FltDeleteStreamContext function (fltkernel.h)
FltDeleteStreamContext removes a context that a given minifilter driver instance has set for a given stream and marks the context for deletion.
Syntax
NTSTATUS FLTAPI FltDeleteStreamContext(
[in] PFLT_INSTANCE Instance,
[in] PFILE_OBJECT FileObject,
[out] PFLT_CONTEXT *OldContext
);
Parameters
[in] Instance
Opaque instance pointer for the minifilter driver instance whose context is to be removed from the list of contexts attached to the file stream.
[in] FileObject
Pointer to a file object for the file stream.
[out] OldContext
Pointer to a caller-allocated variable that receives the address of the deleted context. This parameter is optional and can be NULL. If OldContext is not NULL and does not point to NULL_CONTEXT, the caller is responsible for calling FltReleaseContext to release this context when it is no longer needed.
Return value
FltDeleteStreamContext returns STATUS_SUCCESS or an appropriate NTSTATUS value such as one of the following:
| Return code | Description |
|---|---|
| STATUS_FLT_DELETING_OBJECT | The specified Instance is being torn down. This is an error code. |
| STATUS_NOT_FOUND | No matching context was found. This is an error code. |
| STATUS_NOT_SUPPORTED | The file system does not support per-stream contexts for this file stream. This is an error code. |
Remarks
For more information about contexts, see About minifilter contexts.
Because contexts are reference-counted, it is not usually necessary for a minifilter driver to call a routine such as FltDeleteStreamContext to explicitly delete a context.
A minifilter driver calls FltDeleteStreamContext to remove a context from a file stream and mark the context for deletion. The context is usually freed immediately unless there is an outstanding reference on it (for example, because the context is still in use by another thread).
To allocate a new context, call FltAllocateContext.
To get a stream context, call FltGetStreamContext.
To set a stream context, call FltSetStreamContext.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | fltkernel.h (include Fltkernel.h) |
| Library | FltMgr.lib |
| IRQL | <= APC_LEVEL |