Ocfs2 devel - Sep 2013 - [PATCH 1/1] ocfs2/dlm: ocfs2 dlm umount skip migrating lockres

umount thread could race with migrate handler thread receiving resource
migration request from other node. When this happens, migrating thread
could set this node as the master along with DLM_LOCK_RES_MIGRATING flag.
umount thread should skip migrating this newly owned lockres until
DLM_LOCK_RES_MIGRATING flag is unset by migrate handler thread. umount
thread will ultimately migrate this lockres during another pass of the
lockres hash list.

Signed-off-by: Tariq Saeed <tariq.x.saeed at oracle.com>
Signed-off-by: Srinivas Eeda <srinivas.eeda at oracle.com> 
---
 fs/ocfs2/dlm/dlmmaster.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 33ecbe0..1643b58 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2360,6 +2360,10 @@ static int dlm_is_lockres_migrateable(struct dlm_ctxt
*dlm,
 	if (res->owner != dlm->node_num)
 		return 0;
 
+	if (res->state & DLM_LOCK_RES_MIGRATING) {
+		return 0;
+	}
+
         for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
 		queue = dlm_list_idx_to_ptr(res, idx);
 		list_for_each_entry(lock, queue, list) {
-- 
1.7.1

On 2013/9/12 2:40, Tariq Saeed wrote:
> umount thread could race with migrate handler thread receiving resource
> migration request from other node. When this happens, migrating thread
> could set this node as the master along with DLM_LOCK_RES_MIGRATING flag.
> umount thread should skip migrating this newly owned lockres until
> DLM_LOCK_RES_MIGRATING flag is unset by migrate handler thread. umount
> thread will ultimately migrate this lockres during another pass of the
> lockres hash list.
> 
> Signed-off-by: Tariq Saeed <tariq.x.saeed at oracle.com>
> Signed-off-by: Srinivas Eeda <srinivas.eeda at oracle.com> 
> ---
>  fs/ocfs2/dlm/dlmmaster.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index 33ecbe0..1643b58 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -2360,6 +2360,10 @@ static int dlm_is_lockres_migrateable(struct
dlm_ctxt *dlm,
>  	if (res->owner != dlm->node_num)
>  		return 0;
>  
> +	if (res->state & DLM_LOCK_RES_MIGRATING) {
> +		return 0;
> +	}
> +
>          for (idx = DLM_GRANTED_LIST; idx <= DLM_BLOCKED_LIST; idx++) {
>  		queue = dlm_list_idx_to_ptr(res, idx);
>  		list_for_each_entry(lock, queue, list) {
> 
This patch was sent before by Jiufei Xue on Aug 2012, which was titled
as "ocfs2: delay migration when the lockres is in migration state".
Please refer the below link for details:
https://oss.oracle.com/pipermail/ocfs2-devel/2012-August/008670.html

As I remembered, the patch was alerady acked by Sunil and Joel, and then
it was in ocfs2.git.
I am not sure why it wasn't merged to mainline.