Memory leak on UBI volume truncating
Artem Bityutskiy
dedekind1 at gmail.com
Mon Jan 18 05:03:04 EST 2010
On Mon, 2010-01-18 at 09:36 +0100, Marek Skuczynski wrote:
> 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.
Cool. I'll push the fix and also send it to -stable a bit later. Thanks
for catching this.
--
Best Regards,
Artem Bityutskiy (Артём Битюцкий)
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