[PATCH 4.4 12/25] async_pq_val: fix DMA memory leak

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Justin Maggard <jmaggar...@gmail.com>

commit c84750906b4818d4929fbf73a4ae6c113b94f52b upstream.

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 <jmagg...@netgear.com>
Reviewed-by: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Vinod Koul <vinod.k...@intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 crypto/async_tx/async_pq.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -368,8 +368,6 @@ async_syndrome_val(struct page **blocks,
 
                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);
@@ -424,9 +422,11 @@ async_syndrome_val(struct page **blocks,
                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);