From patchwork Mon Aug 31 19:50:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 310586 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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 17311C433E2 for ; Mon, 31 Aug 2020 19:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D879520936 for ; Mon, 31 Aug 2020 19:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598903431; bh=91iSUjJrhFtccxGcUDJHA9DbrAgsxr0J3nSJgEJ7bHs=; h=Date:From:To:Subject:List-ID:From; b=Ig2DVB6vOPe7EUQ/HcKipuIWe5yZLRQQlOK1otC2MnRtbKyAgmgdqL2NH2lJ0dhQV sxrITpmJqA8z6ppklVBekvL/HgW8TjMfulqPUbzdyjNoax9jQEv+/2dixQ1tsYcBKa pZ2KsBqT9s1RRmmlv7sXhb38hGWLvrcvknjm6luk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729803AbgHaTub (ORCPT ); Mon, 31 Aug 2020 15:50:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:35230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727839AbgHaTub (ORCPT ); Mon, 31 Aug 2020 15:50:31 -0400 Received: from X1 (unknown [65.49.58.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4EDCA2083E; Mon, 31 Aug 2020 19:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598903430; bh=91iSUjJrhFtccxGcUDJHA9DbrAgsxr0J3nSJgEJ7bHs=; h=Date:From:To:Subject:From; b=PdnENpJY0eUADtnfrQxCDeTh2fHDs7P1sJV0VIAtzbySJvUXbFcNVhhIAKM3d7cgv IX3SYu7EZvMn7l5mN8B+Cm5NU1pq7WvzKT/qNPp+0NvI3NuBu8RkOnOqjuqVot1ywK 2tuUET68qqBpyEjJXgFaNDCxx9+q9Hv0Wo8CK0A8= Date: Mon, 31 Aug 2020 12:50:29 -0700 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, willy@infradead.org, stable@vger.kernel.org, axboe@kernel.dk, hirofumi@mail.parknet.co.jp Subject: [alternative-merged] fat-avoid-oops-when-bdi-io_pages==0.patch removed from -mm tree Message-ID: <20200831195029.T63Ay%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: fat: avoid oops when bdi->io_pages==0 has been removed from the -mm tree. Its filename was fat-avoid-oops-when-bdi-io_pages==0.patch This patch was dropped because an alternative patch was merged ------------------------------------------------------ From: OGAWA Hirofumi Subject: fat: avoid oops when bdi->io_pages==0 On one system, there was bdi->io_pages==0. This seems to be the bug of a driver somewhere, which perhaps failed to initialize io_pages. We should fix it though - it is better to avoid the divide-by-zero Oops. So add a check for this. Link: http://lkml.kernel.org/r/87ft85osn6.fsf@mail.parknet.co.jp Signed-off-by: OGAWA Hirofumi Cc: Matthew Wilcox Cc: Jens Axboe Cc: [5.8+] Signed-off-by: Andrew Morton --- fs/fat/fatent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/fat/fatent.c~fat-avoid-oops-when-bdi-io_pages==0 +++ a/fs/fat/fatent.c @@ -660,7 +660,7 @@ static void fat_ra_init(struct super_blo if (fatent->entry >= ent_limit) return; - if (ra_pages > sb->s_bdi->io_pages) + if (sb->s_bdi->io_pages && ra_pages > sb->s_bdi->io_pages) ra_pages = rounddown(ra_pages, sb->s_bdi->io_pages); reada_blocks = ra_pages << (PAGE_SHIFT - sb->s_blocksize_bits + 1);