[Ocfs2-devel] [PATCH] ocfs2: free the mle while the res had one, to avoid mle memory leak.

[Ocfs2-devel] [PATCH] ocfs2: free the mle while the res had one, to avoid mle memory leak.

[Guozhonghua]

In the function dlm_migrate_request_handler, while the ret is --EEXIST, the mle should be freed, otherwise the memory will be leaked.

Signed-off-by: Guozhonghua <guozhonghua@h3c.com>

--- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
+++ ocfs2/dlm/dlmmaster.c       2016-09-13 15:27:05.014675736 +0800
@@ -3188,6 +3188,9 @@ int dlm_migrate_request_handler(struct o
                                    migrate->new_master,
                                    migrate->master);

+       if (ret < 0)
+               kmem_cache_free(dlm_mle_cache, mle);
+
        spin_unlock(&dlm->master_lock);
 unlock:
        spin_unlock(&dlm->spinlock);


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[Ocfs2-devel] [PATCH] ocfs2: free the mle while the res had one, to avoid mle memory leak.

[Eric Ren]

Hi,
On 09/13/2016 03:52 PM, Guozhonghua wrote:
> In the function dlm_migrate_request_handler, while the ret is --EEXIST, the mle should be freed, otherwise the memory will be leaked.
Keep your commit comments within 75 or 78 (I don't remember clearly but git will warn
if you don't keep its rule) characters per line.
>
> Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
>
> --- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
Please use `git format-patch` to create patch. FYI:
http://wiki.openhatch.org/How_to_generate_patches_with_git_format-patch

Sorry, I don't familiar with ocfs2/dlm code, so cannot review this patch.

Eric
> +++ ocfs2/dlm/dlmmaster.c       2016-09-13 15:27:05.014675736 +0800
> @@ -3188,6 +3188,9 @@ int dlm_migrate_request_handler(struct o
>                                      migrate->new_master,
>                                      migrate->master);
>
> +       if (ret < 0)
> +               kmem_cache_free(dlm_mle_cache, mle);
> +
>          spin_unlock(&dlm->master_lock);
>   unlock:
>          spin_unlock(&dlm->spinlock);
>
>
> -------------------------------------------------------------------------------------------------------------------------------------
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> ???
> This e-mail and its attachments contain confidential information from H3C, which is
> intended only for the person or entity whose address is listed above. Any use of the
> information contained herein in any way (including, but not limited to, total or partial
> disclosure, reproduction, or dissemination) by persons other than the intended
> recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender
> by phone or email immediately and delete it!
> _______________________________________________
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> Ocfs2-devel at oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel

[Ocfs2-devel] [PATCH] ocfs2: free the mle while the res had one, to avoid mle memory leak.

[Andrew Morton]

On Tue, 13 Sep 2016 07:52:30 +0000 Guozhonghua <guozhonghua@h3c.com> wrote:

> In the function dlm_migrate_request_handler, while the ret is --EEXIST, the mle should be freed, otherwise the memory will be leaked.
> 
> Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
> 
> --- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
> +++ ocfs2/dlm/dlmmaster.c       2016-09-13 15:27:05.014675736 +0800
> @@ -3188,6 +3188,9 @@ int dlm_migrate_request_handler(struct o
>                                     migrate->new_master,
>                                     migrate->master);
> 
> +       if (ret < 0)
> +               kmem_cache_free(dlm_mle_cache, mle);
> +
>         spin_unlock(&dlm->master_lock);
>  unlock:
>         spin_unlock(&dlm->spinlock);

Looks OK to me.

I wonder if there's another bug here.  If dlm_add_migration_mle()
failed, is it correct to go ahead and detach `oldmle'?

[Ocfs2-devel] [PATCH] ocfs2: free the mle while the res had one, to avoid mle memory leak.

[Joseph Qi]

Hi Andrew,
-EEXIST can only happen in case of "I am the master". So
dlm_migrate_request_handler won't get this return value.
I think commit 32e493265b2b ("ocfs2/dlm: do not insert a new mle when
another process is already migrating") has already considered the
case.
So NAK.

Thanks,
Joseph

On 2016/9/14 5:20, Andrew Morton wrote:
> On Tue, 13 Sep 2016 07:52:30 +0000 Guozhonghua <guozhonghua@h3c.com> wrote:
> 
>> In the function dlm_migrate_request_handler, while the ret is --EEXIST, the mle should be freed, otherwise the memory will be leaked.
>>
>> Signed-off-by: Guozhonghua <guozhonghua@h3c.com>
>>
>> --- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
>> +++ ocfs2/dlm/dlmmaster.c       2016-09-13 15:27:05.014675736 +0800
>> @@ -3188,6 +3188,9 @@ int dlm_migrate_request_handler(struct o
>>                                     migrate->new_master,
>>                                     migrate->master);
>>
>> +       if (ret < 0)
>> +               kmem_cache_free(dlm_mle_cache, mle);
>> +
>>         spin_unlock(&dlm->master_lock);
>>  unlock:
>>         spin_unlock(&dlm->spinlock);
> 
> Looks OK to me.
> 
> I wonder if there's another bug here.  If dlm_add_migration_mle()
> failed, is it correct to go ahead and detach `oldmle'?
> 
> 
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>