Acked-by: Srinivas Eeda <[email protected]>

Wengang Wang wrote:

> In the following situation, there remains an incorrect bit in refmap on the
> recovery master. Finally the recovery master will fail at purging the lockres
> due to the incorrect bit in refmap.
>
> 1) node A has no interest on lockres A any longer, so it is purging it.
> 2) the owner of lockres A is node B, so node A is sending de-ref message
> to node B.
> 3) at this time, node B crashed. node C becomes the recovery master. it 
> recovers
> lockres A(because the master is the dead node B).
> 4) node A migrated lockres A to node C with a refbit there.
> 5) node A failed to send de-ref message to node B because it crashed. The 
> failure
> is ignored. no other action is done for lockres A any more.
>
> For mormal, re-send the deref message to it to recovery master can fix it. 
> Well,
> ignoring the failure of deref to the original master and not recovering the 
> lockres
> to recovery master has the same effect. And the later is simpler.
>
> Signed-off-by: Wengang Wang <[email protected]>
> ---
>  fs/ocfs2/dlm/dlmrecovery.c |   17 +++++++++++++----
>  fs/ocfs2/dlm/dlmthread.c   |   28 +++++++++++++++++-----------
>  2 files changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
> index 9dfaac7..2b57cc4 100644
> --- a/fs/ocfs2/dlm/dlmrecovery.c
> +++ b/fs/ocfs2/dlm/dlmrecovery.c
> @@ -1997,6 +1997,8 @@ void dlm_move_lockres_to_recovery_list(struct dlm_ctxt 
> *dlm,
>       struct list_head *queue;
>       struct dlm_lock *lock, *next;
>  
> +     assert_spin_locked(&dlm->spinlock);
> +     assert_spin_locked(&res->spinlock);
>       res->state |= DLM_LOCK_RES_RECOVERING;
>       if (!list_empty(&res->recovering)) {
>               mlog(0,
> @@ -2334,11 +2336,18 @@ static void dlm_do_local_recovery_cleanup(struct 
> dlm_ctxt *dlm, u8 dead_node)
>                                            dlm->name, res->lockname.len,
>                                            res->lockname.name, dead_node);
>  
> -                             /* the wake_up for this will happen when the
> -                              * RECOVERING flag is dropped later */
> -                             res->state &= ~DLM_LOCK_RES_DROPPING_REF;
> +                             /*
> +                              * don't migrate a lockres which is in progress
> +                              * of dropping ref
> +                              */
> +                             if (res->state & DLM_LOCK_RES_DROPPING_REF) {
> +                                     mlog(ML_NOTICE, "%.*s ignored for "
> +                                          "migration\n", res->lockname.len,
> +                                          res->lockname.name);
> +                             } else
> +                                     dlm_move_lockres_to_recovery_list(dlm,
> +                                                                       res);
>  
> -                             dlm_move_lockres_to_recovery_list(dlm, res);
>                       } else if (res->owner == dlm->node_num) {
>                               dlm_free_dead_locks(dlm, res, dead_node);
>                               __dlm_lockres_calc_usage(dlm, res);
> diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
> index dd78ca3..47420ce 100644
> --- a/fs/ocfs2/dlm/dlmthread.c
> +++ b/fs/ocfs2/dlm/dlmthread.c
> @@ -92,17 +92,23 @@ int __dlm_lockres_has_locks(struct dlm_lock_resource *res)
>   * truly ready to be freed. */
>  int __dlm_lockres_unused(struct dlm_lock_resource *res)
>  {
> -     if (!__dlm_lockres_has_locks(res) &&
> -         (list_empty(&res->dirty) && !(res->state & DLM_LOCK_RES_DIRTY))) {
> -             /* try not to scan the bitmap unless the first two
> -              * conditions are already true */
> -             int bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
> -             if (bit >= O2NM_MAX_NODES) {
> -                     /* since the bit for dlm->node_num is not
> -                      * set, inflight_locks better be zero */
> -                     BUG_ON(res->inflight_locks != 0);
> -                     return 1;
> -             }
> +     int bit;
> +
> +     if (__dlm_lockres_has_locks(res))
> +             return 0;
> +
> +     if (!list_empty(&res->dirty) || res->state & DLM_LOCK_RES_DIRTY)
> +             return 0;
> +
> +     if (res->state & DLM_LOCK_RES_RECOVERING)
> +             return 0;
> +
> +     bit = find_next_bit(res->refmap, O2NM_MAX_NODES, 0);
> +     if (bit >= O2NM_MAX_NODES) {
> +             /* since the bit for dlm->node_num is not
> +              * set, inflight_locks better be zero */
> +             BUG_ON(res->inflight_locks != 0);
> +             return 1;
>       }
>       return 0;
>  }
>   


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