From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A58FC49361 for ; Thu, 17 Jun 2021 03:23:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EFFA613E2 for ; Thu, 17 Jun 2021 03:23:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230055AbhFQDZv (ORCPT ); Wed, 16 Jun 2021 23:25:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:52222 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbhFQDZs (ORCPT ); Wed, 16 Jun 2021 23:25:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EA33D613E2; Thu, 17 Jun 2021 03:23:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623900222; bh=IX9qu+dkkKQ9s2fm1vXelS2dY1wdgE08Sy0O+VjqIUA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TyaIazuPhTaq+/1jmDgtrIErvl9VQ32F+FzxG4z2tM3ES8rFwS0OGJK+6bM8Aw5y2 OPsDJADG2JYRGJjlNjvQyoTYcrK/ckENnA8gFmf4POr8cB1JQbFbvQ3UDfD1Xorg47 VQkOicOZ8YN+LG3OVO384z4zmgU3Cz0eslXh9NFaU5I+i3usQrQvMiFkKsHveeiay0 on6tpXMc9fCC3IOnYByfi0qMVt1ePSI1zB05NQcSH1IVagGxwa5CufUZHhIdXMQdic 3+0lJL94glJiSgKVa5/iMjKyO53vMXlEqWqslI0R1FqEMkIt4B0eNtvNlAevChYiH6 LKP6lKPW1Sssg== Date: Wed, 16 Jun 2021 20:23:40 -0700 From: Eric Biggers To: Satya Tangirala Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Axboe Subject: Re: [PATCH v3 08/10] dm: handle error from blk_ksm_register() Message-ID: References: <20210604195900.2096121-1-satyat@google.com> <20210604195900.2096121-9-satyat@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210604195900.2096121-9-satyat@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 04, 2021 at 07:58:58PM +0000, Satya Tangirala wrote: > Handle any error from blk_ksm_register() in the callers. Previously, > the callers ignored the return value because blk_ksm_register() wouldn't > fail as long as the request_queue didn't have integrity support too, but > as this is no longer the case, it's safer for the callers to just handle > the return value appropriately. > > Signed-off-by: Satya Tangirala > --- > drivers/md/dm-table.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c > index 29cbfc3e3c4b..e44f304b5c1a 100644 > --- a/drivers/md/dm-table.c > +++ b/drivers/md/dm-table.c > @@ -1354,7 +1354,21 @@ static void dm_update_keyslot_manager(struct request_queue *q, > > /* Make the ksm less restrictive */ > if (!q->ksm) { > - blk_ksm_register(t->ksm, q); > + /* > + * This WARN_ON should never trigger since t->ksm isn't be > + * "empty" (i.e. will support at least 1 crypto capability), the > + * request queue doesn't support integrity (since > + * dm_table_construct_keyslot_manager() checks that), and > + * it also satisfies all the block layer constraints > + * "sufficiently" (as in the constraints of the DM device's > + * request queue won't preclude any of the intersection of the > + * supported capabilities of the underlying devices, since if > + * some capability were precluded by the DM device's request > + * queue's constraints, that capability would also have been > + * precluded by one of the child device's request queues) > + */ > + if (WARN_ON(!blk_ksm_register(t->ksm, q))) > + dm_destroy_keyslot_manager(t->ksm); This comment seems to be in the wrong place, as dm_update_keyslot_manager() already assumes that the crypto capabilities are either staying the same or expanding. This isn't something new that this WARN_ON() introduces. I think this explanation should go in dm_table_construct_keyslot_manager() instead, as that is where the new set of crypto capabilities is built. I.e. in dm_table_construct_keyslot_manager() we should explain how we "know" that the new set will really be equal or greater. - Eric