[PATCH] xprtrdma: make sure MRs are unmapped before freeing them

[Dan Aloni <dan@xxxxxxxxxxxx>]

It was observed that on disconnections, these unmaps don't occur. The
relevant path is rpcrdma_mrs_destroy(), being called from
rpcrdma_xprt_disconnect().

Signed-off-by: Dan Aloni <dan@xxxxxxxxxxxx>
---
 net/sunrpc/xprtrdma/frwr_ops.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 7f94c9a19fd3..3899a5310214 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -49,6 +49,19 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
+static void frwr_mr_unmap(struct rpcrdma_mr *mr)
+{
+	struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
+
+	if (mr->mr_dir == DMA_NONE)
+		return;
+
+	trace_xprtrdma_mr_unmap(mr);
+	ib_dma_unmap_sg(r_xprt->rx_ep->re_id->device,
+			mr->mr_sg, mr->mr_nents, mr->mr_dir);
+	mr->mr_dir = DMA_NONE;
+}
+
 /**
  * frwr_release_mr - Destroy one MR
  * @mr: MR allocated by frwr_mr_init
@@ -58,6 +71,8 @@ void frwr_release_mr(struct rpcrdma_mr *mr)
 {
 	int rc;
 
+	frwr_mr_unmap(mr);
+
 	rc = ib_dereg_mr(mr->frwr.fr_mr);
 	if (rc)
 		trace_xprtrdma_frwr_dereg(mr, rc);
@@ -71,12 +86,7 @@ static void frwr_mr_recycle(struct rpcrdma_mr *mr)
 
 	trace_xprtrdma_mr_recycle(mr);
 
-	if (mr->mr_dir != DMA_NONE) {
-		trace_xprtrdma_mr_unmap(mr);
-		ib_dma_unmap_sg(r_xprt->rx_ep->re_id->device,
-				mr->mr_sg, mr->mr_nents, mr->mr_dir);
-		mr->mr_dir = DMA_NONE;
-	}
+	frwr_mr_unmap(mr);
 
 	spin_lock(&r_xprt->rx_buf.rb_lock);
 	list_del(&mr->mr_all);
-- 
2.25.4