I/O Operation to Target Fails with STATUS_PATH_NOT_COVERED

When an I/O operation that is issued to a link target fails with STATUS_PATH_NOT_COVERED (0xC0000257), the client MUST fail the original I/O request.

When an I/O operation issued to a DFS root target server in step 8 of section fails with STATUS_PATH_NOT_COVERED (0xC0000257), it indicates that the portion of the DFS namespace accessed by the client is not contained in the DFS root target server.

To identify the DFS link targets that contain the required portion of the DFS namespace, the client MUST look up the path used for the I/O operation in ReferralCache. On a cache hit, the resulting ReferralCache entry MUST be used in further processing.

Otherwise, the client MUST obtain the file attributes of the DFS link as specified in [MS-CIFS] section or [MS-SMB2] section based on the protocol transport.

If the file attributes include FILE_ATTRIBUTE_REPARSE_POINT, the client MUST issue a DFS link referral request, as specified in section, providing as parameters "LINK", the DFS root target server specified by the TargetHint of the ReferralCache entry corresponding to the DFS namespace, UserCredentials, MaxOutputSize, and Path. The Path parameter MUST be set to the path in the I/O operation issued to the DFS root target in step 8 of section The client MUST process the DFS referral response as specified in section, which will update the ReferralCache.<9> The resulting ReferralCache entry, if any, MUST be used in further processing.