Please ignore this patch. I'll resend this patch along with dlm purge
lockres for completeness.
On 6/9/2010 7:07 PM, Srinivas Eeda wrote:
> dlm_thread sends a deref message to the master node. At the same time,
> another thread sends a new lock request to the master node.
> Since dlm_thread wouldn't know about it, it would unhash the lockres
> after it gets the response. lock request AST would then won't find
> the lockres and hence BUGs.
>
> The fix is to add new state DLM_LOCK_RES_IN_USE which would prevent
> dlm_thread from purging the lockres and/or unhashing lockres.
>
> Signed-off-by: Srinivas Eeda <srinivas.e...@oracle.com>
> ---
> fs/ocfs2/dlm/dlmcommon.h | 1 +
> fs/ocfs2/dlm/dlmlock.c | 4 ++++
> fs/ocfs2/dlm/dlmmaster.c | 5 ++++-
> fs/ocfs2/dlm/dlmthread.c | 4 +++-
> 4 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
> index 0102be3..0290612 100644
> --- a/fs/ocfs2/dlm/dlmcommon.h
> +++ b/fs/ocfs2/dlm/dlmcommon.h
> @@ -280,6 +280,7 @@ static inline void __dlm_set_joining_node(struct dlm_ctxt
> *dlm,
> #define DLM_LOCK_RES_IN_PROGRESS 0x00000010
> #define DLM_LOCK_RES_MIGRATING 0x00000020
> #define DLM_LOCK_RES_DROPPING_REF 0x00000040
> +#define DLM_LOCK_RES_IN_USE 0x00000100
> #define DLM_LOCK_RES_BLOCK_DIRTY 0x00001000
> #define DLM_LOCK_RES_SETREF_INPROG 0x00002000
>
> diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c
> index 7333377..501ac40 100644
> --- a/fs/ocfs2/dlm/dlmlock.c
> +++ b/fs/ocfs2/dlm/dlmlock.c
> @@ -134,6 +134,8 @@ static enum dlm_status dlmlock_master(struct dlm_ctxt
> *dlm,
> if (status != DLM_NORMAL &&
> lock->ml.node != dlm->node_num) {
> /* erf. state changed after lock was dropped. */
> + /* DLM_LOCK_RES_IN_USE is set in dlm_get_lock_resource */
> + res->state &= ~DLM_LOCK_RES_IN_USE;
> spin_unlock(&res->spinlock);
> dlm_error(status);
> return status;
> @@ -180,6 +182,7 @@ static enum dlm_status dlmlock_master(struct dlm_ctxt
> *dlm,
> kick_thread = 1;
> }
> }
> + res->state &= ~DLM_LOCK_RES_IN_USE;
> /* reduce the inflight count, this may result in the lockres
> * being purged below during calc_usage */
> if (lock->ml.node == dlm->node_num)
> @@ -246,6 +249,7 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt
> *dlm,
>
> spin_lock(&res->spinlock);
> res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
> + res->state &= ~DLM_LOCK_RES_IN_USE;
> lock->lock_pending = 0;
> if (status != DLM_NORMAL) {
> if (status == DLM_RECOVERING &&
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index 9289b43..f0f2d97 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -719,6 +719,7 @@ lookup:
> if (tmpres) {
> int dropping_ref = 0;
>
> + tmpres->state |= DLM_LOCK_RES_IN_USE;
> spin_unlock(&dlm->spinlock);
>
> spin_lock(&tmpres->spinlock);
> @@ -731,8 +732,10 @@ lookup:
> if (tmpres->owner == dlm->node_num) {
> BUG_ON(tmpres->state & DLM_LOCK_RES_DROPPING_REF);
> dlm_lockres_grab_inflight_ref(dlm, tmpres);
> - } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF)
> + } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF) {
> + tmpres->state &= ~DLM_LOCK_RES_IN_USE;
> dropping_ref = 1;
> + }
> spin_unlock(&tmpres->spinlock);
>
> /* wait until done messaging the master, drop our ref to allow
> diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
> index 11a6d1f..b2315cb 100644
> --- a/fs/ocfs2/dlm/dlmthread.c
> +++ b/fs/ocfs2/dlm/dlmthread.c
> @@ -93,6 +93,7 @@ int __dlm_lockres_has_locks(struct dlm_lock_resource *res)
> int __dlm_lockres_unused(struct dlm_lock_resource *res)
> {
> if (!__dlm_lockres_has_locks(res) &&
> + !(res->state & DLM_LOCK_RES_IN_USE) &&
> (list_empty(&res->dirty) && !(res->state & DLM_LOCK_RES_DIRTY))) {
> /* try not to scan the bitmap unless the first two
> * conditions are already true */
> @@ -222,7 +223,8 @@ static int dlm_purge_lockres(struct dlm_ctxt *dlm,
> } else
> spin_unlock(&res->spinlock);
>
> - __dlm_unhash_lockres(res);
> + if (__dlm_lockres_unused(res))
> + __dlm_unhash_lockres(res);
>
> /* lockres is not in the hash now. drop the flag and wake up
> * any processes waiting in dlm_get_lock_resource. */
>
_______________________________________________
Ocfs2-devel mailing list
Ocfs2-devel@oss.oracle.com
http://oss.oracle.com/mailman/listinfo/ocfs2-devel
