[Ocfs2-devel] [PATCH 1/1]ocfs2: add spinlock protection when dealing with lockres->purge.

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

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

Wengang Wang wrote:
> when we check/modify lockres->purge, we should with the protection of lockres->spinlock.
> in dlm_purge_lockres(), the checking/modifying is not with the protectin.
> this patch fixes it.
>
> Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
> ---
>  fs/ocfs2/dlm/dlmthread.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
> index d490b66..98569e8 100644
> --- a/fs/ocfs2/dlm/dlmthread.c
> +++ b/fs/ocfs2/dlm/dlmthread.c
> @@ -212,14 +212,18 @@ static int dlm_purge_lockres(struct dlm_ctxt *dlm,
>  		spin_lock(&dlm->spinlock);
>  	}
>  
> +	spin_lock(&res->spinlock);
>  	if (!list_empty(&res->purge)) {
>  		mlog(0, "removing lockres %.*s:%p from purgelist, "
>  		     "master = %d\n", res->lockname.len, res->lockname.name,
>  		     res, master);
>  		list_del_init(&res->purge);
> +		spin_unlock(&res->spinlock);
>  		dlm_lockres_put(res);
>  		dlm->purge_count--;
> -	}
> +	} else
> +		spin_unlock(&res->spinlock);
> +
>  	__dlm_unhash_lockres(res);
>  
>  	/* lockres is not in the hash now.  drop the flag and wake up
>