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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 4DC79C43218 for ; Sat, 27 Apr 2019 06:18:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28D062077B for ; Sat, 27 Apr 2019 06:18:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726181AbfD0GSQ (ORCPT ); Sat, 27 Apr 2019 02:18:16 -0400 Received: from verein.lst.de ([213.95.11.211]:52344 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726001AbfD0GSQ (ORCPT ); Sat, 27 Apr 2019 02:18:16 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id DEBE668BFE; Sat, 27 Apr 2019 08:17:59 +0200 (CEST) Date: Sat, 27 Apr 2019 08:17:59 +0200 From: Christoph Hellwig To: Andreas Gruenbacher Cc: cluster-devel@redhat.com, Christoph Hellwig , Bob Peterson , Jan Kara , Dave Chinner , Ross Lagerwall , Mark Syms , Edwin =?iso-8859-1?B?VPZy9ms=?= , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v5 1/3] iomap: Fix use-after-free error in page_done callback Message-ID: <20190427061759.GA21795@lst.de> References: <20190426131127.19164-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190426131127.19164-1-agruenba@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This looks ok to me, holding the page over the i_size update and mark_inode_dirty should be ok. But I think it would be a lot cleaner if rebased ontop of this cleanup, which you could add to the front of the series: --- >From 908dbc5e7c26035f992fef84886976e0cda10b98 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 27 Apr 2019 08:13:38 +0200 Subject: iomap: cleanup __generic_write_end calling conventions Move the call to __generic_write_end into the common code flow instead of duplicating it in each of the three branches. This requires open coding the generic_write_end for the buffer_head case. Signed-off-by: Christoph Hellwig --- fs/iomap.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/fs/iomap.c b/fs/iomap.c index abdd18e404f8..cfc8a10b3fd8 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -738,13 +738,11 @@ __iomap_write_end(struct inode *inode, loff_t pos, unsigned len, * uptodate page as a zero-length write, and force the caller to redo * the whole thing. */ - if (unlikely(copied < len && !PageUptodate(page))) { - copied = 0; - } else { - iomap_set_range_uptodate(page, offset_in_page(pos), len); - iomap_set_page_dirty(page); - } - return __generic_write_end(inode, pos, copied, page); + if (unlikely(copied < len && !PageUptodate(page))) + return 0; + iomap_set_range_uptodate(page, offset_in_page(pos), len); + iomap_set_page_dirty(page); + return copied; } static int @@ -761,7 +759,6 @@ iomap_write_end_inline(struct inode *inode, struct page *page, kunmap_atomic(addr); mark_inode_dirty(inode); - __generic_write_end(inode, pos, copied, page); return copied; } @@ -774,12 +771,13 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, if (iomap->type == IOMAP_INLINE) { ret = iomap_write_end_inline(inode, page, iomap, pos, copied); } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { - ret = generic_write_end(NULL, inode->i_mapping, pos, len, - copied, page, NULL); + ret = block_write_end(NULL, inode->i_mapping, pos, len, copied, + page, NULL); } else { ret = __iomap_write_end(inode, pos, len, copied, page, iomap); } + ret = __generic_write_end(inode, pos, ret, page); if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); -- 2.20.1