From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex chen Date: Tue, 31 Oct 2017 20:41:39 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2/cluster: unlock the o2hb_live_lock before the o2nm_depend_item() Message-ID: <59F86F83.7010501@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com In the following situation, the down_write() will be called under the spin_lock(), which may lead a soft lockup: o2hb_region_inc_user spin_lock(&o2hb_live_lock) o2hb_region_pin o2nm_depend_item configfs_depend_item inode_lock down_write -->here may sleep and reschedule So we should unlock the o2hb_live_lock before the o2nm_depend_item(), and get item reference in advance to prevent the region to be released. Signed-off-by: Alex Chen Reviewed-by: Yiwen Jiang Reviewed-by: Jun Piao --- fs/ocfs2/cluster/heartbeat.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index d020604..f1142a9 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -2399,6 +2399,9 @@ static int o2hb_region_pin(const char *region_uuid) if (reg->hr_item_pinned || reg->hr_item_dropped) goto skip_pin; + config_item_get(®->hr_item); + spin_unlock(&o2hb_live_lock); + /* Ignore ENOENT only for local hb (userdlm domain) */ ret = o2nm_depend_item(®->hr_item); if (!ret) { @@ -2410,9 +2413,14 @@ static int o2hb_region_pin(const char *region_uuid) else { mlog(ML_ERROR, "Pin region %s fails with %d\n", uuid, ret); + config_item_put(®->hr_item); + spin_lock(&o2hb_live_lock); break; } } + + config_item_put(®->hr_item); + spin_lock(&o2hb_live_lock); skip_pin: if (found) break; -- 1.9.5.msysgit.1