multiple MDT threads blocked by one declare_create call due OST fail.
rwsem_down_write_failed
call_rwsem_down_write_failed
lod_qos_prep_create
lod_declare_striped_object
lod_declare_object_create
mdd_declare_object_create_internal
mdd_declare_create
mdd_create
mdo_create
mdt_reint_open
mdt_reint_rec
mdt_reint_internal
mdt_intent_reint
mdt_intent_policy
ldlm_lock_enqueue
ldlm_handle_enqueue0
tgt_enqueue
tgt_request_handle
ptlrpc_main
kthread
vs
osp_precreate_reserve
osp_declare_object_create
lod_qos_declare_object_on
lod_alloc_rr.clone.2
lod_qos_prep_create
lod_declare_striped_object
lod_declare_object_create
mdd_declare_object_create_internal
mdd_declare_create
mdd_create
mdo_create
mdt_reint_open
mdt_reint_rec
mdt_reint_internal
mdt_intent_reint
mdt_intent_policy
ldlm_lock_enqueue
ldlm_handle_enqueue0
tgt_enqueue
tgt_request_handle
ptlrpc_main
kthread
kernel_thread