From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 11C386B027F for ; Tue, 7 Aug 2018 11:39:16 -0400 (EDT) Received: by mail-qk0-f200.google.com with SMTP id v65-v6so16806855qka.23 for ; Tue, 07 Aug 2018 08:39:16 -0700 (PDT) Received: from EUR04-VI1-obe.outbound.protection.outlook.com (mail-eopbgr80137.outbound.protection.outlook.com. [40.107.8.137]) by mx.google.com with ESMTPS id a125-v6si1575984qkb.47.2018.08.07.08.39.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 07 Aug 2018 08:39:15 -0700 (PDT) Subject: [PATCH RFC 08/10] xfs: Introduce xfs_fs_destroy_super() From: Kirill Tkhai Date: Tue, 07 Aug 2018 18:39:05 +0300 Message-ID: <153365634503.19074.14972123229522734895.stgit@localhost.localdomain> In-Reply-To: <153365347929.19074.12509495712735843805.stgit@localhost.localdomain> References: <153365347929.19074.12509495712735843805.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, gregkh@linuxfoundation.org, rafael@kernel.org, viro@zeniv.linux.org.uk, darrick.wong@oracle.com, paulmck@linux.vnet.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, hughd@google.com, shuah@kernel.org, robh@kernel.org, ulf.hansson@linaro.org, aspriel@gmail.com, vivek.gautam@codeaurora.org, robin.murphy@arm.com, joe@perches.com, heikki.krogerus@linux.intel.com, ktkhai@virtuozzo.com, sfr@canb.auug.org.au, vdavydov.dev@gmail.com, mhocko@suse.com, chris@chris-wilson.co.uk, penguin-kernel@I-love.SAKURA.ne.jp, aryabinin@virtuozzo.com, willy@infradead.org, ying.huang@intel.com, shakeelb@google.com, jbacik@fb.com, mingo@kernel.org, mhiramat@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org xfs_fs_nr_cached_objects() touches sb->s_fs_info, and this patch makes it to be destructed later. After this patch xfs_fs_nr_cached_objects() is safe for splitting unregister_shrinker(): mp->m_perag_tree is stable till destroy_super_work(), while iteration over it is already RCU-protected by internal XFS business. Signed-off-by: Kirill Tkhai --- fs/xfs/xfs_super.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 9e2ce4cd98e1..c1e00dd06893 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1774,11 +1774,20 @@ xfs_fs_put_super( xfs_destroy_mount_workqueues(mp); xfs_close_devices(mp); - sb->s_fs_info = NULL; xfs_free_fsname(mp); - kfree(mp); } +STATIC void +xfs_fs_destroy_super( + struct super_block *sb) +{ + if (sb->s_fs_info) { + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; + } +} + + STATIC struct dentry * xfs_fs_mount( struct file_system_type *fs_type, @@ -1816,6 +1825,7 @@ static const struct super_operations xfs_super_operations = { .dirty_inode = xfs_fs_dirty_inode, .drop_inode = xfs_fs_drop_inode, .put_super = xfs_fs_put_super, + .destroy_super = xfs_fs_destroy_super, .sync_fs = xfs_fs_sync_fs, .freeze_fs = xfs_fs_freeze, .unfreeze_fs = xfs_fs_unfreeze,