svcrdma: avoid duplicate dma unmapping during error recovery

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")
Cc: [email protected]
Signed-off-by: Sriharsha Basavapatna <[email protected]>
Reviewed-by: Chuck Lever <[email protected]>
Reviewed-by: Yuval Shaia <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 57d35fbb1c28570b5c23f5e06974e8b902853846..172b537f8cfc942ef62574b74cff7ac5f421fba9 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -347,8 +347,6 @@ 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;