From patchwork Mon Sep 13 13:16:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 510360 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 82621C433EF for ; Mon, 13 Sep 2021 14:46:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C35F603E5 for ; Mon, 13 Sep 2021 14:46:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346322AbhIMOrZ (ORCPT ); Mon, 13 Sep 2021 10:47:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:60498 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346398AbhIMOpS (ORCPT ); Mon, 13 Sep 2021 10:45:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 97375603E5; Mon, 13 Sep 2021 13:58:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631541502; bh=2HqpvZymOdCHaQf2VAqiXp2GlpNsxp2W56uhyfMbyRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ErkHyScZek/DDDURfRen4co+bd2LFi1c7Nr3Ibv0MhCpUxlGyE0vrmc5lom1c+Yzq Eexr3SMEua7/asR2Bg0906SC9pSmdv+hbf40GHpUkDdCgLeR89EQ45IlD/3vjrRCD3 RfW3IwN7CCTFsy08RHLkVF5XkVPG7MAaMc8arYM8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xie Yongji , Miklos Szeredi , syzbot+bea44a5189836d956894@syzkaller.appspotmail.com Subject: [PATCH 5.14 323/334] fuse: truncate pagecache on atomic_o_trunc Date: Mon, 13 Sep 2021 15:16:17 +0200 Message-Id: <20210913131124.351841317@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131113.390368911@linuxfoundation.org> References: <20210913131113.390368911@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Miklos Szeredi commit 76224355db7570cbe6b6f75c8929a1558828dd55 upstream. fuse_finish_open() will be called with FUSE_NOWRITE in case of atomic O_TRUNC. This can deadlock with fuse_wait_on_page_writeback() in fuse_launder_page() triggered by invalidate_inode_pages2(). Fix by replacing invalidate_inode_pages2() in fuse_finish_open() with a truncate_pagecache() call. This makes sense regardless of FOPEN_KEEP_CACHE or fc->writeback cache, so do it unconditionally. Reported-by: Xie Yongji Reported-and-tested-by: syzbot+bea44a5189836d956894@syzkaller.appspotmail.com Fixes: e4648309b85a ("fuse: truncate pending writes on O_TRUNC") Cc: Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/file.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -198,12 +198,11 @@ void fuse_finish_open(struct inode *inod struct fuse_file *ff = file->private_data; struct fuse_conn *fc = get_fuse_conn(inode); - if (!(ff->open_flags & FOPEN_KEEP_CACHE)) - invalidate_inode_pages2(inode->i_mapping); if (ff->open_flags & FOPEN_STREAM) stream_open(inode, file); else if (ff->open_flags & FOPEN_NONSEEKABLE) nonseekable_open(inode, file); + if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) { struct fuse_inode *fi = get_fuse_inode(inode); @@ -211,10 +210,14 @@ void fuse_finish_open(struct inode *inod fi->attr_version = atomic64_inc_return(&fc->attr_version); i_size_write(inode, 0); spin_unlock(&fi->lock); + truncate_pagecache(inode, 0); fuse_invalidate_attr(inode); if (fc->writeback_cache) file_update_time(file); + } else if (!(ff->open_flags & FOPEN_KEEP_CACHE)) { + invalidate_inode_pages2(inode->i_mapping); } + if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache) fuse_link_write_file(file); }