From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp2120.oracle.com ([141.146.126.78]:46716 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753725AbeFUSbN (ORCPT ); Thu, 21 Jun 2018 14:31:13 -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 w5LITGnD013647 for ; Thu, 21 Jun 2018 18:31:12 GMT Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp2120.oracle.com with ESMTP id 2jmtgx35hw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 21 Jun 2018 18:31:12 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w5LIVBCj015627 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 21 Jun 2018 18:31:11 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w5LIVBbA030951 for ; Thu, 21 Jun 2018 18:31:11 GMT Subject: [PATCH 1/8] xfs: allow empty transactions while frozen From: "Darrick J. Wong" Date: Thu, 21 Jun 2018 11:31:10 -0700 Message-ID: <152960587035.26246.9220199251468325711.stgit@magnolia> In-Reply-To: <152960586416.26246.8634761888260524091.stgit@magnolia> References: <152960586416.26246.8634761888260524091.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org From: Darrick J. Wong In commit e89c041338ed6ef ("xfs: implement the GETFSMAP ioctl") we created the ability to obtain empty transactions. These transactions have no log or block reservations and therefore can't modify anything. Since they're also NO_WRITECOUNT they can run while the fs is frozen, so we don't need to WARN_ON about that usage. Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_trans.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index e040af120b69..524f543c5b82 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -258,7 +258,12 @@ xfs_trans_alloc( if (!(flags & XFS_TRANS_NO_WRITECOUNT)) sb_start_intwrite(mp->m_super); - WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE); + /* + * Zero-reservation ("empty") transactions can't modify anything, so + * they're allowed to run while we're frozen. + */ + WARN_ON(resp->tr_logres > 0 && + mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE); atomic_inc(&mp->m_active_trans); tp = kmem_zone_zalloc(xfs_trans_zone,