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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 76FFFC433DB for ; Tue, 30 Mar 2021 16:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CA86619D0 for ; Tue, 30 Mar 2021 16:18:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231812AbhC3QRg (ORCPT ); Tue, 30 Mar 2021 12:17:36 -0400 Received: from verein.lst.de ([213.95.11.211]:59533 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231951AbhC3QRR (ORCPT ); Tue, 30 Mar 2021 12:17:17 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 4252368B05; Tue, 30 Mar 2021 18:17:15 +0200 (CEST) Date: Tue, 30 Mar 2021 18:17:15 +0200 From: Christoph Hellwig To: Joel Stanley Cc: David Woodhouse , Richard Weinberger , Al Viro , Kees Cook , Christoph Hellwig , "William A . Kennington III" , Lei YU , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] jffs2: Hook up splice_write callback Message-ID: <20210330161715.GA12783@lst.de> References: <20210330134537.423447-1-joel@jms.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210330134537.423447-1-joel@jms.id.au> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 31, 2021 at 12:15:37AM +1030, Joel Stanley wrote: > overlayfs using jffs2 as the upper filesystem would fail in some cases > since moving to v5.10. The test case used was to run 'touch' on a file > that exists in the lower fs, causing the modification time to be > updated. It returns EINVAL when the bug is triggered. > > A bisection showed this was introduced in v5.9-rc1, with commit > 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops"). > Reverting that commit restores the expected behaviour. > > Some digging showed that this was due to jffs2 lacking an implementation > of splice_write. (For unknown reasons the warn_unsupported that should > trigger was not displaying any output). > > Adding this patch resolved the issue and the test now passes. Looks good: Reviewed-by: Christoph Hellwig