Add missing dmaengine_unmap_put(), so we don't OOM during RAID6 sync.
Fixes: 1786b943dad0 ("async_pq_val: convert to dmaengine_unmap_data")
Signed-off-by: Justin Maggard <jmaggard@netgear.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
 
                dma_set_unmap(tx, unmap);
                async_tx_submit(chan, tx, submit);
-
-               return tx;
        } else {
                struct page *p_src = P(blocks, disks);
                struct page *q_src = Q(blocks, disks);
                submit->cb_param = cb_param_orig;
                submit->flags = flags_orig;
                async_tx_sync_epilog(submit);
-
-               return NULL;
+               tx = NULL;
        }
+       dmaengine_unmap_put(unmap);
+
+       return tx;
 }
 EXPORT_SYMBOL_GPL(async_syndrome_val);