[Ocfs2-devel] [PATCH 1/1] o2dlm: force free mles during dlm exit

[Sunil Mushran <sunil.mushran@oracle.com>]

I hope this has been tested.

Acked-by: Sunil Mushran <sunil.mushran@oracle.com>

On 09/21/2010 04:27 PM, Srinivas Eeda wrote:
> While umounting, a block mle doesn't get freed if dlm is shutdown after
> master request is received but before assert master. This results in unclean
> shutdown of dlm domain.
>
> This patch frees all mles that lie around after other nodes were notified about
> exiting the dlm and marking dlm state as leaving. Only block mles are expected
> to be around, so we log ERROR for other mles but still free them.
>
> Signed-off-by: Srinivas Eeda<srinivas.eeda@oracle.com>
> ---
>   fs/ocfs2/dlm/dlmcommon.h |    1 +
>   fs/ocfs2/dlm/dlmdomain.c |    1 +
>   fs/ocfs2/dlm/dlmmaster.c |   40 ++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 42 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
> index 4b6ae2c..7652989 100644
> --- a/fs/ocfs2/dlm/dlmcommon.h
> +++ b/fs/ocfs2/dlm/dlmcommon.h
> @@ -1030,6 +1030,7 @@ int dlm_drop_lockres_ref(struct dlm_ctxt *dlm,
>   			 struct dlm_lock_resource *res);
>   void dlm_clean_master_list(struct dlm_ctxt *dlm,
>   			   u8 dead_node);
> +void dlm_force_free_mles(struct dlm_ctxt *dlm);
>   int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock);
>   int __dlm_lockres_has_locks(struct dlm_lock_resource *res);
>   int __dlm_lockres_unused(struct dlm_lock_resource *res);
> diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
> index 153abb5..11a5c87 100644
> --- a/fs/ocfs2/dlm/dlmdomain.c
> +++ b/fs/ocfs2/dlm/dlmdomain.c
> @@ -693,6 +693,7 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm)
>
>   		dlm_mark_domain_leaving(dlm);
>   		dlm_leave_domain(dlm);
> +		dlm_force_free_mles(dlm);
>   		dlm_complete_dlm_shutdown(dlm);
>   	}
>   	dlm_put(dlm);
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index ffb4c68..f564b0e 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -3433,3 +3433,43 @@ void dlm_lockres_release_ast(struct dlm_ctxt *dlm,
>   	wake_up(&res->wq);
>   	wake_up(&dlm->migration_wq);
>   }
> +
> +void dlm_force_free_mles(struct dlm_ctxt *dlm)
> +{
> +	int i;
> +	struct hlist_head *bucket;
> +	struct dlm_master_list_entry *mle;
> +	struct hlist_node *tmp, *list;
> +
> +	/*
> +	 * We notified all other nodes that we are exiting the domain and
> +	 * marked the dlm state to DLM_CTXT_LEAVING. If any mles are still
> +	 * around we force free them and wake any processes that are waiting
> +	 * on the mles
> +	 */
> +	spin_lock(&dlm->spinlock);
> +	spin_lock(&dlm->master_lock);
> +
> +	BUG_ON(dlm->dlm_state != DLM_CTXT_LEAVING);
> +	BUG_ON((find_next_bit(dlm->domain_map, O2NM_MAX_NODES, 0)<  O2NM_MAX_NODES));
> +
> +	for (i = 0; i<  DLM_HASH_BUCKETS; i++) {
> +		bucket = dlm_master_hash(dlm, i);
> +		hlist_for_each_safe(list, tmp, bucket) {
> +			mle = hlist_entry(list, struct dlm_master_list_entry,
> +					  master_hash_node);
> +			if (mle->type != DLM_MLE_BLOCK) {
> +				mlog(ML_ERROR, "bad mle: %p\n", mle);
> +				dlm_print_one_mle(mle);
> +			}
> +			atomic_set(&mle->woken, 1);
> +			wake_up(&mle->wq);
> +
> +			__dlm_unlink_mle(dlm, mle);
> +			__dlm_mle_detach_hb_events(dlm, mle);
> +			__dlm_put_mle(mle);
> +		}
> +	}
> +	spin_unlock(&dlm->master_lock);
> +	spin_unlock(&dlm->spinlock);
> +}
>