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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A9DAC77B73 for ; Wed, 24 May 2023 13:33:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CA76E900007; Wed, 24 May 2023 09:33:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C3089900002; Wed, 24 May 2023 09:33:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD1AF900007; Wed, 24 May 2023 09:33:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 95AAE900002 for ; Wed, 24 May 2023 09:33:30 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 44DCB1609A9 for ; Wed, 24 May 2023 13:33:30 +0000 (UTC) X-FDA: 80825240580.13.72BA69E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf27.hostedemail.com (Postfix) with ESMTP id E33B740016 for ; Wed, 24 May 2023 13:33:27 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=eq1oO18n; spf=none (imf27.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684935208; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PlI3NINuTp5y2t5Z+4wg7vfiTt8lvB4SyLbHC5tKASU=; b=QmI52zxJZSHkKwjcqj6ILa5qNpNbJJ1kU7tCFB1u2ZLxbsr+rxjICQApeWcpkc5ha5uHF2 uPrZM2wKXz0PcDmQ498Cr8Si/WEZF3PflZsk9YTtjW/E1wdBr0BXlIFPjW0te5AlB3Hq20 kiyDg/H736UkudRURi6QG2RoOs8dd9E= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684935208; a=rsa-sha256; cv=none; b=KmmyUxXqEj+ibEDuzpXo9ZaYWICDTrXTaQvEJykdUL4OjOyj9FMfQ09BAgdoMI9DVja9Tk N6XJJ/yAvx8mUhRt25Ber/Bwxg++nlw4tR53Voe2if6hidUtUF0HIY0TMNxenQzR1SdiTM wKOwUrYp6uNKzrHnKqwhbQj2HRuss3g= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=eq1oO18n; spf=none (imf27.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none 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=PlI3NINuTp5y2t5Z+4wg7vfiTt8lvB4SyLbHC5tKASU=; b=eq1oO18nKmxdfx79+rZ3TTo5Q2 2/F3VHC9ngHsBakNRFv680ymTTyCK9hQMC/hF/6ByoTd1QX5Huc2qSnkfOtIpqNxg3U3KILlEnohH tk1m/vJLtoK5KkcBjlU2kaBM3cLYnmqGoN2Zya9Htl2CZTaH4W94BgkzuYeaOzmShvPd+qb3ym5EL yonGPZiSfd3yzH3hEQFRUsVsx849CuZTYjYDAClbFB7R6Y5PcboAB1JCCXjmLj8dakGubsyS8QwrS jjlaR0JAq6BqcKNmdvnkHdN+wsZcZz5xjzhHDugGtoEqqn7cXDiJJ1Gi7vDVBHa/uqXa8DUbUI1v1 peQuoiEw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1q1oc5-00BF3M-Tz; Wed, 24 May 2023 13:33:13 +0000 Date: Wed, 24 May 2023 14:33:13 +0100 From: Matthew Wilcox To: Dave Chinner Cc: Hannes Reinecke , Christoph Hellwig , Jens Axboe , Miklos Szeredi , "Darrick J. Wong" , Andrew Morton , David Howells , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 16/17] block: use iomap for writes to block devices Message-ID: References: <20230424054926.26927-1-hch@lst.de> <20230424054926.26927-17-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: E33B740016 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: b1q95hpcrzupoop9t15geu395j7x9u87 X-HE-Tag: 1684935207-424037 X-HE-Meta: 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 dh6haeld UUQAx6ojz4IsL+VXGZ7TkaQKH4xO34Jh15z4byN5VhJwq80UlQEke+pnWkV5NwmlPq10C3EbtyomeoZDPYh9bwvyY+rU+2UdzGerE2WSR0iwR6eq2MbYFpIo6XYQrboaxXJw1E8DrzT2eVGnySY5vka6s0y83Ccifn7UGRLU5DLF0tpbjOgVLsZnhV/+oD78dJahD X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 24, 2023 at 08:27:13AM +1000, Dave Chinner wrote: > On Fri, May 19, 2023 at 04:22:01PM +0200, Hannes Reinecke wrote: > > I'm hitting this during booting: > > [ 5.016324] > > [ 5.030256] iomap_iter+0x11a/0x350 > > [ 5.030264] iomap_readahead+0x1eb/0x2c0 > > [ 5.030272] read_pages+0x5d/0x220 > > [ 5.030279] page_cache_ra_unbounded+0x131/0x180 > > [ 5.030284] filemap_get_pages+0xff/0x5a0 > > Why is filemap_get_pages() using unbounded readahead? Surely > readahead should be limited to reading within EOF.... It isn't using unbounded readahead; that's an artifact of this incomplete stack trace. Actual call stack: page_cache_ra_unbounded do_page_cache_ra ondemand_readahead page_cache_sync_ra page_cache_sync_readahead filemap_get_pages As you can see, do_page_cache_ra() does limit readahead to i_size. Is ractl->mapping->host the correct way to find the inode? I always get confused. > I think Christoph's code is correct. IMO, any attempt to read beyond > the end of the device should throw out a warning and return an > error, not silently return zeros. > > If readahead is trying to read beyond the end of the device, then it > really seems to me like the problem here is readahead, not the iomap > code detecting the OOB read request.... > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com