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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 A8FC0C433E1 for ; Sat, 22 Aug 2020 13:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 894C02072D for ; Sat, 22 Aug 2020 13:13:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iTfHddlf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbgHVNNX (ORCPT ); Sat, 22 Aug 2020 09:13:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727827AbgHVNNW (ORCPT ); Sat, 22 Aug 2020 09:13:22 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9912C061573; Sat, 22 Aug 2020 06:13:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=W7icbdrjXIMjEIuPepc0EKhRXc/76Hvc8/WClwhuPEY=; b=iTfHddlfukLpE8OPjam/73lwat Co5qhCkH1ok53KdJjF15cQ+6VVRx2sX8go2p8vEZAJVXb7nmdctqb/wcJBZ3ECDpeyBbByBFiDfFk ibnHWaKau2hb5v2Bbs4Ty8c3/k/SLWdQijHR4hzrSaFd6CYe9udAad3XhRJoxOTj/TfTqz/fLzInQ e2pmszP0jSl4eSoRujZzznOd8aupwNj6WyTtbkhZh14Am1hZKzl1FAjNOsDC16b021I6ukuFfalmp 3uFUVbo01VL91mhXWHtjjIDa51Kt3Bj1M9YRb0VmGG0dePYDNXR6mWtIoyg8PThBtxMfG+cT8yj22 ZmtmDXTQ==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k9TKa-0004jA-Ez; Sat, 22 Aug 2020 13:13:12 +0000 Date: Sat, 22 Aug 2020 14:13:12 +0100 From: Christoph Hellwig To: Dave Chinner Cc: Ritesh Harjani , Anju T Sudhakar , hch@infradead.org, darrick.wong@oracle.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, willy@infradead.org Subject: Re: [PATCH] iomap: Fix the write_count in iomap_add_to_ioend(). Message-ID: <20200822131312.GA17997@infradead.org> References: <20200819102841.481461-1-anju@linux.vnet.ibm.com> <20200820231140.GE7941@dread.disaster.area> <20200821044533.BBFD1A405F@d06av23.portsmouth.uk.ibm.com> <20200821215358.GG7941@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200821215358.GG7941@dread.disaster.area> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, Aug 22, 2020 at 07:53:58AM +1000, Dave Chinner wrote: > but iomap only allows BIO_MAX_PAGES when creating the bio. And: > > #define BIO_MAX_PAGES 256 > > So even on a 64k page machine, we should not be building a bio with > more than 16MB of data in it. So how are we getting 4GB of data into > it? BIO_MAX_PAGES is the number of bio_vecs in the bio, it has no direct implication on the size, as each entry can fit up to UINT_MAX bytes.