svcrdma: avoid duplicate dma unmapping during error recovery

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>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index ff4f01e527ecc08a1480ecba8f00d41a90a76571..d4e0d648bcea0ff6f2b0d98512d19c5f5d3e6a10 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -346,8 +346,6 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
        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;