From patchwork Wed Aug 31 16:58:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 12961133 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DD8CC0502A for ; Wed, 31 Aug 2022 16:58:49 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.395941.635843 (Exim 4.92) (envelope-from ) id 1oTR2z-0002mg-Q4; Wed, 31 Aug 2022 16:58:37 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 395941.635843; Wed, 31 Aug 2022 16:58:37 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oTR2z-0002mZ-LQ; Wed, 31 Aug 2022 16:58:37 +0000 Received: by outflank-mailman (input) for mailman id 395941; Wed, 31 Aug 2022 16:58:35 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oTR2x-0002W4-O6 for xen-devel@lists.xenproject.org; Wed, 31 Aug 2022 16:58:35 +0000 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 2678888c-294e-11ed-934f-f50d60e1c1bd; Wed, 31 Aug 2022 18:58:34 +0200 (CEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 2713EB821AD; Wed, 31 Aug 2022 16:58:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22B88C433C1; Wed, 31 Aug 2022 16:58:32 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 2678888c-294e-11ed-934f-f50d60e1c1bd DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661965112; bh=2M6XIQVeSqrPrYytDvGmk8JSZnX1cUCppYJ4t0zteug=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r+yj2nUL8cBvYHbhNGByKXHfolByjrFRe687uj1BUUB6mIbeXN2akLAiQRdvStbqP NMb5qiC+ThAz7uY10jHDz33BEKstZU2iTWJpSn0pPMwG29otA0+v7b4oevDXX9xywt daiS3FmM4D7SFz4ZS2QhL+z/hmZONNOucXCZH3i5gYjg1q8QBAYtaXJ65YwQKdQzb0 vUEOeCFozOnzBRrMkAQ5iuwNZdviUg+Q7J75Jt4uuZwxML8bP5XUh9fA3KShUEsq9Y 3L8j6pjOgw50j/r6rdnjpE4dC/uRqcRZVpRbxbOCphVbmdYWOEHGFNP8VkJoa9oNlQ OeAJ+c6yTMvqA== From: SeongJae Park To: jgross@suse.com, roger.pau@citrix.com Cc: SeongJae Park , marmarek@invisiblethingslab.com, mheyne@amazon.de, xen-devel@lists.xenproject.org, axboe@kernel.dk, ptyadav@amazon.de, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v2 1/3] xen-blkback: Advertise feature-persistent as user requested Date: Wed, 31 Aug 2022 16:58:22 +0000 Message-Id: <20220831165824.94815-2-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220831165824.94815-1-sj@kernel.org> References: <20220831165824.94815-1-sj@kernel.org> MIME-Version: 1.0 The advertisement of the persistent grants feature (writing 'feature-persistent' to xenbus) should mean not the decision for using the feature but only the availability of the feature. However, commit aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants") made a field of blkback, which was a place for saving only the negotiation result, to be used for yet another purpose: caching of the 'feature_persistent' parameter value. As a result, the advertisement, which should follow only the parameter value, becomes inconsistent. This commit fixes the misuse of the semantic by making blkback saves the parameter value in a separate place and advertises the support based on only the saved value. Fixes: aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants") Cc: # 5.10.x Suggested-by: Juergen Gross Signed-off-by: SeongJae Park Reviewed-by: Pratyush Yadav --- drivers/block/xen-blkback/common.h | 3 +++ drivers/block/xen-blkback/xenbus.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index bda5c815e441..a28473470e66 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -226,6 +226,9 @@ struct xen_vbd { sector_t size; unsigned int flush_support:1; unsigned int discard_secure:1; + /* Connect-time cached feature_persistent parameter value */ + unsigned int feature_gnt_persistent_parm:1; + /* Persistent grants feature negotiation result */ unsigned int feature_gnt_persistent:1; unsigned int overflow_max_grants:1; }; diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index ee7ad2fb432d..c0227dfa4688 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -907,7 +907,7 @@ static void connect(struct backend_info *be) xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support); err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", - be->blkif->vbd.feature_gnt_persistent); + be->blkif->vbd.feature_gnt_persistent_parm); if (err) { xenbus_dev_fatal(dev, err, "writing %s/feature-persistent", dev->nodename); @@ -1085,7 +1085,9 @@ static int connect_ring(struct backend_info *be) return -ENOSYS; } - blkif->vbd.feature_gnt_persistent = feature_persistent && + blkif->vbd.feature_gnt_persistent_parm = feature_persistent; + blkif->vbd.feature_gnt_persistent = + blkif->vbd.feature_gnt_persistent_parm && xenbus_read_unsigned(dev->otherend, "feature-persistent", 0); blkif->vbd.overflow_max_grants = 0;