[PATCH 6.1 075/127] ceph: defer stopping mdsc delayed_work

Greg Kroah-Hartman
2023-08-09T10:56:06Z

From: Xiubo Li <xiubli@redhat.com>

commit e7e607bd00481745550389a29ecabe33e13d67cf upstream.

Flushing the dirty buffer may take a long time if the cluster is
overloaded or if there is network issue. So we should ping the
MDSs periodically to keep alive, else the MDS will blocklist
the kclient.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/61843
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ceph/mds_client.c | 4 ++--
fs/ceph/mds_client.h | 5 +++++
fs/ceph/super.c | 10 ++++++++++
3 files changed, 17 insertions(+), 2 deletions(-)

--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4758,7 +4758,7 @@ static void delayed_work(struct work_str

dout("mdsc delayed_work\n");

- if (mdsc->stopping)
+ if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
return;

mutex_lock(&mdsc->mutex);
@@ -4937,7 +4937,7 @@ void send_flush_mdlog(struct ceph_mds_se
void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
{
dout("pre_umount\n");
- mdsc->stopping = 1;
+ mdsc->stopping = CEPH_MDSC_STOPPING_BEGIN;

ceph_mdsc_iterate_sessions(mdsc, send_flush_mdlog, true);
ceph_mdsc_iterate_sessions(mdsc, lock_unlock_session, false);
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -380,6 +380,11 @@ struct cap_wait {
int want;
};

+enum {
+ CEPH_MDSC_STOPPING_BEGIN = 1,
+ CEPH_MDSC_STOPPING_FLUSHED = 2,
+};
+
/*
* mds client state
*/
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -1374,6 +1374,16 @@ static void ceph_kill_sb(struct super_bl
ceph_mdsc_pre_umount(fsc->mdsc);
flush_fs_workqueues(fsc);

+ /*
+ * Though the kill_anon_super() will finally trigger the
+ * sync_filesystem() anyway, we still need to do it here
+ * and then bump the stage of shutdown to stop the work
+ * queue as earlier as possible.
+ */
+ sync_filesystem(s);
+
+ fsc->mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
+
kill_anon_super(s);

fsc->client->extra_mon_dispatch = NULL;