svcrdma: Cleanup queued, but unprocessed I/O in svc_rdma_free

When the transport is closing, the DTO tasklet may queue data
that never gets processed. Clean up resources associated with
this I/O.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>

1 files changed, 35 insertions, 3 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index b412a49c46fc..b1ff08d7da6c 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -976,13 +976,42 @@ static void __svc_rdma_free(struct work_struct *work)
         /* We should only be called from kref_put */
         BUG_ON(atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0);
 
+        /*
+         * Destroy queued, but not processed read completions. Note
+         * that this cleanup has to be done before destroying the
+         * cm_id because the device ptr is needed to unmap the dma in
+         * svc_rdma_put_context.
+         */
+        spin_lock_bh(&rdma->sc_read_complete_lock);
+        while (!list_empty(&rdma->sc_read_complete_q)) {
+                struct svc_rdma_op_ctxt *ctxt;
+                ctxt = list_entry(rdma->sc_read_complete_q.next,
+                                  struct svc_rdma_op_ctxt,
+                                  dto_q);
+                list_del_init(&ctxt->dto_q);
+                svc_rdma_put_context(ctxt, 1);
+        }
+        spin_unlock_bh(&rdma->sc_read_complete_lock);
+
+        /* Destroy queued, but not processed recv completions */
+        spin_lock_bh(&rdma->sc_rq_dto_lock);
+        while (!list_empty(&rdma->sc_rq_dto_q)) {
+                struct svc_rdma_op_ctxt *ctxt;
+                ctxt = list_entry(rdma->sc_rq_dto_q.next,
+                                  struct svc_rdma_op_ctxt,
+                                  dto_q);
+                list_del_init(&ctxt->dto_q);
+                svc_rdma_put_context(ctxt, 1);
+        }
+        spin_unlock_bh(&rdma->sc_rq_dto_lock);
+
+        /* Warn if we leaked a resource or under-referenced */
+        WARN_ON(atomic_read(&rdma->sc_ctxt_used) != 0);
+
         /* Destroy the QP if present (not a listener) */
         if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
                 ib_destroy_qp(rdma->sc_qp);
 
-        /* Destroy the CM ID */
-        rdma_destroy_id(rdma->sc_cm_id);
-
         if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
                 ib_destroy_cq(rdma->sc_sq_cq);
 
@@ -995,6 +1024,9 @@ static void __svc_rdma_free(struct work_struct *work)
         if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
                 ib_dealloc_pd(rdma->sc_pd);
 
+        /* Destroy the CM ID */
+        rdma_destroy_id(rdma->sc_cm_id);
+
         destroy_context_cache(rdma);
         kfree(rdma);
 }