drivers/storage/classpnp/clntirp.c

   1 /*++
   2
   3 Copyright (C) Microsoft Corporation, 1991 - 1999
   4
   5 Module Name:
   6
   7     clntirp.c
   8
   9 Abstract:
  10
  11     Client IRP queuing routines for CLASSPNP
  12
  13 Environment:
  14
  15     kernel mode only
  16
  17 Notes:
  18
  19
  20 Revision History:
  21
  22 --*/
  23
  24 #include "classp.h"
  25 #include "debug.h"
  26
  27 /*
  28  *  EnqueueDeferredClientIrp
  29  *
  30  *      Note: we currently do not support Cancel for storage irps.
  31  */
  32 VOID NTAPI EnqueueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData, PIRP Irp)
  33 {
  34     KIRQL oldIrql;
  35
  36     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  37     InsertTailList(&FdoData->DeferredClientIrpList, &Irp->Tail.Overlay.ListEntry);
  38     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  39 }
  40
  41
  42 /*
  43  *  DequeueDeferredClientIrp
  44  *
  45  */
  46 PIRP NTAPI DequeueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData)
  47 {
  48     KIRQL oldIrql;
  49     PLIST_ENTRY listEntry;
  50     PIRP irp;
  51
  52     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  53     if (IsListEmpty(&FdoData->DeferredClientIrpList)){
  54         listEntry = NULL;
  55     }
  56     else {
  57         listEntry = RemoveHeadList(&FdoData->DeferredClientIrpList);
  58     }
  59     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  60
  61     if (listEntry == NULL) {
  62         irp = NULL;
  63     } else {
  64         irp = CONTAINING_RECORD(listEntry, IRP, Tail.Overlay.ListEntry);
  65         ASSERT(irp->Type == IO_TYPE_IRP);
  66         InitializeListHead(&irp->Tail.Overlay.ListEntry);
  67     }
  68
  69     return irp;
  70 }