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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 AEA0AC43441 for ; Sun, 11 Nov 2018 20:40:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7450D20869 for ; Sun, 11 Nov 2018 20:40:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7450D20869 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729946AbeKLFsF (ORCPT ); Mon, 12 Nov 2018 00:48:05 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49372 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729830AbeKLFsD (ORCPT ); Mon, 12 Nov 2018 00:48:03 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsN-0000lI-Ur; Sun, 11 Nov 2018 19:58:32 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsN-0001N9-PL; Sun, 11 Nov 2018 19:58:31 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Miklos Szeredi" , "Chad Austin" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 014/366] fuse: atomic_o_trunc should truncate pagecache In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit df0e91d488276086bc07da2e389986cae0048c37 upstream. Fuse has an "atomic_o_trunc" mode, where userspace filesystem uses the O_TRUNC flag in the OPEN request to truncate the file atomically with the open. In this mode there's no need to send a SETATTR request to userspace after the open, so fuse_do_setattr() checks this mode and returns. But this misses the important step of truncating the pagecache. Add the missing parts of truncation to the ATTR_OPEN branch. Reported-by: Chad Austin Fixes: 6ff958edbf39 ("fuse: add atomic open+truncate support") Signed-off-by: Miklos Szeredi Signed-off-by: Ben Hutchings --- fs/fuse/dir.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1728,8 +1728,19 @@ int fuse_do_setattr(struct dentry *dentr return err; if (attr->ia_valid & ATTR_OPEN) { - if (fc->atomic_o_trunc) + /* This is coming from open(..., ... | O_TRUNC); */ + WARN_ON(!(attr->ia_valid & ATTR_SIZE)); + WARN_ON(attr->ia_size != 0); + if (fc->atomic_o_trunc) { + /* + * No need to send request to userspace, since actual + * truncation has already been done by OPEN. But still + * need to truncate page cache. + */ + i_size_write(inode, 0); + truncate_pagecache(inode, 0); return 0; + } file = NULL; }