Commit bef5502d authored by xuejiufei's avatar xuejiufei Committed by Linus Torvalds

ocfs2/dlm: ignore cleaning the migration mle that is inuse

We have found that migration source will trigger a BUG that the refcount
of mle is already zero before put when the target is down during
migration.  The situation is as follows:

dlm_migrate_lockres
  dlm_add_migration_mle
  dlm_mark_lockres_migrating
  dlm_get_mle_inuse
  <<<<<< Now the refcount of the mle is 2.
  dlm_send_one_lockres and wait for the target to become the
  new master.
  <<<<<< o2hb detect the target down and clean the migration
  mle. Now the refcount is 1.

dlm_migrate_lockres woken, and put the mle twice when found the target
goes down which trigger the BUG with the following message:

  "ERROR: bad mle: ".
Signed-off-by: 's avatarJiufei Xue <xuejiufei@huawei.com>
Reviewed-by: 's avatarJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1cce4df0
......@@ -2519,6 +2519,11 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
spin_lock(&dlm->master_lock);
ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
namelen, target, dlm->node_num);
/* get an extra reference on the mle.
* otherwise the assert_master from the new
* master will destroy this.
*/
dlm_get_mle_inuse(mle);
spin_unlock(&dlm->master_lock);
spin_unlock(&dlm->spinlock);
......@@ -2554,6 +2559,7 @@ fail:
if (mle_added) {
dlm_mle_detach_hb_events(dlm, mle);
dlm_put_mle(mle);
dlm_put_mle_inuse(mle);
} else if (mle) {
kmem_cache_free(dlm_mle_cache, mle);
mle = NULL;
......@@ -2571,17 +2577,6 @@ fail:
* ensure that all assert_master work is flushed. */
flush_workqueue(dlm->dlm_worker);
/* get an extra reference on the mle.
* otherwise the assert_master from the new
* master will destroy this.
* also, make sure that all callers of dlm_get_mle
* take both dlm->spinlock and dlm->master_lock */
spin_lock(&dlm->spinlock);
spin_lock(&dlm->master_lock);
dlm_get_mle_inuse(mle);
spin_unlock(&dlm->master_lock);
spin_unlock(&dlm->spinlock);
/* notify new node and send all lock state */
/* call send_one_lockres with migration flag.
* this serves as notice to the target node that a
......@@ -3312,6 +3307,15 @@ top:
mle->new_master != dead_node)
continue;
if (mle->new_master == dead_node && mle->inuse) {
mlog(ML_NOTICE, "%s: target %u died during "
"migration from %u, the MLE is "
"still keep used, ignore it!\n",
dlm->name, dead_node,
mle->master);
continue;
}
/* If we have reached this point, this mle needs to be
* removed from the list and freed. */
dlm_clean_migration_mle(dlm, mle);
......
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