
DBGTRACE(ClassDebugTrace, ("Extremely unlikely condition (non-fatal): %d packets dequeued at once for Fdo %p. NumTotalTransferPackets=%d (2).", MinWorkingSetTransferPackets, Fdo, fdoData->NumTotalTransferPackets));
}
}
KeReleaseSpinLock(&fdoData->SpinLock, oldIrql);
if (pktToDelete){
DestroyTransferPacket(pktToDelete);
}
}
}
}
/*
* BUGBUG RESTORE
* This is a new implementation of the function that doesn't thrash memory
* or depend on the srbLookasideList.
* HOWEVER, it seems to cause pagefile initialization to fail during boot
* for some reason. Need to resolve this before switching to this function.
*/
NTSTATUS
NTAPI
ClasspEjectionControl(
IN PDEVICE_OBJECT Fdo,
IN PIRP Irp,
IN MEDIA_LOCK_TYPE LockType,
IN BOOLEAN Lock
)
{
PFUNCTIONAL_DEVICE_EXTENSION fdoExt = Fdo->DeviceExtension;
PFILE_OBJECT_EXTENSION fsContext;
BOOLEAN fileHandleOk = TRUE;
BOOLEAN countChanged = FALSE;
NTSTATUS status;
PAGED_CODE();
status = KeWaitForSingleObject(
&fdoExt->EjectSynchronizationEvent,
UserRequest,
UserMode,
FALSE,
NULL);
ASSERT(status == STATUS_SUCCESS);
/*
* If this is a "secured" request, we have to make sure
* that the file handle is valid.
*/
if (LockType == SecureMediaLock){
PIO_STACK_LOCATION thisSp = IoGetCurrentIrpStackLocation(Irp);
/*
* Make sure that the file object we are supplied has a
* proper FsContext before we try doing a secured lock.
*/
if (thisSp->FileObject){
PCOMMON_DEVICE_EXTENSION commonExt = (PCOMMON_DEVICE_EXTENSION)fdoExt;
fsContext = ClasspGetFsContext(commonExt, thisSp->FileObject);
}
else {
fsContext = NULL;
}
if (!fsContext){
ASSERT(fsContext);
fileHandleOk = FALSE;
}
}
if (fileHandleOk){
/*
* Adjust the lock counts and make sure they make sense.
*/
status = STATUS_SUCCESS;
if (Lock){
switch(LockType) {
case SimpleMediaLock:
fdoExt->LockCount++;
countChanged = TRUE;
break;
case SecureMediaLock:
fsContext->LockCount++;
fdoExt->ProtectedLockCount++;
countChanged = TRUE;
break;
case InternalMediaLock:
fdoExt->InternalLockCount++;
countChanged = TRUE;
break;
}
}
else {
/*
* This is an unlock command. If it's a secured one then make sure
* the caller has a lock outstanding or return an error.
*/
switch (LockType){
case SimpleMediaLock:
if (fdoExt->LockCount > 0){
fdoExt->LockCount--;
countChanged = TRUE;
}
else {
ASSERT(fdoExt->LockCount > 0);
status = STATUS_INTERNAL_ERROR;
}
break;
case SecureMediaLock:
if (fsContext->LockCount > 0){
ASSERT(fdoExt->ProtectedLockCount > 0);
fsContext->LockCount--;
fdoExt->ProtectedLockCount--;
countChanged = TRUE;
}
else {
ASSERT(fsContext->LockCount > 0);
status = STATUS_INVALID_DEVICE_STATE;
}
break;
case InternalMediaLock:
ASSERT(fdoExt->InternalLockCount > 0);
fdoExt->InternalLockCount--;
countChanged = TRUE;
break;
}
}
if (NT_SUCCESS(status)){
/*
* We only send an unlock command to the drive if
* all the lock counts have dropped to zero.
*/
if (!Lock &&
(fdoExt->ProtectedLockCount ||
fdoExt->InternalLockCount ||
fdoExt->LockCount)){
/*
* The lock count is still positive, so don't unlock yet.
*/
status = STATUS_SUCCESS;
}
else if (!TEST_FLAG(Fdo->Characteristics, FILE_REMOVABLE_MEDIA)) {
/*
* The device isn't removable media. don't send a cmd.
*/
status = STATUS_SUCCESS;
}
else {
TRANSFER_PACKET *pkt;
pkt = DequeueFreeTransferPacket(Fdo, TRUE);
if (pkt){
KEVENT event;
/*
* Store the number of packets servicing the irp (one)
* inside the original IRP. It will be used to counted down
* to zero when the packet completes.
* Initialize the original IRP's status to success.
* If the packet fails, we will set it to the error status.
*/
Irp->Tail.Overlay.DriverContext[0] = LongToPtr(1);
Irp->IoStatus.Status = STATUS_SUCCESS;
/*
* Set this up as a SYNCHRONOUS transfer, submit it,
* and wait for the packet to complete. The result
* status will be written to the original irp.
*/
KeInitializeEvent(&event, SynchronizationEvent, FALSE);
SetupEjectionTransferPacket(pkt, Lock, &event, Irp);
SubmitTransferPacket(pkt);
KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);
status = Irp->IoStatus.Status;
}
else {
status = STATUS_INSUFFICIENT_RESOURCES;
}
}
}
}
else {
status = STATUS_INVALID_PARAMETER;
}
if (!NT_SUCCESS(status) && countChanged) {
//
// have to revert to previous counts if the
// lock/unlock operation actually failed.
//
if(Lock) {
switch(LockType) {
case SimpleMediaLock: {
FdoExtension->LockCount--;
break;
}
case SecureMediaLock: {
fsContext->LockCount--;
FdoExtension->ProtectedLockCount--;
break;
}
case InternalMediaLock: {
FdoExtension->InternalLockCount--;
break;
}
}
} else {
switch(LockType) {
case SimpleMediaLock: {
FdoExtension->LockCount++;
break;
}
case SecureMediaLock: {
fsContext->LockCount++;
FdoExtension->ProtectedLockCount++;
break;
}
case InternalMediaLock: {
FdoExtension->InternalLockCount++;
break;
}
}
}
}
KeSetEvent(&fdoExt->EjectSynchronizationEvent, IO_NO_INCREMENT, FALSE);
return status;
}