ceph: flush msgr_wq during mds_client shutdown
The release method for mds connections uses a backpointer to the
mds_client, so we need to flush the workqueue of any pending work (and
ceph_connection references) prior to freeing the mds_client. This fixes
an oops easily triggered under UML by
while true ; do mount ... ; umount ... ; done
Also fix an outdated comment: the flush in ceph_destroy_client only flushes
OSD connections out. This bug is basically an artifact of the ceph ->
ceph+libceph conversion.
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index a1ee8fa..f60b07b 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3215,9 +3215,15 @@
{
struct ceph_mds_client *mdsc = fsc->mdsc;
+ dout("mdsc_destroy %p\n", mdsc);
ceph_mdsc_stop(mdsc);
+
+ /* flush out any connection work with references to us */
+ ceph_msgr_flush();
+
fsc->mdsc = NULL;
kfree(mdsc);
+ dout("mdsc_destroy %p done\n", mdsc);
}
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 95f96ab..9bbb356 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -394,8 +394,8 @@
ceph_osdc_stop(&client->osdc);
/*
- * make sure mds and osd connections close out before destroying
- * the auth module, which is needed to free those connections'
+ * make sure osd connections close out before destroying the
+ * auth module, which is needed to free those connections'
* ceph_authorizers.
*/
ceph_msgr_flush();