[Ocfs2-devel] [PATCH] ocfs2: delay migration when the lockres is in migration state

[Joel Becker]

On Tue, Aug 14, 2012 at 10:06:37AM +0800, Xue jiufei wrote:
>   We trigger a bug in __dlm_lockres_reserve_ast() when we parallel umount 4 nodes. The situation is as follows:
>   1) Node A migrate all lockres it owned(eg. lockres A) to other nodes say node B when it umounts.  
>   2) Receiving MIG_LOCKRES message from A, Node B masters the lockres A with DLM_LOCK_RES_MIGRATING state set. 
>   3) Then we umount ocfs2 on node B. It also should migrate lockres A to another node, say node C. But now, DLM_LOCK_RES_MIGRATING state 
> of lockers A is not cleared. Node B triggered the BUG on lockres with state DLM_LOCK_RES_MIGRATING.
> 
> Signed-off-by: Xuejiufei <xuejiufei at huawei.com>

This patch is now part of the fixes branch of ocfs2.git.

Joel

> ---
>  fs/ocfs2/dlm/dlmmaster.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index 005261c..6c35406 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -2357,6 +2357,10 @@ static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,
>  
>  	assert_spin_locked(&res->spinlock);
>  
> +	/* delay migration when the lockres is in MIGRATING state */
> +	if (res->state & DLM_LOCK_RES_MIGRATING)
> +		return 0;
> +
>  	if (res->owner != dlm->node_num)
>  		return 0;
>  
> -- 1.7.9.7 

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