[reactos] 02/02: [USBSTOR] Move PDO's Inquiry data and FDO's SCSI context to their Device Extensions. This way the driver can better handle low memory situations

[Victor Perevertkin]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=94e61c3080fe83efcc613…
commit 94e61c3080fe83efcc613d0d77ade45cb0848808
Author:     Victor Perevertkin <victor.perevertkin(a)reactos.org>
AuthorDate: Fri Jun 12 16:51:42 2020 +0300
Commit:     Victor Perevertkin <victor.perevertkin(a)reactos.org>
CommitDate: Fri Jun 12 16:55:27 2020 +0300
    [USBSTOR] Move PDO's Inquiry data and FDO's SCSI context
    to their Device Extensions.
    This way the driver can better handle low memory situations
---
 drivers/usb/usbstor/disk.c    |   5 +-
 drivers/usb/usbstor/error.c   |  11 ++---
 drivers/usb/usbstor/pdo.c     |  35 ++++----------
 drivers/usb/usbstor/scsi.c    | 109 +++++++++++++++++-------------------------
 drivers/usb/usbstor/usbstor.h | 101 +++++++++++++++++++-------------------
 5 files changed, 113 insertions(+), 148 deletions(-)
diff --git a/drivers/usb/usbstor/disk.c b/drivers/usb/usbstor/disk.c
index b73ca91292c..1e5bd1299fb 100644
--- a/drivers/usb/usbstor/disk.c
+++ b/drivers/usb/usbstor/disk.c
@@ -283,8 +283,7 @@ USBSTOR_HandleQueryProperty(
         ASSERT(FDODeviceExtension);
         ASSERT(FDODeviceExtension->Common.IsFDO);
-        InquiryData = PDODeviceExtension->InquiryData;
-        ASSERT(InquiryData);
+        InquiryData = (PINQUIRYDATA)&PDODeviceExtension->InquiryData;
         // compute extra parameters length
         FieldLengthVendor = USBSTOR_GetFieldLength(InquiryData->VendorId, 8);
@@ -507,7 +506,7 @@ USBSTOR_HandleDeviceControl(
             // Note: INQUIRYDATA structure is larger than INQUIRYDATABUFFERSIZE
             RtlZeroMemory(InquiryData, sizeof(INQUIRYDATA));
-            RtlCopyMemory(InquiryData, PDODeviceExtension->InquiryData,
INQUIRYDATABUFFERSIZE);
+            RtlCopyMemory(InquiryData, &PDODeviceExtension->InquiryData,
sizeof(PDODeviceExtension->InquiryData));
             InquiryData->Versions = 0x04;
             InquiryData->ResponseDataFormat = 0x02; // some devices set this to 1
diff --git a/drivers/usb/usbstor/error.c b/drivers/usb/usbstor/error.c
index 3964b2c7b4d..1c773ab6709 100644
--- a/drivers/usb/usbstor/error.c
+++ b/drivers/usb/usbstor/error.c
@@ -77,15 +77,15 @@ USBSTOR_ResetPipeWorkItemRoutine(
     IN PVOID Ctx)
 {
     NTSTATUS Status;
-    PIRP_CONTEXT Context = (PIRP_CONTEXT)Ctx;
-    PFDO_DEVICE_EXTENSION FDODeviceExtension =
(PFDO_DEVICE_EXTENSION)FdoDevice->DeviceExtension;
+    PFDO_DEVICE_EXTENSION FDODeviceExtension = (PFDO_DEVICE_EXTENSION)Ctx;
+    PIRP_CONTEXT Context = &FDODeviceExtension->CurrentIrpContext;
     // clear stall on the corresponding pipe
     Status = USBSTOR_ResetPipeWithHandle(FDODeviceExtension->LowerDeviceObject,
Context->Urb.UrbBulkOrInterruptTransfer.PipeHandle);
     DPRINT1("USBSTOR_ResetPipeWithHandle Status %x\n", Status);
     // now resend the csw as the stall got cleared
-    USBSTOR_SendCSWRequest(Context, Context->Irp);
+    USBSTOR_SendCSWRequest(FDODeviceExtension, Context->Irp);
 }
 VOID
@@ -133,15 +133,14 @@ USBSTOR_ResetDeviceWorkItemRoutine(
 VOID
 NTAPI
 USBSTOR_QueueResetPipe(
-    IN PFDO_DEVICE_EXTENSION FDODeviceExtension,
-    IN PIRP_CONTEXT Context)
+    IN PFDO_DEVICE_EXTENSION FDODeviceExtension)
 {
     DPRINT("USBSTOR_QueueResetPipe\n");
     IoQueueWorkItem(FDODeviceExtension->ResetDeviceWorkItem,
                     USBSTOR_ResetPipeWorkItemRoutine,
                     CriticalWorkQueue,
-                    Context);
+                    FDODeviceExtension);
 }
 VOID
diff --git a/drivers/usb/usbstor/pdo.c b/drivers/usb/usbstor/pdo.c
index 50996e396c6..e89eb45d382 100644
--- a/drivers/usb/usbstor/pdo.c
+++ b/drivers/usb/usbstor/pdo.c
@@ -137,8 +137,7 @@ USBSTOR_PdoHandleQueryDeviceText(
     IoStack = IoGetCurrentIrpStackLocation(Irp);
     DeviceExtension = (PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
-    ASSERT(DeviceExtension->InquiryData);
-    InquiryData = DeviceExtension->InquiryData;
+    InquiryData = (PINQUIRYDATA)&DeviceExtension->InquiryData;
     switch (IoStack->Parameters.QueryDeviceText.DeviceTextType)
     {
@@ -191,8 +190,7 @@ USBSTOR_PdoHandleQueryDeviceId(
     UNICODE_STRING DeviceId;
     DeviceExtension = (PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
-    ASSERT(DeviceExtension->InquiryData);
-    InquiryData = DeviceExtension->InquiryData;
+    InquiryData = (PINQUIRYDATA)&DeviceExtension->InquiryData;
     DeviceType = USBSTOR_GetDeviceType(InquiryData);
@@ -282,7 +280,7 @@ USBSTOR_PdoHandleQueryHardwareId(
     PDODeviceExtension = (PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
     FDODeviceExtension =
(PFDO_DEVICE_EXTENSION)PDODeviceExtension->LowerDeviceObject->DeviceExtension;
     ASSERT(FDODeviceExtension->DeviceDescriptor);
-    InquiryData = PDODeviceExtension->InquiryData;
+    InquiryData = (PINQUIRYDATA)&PDODeviceExtension->InquiryData;
     DeviceType = USBSTOR_GetDeviceType(InquiryData);
     GenericType = USBSTOR_GetGenericType(InquiryData);
@@ -404,7 +402,7 @@ USBSTOR_PdoHandleQueryCompatibleId(
     PDODeviceExtension = (PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
     FDODeviceExtension =
(PFDO_DEVICE_EXTENSION)PDODeviceExtension->LowerDeviceObject->DeviceExtension;
     ASSERT(FDODeviceExtension->DeviceDescriptor);
-    DeviceType = USBSTOR_GetDeviceType(PDODeviceExtension->InquiryData);
+    DeviceType =
USBSTOR_GetDeviceType((PINQUIRYDATA)&PDODeviceExtension->InquiryData);
     // format instance id
     Length = sprintf(Buffer, "USBSTOR\\%s", DeviceType) + 1;
@@ -573,10 +571,6 @@ USBSTOR_PdoHandlePnp(
                bDelete = FALSE;
            }
-           // clean up the device extension
-           ASSERT(DeviceExtension->InquiryData);
-           ExFreePoolWithTag(DeviceExtension->InquiryData, USB_STOR_TAG);
-
            Irp->IoStatus.Status = STATUS_SUCCESS;
            IoCompleteRequest(Irp, IO_NO_INCREMENT);
@@ -804,19 +798,10 @@ USBSTOR_FillInquiryData(
     IN PDEVICE_OBJECT PDODeviceObject)
 {
     NTSTATUS Status = STATUS_INSUFFICIENT_RESOURCES;
-    PPDO_DEVICE_EXTENSION PDODeviceExtension;
+    PPDO_DEVICE_EXTENSION PDODeviceExtension =
(PPDO_DEVICE_EXTENSION)PDODeviceObject->DeviceExtension;
     CDB Cdb;
     ULONG DataTransferLength = INQUIRYDATABUFFERSIZE;
-    PINQUIRYDATA InquiryData;
-
-    PDODeviceExtension = (PPDO_DEVICE_EXTENSION)PDODeviceObject->DeviceExtension;
-    InquiryData = ExAllocatePoolWithTag(NonPagedPool, INQUIRYDATABUFFERSIZE,
USB_STOR_TAG);
-
-    if (!InquiryData)
-    {
-        DPRINT1("USBSTOR_FillInquiryData failed with %x\n", Status);
-        return Status;
-    }
+    PINQUIRYDATA InquiryData = (PINQUIRYDATA)&PDODeviceExtension->InquiryData;
     RtlZeroMemory(&Cdb, sizeof(Cdb));
     Cdb.CDB6INQUIRY.OperationCode = SCSIOP_INQUIRY;
@@ -827,7 +812,6 @@ USBSTOR_FillInquiryData(
     if (!NT_SUCCESS(Status))
     {
         DPRINT1("USBSTOR_FillInquiryData failed with %x\n", Status);
-        ExFreePoolWithTag(InquiryData, USB_STOR_TAG);
         return Status;
     }
@@ -846,7 +830,6 @@ USBSTOR_FillInquiryData(
     DPRINT("Revision %c%c%c%c\n", InquiryData->ProductRevisionLevel[0],
InquiryData->ProductRevisionLevel[1], InquiryData->ProductRevisionLevel[2],
InquiryData->ProductRevisionLevel[3]);
-    PDODeviceExtension->InquiryData = InquiryData;
     return Status;
 }
@@ -859,6 +842,7 @@ USBSTOR_CreatePDO(
     NTSTATUS Status;
     PPDO_DEVICE_EXTENSION PDODeviceExtension;
     PFDO_DEVICE_EXTENSION FDODeviceExtension;
+    PINQUIRYDATA InquiryData;
     FDODeviceExtension = (PFDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
@@ -874,6 +858,7 @@ USBSTOR_CreatePDO(
     PDO->StackSize = DeviceObject->StackSize;
     PDODeviceExtension = (PPDO_DEVICE_EXTENSION)PDO->DeviceExtension;
+    InquiryData = (PINQUIRYDATA)&PDODeviceExtension->InquiryData;
     // initialize device extension
     RtlZeroMemory(PDODeviceExtension, sizeof(PDO_DEVICE_EXTENSION));
@@ -899,8 +884,8 @@ USBSTOR_CreatePDO(
         return Status;
     }
-    if (PDODeviceExtension->InquiryData->DeviceType != DIRECT_ACCESS_DEVICE
&&
-        PDODeviceExtension->InquiryData->DeviceType !=
READ_ONLY_DIRECT_ACCESS_DEVICE)
+    if (InquiryData->DeviceType != DIRECT_ACCESS_DEVICE &&
+        InquiryData->DeviceType != READ_ONLY_DIRECT_ACCESS_DEVICE)
     {
         return STATUS_NOT_SUPPORTED;
     }
diff --git a/drivers/usb/usbstor/scsi.c b/drivers/usb/usbstor/scsi.c
index 946065649dd..d32aa0941cd 100644
--- a/drivers/usb/usbstor/scsi.c
+++ b/drivers/usb/usbstor/scsi.c
@@ -65,10 +65,10 @@ USBSTOR_IssueBulkOrInterruptRequest(
     IN ULONG TransferBufferLength,
     IN PVOID TransferBuffer,
     IN PMDL TransferBufferMDL,
-    IN PIO_COMPLETION_ROUTINE CompletionRoutine,
-    IN PIRP_CONTEXT Context)
+    IN PIO_COMPLETION_ROUTINE CompletionRoutine)
 {
     PIO_STACK_LOCATION NextStack;
+    PIRP_CONTEXT Context = &FDODeviceExtension->CurrentIrpContext;
     RtlZeroMemory(&Context->Urb, sizeof(struct _URB_BULK_OR_INTERRUPT_TRANSFER));
@@ -88,7 +88,7 @@ USBSTOR_IssueBulkOrInterruptRequest(
     IoSetCompletionRoutine(Irp,
                            CompletionRoutine,
-                           Context,
+                           FDODeviceExtension,
                            TRUE,
                            TRUE,
                            TRUE);
@@ -107,9 +107,9 @@ USBSTOR_IsCSWValid(
         return FALSE;
     }
-    if (Context->csw.Tag != PtrToUlong(&Context->csw))
+    if (Context->csw.Tag != PtrToUlong(Context->Irp))
     {
-        DPRINT1("[USBSTOR] Expected Tag %Ix but got %x\n",
PtrToUlong(&Context->csw), Context->csw.Tag);
+        DPRINT1("[USBSTOR] Expected Tag %Ix but got %x\n",
PtrToUlong(Context->Irp), Context->csw.Tag);
         return FALSE;
     }
@@ -120,8 +120,7 @@ static
 NTSTATUS
 USBSTOR_IssueRequestSense(
     IN PFDO_DEVICE_EXTENSION FDODeviceExtension,
-    IN PIRP Irp,
-    IN PIRP_CONTEXT Context);
+    IN PIRP Irp);
 IO_COMPLETION_ROUTINE USBSTOR_CSWCompletionRoutine;
@@ -138,13 +137,12 @@ USBSTOR_CSWCompletionRoutine(
     PFDO_DEVICE_EXTENSION FDODeviceExtension;
     PSCSI_REQUEST_BLOCK Request;
-    Context = (PIRP_CONTEXT)Ctx;
-
     DPRINT("USBSTOR_CSWCompletionRoutine Irp %p Ctx %p Status %x\n", Irp, Ctx,
Irp->IoStatus.Status);
     IoStack = IoGetCurrentIrpStackLocation(Irp);
     PDODeviceExtension =
(PPDO_DEVICE_EXTENSION)IoStack->DeviceObject->DeviceExtension;
-    FDODeviceExtension = Context->FDODeviceExtension;
+    FDODeviceExtension = (PFDO_DEVICE_EXTENSION)Ctx;
+    Context = &FDODeviceExtension->CurrentIrpContext;
     Request = IoStack->Parameters.Scsi.Srb;
     ASSERT(Request);
@@ -158,7 +156,7 @@ USBSTOR_CSWCompletionRoutine(
                 ++Context->StallRetryCount;
                 // clear stall and resend cbw
-                USBSTOR_QueueResetPipe(FDODeviceExtension, Context);
+                USBSTOR_QueueResetPipe(FDODeviceExtension);
                 return STATUS_MORE_PROCESSING_REQUIRED;
             }
@@ -211,7 +209,7 @@ USBSTOR_CSWCompletionRoutine(
               Request->SenseInfoBufferLength &&
               Request->SenseInfoBuffer)
         {
-            USBSTOR_IssueRequestSense(FDODeviceExtension, Irp, Context);
+            USBSTOR_IssueRequestSense(FDODeviceExtension, Irp);
             return STATUS_MORE_PROCESSING_REQUIRED;
         }
@@ -224,7 +222,6 @@ USBSTOR_CSWCompletionRoutine(
     USBSTOR_QueueTerminateRequest(PDODeviceExtension->LowerDeviceObject, Irp);
     USBSTOR_QueueNextRequest(PDODeviceExtension->LowerDeviceObject);
-    ExFreePoolWithTag(Context, USB_STOR_TAG);
     return STATUS_CONTINUE_COMPLETION;
 ResetRecovery:
@@ -238,24 +235,22 @@ ResetRecovery:
     USBSTOR_QueueTerminateRequest(PDODeviceExtension->LowerDeviceObject, Irp);
     USBSTOR_QueueResetDevice(FDODeviceExtension);
-    ExFreePoolWithTag(Context, USB_STOR_TAG);
     return STATUS_CONTINUE_COMPLETION;
 }
 NTSTATUS
 USBSTOR_SendCSWRequest(
-    PIRP_CONTEXT Context,
+    PFDO_DEVICE_EXTENSION FDODeviceExtension,
     PIRP Irp)
 {
-    return USBSTOR_IssueBulkOrInterruptRequest(Context->FDODeviceExtension,
+    return USBSTOR_IssueBulkOrInterruptRequest(FDODeviceExtension,
                                                Irp,
-
Context->FDODeviceExtension->InterfaceInformation->Pipes[Context->FDODeviceExtension->BulkInPipeIndex].PipeHandle,
+
FDODeviceExtension->InterfaceInformation->Pipes[FDODeviceExtension->BulkInPipeIndex].PipeHandle,
                                                USBD_TRANSFER_DIRECTION_IN,
                                                sizeof(CSW),
-                                               &Context->csw,
+
&FDODeviceExtension->CurrentIrpContext.csw,
                                                NULL,
-                                               USBSTOR_CSWCompletionRoutine,
-                                               Context);
+                                               USBSTOR_CSWCompletionRoutine);
 }
 IO_COMPLETION_ROUTINE USBSTOR_DataCompletionRoutine;
@@ -270,17 +265,19 @@ USBSTOR_DataCompletionRoutine(
     PIRP_CONTEXT Context;
     PIO_STACK_LOCATION IoStack;
     PSCSI_REQUEST_BLOCK Request;
+    PFDO_DEVICE_EXTENSION FDODeviceExtension;
     PPDO_DEVICE_EXTENSION PDODeviceExtension;
     DPRINT("USBSTOR_DataCompletionRoutine Irp %p Ctx %p Status %x\n", Irp, Ctx,
Irp->IoStatus.Status);
-    Context = (PIRP_CONTEXT)Ctx;
+    FDODeviceExtension = (PFDO_DEVICE_EXTENSION)Ctx;
+    Context = &FDODeviceExtension->CurrentIrpContext;
     IoStack = IoGetCurrentIrpStackLocation(Irp);
     Request = IoStack->Parameters.Scsi.Srb;
     PDODeviceExtension =
(PPDO_DEVICE_EXTENSION)IoStack->DeviceObject->DeviceExtension;
     // for Sense Request a partial MDL was already freed (if existed)
-    if (Request == Context->FDODeviceExtension->ActiveSrb &&
+    if (Request == FDODeviceExtension->ActiveSrb &&
         Context->Urb.UrbBulkOrInterruptTransfer.TransferBufferMDL !=
Irp->MdlAddress)
     {
         IoFreeMdl(Context->Urb.UrbBulkOrInterruptTransfer.TransferBufferMDL);
@@ -298,7 +295,7 @@ USBSTOR_DataCompletionRoutine(
         }
         Request->DataTransferLength =
Context->Urb.UrbBulkOrInterruptTransfer.TransferBufferLength;
-        USBSTOR_SendCSWRequest(Context, Irp);
+        USBSTOR_SendCSWRequest(FDODeviceExtension, Irp);
     }
     else if (USBD_STATUS(Context->Urb.UrbHeader.Status) ==
USBD_STATUS(USBD_STATUS_STALL_PID))
     {
@@ -308,7 +305,7 @@ USBSTOR_DataCompletionRoutine(
         Request->DataTransferLength =
Context->Urb.UrbBulkOrInterruptTransfer.TransferBufferLength;
         // clear stall and resend cbw
-        USBSTOR_QueueResetPipe(Context->FDODeviceExtension, Context);
+        USBSTOR_QueueResetPipe(FDODeviceExtension);
     }
     else
     {
@@ -317,9 +314,8 @@ USBSTOR_DataCompletionRoutine(
         Request->SrbStatus = SRB_STATUS_BUS_RESET;
         USBSTOR_QueueTerminateRequest(PDODeviceExtension->LowerDeviceObject, Irp);
-        USBSTOR_QueueResetDevice(Context->FDODeviceExtension);
+        USBSTOR_QueueResetDevice(FDODeviceExtension);
-        ExFreePoolWithTag(Context, USB_STOR_TAG);
         return STATUS_CONTINUE_COMPLETION;
     }
@@ -339,6 +335,7 @@ USBSTOR_CBWCompletionRoutine(
     PIO_STACK_LOCATION IoStack;
     PSCSI_REQUEST_BLOCK Request;
     PPDO_DEVICE_EXTENSION PDODeviceExtension;
+    PFDO_DEVICE_EXTENSION FDODeviceExtension;
     USBD_PIPE_HANDLE PipeHandle;
     ULONG TransferFlags;
     PMDL Mdl = NULL;
@@ -346,7 +343,8 @@ USBSTOR_CBWCompletionRoutine(
     DPRINT("USBSTOR_CBWCompletionRoutine Irp %p Ctx %p Status %x\n", Irp, Ctx,
Irp->IoStatus.Status);
-    Context = (PIRP_CONTEXT)Ctx;
+    FDODeviceExtension = (PFDO_DEVICE_EXTENSION)Ctx;
+    Context = &FDODeviceExtension->CurrentIrpContext;
     IoStack = IoGetCurrentIrpStackLocation(Irp);
     Request = IoStack->Parameters.Scsi.Srb;
     PDODeviceExtension =
(PPDO_DEVICE_EXTENSION)IoStack->DeviceObject->DeviceExtension;
@@ -358,10 +356,10 @@ USBSTOR_CBWCompletionRoutine(
     // a request without the buffer AND not a sense request
     // for a sense request we provide just a TransferBuffer, an Mdl will be allocated by
usbport (see below)
-    if (!Irp->MdlAddress && Request ==
Context->FDODeviceExtension->ActiveSrb)
+    if (!Irp->MdlAddress && Request == FDODeviceExtension->ActiveSrb)
     {
         Request->SrbStatus = SRB_STATUS_SUCCESS;
-        USBSTOR_SendCSWRequest(Context, Irp);
+        USBSTOR_SendCSWRequest(FDODeviceExtension, Irp);
         return STATUS_MORE_PROCESSING_REQUIRED;
     }
@@ -369,12 +367,12 @@ USBSTOR_CBWCompletionRoutine(
     if ((Request->SrbFlags & SRB_FLAGS_UNSPECIFIED_DIRECTION) ==
SRB_FLAGS_DATA_IN)
     {
-        PipeHandle =
Context->FDODeviceExtension->InterfaceInformation->Pipes[Context->FDODeviceExtension->BulkInPipeIndex].PipeHandle;
+        PipeHandle =
FDODeviceExtension->InterfaceInformation->Pipes[FDODeviceExtension->BulkInPipeIndex].PipeHandle;
         TransferFlags = USBD_TRANSFER_DIRECTION_IN | USBD_SHORT_TRANSFER_OK;
     }
     else if ((Request->SrbFlags & SRB_FLAGS_UNSPECIFIED_DIRECTION) ==
SRB_FLAGS_DATA_OUT)
     {
-        PipeHandle =
Context->FDODeviceExtension->InterfaceInformation->Pipes[Context->FDODeviceExtension->BulkOutPipeIndex].PipeHandle;
+        PipeHandle =
FDODeviceExtension->InterfaceInformation->Pipes[FDODeviceExtension->BulkOutPipeIndex].PipeHandle;
         TransferFlags = USBD_TRANSFER_DIRECTION_OUT;
     }
     else
@@ -385,7 +383,7 @@ USBSTOR_CBWCompletionRoutine(
     }
     // if it is not a Sense Request
-    if (Request == Context->FDODeviceExtension->ActiveSrb)
+    if (Request == FDODeviceExtension->ActiveSrb)
     {
         if (MmGetMdlVirtualAddress(Irp->MdlAddress) == Request->DataBuffer)
         {
@@ -420,29 +418,27 @@ USBSTOR_CBWCompletionRoutine(
         TransferBuffer = Request->DataBuffer;
     }
-    USBSTOR_IssueBulkOrInterruptRequest(Context->FDODeviceExtension,
+    USBSTOR_IssueBulkOrInterruptRequest(FDODeviceExtension,
                                         Irp,
                                         PipeHandle,
                                         TransferFlags,
                                         Request->DataTransferLength,
                                         TransferBuffer,
                                         Mdl,
-                                        USBSTOR_DataCompletionRoutine,
-                                        Context);
+                                        USBSTOR_DataCompletionRoutine);
     return STATUS_MORE_PROCESSING_REQUIRED;
 ResetRecovery:
-    Request = Context->FDODeviceExtension->ActiveSrb;
+    Request = FDODeviceExtension->ActiveSrb;
     IoStack->Parameters.Scsi.Srb = Request;
     Irp->IoStatus.Information = 0;
     Irp->IoStatus.Status = STATUS_IO_DEVICE_ERROR;
     Request->SrbStatus = SRB_STATUS_BUS_RESET;
     USBSTOR_QueueTerminateRequest(PDODeviceExtension->LowerDeviceObject, Irp);
-    USBSTOR_QueueResetDevice(Context->FDODeviceExtension);
+    USBSTOR_QueueResetDevice(FDODeviceExtension);
-    ExFreePoolWithTag(Context, USB_STOR_TAG);
     return STATUS_CONTINUE_COMPLETION;
 }
@@ -461,12 +457,12 @@ static
 NTSTATUS
 USBSTOR_SendCBWRequest(
     IN PFDO_DEVICE_EXTENSION FDODeviceExtension,
-    IN PIRP Irp,
-    IN PIRP_CONTEXT Context)
+    IN PIRP Irp)
 {
     PPDO_DEVICE_EXTENSION PDODeviceExtension;
     PIO_STACK_LOCATION IoStack;
     PSCSI_REQUEST_BLOCK Request;
+    PIRP_CONTEXT Context = &FDODeviceExtension->CurrentIrpContext;
     RtlZeroMemory(&Context->cbw, sizeof(CBW));
     RtlZeroMemory(&Context->Urb, sizeof(URB));
@@ -475,8 +471,9 @@ USBSTOR_SendCBWRequest(
     PDODeviceExtension = IoStack->DeviceObject->DeviceExtension;
     Request = IoStack->Parameters.Scsi.Srb;
+    // Make a CBW structure from SCSI request block
     Context->cbw.Signature = CBW_SIGNATURE;
-    Context->cbw.Tag = PtrToUlong(&Context->cbw);
+    Context->cbw.Tag = PtrToUlong(Irp);
     Context->cbw.DataTransferLength = Request->DataTransferLength;
     Context->cbw.Flags = ((UCHAR)Request->SrbFlags &
SRB_FLAGS_UNSPECIFIED_DIRECTION) << 1;
     Context->cbw.LUN = PDODeviceExtension->LUN;
@@ -489,7 +486,6 @@ USBSTOR_SendCBWRequest(
     // initialize rest of context
     Context->Irp = Irp;
-    Context->FDODeviceExtension = FDODeviceExtension;
     Context->StallRetryCount = 0;
     return USBSTOR_IssueBulkOrInterruptRequest(
@@ -500,16 +496,14 @@ USBSTOR_SendCBWRequest(
         sizeof(CBW),
         &Context->cbw,
         NULL,
-        USBSTOR_CBWCompletionRoutine,
-        Context);
+        USBSTOR_CBWCompletionRoutine);
 }
 static
 NTSTATUS
 USBSTOR_IssueRequestSense(
     IN PFDO_DEVICE_EXTENSION FDODeviceExtension,
-    IN PIRP Irp,
-    IN PIRP_CONTEXT Context)
+    IN PIRP Irp)
 {
     PIO_STACK_LOCATION IoStack;
     PSCSI_REQUEST_BLOCK CurrentSrb;
@@ -518,7 +512,7 @@ USBSTOR_IssueRequestSense(
     DPRINT("USBSTOR_IssueRequestSense: \n");
     CurrentSrb = FDODeviceExtension->ActiveSrb;
-    SenseSrb = &Context->SenseSrb;
+    SenseSrb = &FDODeviceExtension->CurrentIrpContext.SenseSrb;
     IoStack = IoGetCurrentIrpStackLocation(Irp);
     IoStack->Parameters.Scsi.Srb = SenseSrb;
@@ -541,7 +535,7 @@ USBSTOR_IssueRequestSense(
     SrbGetCdb(SenseSrb)->CDB6GENERIC.OperationCode = SCSIOP_REQUEST_SENSE;
     SrbGetCdb(SenseSrb)->AsByte[4] = CurrentSrb->SenseInfoBufferLength;
-    return USBSTOR_SendCBWRequest(FDODeviceExtension, Irp, Context);
+    return USBSTOR_SendCBWRequest(FDODeviceExtension, Irp);
 }
 NTSTATUS
@@ -549,13 +543,10 @@ USBSTOR_HandleExecuteSCSI(
     IN PDEVICE_OBJECT DeviceObject,
     IN PIRP Irp)
 {
-    NTSTATUS Status;
     PIO_STACK_LOCATION IoStack;
     PSCSI_REQUEST_BLOCK Request;
-    PPDO_DEVICE_EXTENSION PDODeviceExtension;
-    PIRP_CONTEXT Context;
+    PPDO_DEVICE_EXTENSION PDODeviceExtension =
(PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
-    PDODeviceExtension = (PPDO_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
     ASSERT(PDODeviceExtension->Common.IsFDO == FALSE);
     IoStack = IoGetCurrentIrpStackLocation(Irp);
@@ -564,17 +555,7 @@ USBSTOR_HandleExecuteSCSI(
     DPRINT("USBSTOR_HandleExecuteSCSI Operation Code %x, Length %lu\n",
SrbGetCdb(Request)->CDB10.OperationCode, Request->DataTransferLength);
     // check that we're sending to the right LUN
-    ASSERT(SrbGetCdb(Request)->CDB10.LogicalUnitNumber == (PDODeviceExtension->LUN
& MAX_LUN));
-    Context = ExAllocatePoolWithTag(NonPagedPool, sizeof(IRP_CONTEXT), USB_STOR_TAG);
-
-    if (!Context)
-    {
-        Status = STATUS_INSUFFICIENT_RESOURCES;
-    }
-    else
-    {
-        Status =
USBSTOR_SendCBWRequest(PDODeviceExtension->LowerDeviceObject->DeviceExtension, Irp,
Context);
-    }
+    ASSERT(SrbGetCdb(Request)->CDB10.LogicalUnitNumber == PDODeviceExtension->LUN);
-    return Status;
+    return
USBSTOR_SendCBWRequest(PDODeviceExtension->LowerDeviceObject->DeviceExtension, Irp);
 }
diff --git a/drivers/usb/usbstor/usbstor.h b/drivers/usb/usbstor/usbstor.h
index 9e8b50e5701..71e90708311 100644
--- a/drivers/usb/usbstor/usbstor.h
+++ b/drivers/usb/usbstor/usbstor.h
@@ -61,6 +61,52 @@
 #define MAX_LUN 0xF
 #define USBSTOR_DEFAULT_MAX_TRANSFER_LENGTH 0x10000
+#define CBW_SIGNATURE 0x43425355
+#define CSW_SIGNATURE 0x53425355
+
+#include <pshpack1.h>
+
+typedef struct
+{
+    ULONG Signature;                                                 // CBW signature
+    ULONG Tag;                                                       // CBW Tag of
operation
+    ULONG DataTransferLength;                                        // data transfer
length
+    UCHAR Flags;                                                     // CBW Flags
endpoint direction
+    UCHAR LUN;                                                       // lun unit
+    UCHAR CommandBlockLength;                                        // Command block
length
+    UCHAR CommandBlock[16];
+} CBW, *PCBW;
+
+C_ASSERT(sizeof(CBW) == 31);
+
+#define CSW_STATUS_COMMAND_PASSED 0x00
+#define CSW_STATUS_COMMAND_FAILED 0x01
+#define CSW_STATUS_PHASE_ERROR    0x02
+
+typedef struct
+{
+    ULONG Signature;                                                 // CSW signature
+    ULONG Tag;                                                       // CSW tag
+    ULONG DataResidue;                                               // CSW data transfer
diff
+    UCHAR Status;                                                    // CSW status
+} CSW, *PCSW;
+
+#include <poppack.h>
+
+typedef struct
+{
+    PIRP Irp;
+    ULONG ErrorIndex;
+    ULONG StallRetryCount;                                            // the number of
retries after receiving USBD_STATUS_STALL_PID status
+    union
+    {
+        CBW cbw;
+        CSW csw;
+    };
+    URB Urb;
+    SCSI_REQUEST_BLOCK SenseSrb;
+} IRP_CONTEXT, *PIRP_CONTEXT;
+
 typedef struct __COMMON_DEVICE_EXTENSION__
 {
     BOOLEAN IsFDO;
@@ -99,6 +145,7 @@ typedef struct
     KSPIN_LOCK CommonLock;
     PIO_WORKITEM ResetDeviceWorkItem;
     ULONG Flags;
+    IRP_CONTEXT CurrentIrpContext;
 }FDO_DEVICE_EXTENSION, *PFDO_DEVICE_EXTENSION;
 typedef struct
@@ -108,57 +155,12 @@ typedef struct
     UCHAR LUN;
// lun id
     BOOLEAN Claimed;
// indicating if it has been claimed by upper driver
     PDEVICE_OBJECT LowerDeviceObject;
// points to FDO
-    PINQUIRYDATA InquiryData;
// USB SCSI inquiry data
     PDEVICE_OBJECT *PDODeviceObject;
// entry in pdo list
     PDEVICE_OBJECT Self;
// self
+    // the whole structure is not stored
+    UCHAR InquiryData[INQUIRYDATABUFFERSIZE];
// USB SCSI inquiry data
 }PDO_DEVICE_EXTENSION, *PPDO_DEVICE_EXTENSION;
-#define CBW_SIGNATURE 0x43425355
-#define CSW_SIGNATURE 0x53425355
-
-#include <pshpack1.h>
-typedef struct
-{
-    ULONG Signature;                                                 // CBW signature
-    ULONG Tag;                                                       // CBW Tag of
operation
-    ULONG DataTransferLength;                                        // data transfer
length
-    UCHAR Flags;                                                     // CBW Flags
endpoint direction
-    UCHAR LUN;                                                       // lun unit
-    UCHAR CommandBlockLength;                                        // Command block
length
-    UCHAR CommandBlock[16];
-}CBW, *PCBW;
-
-C_ASSERT(sizeof(CBW) == 31);
-
-#define CSW_STATUS_COMMAND_PASSED 0x00
-#define CSW_STATUS_COMMAND_FAILED 0x01
-#define CSW_STATUS_PHASE_ERROR    0x02
-
-typedef struct
-{
-    ULONG Signature;                                                 // CSW signature
-    ULONG Tag;                                                       // CSW tag
-    ULONG DataResidue;                                               // CSW data transfer
diff
-    UCHAR Status;                                                    // CSW status
-}CSW, *PCSW;
-
-#include <poppack.h>
-
-typedef struct
-{
-    PIRP Irp;
-    PFDO_DEVICE_EXTENSION FDODeviceExtension;
-    ULONG ErrorIndex;
-    ULONG StallRetryCount;                                            // the number of
retries after receiving USBD_STATUS_STALL_PID status
-    union
-    {
-        CBW cbw;
-        CSW csw;
-    };
-    URB Urb;
-    SCSI_REQUEST_BLOCK SenseSrb;
-} IRP_CONTEXT, *PIRP_CONTEXT;
-
 typedef struct _ERRORHANDLER_WORKITEM_DATA
 {
     PDEVICE_OBJECT DeviceObject;
@@ -267,7 +269,7 @@ USBSTOR_HandleExecuteSCSI(
 NTSTATUS
 USBSTOR_SendCSWRequest(
-    PIRP_CONTEXT Context,
+    PFDO_DEVICE_EXTENSION FDODeviceExtension,
     PIRP Irp);
@@ -351,8 +353,7 @@ USBSTOR_TimerRoutine(
 VOID
 NTAPI
 USBSTOR_QueueResetPipe(
-    IN PFDO_DEVICE_EXTENSION FDODeviceExtension,
-    IN PIRP_CONTEXT Context);
+    IN PFDO_DEVICE_EXTENSION FDODeviceExtension);
 VOID
 NTAPI