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sys: notify implementation

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This commit is contained in:
Bill Zissimopoulos
2020-10-08 15:31:41 -07:00
parent 01f91c771d
commit 7f360827f6
9 changed files with 204 additions and 12 deletions
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63
src/sys/volume.c
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@ -52,6 +52,8 @@ NTSTATUS FspVolumeStop(
PDEVICE_OBJECT FsctlDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
NTSTATUS FspVolumeNotify(
PDEVICE_OBJECT FsctlDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
static NTSTATUS FspVolumeNotifyLock(
PDEVICE_OBJECT FsvolDeviceObject);
static WORKER_THREAD_ROUTINE FspVolumeNotifyWork;
NTSTATUS FspVolumeWork(
PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
@ -72,6 +74,7 @@ NTSTATUS FspVolumeWork(
#pragma alloc_text(PAGE, FspVolumeTransactFsext)
#pragma alloc_text(PAGE, FspVolumeStop)
#pragma alloc_text(PAGE, FspVolumeNotify)
#pragma alloc_text(PAGE, FspVolumeNotifyLock)
#pragma alloc_text(PAGE, FspVolumeNotifyWork)
#pragma alloc_text(PAGE, FspVolumeWork)
#endif
@ -473,6 +476,10 @@ static VOID FspVolumeDeleteNoLock(
FspMupUnregister(Globals->FsmupDeviceObject, FsvolDeviceObject);
}
/* release the volume notify lock if held (so that any pending rename will abort) */
if (1 == InterlockedCompareExchange(&FsvolDeviceExtension->VolumeNotifyLock, 0, 1))
FspFsvolDeviceFileRenameReleaseOwner(FsvolDeviceObject, FsvolDeviceObject);
/* release the volume device object */
FspDeviceDereference(FsvolDeviceObject);
}
@ -1095,6 +1102,9 @@ NTSTATUS FspVolumeNotify(
FSP_VOLUME_NOTIFY_WORK_ITEM *NotifyWorkItem = 0;
NTSTATUS Result;
if (0 == InputBufferLength)
return FspVolumeNotifyLock(FsvolDeviceObject);
if (!FspDeviceReference(FsvolDeviceObject))
return STATUS_CANCELLED;
@ -1145,6 +1155,43 @@ fail:
return Result;
}
static NTSTATUS FspVolumeNotifyLock(
PDEVICE_OBJECT FsvolDeviceObject)
{
PAGED_CODE();
NTSTATUS Result;
if (!FspDeviceReference(FsvolDeviceObject))
return STATUS_CANCELLED;
/*
* Acquire the rename lock shared to disallow concurrent RENAME's.
*
* This guards against the race where a file that we want to invalidate
* is being concurrently renamed to a different name. Thus we may think
* that the file is not open and not invalidate its caches, whereas the
* file has simply changed name.
*/
Result = STATUS_CANT_WAIT;
if (FspFsvolDeviceFileRenameTryAcquireShared(FsvolDeviceObject))
{
FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(FsvolDeviceObject);
if (0 == InterlockedCompareExchange(&FsvolDeviceExtension->VolumeNotifyLock, 1, 0))
{
FspFsvolDeviceFileRenameSetOwner(FsvolDeviceObject, FsvolDeviceObject);
Result = STATUS_SUCCESS;
}
else
FspFsvolDeviceFileRenameRelease(FsvolDeviceObject);
}
FspDeviceDereference(FsvolDeviceObject);
return Result;
}
static VOID FspVolumeNotifyWork(PVOID NotifyWorkItem0)
{
PAGED_CODE();
@ -1162,16 +1209,6 @@ static VOID FspVolumeNotifyWork(PVOID NotifyWorkItem0)
ULONG StreamType = FspFileNameStreamTypeNone;
NTSTATUS Result;
/*
* Acquire the rename lock shared to disallow concurrent RENAME's.
*
* This guards against the race where a file that we want to invalidate
* is being concurrently renamed to a different name. Thus we may think
* that the file is not open and not invalidate its caches, whereas the
* file has simply changed name.
*/
FspFsvolDeviceFileRenameAcquireShared(FsvolDeviceObject);
/* iterate over notify information and invalidate/notify each file */
for (; (PUINT8)NotifyInfo + sizeof(NotifyInfo->Size) <= NotifyInfoEnd;
NotifyInfo = (PVOID)((PUINT8)NotifyInfo + FSP_FSCTL_DEFAULT_ALIGN_UP(NotifyInfoSize)))
@ -1179,7 +1216,11 @@ static VOID FspVolumeNotifyWork(PVOID NotifyWorkItem0)
NotifyInfoSize = NotifyInfo->Size;
if (sizeof(FSP_FSCTL_NOTIFY_INFO) > NotifyInfoSize)
{
if (1 == InterlockedCompareExchange(&FsvolDeviceExtension->VolumeNotifyLock, 0, 1))
FspFsvolDeviceFileRenameReleaseOwner(FsvolDeviceObject, FsvolDeviceObject);
break;
}
FileName.Length =
FileName.MaximumLength = (USHORT)(NotifyInfoSize - sizeof(FSP_FSCTL_NOTIFY_INFO));
@ -1229,8 +1270,6 @@ static VOID FspVolumeNotifyWork(PVOID NotifyWorkItem0)
}
}
FspFsvolDeviceFileRenameRelease(FsvolDeviceObject);
if (0 != FullFileName.Buffer)
FspFree(FullFileName.Buffer);