NFSD: Check layout type when returning client layouts

According to RFC5661:
" When lr_returntype is LAYOUTRETURN4_FSID, the current filehandle is used
   to identify the file system and all layouts matching the client ID,
   the fsid of the file system, lora_layout_type, and lora_iomode are
   returned.  When lr_returntype is LAYOUTRETURN4_ALL, all layouts
   matching the client ID, lora_layout_type, and lora_iomode are
   returned and the current filehandle is not used. "

When returning client layouts, always check layout type.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4layouts.c

@@ -513,6 +513,9 @@ nfsd4_return_client_layouts(struct svc_rqst *rqstp,
 
 	spin_lock(&clp->cl_lock);
 	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
+		if (ls->ls_layout_type != lrp->lr_layout_type)
+			continue;
+
 		if (lrp->lr_return_type == RETURN_FSID &&
 		    !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
 				   &cstate->current_fh.fh_handle))