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sys: FspFsvolDeviceInsertContext: can no longer fail because of low memory

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This commit is contained in:
Bill Zissimopoulos
2015-12-05 23:00:33 -08:00
parent bdc7033740
commit df340872f7
3 changed files with 74 additions and 49 deletions
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82
src/sys/create.c
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@ -346,6 +346,20 @@ VOID FspFsvolCreateComplete(
{
FSP_ENTER_IOC(PAGED_CODE());
/*
* NOTE:
* In the following we may have to close the just opened file object. But we must
* never close a file we just created, because this will leave an orphan file on
* the disk.
*
* Files may have to be closed if a security access or share access check fails. In
* both those cases we were opening an existing file and so it is safe to close it.
*
* Because of how IRP_MJ_CREATE works in Windows, it is difficult to improve on this
* scheme without introducing a 2-phase Create protocol, which is undesirable as it
* means two trips into user-mode for a single Create request.
*/
PDEVICE_OBJECT DeviceObject = IrpSp->DeviceObject;
FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(DeviceObject);
FSP_FSVRT_DEVICE_EXTENSION *FsvrtDeviceExtension =
@ -400,11 +414,11 @@ VOID FspFsvolCreateComplete(
goto reparse_fail;
}
ExFreePool(FileObject->FileName.Buffer);
FileObject->FileName.Length = 0;
FileObject->FileName.MaximumLength = ReparseFileName.Length;
FileObject->FileName.Buffer = Buffer;
RtlCopyUnicodeString(&FileObject->FileName, &ReparseFileName);
}
FileObject->FileName.Length = 0;
RtlCopyUnicodeString(&FileObject->FileName, &ReparseFileName);
}
else
if (IO_REMOUNT == Response->IoStatus.Information)
@ -471,43 +485,43 @@ VOID FspFsvolCreateComplete(
ExAcquireResourceExclusiveLite(&FsvolDeviceExtension->Base.Resource, TRUE);
try
{
/* attempt to insert the newly created FsContext into our generic table */
/* insert the newly created FsContext into our generic table */
FsContext = FspFsvolDeviceInsertContext(DeviceObject,
FsContext->UserContext, FsContext, &Inserted);
if (0 == FsContext)
Result = STATUS_INSUFFICIENT_RESOURCES;
FsContext->UserContext, FsContext, &FsContext->ElementStorage, &Inserted);
ASSERT(0 != FsContext);
/* share access check */
if (Inserted)
{
/*
* This is a newly created FsContext. Set its share access and
* increment its open count. There is no need to acquire the
* FsContext's Resource (because it is newly created).
*/
IoSetShareAccess(AccessState->PreviouslyGrantedAccess,
ShareAccess, FileObject, &FsContext->ShareAccess);
FspFileContextOpen(FsContext);
Result = STATUS_SUCCESS;
}
else
{
/* share access check */
if (Inserted)
{
/*
* This is a newly created FsContext. Set its share access and
* increment its open count. There is no need to acquire the
* FsContext's Resource (because it is newly created).
*/
IoSetShareAccess(AccessState->PreviouslyGrantedAccess,
ShareAccess, FileObject, &FsContext->ShareAccess);
FspFileContextOpen(FsContext);
Result = STATUS_SUCCESS;
}
/*
* This is an existing FsContext. We must acquire its Resource and
* check if there is a delete pending and the share access. Only if
* both tests succeed we increment the open count and report success.
*/
ExAcquireResourceExclusiveLite(FsContext->Header.Resource, TRUE);
if (FsContext->DeletePending)
Result = STATUS_DELETE_PENDING;
else
Result = IoCheckShareAccess(AccessState->PreviouslyGrantedAccess,
ShareAccess, FileObject, &FsContext->ShareAccess, TRUE);
if (NT_SUCCESS(Result))
{
/*
* This is an existing FsContext. We must acquire its Resource and
* check if there is a delete pending and the share access. Only if
* both tests succeed we increment the open count and report success.
*/
ExAcquireResourceExclusiveLite(FsContext->Header.Resource, TRUE);
if (FsContext->DeletePending)
Result = STATUS_DELETE_PENDING;
else
Result = IoCheckShareAccess(AccessState->PreviouslyGrantedAccess,
ShareAccess, FileObject, &FsContext->ShareAccess, TRUE);
if (NT_SUCCESS(Result))
FspFileContextOpen(FsContext);
ExReleaseResourceLite(FsContext->Header.Resource);
FspFileContextRetain(FsContext);
FspFileContextOpen(FsContext);
}
ExReleaseResourceLite(FsContext->Header.Resource);
}
}
finally
@ -515,7 +529,7 @@ VOID FspFsvolCreateComplete(
ExReleaseResourceLite(&FsvolDeviceExtension->Base.Resource);
}
/* did we fail to insert? */
/* did we fail our share access checks? */
if (!NT_SUCCESS(Result))
{
ASSERT(!Inserted);