From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejun Heo , Al Viro , Steven Whitehouse Subject: [PATCH 3.4 35/43] GFS2: dont hold s_umount over blkdev_put Date: Mon, 6 Jan 2014 14:39:52 -0800 Message-Id: <20140106223943.254898539@linuxfoundation.org> In-Reply-To: <20140106223942.259651490@linuxfoundation.org> References: <20140106223942.259651490@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Whitehouse commit dfe5b9ad83a63180f358b27d1018649a27b394a9 upstream. This is a GFS2 version of Tejun's patch: 4f331f01b9c43bf001d3ffee578a97a1e0633eac vfs: don't hold s_umount over close_bdev_exclusive() call In this case its blkdev_put itself that is the issue and this patch uses the same solution of dropping and retaking s_umount. Reported-by: Tejun Heo Reported-by: Al Viro Signed-off-by: Steven Whitehouse Signed-off-by: Greg Kroah-Hartman --- fs/gfs2/ops_fstype.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -1298,8 +1298,18 @@ static struct dentry *gfs2_mount(struct if (IS_ERR(s)) goto error_bdev; - if (s->s_root) + if (s->s_root) { + /* + * s_umount nests inside bd_mutex during + * __invalidate_device(). blkdev_put() acquires + * bd_mutex and can't be called under s_umount. Drop + * s_umount temporarily. This is safe as we're + * holding an active reference. + */ + up_write(&s->s_umount); blkdev_put(bdev, mode); + down_write(&s->s_umount); + } memset(&args, 0, sizeof(args)); args.ar_quota = GFS2_QUOTA_DEFAULT;