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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 7C43EC43441 for ; Sun, 11 Nov 2018 23:14:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E36B20817 for ; Sun, 11 Nov 2018 23:14:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="lnS4Ipof" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E36B20817 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S2390013AbeKLJE4 (ORCPT ); Mon, 12 Nov 2018 04:04:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:49844 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389881AbeKLIVp (ORCPT ); Mon, 12 Nov 2018 03:21:45 -0500 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5CA17208A3; Sun, 11 Nov 2018 22:31:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975508; bh=SNPbVXnoz0liD53V6QWZSv32elts4kdqtMZVrI6l/ts=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lnS4IpofSnO/TFYWq6nw03DQRlJTW8d33KBCUw2zZ3HBC0NzTj4fJlOKs5JsuoPnX WlhyXw5a8iq6TQw2VDBko6Y8n2IWYgk8HxfiVBLAVRm8/4ngq8/h893Bovod8Y86Nb AcCiGymiiPTV3Ayi0elSYl0xAAdHZYW0VlwkWUyo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Omar Sandoval , Josef Bacik , David Sterba Subject: [PATCH 4.18 330/350] btrfs: protect space cache inode alloc with GFP_NOFS Date: Sun, 11 Nov 2018 14:23:14 -0800 Message-Id: <20181111221721.893563493@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik commit 84de76a2fb217dc1b6bc2965cc397d1648aa1404 upstream. If we're allocating a new space cache inode it's likely going to be under a transaction handle, so we need to use memalloc_nofs_save() in order to avoid deadlocks, and more importantly lockdep messages that make xfstests fail. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Omar Sandoval Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/free-space-cache.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "ctree.h" #include "free-space-cache.h" #include "transaction.h" @@ -47,6 +48,7 @@ static struct inode *__lookup_free_space struct btrfs_free_space_header *header; struct extent_buffer *leaf; struct inode *inode = NULL; + unsigned nofs_flag; int ret; key.objectid = BTRFS_FREE_SPACE_OBJECTID; @@ -68,7 +70,13 @@ static struct inode *__lookup_free_space btrfs_disk_key_to_cpu(&location, &disk_key); btrfs_release_path(path); + /* + * We are often under a trans handle at this point, so we need to make + * sure NOFS is set to keep us from deadlocking. + */ + nofs_flag = memalloc_nofs_save(); inode = btrfs_iget(fs_info->sb, &location, root, NULL); + memalloc_nofs_restore(nofs_flag); if (IS_ERR(inode)) return inode; if (is_bad_inode(inode)) {