RDMA/core: Do not allow alloc_commit to fail

This is a left over from an earlier version that creates a lot of
complexity for error unwind, particularly for FD uobjects.

The only reason this was done is so that anon_inode_get_file() could be
called with the final fops and a fully setup uobject. Both need to be
setup since unwinding anon_inode_get_file() via fput will call the
driver's release().

Now that the driver does not provide release, we no longer need to worry
about this complicated sequence, simply create the struct file at the
start and allow the core code's release function to deal with the abort
case.

This allows all the confusing error paths around commit to be removed.

Link: https://lore.kernel.org/r/1578504126-9400-5-git-send-email-yishaih@mellanox.com
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 12 insertions, 33 deletions

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 269938f59d3f..538affbc517e 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -220,24 +220,17 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
 	return ret;
 }
 
-static int uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
-				  struct uverbs_objs_arr_attr *attr,
-				  bool commit, struct uverbs_attr_bundle *attrs)
+static void uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
+				   struct uverbs_objs_arr_attr *attr,
+				   bool commit,
+				   struct uverbs_attr_bundle *attrs)
 {
 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
-	int current_ret;
-	int ret = 0;
 	size_t i;
 
-	for (i = 0; i != attr->len; i++) {
-		current_ret = uverbs_finalize_object(attr->uobjects[i],
-						     spec->u2.objs_arr.access,
-						     commit, attrs);
-		if (!ret)
-			ret = current_ret;
-	}
-
-	return ret;
+	for (i = 0; i != attr->len; i++)
+		uverbs_finalize_object(attr->uobjects[i],
+				       spec->u2.objs_arr.access, commit, attrs);
 }
 
 static int uverbs_process_attr(struct bundle_priv *pbundle,
@@ -495,26 +488,22 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle,
 	return ret;
 }
 
-static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
+static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
 {
 	unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
 	struct bundle_alloc_head *memblock;
 	unsigned int i;
-	int ret = 0;
 
 	/* fast path for simple uobjects */
 	i = -1;
 	while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
 				  i + 1)) < key_bitmap_len) {
 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
-		int current_ret;
 
-		current_ret = uverbs_finalize_object(
+		uverbs_finalize_object(
 			attr->obj_attr.uobject,
 			attr->obj_attr.attr_elm->spec.u.obj.access, commit,
 			&pbundle->bundle);
-		if (!ret)
-			ret = current_ret;
 	}
 
 	i = -1;
@@ -523,7 +512,6 @@ static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
 		const struct uverbs_api_attr *attr_uapi;
 		void __rcu **slot;
-		int current_ret;
 
 		slot = uapi_get_attr_for_method(
 			pbundle,
@@ -534,11 +522,8 @@ static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 		attr_uapi = rcu_dereference_protected(*slot, true);
 
 		if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
-			current_ret = uverbs_free_idrs_array(
-				attr_uapi, &attr->objs_arr_attr, commit,
-				&pbundle->bundle);
-			if (!ret)
-				ret = current_ret;
+			uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr,
+					       commit, &pbundle->bundle);
 		}
 	}
 
@@ -548,8 +533,6 @@ static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 		memblock = memblock->next;
 		kvfree(tmp);
 	}
-
-	return ret;
 }
 
 static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
@@ -562,7 +545,6 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
 	struct bundle_priv *pbundle;
 	struct bundle_priv onstack;
 	void __rcu **slot;
-	int destroy_ret;
 	int ret;
 
 	if (unlikely(hdr->driver_id != uapi->driver_id))
@@ -610,10 +592,7 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
 	memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
 
 	ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
-	destroy_ret = bundle_destroy(pbundle, ret == 0);
-	if (unlikely(destroy_ret && !ret))
-		return destroy_ret;
-
+	bundle_destroy(pbundle, ret == 0);
 	return ret;
 }