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 7F8D1C7EE23 for ; Tue, 9 May 2023 20:49:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C60156B0071; Tue, 9 May 2023 16:49:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C11BE6B0072; Tue, 9 May 2023 16:49:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFF326B0074; Tue, 9 May 2023 16:49:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A09876B0071 for ; Tue, 9 May 2023 16:49:09 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 68DA51C71B1 for ; Tue, 9 May 2023 20:49:09 +0000 (UTC) X-FDA: 80771906418.23.0E7B0E4 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf02.hostedemail.com (Postfix) with ESMTP id 5223980005 for ; Tue, 9 May 2023 20:49:07 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=none; spf=none (imf02.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1683665347; 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; bh=hAPwn+soF3NUvEHou/jHd/DE9SG2Rbo66fBpPbsh5n8=; b=u0zovQKVACnZ+od7Y7xiI84cpOWt/N6p24VVfEr0nsIi8n3IRda/601kV1mYj8/2A0XK+a 6P6faoY5X/15lfBfv1AH35WKc/lRxmi9pSBoh2siLd7Htcc8dG6z/BI10L5Sy3N+wN8w8L TQ49oxXiMfZvwnqAI0+DkFKlw7+zk1g= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=none; spf=none (imf02.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1683665347; a=rsa-sha256; cv=none; b=nacLTLtv0cLgF6XPAXvlZeEd2zGn/UNJFrKrqz/AZDQFGz/xKY8/6zVm6AResKg9ADAV2r cEY44C+2OxuhT+ZkPn5YV177mqtKYQs3eYNGgiA63AL01iOifoR1HsEdVVgS6Xbx3zlECd wGEGd5SE0+MeW8uY2PkY3VmJ/VT8JHQ= Received: by verein.lst.de (Postfix, from userid 2407) id 8CD1F6732A; Tue, 9 May 2023 22:49:02 +0200 (CEST) Date: Tue, 9 May 2023 22:49:02 +0200 From: Christoph Hellwig To: Linus Torvalds Cc: Dan Carpenter , Anna Schumaker , Trond Myklebust , Andrew Morton , "Matthew Wilcox (Oracle)" , Josef Bacik , Johannes Weiner , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, syzbot+48011b86c8ea329af1b9@syzkaller.appspotmail.com, Christoph Hellwig , David Sterba , Bob Peterson , Andreas Gruenbacher Subject: Re: [PATCH] filemap: Handle error return from __filemap_get_folio() Message-ID: <20230509204902.GA2047@lst.de> References: <20230506160415.2992089-1-willy@infradead.org> <20230506104122.e9ab27f59fd3d8294cb1356d@linux-foundation.org> <7bd22265-f46c-4347-a856-eecd1429dcce@kili.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Stat-Signature: 13s5qts6bqpskj4x7hedbjg35swnddgy X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5223980005 X-Rspam-User: X-HE-Tag: 1683665347-452502 X-HE-Meta: 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 mkHyiRzp +H+JCJhixFOL2mrQdFEkT4dAnfvb9zOWxRJIy5ZaklEIMT8PHsMNuoaSHy0cQ/3yH6kUkgCY2NPlbUDUGalnDkfY6NFducqSWyAJ3MKalgxdRHsV0yX+4UzP1xftGvUbwAVdz4XaXZAGg45Qu/fCfnhwxyf+Gn7zIHZhFgMkBTS8TcbAXaSMjWmexLqh6W2xQwkt9KljZiuchwt68CcL4y6ZSOyPKhL3lpD1PQaWjV4i92u2J+FP1PwE1Hw== 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 Tue, May 09, 2023 at 10:37:12AM -0700, Linus Torvalds wrote: > In fs/btrfs/extent_io.c, we have > > while (index <= end_index) { > folio = filemap_get_folio(mapping, index); > filemap_dirty_folio(mapping, folio); > > and in fs/gfs2/lops.c we have a similar case of filemap_get_folio -> > folio_wait_locked use without checking for any errors. > > I assume it's probably hard to trigger errors in those paths, but it > does look dodgy. The pages are pinned at the point. That being said this code is absolutely for many other reasons and needs to go away. I've been looking into it, but it will probably take several more months to unpile the onion to get to the hear of the btrfs writeback code problems..