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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 AF0F6C2BD09 for ; Thu, 27 Jun 2024 06:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=abyuWLLhH2vmfAInoW4MufjI8udDV/7HiRaYhb1cGIA=; b=c1al8Pd++z8fIXOM+tCTM4Eois HSfZP+vVrqVP1R6XfZaLdus02euzfDFPCKaQOoV1LUMWGCRxO7RUT8YRdGPOhselxYQHBwGzW29ZX B9FGuue4IrxZBHFNgHW2/ULG48svq4vLZhtBT3wPwcArm093VeVF1PkCqW5d4xsT3UT8zEfbNHIO4 inMTEeNspA17UiU7Zffb3H09K5pXkYHBBvJjJllGS3GeaZRnkBEKynYNW1Z+Os+tFNzLSZktzeHxw VU6KRcK94TsNy7EbjFAOVRtklBBWDsbJ+0mmWy7sT8kzkV8SsshMjZihe/UKJmJ7YcqMXrGiCuLpx GcGpGvcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sMiOW-00000009M9h-1I3m; Thu, 27 Jun 2024 06:14:08 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sMiOT-00000009M9G-08tw for linux-nvme@lists.infradead.org; Thu, 27 Jun 2024 06:14:06 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6143968AFE; Thu, 27 Jun 2024 08:14:01 +0200 (CEST) Date: Thu, 27 Jun 2024 08:14:01 +0200 From: Christoph Hellwig To: Anuj Gupta Cc: asml.silence@gmail.com, mpatocka@redhat.com, axboe@kernel.dk, hch@lst.de, kbusch@kernel.org, martin.petersen@oracle.com, io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Kanchan Joshi Subject: Re: [PATCH v2 03/10] block: copy bip_max_vcnt vecs instead of bip_vcnt during clone Message-ID: <20240627061401.GA16047@lst.de> References: <20240626100700.3629-1-anuj20.g@samsung.com> <20240626100700.3629-4-anuj20.g@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240626100700.3629-4-anuj20.g@samsung.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240626_231405_245890_99758E0B X-CRM114-Status: GOOD ( 13.57 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Jun 26, 2024 at 03:36:53PM +0530, Anuj Gupta wrote: > If bio_integrity_copy_user is used to process the meta buffer, bip_max_vcnt > is one greater than bip_vcnt. Why? > @@ -647,12 +647,12 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src, > > BUG_ON(bip_src == NULL); > > - bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt); > + bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_max_vcnt); > if (IS_ERR(bip)) > return PTR_ERR(bip); > > memcpy(bip->bip_vec, bip_src->bip_vec, > - bip_src->bip_vcnt * sizeof(struct bio_vec)); > + bip_src->bip_max_vcnt * sizeof(struct bio_vec)); > > bip->bip_vcnt = bip_src->bip_vcnt; > bip->bip_iter = bip_src->bip_iter; So trying to compare this to how the bio data path is cloned, it seems like bio_integrity_clone is still copying the bvec array. With the concept of the immutable bvecs we've had for years this should not be required. That is reuse the actual bio_vecs, and just copy the iter similar to bio_alloc_clone/__bio_clone.