Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband

Pull InfiniBand/RDMA changes for the 3.4 merge window from Roland Dreier:
 "Nothing big really stands out; by patch count lots of fixes to the
  mlx4 driver plus some cleanups and fixes to the core and other
  drivers."

* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (28 commits)
  mlx4_core: Scale size of MTT table with system RAM
  mlx4_core: Allow dynamic MTU configuration for IB ports
  IB/mlx4: Fix info returned when querying IBoE ports
  IB/mlx4: Fix possible missed completion event
  mlx4_core: Report thermal error events
  mlx4_core: Fix one more static exported function
  IB: Change CQE "csum_ok" field to a bit flag
  RDMA/iwcm: Reject connect requests if cmid is not in LISTEN state
  RDMA/cxgb3: Don't pass irq flags to flush_qp()
  mlx4_core: Get rid of redundant ext_port_cap flags
  RDMA/ucma: Fix AB-BA deadlock
  IB/ehca: Fix ilog2() compile failure
  IB: Use central enum for speed instead of hard-coded values
  IB/iser: Post initial receive buffers before sending the final login request
  IB/iser: Free IB connection resources in the proper place
  IB/srp: Consolidate repetitive sysfs code
  IB/srp: Use pr_fmt() and pr_err()/pr_warn()
  IB/core: Fix SDR rates in sysfs
  mlx4: Enforce device max FMR maps in FMR alloc
  IB/mlx4: Set bad_wr for invalid send opcode
  ...

1 files changed, 18 insertions, 19 deletions

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 5034a87..5861cdb 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -449,24 +449,6 @@ static void ucma_cleanup_multicast(struct ucma_context *ctx)
 	mutex_unlock(&mut);
 }
 
-static void ucma_cleanup_events(struct ucma_context *ctx)
-{
-	struct ucma_event *uevent, *tmp;
-
-	list_for_each_entry_safe(uevent, tmp, &ctx->file->event_list, list) {
-		if (uevent->ctx != ctx)
-			continue;
-
-		list_del(&uevent->list);
-
-		/* clear incoming connections. */
-		if (uevent->resp.event == RDMA_CM_EVENT_CONNECT_REQUEST)
-			rdma_destroy_id(uevent->cm_id);
-
-		kfree(uevent);
-	}
-}
-
 static void ucma_cleanup_mc_events(struct ucma_multicast *mc)
 {
 	struct ucma_event *uevent, *tmp;
@@ -480,9 +462,16 @@ static void ucma_cleanup_mc_events(struct ucma_multicast *mc)
 	}
 }
 
+/*
+ * We cannot hold file->mut when calling rdma_destroy_id() or we can
+ * deadlock.  We also acquire file->mut in ucma_event_handler(), and
+ * rdma_destroy_id() will wait until all callbacks have completed.
+ */
 static int ucma_free_ctx(struct ucma_context *ctx)
 {
 	int events_reported;
+	struct ucma_event *uevent, *tmp;
+	LIST_HEAD(list);
 
 	/* No new events will be generated after destroying the id. */
 	rdma_destroy_id(ctx->cm_id);
@@ -491,10 +480,20 @@ static int ucma_free_ctx(struct ucma_context *ctx)
 
 	/* Cleanup events not yet reported to the user. */
 	mutex_lock(&ctx->file->mut);
-	ucma_cleanup_events(ctx);
+	list_for_each_entry_safe(uevent, tmp, &ctx->file->event_list, list) {
+		if (uevent->ctx == ctx)
+			list_move_tail(&uevent->list, &list);
+	}
 	list_del(&ctx->list);
 	mutex_unlock(&ctx->file->mut);
 
+	list_for_each_entry_safe(uevent, tmp, &list, list) {
+		list_del(&uevent->list);
+		if (uevent->resp.event == RDMA_CM_EVENT_CONNECT_REQUEST)
+			rdma_destroy_id(uevent->cm_id);
+		kfree(uevent);
+	}
+
 	events_reported = ctx->events_reported;
 	kfree(ctx);
 	return events_reported;