Commit f553246f authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

RDMA/core: Change how failing destroy is handled during uobj abort 

Currently it triggers a WARN_ON and then goes ahead and destroys the
uobject anyhow, leaking any driver memory.

The only place that leaks driver memory should be during FD close() in
uverbs_destroy_ufile_hw().

Drivers are only allowed to fail destroy uobjects if they guarantee
destroy will eventually succeed. uverbs_destroy_ufile_hw() provides the
loop to give the driver that chance.

Link: https://lore.kernel.org/r/20200902081708.746631-1-leon@kernel.org


Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 00b3c118

drivers/infiniband/core/rdma_core.c

+15 −15
Original line number Diff line number Diff line
@@ -130,17 +130,6 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj, 
	lockdep_assert_held(&ufile->hw_destroy_rwsem);

	assert_uverbs_usecnt(uobj, UVERBS_LOOKUP_WRITE);



	if (reason == RDMA_REMOVE_ABORT_HWOBJ) {

		reason = RDMA_REMOVE_ABORT;

		ret = uobj->uapi_object->type_class->destroy_hw(uobj, reason,

								attrs);

		/*

		 * Drivers are not permitted to ignore RDMA_REMOVE_ABORT, see

		 * ib_is_destroy_retryable, cleanup_retryable == false here.

		 */

		WARN_ON(ret);

	}



	if (reason == RDMA_REMOVE_ABORT) {

		WARN_ON(!list_empty(&uobj->list));

		WARN_ON(!uobj->context);
@@ -674,11 +663,22 @@ void rdma_alloc_abort_uobject(struct ib_uobject *uobj, 
			      bool hw_obj_valid)

{

	struct ib_uverbs_file *ufile = uobj->ufile;

	int ret;



	uverbs_destroy_uobject(uobj,

			       hw_obj_valid ? RDMA_REMOVE_ABORT_HWOBJ :

					      RDMA_REMOVE_ABORT,

			       attrs);

	if (hw_obj_valid) {

		ret = uobj->uapi_object->type_class->destroy_hw(

			uobj, RDMA_REMOVE_ABORT, attrs);

		/*

		 * If the driver couldn't destroy the object then go ahead and

		 * commit it. Leaking objects that can't be destroyed is only

		 * done during FD close after the driver has a few more tries to

		 * destroy it.

		 */

		if (WARN_ON(ret))

			return rdma_alloc_commit_uobject(uobj, attrs);

	}



	uverbs_destroy_uobject(uobj, RDMA_REMOVE_ABORT, attrs);



	/* Matches the down_read in rdma_alloc_begin_uobject */

	up_read(&ufile->hw_destroy_rwsem);

include/rdma/ib_verbs.h

+0 −5
Original line number Diff line number Diff line
@@ -1463,11 +1463,6 @@ enum rdma_remove_reason { 
	RDMA_REMOVE_DRIVER_REMOVE,

	/* uobj is being cleaned-up before being committed */

	RDMA_REMOVE_ABORT,

	/*

	 * uobj has been fully created, with the uobj->object set, but is being

	 * cleaned up before being comitted

	 */

	RDMA_REMOVE_ABORT_HWOBJ,

};



struct ib_rdmacg_object {

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