FltGetVolumeContext function (fltkernel.h)
The FltGetVolumeContext routine retrieves a context that was set for a volume by a given minifilter driver.
Syntax
NTSTATUS FLTAPI FltGetVolumeContext(
[in] PFLT_FILTER Filter,
[in] PFLT_VOLUME Volume,
[out] PFLT_CONTEXT *Context
);
Parameters
[in] Filter
Opaque filter pointer for the caller. This parameter is required and cannot be NULL.
[in] Volume
Opaque pointer for the volume whose context is being retrieved. This parameter is required and cannot be NULL.
[out] Context
Pointer to a caller-allocated variable that receives the address of the requested context. This parameter is required and can't be set to NULL.
Return value
FltGetVolumeContext returns STATUS_SUCCESS when it successfully returns the requested context. Otherwise, it returns an appropriate NTSTATUS value such as the following:
| Return code | Description |
|---|---|
| STATUS_NOT_FOUND | No matching context was found on this file at this time, so FltMgr set Context to NULL_CONTEXT. This is an error code. |
Remarks
For more information about contexts, see About minifilter contexts.
FltGetVolumeContext increments the reference count on the context that the Context parameter points to. When this context pointer is no longer needed, the caller must decrement its reference count by calling FltReleaseContext. Thus every successful call to FltGetVolumeContext must be matched by a subsequent call to FltReleaseContext.
To set a context for a volume, call FltSetVolumeContext.
To allocate a new context, call FltAllocateContext.
To delete a volume context, call FltDeleteVolumeContext or FltDeleteContext.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | fltkernel.h (include Fltkernel.h) |
| Library | FltMgr.lib |
| DLL | Fltmgr.sys |
| IRQL | <= APC_LEVEL |