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
  26 /*
  27  *  EnqueueDeferredClientIrp
  28  *
  29  *      Note: we currently do not support Cancel for storage irps.
  30  */
  31 VOID NTAPI EnqueueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData, PIRP Irp)
  32 {
  33     KIRQL oldIrql;
  34
  35     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  36     InsertTailList(&FdoData->DeferredClientIrpList, &Irp->Tail.Overlay.ListEntry);
  37     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  38 }
  39
  40
  41 /*
  42  *  DequeueDeferredClientIrp
  43  *
  44  */
  45 PIRP NTAPI DequeueDeferredClientIrp(PCLASS_PRIVATE_FDO_DATA FdoData)
  46 {
  47     KIRQL oldIrql;
  48     PLIST_ENTRY listEntry;
  49     PIRP irp;
  50
  51     KeAcquireSpinLock(&FdoData->SpinLock, &oldIrql);
  52     if (IsListEmpty(&FdoData->DeferredClientIrpList)){
  53         listEntry = NULL;
  54     }
  55     else {
  56         listEntry = RemoveHeadList(&FdoData->DeferredClientIrpList);
  57     }
  58     KeReleaseSpinLock(&FdoData->SpinLock, oldIrql);
  59
  60     if (listEntry == NULL) {
  61         irp = NULL;
  62     } else {
  63         irp = CONTAINING_RECORD(listEntry, IRP, Tail.Overlay.ListEntry);
  64         ASSERT(irp->Type == IO_TYPE_IRP);
  65         InitializeListHead(&irp->Tail.Overlay.ListEntry);
  66     }
  67
  68     return irp;
  69 }