Patch "svcrdma: avoid duplicate dma unmapping during error recovery" has been added to the 4.9-stable tree

Patch "svcrdma: avoid duplicate dma unmapping during error recovery" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    svcrdma: avoid duplicate dma unmapping during error recovery

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     svcrdma-avoid-duplicate-dma-unmapping-during-error-recovery.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ce1ca7d2d140a1f4aaffd297ac487f246963dd2f Mon Sep 17 00:00:00 2001
From: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Date: Mon, 9 Jan 2017 16:00:44 +0530
Subject: svcrdma: avoid duplicate dma unmapping during error recovery

From: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>

commit ce1ca7d2d140a1f4aaffd297ac487f246963dd2f upstream.

In rdma_read_chunk_frmr() when ib_post_send() fails, the error code path
invokes ib_dma_unmap_sg() to unmap the sg list. It then invokes
svc_rdma_put_frmr() which in turn tries to unmap the same sg list through
ib_dma_unmap_sg() again. This second unmap is invalid and could lead to
problems when the iova being unmapped is subsequently reused. Remove
the call to unmap in rdma_read_chunk_frmr() and let svc_rdma_put_frmr()
handle it.

Fixes: 412a15c0fe53 ("svcrdma: Port to new memory registration API")
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/sunrpc/xprtrdma/svc_rdma_recvfrom.c |    2 --
 1 file changed, 2 deletions(-)

--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -348,8 +348,6 @@ int rdma_read_chunk_frmr(struct svcxprt_
 	atomic_inc(&rdma_stat_read);
 	return ret;
  err:
-	ib_dma_unmap_sg(xprt->sc_cm_id->device,
-			frmr->sg, frmr->sg_nents, frmr->direction);
 	svc_rdma_put_context(ctxt, 0);
 	svc_rdma_put_frmr(xprt, frmr);
 	return ret;


Patches currently in stable-queue which might be from sriharsha.basavapatna@broadcom.com are

queue-4.9/svcrdma-avoid-duplicate-dma-unmapping-during-error-recovery.patch