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=-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=unavailable 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 A0E01C433FE for ; Mon, 13 Sep 2021 13:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C76461368 for ; Mon, 13 Sep 2021 13:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243177AbhIMNvo (ORCPT ); Mon, 13 Sep 2021 09:51:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:53624 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243518AbhIMNsB (ORCPT ); Mon, 13 Sep 2021 09:48:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D4C9C61260; Mon, 13 Sep 2021 13:32:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631539960; bh=nKAPJuv995/1TKkiAqfaXf7/IW9CiedMX+rgVzIJ4SQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=smUcOG7BFXMz5UKephPWe0hikpkv8IL5xuShYCN6j70fLG0LDMwYxmXXpJD/biEbU rmMBTB//+0AKwKF9+oD9HK6ZWyLAPZIf/YJw1VOuKRu50tRWaPrwXLhs7Z+cYUMzqa T21u+8/t3Q3EuCXRtoeCMzWS2PSe+qZqbPkLJzow= 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 5.10 230/236] fuse: truncate pagecache on atomic_o_trunc Date: Mon, 13 Sep 2021 15:15:35 +0200 Message-Id: <20210913131108.175549755@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131100.316353015@linuxfoundation.org> References: <20210913131100.316353015@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -194,12 +194,11 @@ 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); @@ -207,10 +206,14 @@ 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); }