FsRtlNotifyFilterChangeDirectory function

Description

FsRtlNotifyFilterChangeDirectory creates a notify structure for an IRP_MN_NOTIFY_CHANGE_DIRECTORY request and adds it to the specified notify list.

Parameters

NotifySync [in]

Pointer to an opaque synchronization object for the change directory notify list that is pointed to by the NotifyList parameter.

NotifyList [in]

Pointer to the head of the change directory notify list for the current volume. Each element in the list is an opaque notify structure.

FsContext [in]

Pointer to a unique value assigned by the file system to identify the notify structure to be created as belonging to a particular file object. If a TraverseCallback routine is supplied, FsContext is passed as the NotifyContext parameter to that routine.

FullDirectoryName [in]

Pointer to an ANSI or Unicode string that contains the full name for the directory associated with this notify structure. Ignored if NotifyIrp is NULL.

WatchTree [in]

Set to TRUE if all subdirectories of this directory should also be watched. Set to FALSE if only the directory itself is to be watched. Ignored if NotifyIrp is NULL.

IgnoreBuffer [in]

Set to TRUE to ignore any user buffers and force the directory to be reenumerated. This action speeds the operation. Ignored if NotifyIrp is NULL.

CompletionFilter [in]

Bitmask of flags that specify the types of changes to files or directories that should cause the IRPs in the notify list to be completed. The following table describes the possible flag values.

CompletionFilter is ignored if NotifyIrp is NULL.

NotifyIrp [in, optional]

Pointer to the IRP to be added to the notify list. If NotifyIrp is NULL, this means that the file stream represented by the file object (identified by the FsContext parameter) is being deleted.

TraverseCallback [in, optional]

Optional pointer to a callback routine to be invoked when a change occurs in a subdirectory being watched in a directory tree. This lets the file system check whether the watcher has traverse access to that directory. Such a caller-supplied routine is declared as follows:

NTSTATUS
(*PCHECK_FOR_TRAVERSE_ACCESS) (
    IN PVOID NotifyContext,                     // FsContext
    IN PVOID TargetContext,                     // Context pointer
    IN PSECURITY_SUBJECT_CONTEXT SubjectContext // SubjectContext
    );

For more information about the TargetContext parameter, see the TargetContext parameter of FsRtlNotifyFullReportChange. TraverseCallback is ignored if NotifyIrp is NULL.

SubjectContext [in, optional]

Pointer to a SECURITY_SUBJECT_CONTEXT structure to be passed to TraverseCallback. FsRtlNotifyFilterChangeDirectory releases the context and frees the structure after using it. This parameter is ignored if NotifyIrp is NULL. If a TraverseCallback routine is supplied, SubjectContext is passed as the SubjectContext parameter to that routine.

FilterCallback [in, optional]

Optional pointer to a callback routine to be invoked when a change occurs to the directory. If this callback routine returns TRUE, FsRtlNotifyFilterReportChange completes the pending IRP_MN_NOTIFY_CHANGE_DIRECTORY requests in the notify list; otherwise, it does not. Such a caller-supplied routine is declared as follows:

BOOLEAN
(*PFILTER_REPORT_CHANGE) (
    IN PVOID NotifyContext,                     // FsContext
    IN PVOID FilterContext                      // Context pointer
    );

Remarks

FsRtlNotifyFilterChangeDirectory is called by a file system that has received an IRP with major function code IRP_MJ_DIRECTORY_CONTROL, minor function code IRP_MN_NOTIFY_CHANGE_DIRECTORY.

The file system calls FsRtlNotifyFilterChangeDirectory to create a notify structure to hold the IRP and add the notify structure to the notify list for the current volume.

If NotifyIrp is NULL, FsRtlNotifyFilterChangeDirectory checks whether the notify list already contains any pending IRPs whose file objects match the given FsContext value and, if so, completes the IRPs with STATUS_DELETE_PENDING.

If NotifyIrp is not NULL, FsRtlNotifyFilterChangeDirectory does the following:

• Checks whether the IRP's file object has undergone cleanup. If so, FsRtlNotifyFilterChangeDirectory completes the IRP with status STATUS_NOTIFY_CLEANUP and does not add it to the notify list.

• If the IRP's file object has not undergone cleanup, FsRtlNotifyFilterChangeDirectory checks whether the notify list already contains a notify structure for the given FsContext value. If such a notify structure is found, and there are pending changes to report, FsRtlNotifyFilterChangeDirectory completes NotifyIrp. If a notify structure is found, but there are no pending changes to report, FsRtlNotifyFilterChangeDirectory marks the IRP pointed to by NotifyIrp as pending and inserts it into the list of notify IRPs in the notify structure. If no such notify structure is found, FsRtlNotifyFilterChangeDirectory marks the IRP pointed to by NotifyIrp as pending, creates a notify structure, and inserts it into the notify list.

When a change occurs to the directory, the file system calls FsRtlNotifyFilterReportChange to complete the pending IRP_MN_NOTIFY_CHANGE_DIRECTORY requests in the notify list.

See also

FsRtlNotifyFilterReportChange

FsRtlNotifyFullChangeDirectory

FsRtlNotifyFullReportChange

IRP_MJ_DIRECTORY_CONTROL

SECURITY_SUBJECT_CONTEXT