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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 47D91C433E6 for ; Mon, 8 Feb 2021 04:36:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 168C964E61 for ; Mon, 8 Feb 2021 04:36:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229716AbhBHEgc (ORCPT ); Sun, 7 Feb 2021 23:36:32 -0500 Received: from mga07.intel.com ([134.134.136.100]:17032 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229590AbhBHEgb (ORCPT ); Sun, 7 Feb 2021 23:36:31 -0500 IronPort-SDR: l/FAM6FSC72CiLe0G+w2+xUn5tZvBRHmYyuvfuwMPQ8npg8+J2zW72vwv2ziThkC+jQ3tTVPpM W8XL2waaGaQg== X-IronPort-AV: E=McAfee;i="6000,8403,9888"; a="245728711" X-IronPort-AV: E=Sophos;i="5.81,161,1610438400"; d="scan'208";a="245728711" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2021 20:35:46 -0800 IronPort-SDR: 4emt90bFPXkomAEhMAD/amfAwA5qVmGt0sO4/tEOTDnxbNYF4BpZw3GHR0aFYD7ulF1hKkEC4B kY6KjbpkbPNQ== X-IronPort-AV: E=Sophos;i="5.81,161,1610438400"; d="scan'208";a="435473654" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2021 20:35:46 -0800 Date: Sun, 7 Feb 2021 20:35:46 -0800 From: Ira Weiny To: Chaitanya Kulkarni Cc: linux-block@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, axboe@kernel.dk, tytso@mit.edu, adilger.kernel@dilger.ca, jaegeuk@kernel.org, chao@kernel.org, johannes.thumshirn@wdc.com, damien.lemoal@wdc.com, bvanassche@acm.org, dongli.zhang@oracle.com, clm@fb.com, dsterba@suse.com, ebiggers@kernel.org, hch@infradead.org, dave.hansen@intel.com Subject: Re: [RFC PATCH 2/8] brd: use memcpy_from_page() in copy_from_brd() Message-ID: <20210208043545.GF5033@iweiny-DESK2.sc.intel.com> References: <20210207190425.38107-1-chaitanya.kulkarni@wdc.com> <20210207190425.38107-3-chaitanya.kulkarni@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210207190425.38107-3-chaitanya.kulkarni@wdc.com> User-Agent: Mutt/1.11.1 (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Feb 07, 2021 at 11:04:19AM -0800, Chaitanya Kulkarni wrote: > Signed-off-by: Chaitanya Kulkarni > --- > drivers/block/brd.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/block/brd.c b/drivers/block/brd.c > index d41b7d489e9f..c1f6d768a1b3 100644 > --- a/drivers/block/brd.c > +++ b/drivers/block/brd.c > @@ -220,7 +220,6 @@ static void copy_from_brd(void *dst, struct brd_device *brd, > sector_t sector, size_t n) > { > struct page *page; > - void *src; > unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; > size_t copy; > > @@ -236,11 +235,9 @@ static void copy_from_brd(void *dst, struct brd_device *brd, > sector += copy >> SECTOR_SHIFT; > copy = n - copy; > page = brd_lookup_page(brd, sector); > - if (page) { > - src = kmap_atomic(page); > - memcpy(dst, src, copy); > - kunmap_atomic(src); > - } else > + if (page) > + memcpy_from_page(dst, page, offset, copy); Why 'offset'? Ira > + else > memset(dst, 0, copy); > } > } > -- > 2.22.1 >