[PATCH rdma-rc 1/3] RDMA/core: Postpone uobject cleanup on failure till FD close

[Leon Romanovsky <leon@kernel.org>]

From: Leon Romanovsky <leonro@nvidia.com>

The drivers were updated to allow return their destroy status,
while the failure during object cleanup is allowed as long as the
driver can guarantee to clean them during FD close().

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/core/rdma_core.c           | 46 ++++++++-----------
 drivers/infiniband/core/uverbs_cmd.c          |  5 +-
 drivers/infiniband/core/uverbs_std_types.c    | 15 +++---
 .../core/uverbs_std_types_counters.c          |  5 +-
 drivers/infiniband/core/uverbs_std_types_cq.c |  4 +-
 drivers/infiniband/core/uverbs_std_types_dm.c |  6 +--
 .../core/uverbs_std_types_flow_action.c       |  6 +--
 drivers/infiniband/core/uverbs_std_types_qp.c |  4 +-
 .../infiniband/core/uverbs_std_types_srq.c    |  4 +-
 drivers/infiniband/core/uverbs_std_types_wq.c |  4 +-
 drivers/infiniband/hw/mlx5/devx.c             |  4 +-
 drivers/infiniband/hw/mlx5/fs.c               |  6 +--
 include/rdma/ib_verbs.h                       | 42 -----------------
 13 files changed, 44 insertions(+), 107 deletions(-)

diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index 5d41785f507b..9d5f2faae181 100644
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -137,15 +137,9 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj,
 	} else if (uobj->object) {
 		ret = uobj->uapi_object->type_class->destroy_hw(uobj, reason,
 								attrs);
-		if (ret) {
-			if (ib_is_destroy_retryable(ret, reason, uobj))
-				return ret;
-
-			/* Nothing to be done, dangle the memory and move on */
-			WARN(true,
-			     "ib_uverbs: failed to remove uobject id %d, driver err=%d",
-			     uobj->id, ret);
-		}
+		if (ret)
+			/* Nothing to be done, wait till ucontext will clean it */
+			return ret;

 		uobj->object = NULL;
 	}
@@ -543,17 +537,9 @@ static int __must_check destroy_hw_idr_uobject(struct ib_uobject *uobj,
 			     struct uverbs_obj_idr_type, type);
 	int ret = idr_type->destroy_object(uobj, why, attrs);

-	/*
-	 * We can only fail gracefully if the user requested to destroy the
-	 * object or when a retry may be called upon an error.
-	 * In the rest of the cases, just remove whatever you can.
-	 */
-	if (ib_is_destroy_retryable(ret, why, uobj))
+	if (ret)
 		return ret;

-	if (why == RDMA_REMOVE_ABORT)
-		return 0;
-
 	ib_rdmacg_uncharge(&uobj->cg_obj, uobj->context->device,
 			   RDMACG_RESOURCE_HCA_OBJECT);

@@ -581,12 +567,8 @@ static int __must_check destroy_hw_fd_uobject(struct ib_uobject *uobj,
 {
 	const struct uverbs_obj_fd_type *fd_type = container_of(
 		uobj->uapi_object->type_attrs, struct uverbs_obj_fd_type, type);
-	int ret = fd_type->destroy_object(uobj, why);
-
-	if (ib_is_destroy_retryable(ret, why, uobj))
-		return ret;

-	return 0;
+	return fd_type->destroy_object(uobj, why);
 }

 static void remove_handle_fd_uobject(struct ib_uobject *uobj)
@@ -879,6 +861,9 @@ static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
 void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
 			     enum rdma_remove_reason reason)
 {
+	struct ib_uobject *obj, *next_obj;
+	unsigned long flags;
+
 	down_write(&ufile->hw_destroy_rwsem);

 	/*
@@ -888,7 +873,6 @@ void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
 	if (!ufile->ucontext)
 		goto done;

-	ufile->ucontext->cleanup_retryable = true;
 	while (!list_empty(&ufile->uobjects))
 		if (__uverbs_cleanup_ufile(ufile, reason)) {
 			/*
@@ -899,10 +883,16 @@ void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
 			break;
 		}

-	ufile->ucontext->cleanup_retryable = false;
-	if (!list_empty(&ufile->uobjects))
-		__uverbs_cleanup_ufile(ufile, reason);
-
+	list_for_each_entry_safe (obj, next_obj, &ufile->uobjects, list) {
+		spin_lock_irqsave(&ufile->uobjects_lock, flags);
+		list_del_init(&obj->list);
+		spin_unlock_irqrestore(&ufile->uobjects_lock, flags);
+		/*
+		 * Pairs with the get in rdma_alloc_commit_uobject(), could
+		 * destroy uobj.
+		 */
+		uverbs_uobject_put(obj);
+	}
 	ufile_destroy_ucontext(ufile, reason);

 done:
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index c89880aec63e..9e6699f54413 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -680,8 +680,7 @@ int ib_uverbs_dealloc_xrcd(struct ib_uobject *uobject, struct ib_xrcd *xrcd,
 		return 0;

 	ret = ib_dealloc_xrcd_user(xrcd, &attrs->driver_udata);
-
-	if (ib_is_destroy_retryable(ret, why, uobject)) {
+	if (ret) {
 		atomic_inc(&xrcd->usecnt);
 		return ret;
 	}
@@ -689,7 +688,7 @@ int ib_uverbs_dealloc_xrcd(struct ib_uobject *uobject, struct ib_xrcd *xrcd,
 	if (inode)
 		xrcd_table_delete(dev, inode);

-	return ret;
+	return 0;
 }

 static int ib_uverbs_reg_mr(struct uverbs_attr_bundle *attrs)
diff --git a/drivers/infiniband/core/uverbs_std_types.c b/drivers/infiniband/core/uverbs_std_types.c
index 0658101fca00..585042ead939 100644
--- a/drivers/infiniband/core/uverbs_std_types.c
+++ b/drivers/infiniband/core/uverbs_std_types.c
@@ -88,7 +88,7 @@ static int uverbs_free_rwq_ind_tbl(struct ib_uobject *uobject,
 		return -EBUSY;

 	ret = rwq_ind_tbl->device->ops.destroy_rwq_ind_table(rwq_ind_tbl);
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	for (i = 0; i < table_size; i++)
@@ -96,7 +96,7 @@ static int uverbs_free_rwq_ind_tbl(struct ib_uobject *uobject,

 	kfree(rwq_ind_tbl);
 	kfree(ind_tbl);
-	return ret;
+	return 0;
 }

 static int uverbs_free_xrcd(struct ib_uobject *uobject,
@@ -108,9 +108,8 @@ static int uverbs_free_xrcd(struct ib_uobject *uobject,
 		container_of(uobject, struct ib_uxrcd_object, uobject);
 	int ret;

-	ret = ib_destroy_usecnt(&uxrcd->refcnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&uxrcd->refcnt))
+		return -EBUSY;

 	mutex_lock(&attrs->ufile->device->xrcd_tree_mutex);
 	ret = ib_uverbs_dealloc_xrcd(uobject, xrcd, why, attrs);
@@ -124,11 +123,9 @@ static int uverbs_free_pd(struct ib_uobject *uobject,
 			  struct uverbs_attr_bundle *attrs)
 {
 	struct ib_pd *pd = uobject->object;
-	int ret;

-	ret = ib_destroy_usecnt(&pd->usecnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&pd->usecnt))
+		return -EBUSY;

 	return ib_dealloc_pd_user(pd, &attrs->driver_udata);
 }
diff --git a/drivers/infiniband/core/uverbs_std_types_counters.c b/drivers/infiniband/core/uverbs_std_types_counters.c
index b3c6c066b601..999da9c79866 100644
--- a/drivers/infiniband/core/uverbs_std_types_counters.c
+++ b/drivers/infiniband/core/uverbs_std_types_counters.c
@@ -42,9 +42,8 @@ static int uverbs_free_counters(struct ib_uobject *uobject,
 	struct ib_counters *counters = uobject->object;
 	int ret;

-	ret = ib_destroy_usecnt(&counters->usecnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&counters->usecnt))
+		return -EBUSY;

 	ret = counters->device->ops.destroy_counters(counters);
 	if (ret)
diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
index 253dabb71f0e..b5e8a6aebecf 100644
--- a/drivers/infiniband/core/uverbs_std_types_cq.c
+++ b/drivers/infiniband/core/uverbs_std_types_cq.c
@@ -46,7 +46,7 @@ static int uverbs_free_cq(struct ib_uobject *uobject,
 	int ret;

 	ret = ib_destroy_cq_user(cq, &attrs->driver_udata);
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	ib_uverbs_release_ucq(
@@ -55,7 +55,7 @@ static int uverbs_free_cq(struct ib_uobject *uobject,
 					ev_queue) :
 			   NULL,
 		ucq);
-	return ret;
+	return 0;
 }

 static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
diff --git a/drivers/infiniband/core/uverbs_std_types_dm.c b/drivers/infiniband/core/uverbs_std_types_dm.c
index d5a1de33c2c9..98c522cf86d6 100644
--- a/drivers/infiniband/core/uverbs_std_types_dm.c
+++ b/drivers/infiniband/core/uverbs_std_types_dm.c
@@ -39,11 +39,9 @@ static int uverbs_free_dm(struct ib_uobject *uobject,
 			  struct uverbs_attr_bundle *attrs)
 {
 	struct ib_dm *dm = uobject->object;
-	int ret;

-	ret = ib_destroy_usecnt(&dm->usecnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&dm->usecnt))
+		return -EBUSY;

 	return dm->device->ops.dealloc_dm(dm, attrs);
 }
diff --git a/drivers/infiniband/core/uverbs_std_types_flow_action.c b/drivers/infiniband/core/uverbs_std_types_flow_action.c
index 459cf165b231..d42ed7ff223e 100644
--- a/drivers/infiniband/core/uverbs_std_types_flow_action.c
+++ b/drivers/infiniband/core/uverbs_std_types_flow_action.c
@@ -39,11 +39,9 @@ static int uverbs_free_flow_action(struct ib_uobject *uobject,
 				   struct uverbs_attr_bundle *attrs)
 {
 	struct ib_flow_action *action = uobject->object;
-	int ret;

-	ret = ib_destroy_usecnt(&action->usecnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&action->usecnt))
+		return -EBUSY;

 	return action->device->ops.destroy_flow_action(action);
 }
diff --git a/drivers/infiniband/core/uverbs_std_types_qp.c b/drivers/infiniband/core/uverbs_std_types_qp.c
index 198c3cd6f8b9..c00cfb5ed387 100644
--- a/drivers/infiniband/core/uverbs_std_types_qp.c
+++ b/drivers/infiniband/core/uverbs_std_types_qp.c
@@ -32,14 +32,14 @@ static int uverbs_free_qp(struct ib_uobject *uobject,
 	}

 	ret = ib_destroy_qp_user(qp, &attrs->driver_udata);
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	if (uqp->uxrcd)
 		atomic_dec(&uqp->uxrcd->refcnt);

 	ib_uverbs_release_uevent(&uqp->uevent);
-	return ret;
+	return 0;
 }

 static int check_creation_flags(enum ib_qp_type qp_type,
diff --git a/drivers/infiniband/core/uverbs_std_types_srq.c b/drivers/infiniband/core/uverbs_std_types_srq.c
index c0ecbba26bf4..e5513f828bdc 100644
--- a/drivers/infiniband/core/uverbs_std_types_srq.c
+++ b/drivers/infiniband/core/uverbs_std_types_srq.c
@@ -18,7 +18,7 @@ static int uverbs_free_srq(struct ib_uobject *uobject,
 	int ret;

 	ret = ib_destroy_srq_user(srq, &attrs->driver_udata);
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	if (srq_type == IB_SRQT_XRC) {
@@ -30,7 +30,7 @@ static int uverbs_free_srq(struct ib_uobject *uobject,
 	}

 	ib_uverbs_release_uevent(uevent);
-	return ret;
+	return 0;
 }

 static int UVERBS_HANDLER(UVERBS_METHOD_SRQ_CREATE)(
diff --git a/drivers/infiniband/core/uverbs_std_types_wq.c b/drivers/infiniband/core/uverbs_std_types_wq.c
index f2e6a625724a..7ded8339346f 100644
--- a/drivers/infiniband/core/uverbs_std_types_wq.c
+++ b/drivers/infiniband/core/uverbs_std_types_wq.c
@@ -17,11 +17,11 @@ static int uverbs_free_wq(struct ib_uobject *uobject,
 	int ret;

 	ret = ib_destroy_wq_user(wq, &attrs->driver_udata);
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	ib_uverbs_release_uevent(&uwq->uevent);
-	return ret;
+	return 0;
 }

 static int UVERBS_HANDLER(UVERBS_METHOD_WQ_CREATE)(
diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c
index 26c6bbb5e77a..7f4b186c146a 100644
--- a/drivers/infiniband/hw/mlx5/devx.c
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -1308,7 +1308,7 @@ static int devx_obj_cleanup(struct ib_uobject *uobject,
 	else
 		ret = mlx5_cmd_exec(obj->ib_dev->mdev, obj->dinbox,
 				    obj->dinlen, out, sizeof(out));
-	if (ib_is_destroy_retryable(ret, why, uobject))
+	if (ret)
 		return ret;

 	devx_event_table = &dev->devx_event_table;
@@ -2175,7 +2175,7 @@ static int devx_umem_cleanup(struct ib_uobject *uobject,
 	int err;

 	err = mlx5_cmd_exec(obj->mdev, obj->dinbox, obj->dinlen, out, sizeof(out));
-	if (ib_is_destroy_retryable(err, why, uobject))
+	if (err)
 		return err;

 	ib_umem_release(obj->umem);
diff --git a/drivers/infiniband/hw/mlx5/fs.c b/drivers/infiniband/hw/mlx5/fs.c
index 492cfe063bca..25da0b05b4e2 100644
--- a/drivers/infiniband/hw/mlx5/fs.c
+++ b/drivers/infiniband/hw/mlx5/fs.c
@@ -2035,11 +2035,9 @@ static int flow_matcher_cleanup(struct ib_uobject *uobject,
 				struct uverbs_attr_bundle *attrs)
 {
 	struct mlx5_ib_flow_matcher *obj = uobject->object;
-	int ret;

-	ret = ib_destroy_usecnt(&obj->usecnt, why, uobject);
-	if (ret)
-		return ret;
+	if (atomic_read(&obj->usecnt))
+		return -EBUSY;

 	kfree(obj);
 	return 0;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index d1b8f374aafa..d68868173f92 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1481,8 +1481,6 @@ struct ib_ucontext {
 	struct ib_device       *device;
 	struct ib_uverbs_file  *ufile;

-	bool cleanup_retryable;
-
 	struct ib_rdmacg_object	cg_obj;
 	/*
 	 * Implementation details of the RDMA core, don't use in drivers:
@@ -2898,46 +2896,6 @@ static inline bool ib_is_udata_cleared(struct ib_udata *udata,
 	return ib_is_buffer_cleared(udata->inbuf + offset, len);
 }

-/**
- * ib_is_destroy_retryable - Check whether the uobject destruction
- * is retryable.
- * @ret: The initial destruction return code
- * @why: remove reason
- * @uobj: The uobject that is destroyed
- *
- * This function is a helper function that IB layer and low-level drivers
- * can use to consider whether the destruction of the given uobject is
- * retry-able.
- * It checks the original return code, if it wasn't success the destruction
- * is retryable according to the ucontext state (i.e. cleanup_retryable) and
- * the remove reason. (i.e. why).
- * Must be called with the object locked for destroy.
- */
-static inline bool ib_is_destroy_retryable(int ret, enum rdma_remove_reason why,
-					   struct ib_uobject *uobj)
-{
-	return ret && (why == RDMA_REMOVE_DESTROY ||
-		       uobj->context->cleanup_retryable);
-}
-
-/**
- * ib_destroy_usecnt - Called during destruction to check the usecnt
- * @usecnt: The usecnt atomic
- * @why: remove reason
- * @uobj: The uobject that is destroyed
- *
- * Non-zero usecnts will block destruction unless destruction was triggered by
- * a ucontext cleanup.
- */
-static inline int ib_destroy_usecnt(atomic_t *usecnt,
-				    enum rdma_remove_reason why,
-				    struct ib_uobject *uobj)
-{
-	if (atomic_read(usecnt) && ib_is_destroy_retryable(-EBUSY, why, uobj))
-		return -EBUSY;
-	return 0;
-}
-
 /**
  * ib_modify_qp_is_ok - Check that the supplied attribute mask
  * contains all required attributes and no attributes not allowed for
--
2.26.2