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sys: ioq: control pending queue with semaphore

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This commit is contained in:
Bill Zissimopoulos
2015-11-23 22:51:03 -08:00
parent 50f2ba8cee
commit e688a98ca9
2 changed files with 59 additions and 18 deletions
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3
src/sys/driver.h
View File

@@ -149,13 +149,14 @@ typedef struct
{
KSPIN_LOCK SpinLock;
int Enabled;
KSEMAPHORE PendingSemaphore;
LIST_ENTRY PendingIrpList, ProcessIrpList;
IO_CSQ PendingIoCsq, ProcessIoCsq;
} FSP_IOQ;
VOID FspIoqInitialize(FSP_IOQ *Ioq);
VOID FspIoqEnable(FSP_IOQ *Ioq, int Delta);
BOOLEAN FspIoqPostIrp(FSP_IOQ *Ioq, PIRP Irp);
PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq);
PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq, ULONG millis);
BOOLEAN FspIoqStartProcessingIrp(FSP_IOQ *Ioq, PIRP Irp);
PIRP FspIoqEndProcessingIrp(FSP_IOQ *Ioq, UINT_PTR IrpHint);
VOID FspIoqCancelAll(FSP_IOQ *Ioq);

74
src/sys/ioq.c
View File

@@ -8,20 +8,20 @@
/*
* An FSP_IOQ encapsulates the main FSP mechanism for handling IRP's.
* It has two queues: a "pending" queue for managing newly arrived IRP's
* and a "processing" queue for managing IRP's currently being processed
* It has two queues: a "Pending" queue for managing newly arrived IRP's
* and a "Processing" queue for managing IRP's currently being processed
* (i.e. sent to the user-mode file system for further processing).
*
* IRP's arrive at a MajorFunction (MJ) and are then posted to the device's
* FSP_IOQ and marked pending. When the user-mode file system performs
* FSP_FSCTL_TRANSACT, the IRP's are removed from the pending queue and
* FSP_FSCTL_TRANSACT, the IRP's are removed from the Pending queue and
* are then marshalled to the user process; prior to that they are added
* to the processing queue. At a later time the user-mode will perform
* to the Processing queue. At a later time the user-mode will perform
* another FSP_FSCTL_TRANSACT at which time any processed IRP's will be
* marshalled back to us and will be then removed from the processing queue
* marshalled back to us and will be then removed from the Processing queue
* and completed.
*
* State diagram:
* IRP State diagram:
* +--------------------+
* | | | StartProcessingIrp
* v | v
@@ -36,13 +36,18 @@
* +------------+ | | IN |
* | | +------------+
* | NextPendingIrp | |
* v | | CompleteIrp
* v | | CompleteRequest
* +------------+ | v
* | TRANSACT | | +------------+
* | OUT | | | Completed |
* +------------+ | +------------+
* | |
* +---------------------+
*
* Note that the Pending queue is controlled by a semaphore object, which
* counts how many IRP's are in the queue. The semaphore is incremented for
* every IRP that is inserted into the Pending queue and decremented every
* time an IRP is removed from the Pending queue.
*/
static NTSTATUS FspIoqPendingInsertIrpEx(PIO_CSQ IoCsq, PIRP Irp, PVOID InsertContext)
@@ -52,7 +57,11 @@ static NTSTATUS FspIoqPendingInsertIrpEx(PIO_CSQ IoCsq, PIRP Irp, PVOID InsertCo
if (0 > Ioq->Enabled)
return STATUS_ACCESS_DENIED;
/* SpinLock: acquired, IRQL: DISPATCH_LEVEL */
InsertTailList(&Ioq->PendingIrpList, &Irp->Tail.Overlay.ListEntry);
KeReleaseSemaphore(&Ioq->PendingSemaphore, FSP_IO_INCREMENT, 1, FALSE);
/* KeReleaseSemaphore allowed at DISPATCH_LEVEL with Wait==FALSE */
return STATUS_SUCCESS;
}
@@ -90,6 +99,16 @@ static VOID FspIoqPendingReleaseLock(PIO_CSQ IoCsq, KIRQL Irql)
KeReleaseSpinLock(&Ioq->SpinLock, Irql);
}
static VOID FspIoqPendingCompleteCanceledIrp(PIO_CSQ IoCsq, PIRP Irp)
{
FSP_IOQ *Ioq = CONTAINING_RECORD(IoCsq, FSP_IOQ, PendingIoCsq);
LARGE_INTEGER Timeout = { 0 };
/* SpinLock: not acquired */
KeWaitForSingleObject(&Ioq->PendingSemaphore, Executive, KernelMode, FALSE, &Timeout);
FspCompleteRequest(Irp, STATUS_CANCELLED);
}
static NTSTATUS FspIoqProcessInsertIrpEx(PIO_CSQ IoCsq, PIRP Irp, PVOID InsertContext)
{
FSP_IOQ *Ioq = CONTAINING_RECORD(IoCsq, FSP_IOQ, ProcessIoCsq);
@@ -142,7 +161,7 @@ static VOID FspIoqProcessReleaseLock(PIO_CSQ IoCsq, KIRQL Irql)
KeReleaseSpinLock(&Ioq->SpinLock, Irql);
}
static VOID FspIoqCompleteCanceledIrp(PIO_CSQ IoCsq, PIRP Irp)
static VOID FspIoqProcessCompleteCanceledIrp(PIO_CSQ IoCsq, PIRP Irp)
{
FspCompleteRequest(Irp, STATUS_CANCELLED);
}
@@ -151,6 +170,7 @@ VOID FspIoqInitialize(FSP_IOQ *Ioq)
{
RtlZeroMemory(Ioq, sizeof *Ioq);
KeInitializeSpinLock(&Ioq->SpinLock);
KeInitializeSemaphore(&Ioq->PendingSemaphore, 0, 1000000000);
InitializeListHead(&Ioq->PendingIrpList);
InitializeListHead(&Ioq->ProcessIrpList);
IoCsqInitializeEx(&Ioq->PendingIoCsq,
@@ -159,14 +179,14 @@ VOID FspIoqInitialize(FSP_IOQ *Ioq)
FspIoqPendingPeekNextIrp,
FspIoqPendingAcquireLock,
FspIoqPendingReleaseLock,
FspIoqCompleteCanceledIrp);
FspIoqPendingCompleteCanceledIrp);
IoCsqInitializeEx(&Ioq->ProcessIoCsq,
FspIoqProcessInsertIrpEx,
FspIoqProcessRemoveIrp,
FspIoqProcessPeekNextIrp,
FspIoqProcessAcquireLock,
FspIoqProcessReleaseLock,
FspIoqCompleteCanceledIrp);
FspIoqProcessCompleteCanceledIrp);
}
VOID FspIoqEnable(FSP_IOQ *Ioq, int Delta)
@@ -179,29 +199,49 @@ VOID FspIoqEnable(FSP_IOQ *Ioq, int Delta)
BOOLEAN FspIoqPostIrp(FSP_IOQ *Ioq, PIRP Irp)
{
return STATUS_SUCCESS == IoCsqInsertIrpEx(&Ioq->PendingIoCsq, Irp, 0, 0);
NTSTATUS Result;
Result = IoCsqInsertIrpEx(&Ioq->PendingIoCsq, Irp, 0, 0);
return NT_SUCCESS(Result);
}
PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq)
PIRP FspIoqNextPendingIrp(FSP_IOQ *Ioq, ULONG millis)
{
return IoCsqRemoveNextIrp(&Ioq->PendingIoCsq, (PVOID)1);
NTSTATUS Result;
LARGE_INTEGER Timeout;
PIRP Irp;
Timeout.QuadPart = (LONGLONG)millis * 10000;
Result = KeWaitForSingleObject(&Ioq->PendingSemaphore, Executive, KernelMode, FALSE,
-1 == millis ? 0 : &Timeout);
if (!NT_SUCCESS(Result))
return 0;
Irp = IoCsqRemoveNextIrp(&Ioq->PendingIoCsq, (PVOID)1);
if (0 == Irp)
/* signal the semaphore again; turns out we did not get an IRP! */
KeReleaseSemaphore(&Ioq->PendingSemaphore, FSP_IO_INCREMENT, 1, FALSE);
return Irp;
}
BOOLEAN FspIoqStartProcessingIrp(FSP_IOQ *Ioq, PIRP Irp)
{
return STATUS_SUCCESS == IoCsqInsertIrpEx(&Ioq->ProcessIoCsq, Irp, 0, 0);
NTSTATUS Result;
Result = IoCsqInsertIrpEx(&Ioq->ProcessIoCsq, Irp, 0, 0);
return NT_SUCCESS(Result);
}
PIRP FspIoqEndProcessingIrp(FSP_IOQ *Ioq, UINT_PTR IrpHint)
{
return IoCsqRemoveNextIrp(&Ioq->PendingIoCsq, (PVOID)IrpHint);
return IoCsqRemoveNextIrp(&Ioq->ProcessIoCsq, (PVOID)IrpHint);
}
VOID FspIoqCancelAll(FSP_IOQ *Ioq)
{
PIRP Irp;
while (0 != (Irp = IoCsqRemoveNextIrp(&Ioq->PendingIoCsq, 0)))
FspCompleteRequest(Irp, STATUS_CANCELLED);
FspIoqPendingCompleteCanceledIrp(&Ioq->PendingIoCsq, Irp);
while (0 != (Irp = IoCsqRemoveNextIrp(&Ioq->ProcessIoCsq, 0)))
FspCompleteRequest(Irp, STATUS_CANCELLED);
FspIoqProcessCompleteCanceledIrp(&Ioq->ProcessIoCsq, Irp);
}