From patchwork Fri Apr 20 09:32:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anand Jain X-Patchwork-Id: 10352287 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4129660231 for ; Fri, 20 Apr 2018 09:30:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3250F28627 for ; Fri, 20 Apr 2018 09:30:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 26DAD28662; Fri, 20 Apr 2018 09:30:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8BAD328627 for ; Fri, 20 Apr 2018 09:30:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754290AbeDTJad (ORCPT ); Fri, 20 Apr 2018 05:30:33 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:51492 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754217AbeDTJac (ORCPT ); Fri, 20 Apr 2018 05:30:32 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w3K9Qew4043027 for ; Fri, 20 Apr 2018 09:30:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id; s=corp-2017-10-26; bh=rF6GuirHKaB/8U12B9RwPLsjOop5chA67v6bX+BTtuY=; b=mS0OeGbOaHL57lKesYwMT7HPIXeVftT5BrOyB+xQrWrpuv/hgANDGLCinfE2o6N97Dd3 Ldbfiet4l6nXrQmu4NiOVHoKIp7sZXSLOyYb3hdX6YNr1ketjdCme7wwD6Pi4xrQity+ MM5uc40Pog+z2xyGv4TL94oSCz2LF8+PWmdbudfs4K5/W8uwYZpiXGrkJnPotnJEaxCT +ROgSkTi5krmdqVGa8TjILhXsSjrSlRtrdOYu8NQsEefLey5FLIcDPTobBmr9N5GMD+S sT3ILcJC5sSE2a+rhiNj63h630tLjdHBBDYoPdq/rdnXrrNr+wUAOUWzZmwRBN1XstST WA== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp2120.oracle.com with ESMTP id 2hdrxnksew-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 20 Apr 2018 09:30:31 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w3K9UUJY009943 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 20 Apr 2018 09:30:30 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w3K9UUVR013771 for ; Fri, 20 Apr 2018 09:30:30 GMT Received: from tp.sg.oracle.com (/10.186.49.52) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 20 Apr 2018 09:30:29 +0000 From: Anand Jain To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: fix BUG trying to resume balance without resume flag Date: Fri, 20 Apr 2018 17:32:31 +0800 Message-Id: <20180420093231.17440-1-anand.jain@oracle.com> X-Mailer: git-send-email 2.15.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8868 signatures=668698 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=843 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1804200093 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We set the BTRFS_BALANCE_RESUME flag in the btrfs_recover_balance(), which is not called during the remount. So when resuming from the paused balance we hit BUG. kernel: kernel BUG at fs/btrfs/volumes.c:3890! :: kernel: balance_kthread+0x51/0x60 [btrfs] kernel: kthread+0x111/0x130 :: kernel: RIP: btrfs_balance+0x12e1/0x1570 [btrfs] RSP: ffffba7d0090bde8 Reproducer: On a mounted BTRFS. btrfs balance start --full-balance /btrfs btrfs balance pause /btrfs mount -o remount,ro /dev/sdb /btrfs mount -o remount,rw /dev/sdb /btrfs To fix this set the BTRFS_BALANCE_RESUME flag in btrfs_resume_balance_async() instead of btrfs_recover_balance(). Signed-off-by: Anand Jain --- fs/btrfs/volumes.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 66d2ed96aef1..9c29fdca9075 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -3963,6 +3963,10 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info) return 0; } + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME; + spin_unlock(&fs_info->balance_lock); + tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance"); return PTR_ERR_OR_ZERO(tsk); } @@ -4004,7 +4008,6 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info) bctl->fs_info = fs_info; bctl->flags = btrfs_balance_flags(leaf, item); - bctl->flags |= BTRFS_BALANCE_RESUME; btrfs_balance_data(leaf, item, &disk_bargs); btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);