From patchwork Wed Aug 21 17:57:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11107717 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4424E14DE for ; Wed, 21 Aug 2019 17:57:54 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2DD332082F for ; Wed, 21 Aug 2019 17:57:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DD332082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id B693D21945DE3; Wed, 21 Aug 2019 10:58:51 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=vgoyal@redhat.com; receiver=linux-nvdimm@lists.01.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 42FC32020D322 for ; Wed, 21 Aug 2019 10:58:49 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 56A4E106BB2C; Wed, 21 Aug 2019 17:57:39 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2D0FF5DC1E; Wed, 21 Aug 2019 17:57:39 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id DCA92223D0F; Wed, 21 Aug 2019 13:57:32 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org Subject: [PATCH 19/19] fuse: Take inode lock for dax inode truncation Date: Wed, 21 Aug 2019 13:57:20 -0400 Message-Id: <20190821175720.25901-20-vgoyal@redhat.com> In-Reply-To: <20190821175720.25901-1-vgoyal@redhat.com> References: <20190821175720.25901-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Wed, 21 Aug 2019 17:57:39 +0000 (UTC) X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-fs@redhat.com, dgilbert@redhat.com, stefanha@redhat.com, miklos@szeredi.hu Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" When a file is opened with O_TRUNC, we need to make sure that any other DAX operation is not in progress. DAX expects i_size to be stable. In fuse_iomap_begin() we check for i_size at multiple places and we expect i_size to not change. Another problem is, if we setup a mapping in fuse_iomap_begin(), and file gets truncated and dax read/write happens, KVM currently hangs. It tries to fault in a page which does not exist on host (file got truncated). It probably requries fixing in KVM. So for now, take inode lock. Once KVM is fixed, we might have to have a look at it again. Signed-off-by: Vivek Goyal --- fs/fuse/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index e369a1f92d85..794c55131bd0 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -524,7 +524,7 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir) int err; bool lock_inode = (file->f_flags & O_TRUNC) && fc->atomic_o_trunc && - fc->writeback_cache; + (fc->writeback_cache || IS_DAX(inode)); err = generic_file_open(inode, file); if (err)