Memory leak on UBI volume truncating

[Marek Skuczynski]

Hello Artem,
> On Sun, Jan 17, 2010 at 11:43 AM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
>> On Sun, 2010-01-17 at 12:37 +0200, Artem Bityutskiy wrote:
>>> Hi,
>>>
>>> On Wed, 2010-01-13 at 15:28 +0100, Marek Skuczynski wrote:
>>> > Hello,
>>> >   I have prepare a simple volume update stress test (see test code below).
>>> >   This test has been run for kernel 2.6.23 with some updates from 2.6.28,
>>> >   and always after a few minutes the OOM killer was launched.
>>> >
>>> >   What i found it that each an UBI volume truncate operation with
>>> > ubiupdatevol tool
>>> >   causes memory leak. I think this happens because:
>>> >
>>> >   - ubi_start_update()  param "bytes" is equal 0
>>> >
>>> >   - vol->updating flag is re-set to 0
>>> >
>>> >   - vol->upd_buf is allocated regardless of vol->updating flag,
>>> >      but not released on device close by vol_cdev_release()
>>> >
>>> >   I never run the test on a newer kernel version, so I cannot confirm
>>> > that this problem still exists.
>>> >
>>> >   Please confirm, whether my findings are correct or not, thanks.
>>>
>>> thanks for this finding. Looks like your analysis is right. Does this
>>> simple patch help?
>>
>> Actually this even simpler patch should fix the issue. Could you please
>> test it and let me know if it helps.
>>
>> diff --git a/drivers/mtd/ubi/upd.c b/drivers/mtd/ubi/upd.c
>> index c1d7b88..425bf5a 100644
>> --- a/drivers/mtd/ubi/upd.c
>> +++ b/drivers/mtd/ubi/upd.c
>> @@ -155,6 +155,7 @@ int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
>>                if (err)
>>                        return err;
>>                vol->updating = 0;
>> +               return 0;
>>        }
>>
>>        vol->upd_buf = vmalloc(ubi->leb_size);
>>
>> --

Thanks for you reply. It seems the fix solve the issue.

Regards,
 Marek