RDMA/qib,hfi1: Fix MR reference count leak on write with immediate

commit 1feb40067cf04ae48d65f728d62ca255c9449178 upstream.

The handling of IB_RDMA_WRITE_ONLY_WITH_IMMEDIATE will leak a memory
reference when a buffer cannot be allocated for returning the immediate
data.

The issue is that the rkey validation has already occurred and the RNR
nak fails to release the reference that was fruitlessly gotten.  The
the peer will send the identical single packet request when its RNR
timer pops.

The fix is to release the held reference prior to the rnr nak exit.
This is the only sequence the requires both rkey validation and the
buffer allocation on the same packet.

Tested-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/hfi1/rc.c b/drivers/infiniband/hw/hfi1/rc.c
index 83198a8a87979baeeb58c591fba0e4d06db6e014..4bd5b5caa243f2c2707016aa6dd863980d5f3f0b 100644 (file)
--- a/drivers/infiniband/hw/hfi1/rc.c
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -2366,8 +2366,11 @@ send_last:
                ret = hfi1_rvt_get_rwqe(qp, 1);
                if (ret < 0)
                        goto nack_op_err;
-               if (!ret)
+               if (!ret) {
+                       /* peer will send again */
+                       rvt_put_ss(&qp->r_sge);
                        goto rnr_nak;
+               }
                wc.ex.imm_data = ohdr->u.rc.imm_data;
                wc.wc_flags = IB_WC_WITH_IMM;
                goto send_last;

diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c
index 2097512e75aa01b7ba7beade1011429a54465518..f3fe787c942672544880980d0bcd72bfdd9776e3 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_rc.c
+++ b/drivers/infiniband/hw/qib/qib_rc.c
@@ -2067,8 +2067,10 @@ send_last:
                ret = qib_get_rwqe(qp, 1);
                if (ret < 0)
                        goto nack_op_err;
-               if (!ret)
+               if (!ret) {
+                       rvt_put_ss(&qp->r_sge);
                        goto rnr_nak;
+               }
                wc.ex.imm_data = ohdr->u.rc.imm_data;
                hdrsize += 4;
                wc.wc_flags = IB_WC_WITH_IMM;