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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 C299BC43381 for ; Mon, 25 Feb 2019 18:56:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96A8E2087C for ; Mon, 25 Feb 2019 18:56:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726400AbfBYS4h (ORCPT ); Mon, 25 Feb 2019 13:56:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:37040 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725842AbfBYS4h (ORCPT ); Mon, 25 Feb 2019 13:56:37 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 78FE4ACCD for ; Mon, 25 Feb 2019 18:56:36 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id CF312DA83C; Mon, 25 Feb 2019 19:57:57 +0100 (CET) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH] btrfs: move ulist allocation out of transaction in quota enable Date: Mon, 25 Feb 2019 19:55:44 +0100 Message-Id: <20190225185544.14516-1-dsterba@suse.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The allocation happens with GFP_KERNEL after a transaction has been started, this can potentially cause deadlock if reclaim tries to get the memory by flushing filesystem data. The qgroup_ulist is not used during transaction start as the quotas are not yet enabled but to provide the same semantics, use a temporary variable and assign fs_info::qgroup_ulist as before. Signed-off-by: David Sterba --- fs/btrfs/qgroup.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index c1cd5558a646..9e49d5e132b8 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -887,6 +887,7 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info) struct btrfs_key found_key; struct btrfs_qgroup *qgroup = NULL; struct btrfs_trans_handle *trans = NULL; + struct ulist *tmp_ulist; int ret = 0; int slot; @@ -894,6 +895,12 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info) if (fs_info->quota_root) goto out; + tmp_ulist = ulist_alloc(GFP_KERNEL); + if (!tmp_ulist) { + ret = -ENOMEM; + goto out; + } + /* * 1 for quota root item * 1 for BTRFS_QGROUP_STATUS item @@ -909,12 +916,7 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info) goto out; } - fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL); - if (!fs_info->qgroup_ulist) { - ret = -ENOMEM; - btrfs_abort_transaction(trans, ret); - goto out; - } + fs_info->qgroup_ulist = tmp_ulist; /* * initially create the quota tree -- 2.20.1