RxScavengeFobxsForNetRoot function (scavengr.h)

Article
04/01/2021

RxScavengeFobxsForNetRoot scavenges all of the FOBX structures associated with a given NET_ROOT structure.

Syntax

void RxScavengeFobxsForNetRoot(
  PNET_ROOT NetRoot,
  PFCB      PurgingFcb,
  BOOLEAN   SynchronizeWithScavenger
);

Parameters

NetRoot

A pointer to the NET_ROOT structure for which the FOBX structures need to be scavenged.

PurgingFcb

A pointer to the FCB for which the scavenging should occur.

SynchronizeWithScavenger

A Boolean value that specifies if this routine should synchronize with the scavenger.

Return value

None

Remarks

At cleanup, there are no more user handles associated with the file object. In such cases, the time window between close and cleanup is dictated by the additional references maintained by the memory manager and cache manager. On cleanup, the FOBX is put on a close pending list and removed from the corresponding list when a close operation is received. In the interim, if an open operation is failing with ACCESS_DENIED status, then RDBSS can force a purge and scavenge of the FOBX structure. This is a synchronous operation.

For directory renames, all files under the directory need to be closed. So, a network mini-redirector might call RxPurgeRelatedFobxs and RxScavengeFobxsForNetRoot in response to a IRP_MJ_SET_INFORMATION request to rename a directory. By passing in the NET_ROOT structure for the directory and a NULL FCB, all of the FOBX structures associated with the directory would be purged and scavenged.

The RxScavengeFobxsForNetRoot routine acquires the scavenger mutex, traverses the FobxsToBeFinalized list member of the scavenger object and adds any entries found to tail of the ScavengerFinalizationList member of the scavenger object, and then releases the mutex.

If PurgingFcb is not NULL, and this purging FCB structure is not the same as the FCB associated with the FOBX structure on the FobxsToBeFinalized list member of the scavenger object, RxScavengeFobxsForNetRoot will call the MRxAreFilesAliased callback routine provided by the network mini-redirector if it is supported. The call to MRxAreFilesAliased is to determine if the PFCB is an alias for the FCB associated with the FOBX structure.

On checked builds, RxScavengeAllFobxs causes the system to ASSERT for the following condition:

The NodeTypeCode member of an FOBX structure is not RDBSS_NTC_FOBX.

Requirements

Requirement	Value
Target Platform	Desktop
Header	scavengr.h (include Rxprocs.h)
IRQL	<= APC_LEVEL