On 6/17/2010 7:11 PM, Sunil Mushran wrote:
> This patch looks ok on the surface. Should be usable. But checking into
> the repo is another matter.
ok, won't checkin but will give this as one-off fix for now.
>
> My problem is that this flag is very much like inflight_locks but
> is not the same. inflight_locks are taken only on lockres' that are
> mastered by the node. This new flag does the same but for non
> mastered locks too. A better solution will be to merge the two.
> And that means cleaning up inflight_locks.
will look into this.
>
> The reason for the NAK for check in is that the code is adding
> more messiness to an area that is already very messy.
>
> Sunil
>
> On 06/15/2010 09:43 PM, Srinivas Eeda wrote:
>> This patch fixes the following hole.
>> dlmlock tries to create a new lock on a lockres that is on purge
>> list. It calls
>> dlm_get_lockresource and later adds a lock to blocked list. But in
>> this window,
>> dlm_thread can purge the lockres and unhash it. This will cause a
>> BUG, as when
>> the AST comes back from the master lockres is not found
>>
>> This patch marks the lockres with a new state DLM_LOCK_RES_IN_USE
>> which would
>> protect lockres from dlm_thread purging it.
>>
>> 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 | 1 +
>> 4 files changed, 10 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
>> index 0102be3..6cf3c08 100644
>> --- a/fs/ocfs2/dlm/dlmcommon.h
>> +++ b/fs/ocfs2/dlm/dlmcommon.h
>> @@ -279,6 +279,7 @@ static inline void __dlm_set_joining_node(struct
>> dlm_ctxt *dlm,
>> #define DLM_LOCK_RES_DIRTY 0x00000008
>> #define DLM_LOCK_RES_IN_PROGRESS 0x00000010
>> #define DLM_LOCK_RES_MIGRATING 0x00000020
>> +#define DLM_LOCK_RES_IN_USE 0x00000100
>> #define DLM_LOCK_RES_DROPPING_REF 0x00000040
>> #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 fb0be6c..2b82e0b 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 */
>>
>
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