Ubi patch proposition for 3.10.y

[Willy Tarreau]

Hi Artem,

On Mon, Sep 08, 2014 at 12:58:38PM +0300, Artem Bityutskiy wrote:
> On Fri, 2014-08-29 at 14:26 +0200, jean-philippe francois wrote:
> > Hi,
> > 
> > I think commit 4b3e0a25... [1] (UBI: Call scan_all() with correct
> > offset in error case) should be added to 3.10.y stable branch.
> 
> This is the "fastmap" fix, and fastmap is called experimental. We do not
> have enough confidence it is production ready. Specifically, I'd like to
> hear someone doing extensive power-cut testing with this feature. The
> power-cut tolerance is one of the "selling features" of UBI/UBIFS, after
> all.
> 
> Therefore I never added fastmap fixes to the stable queue.
> 
> But if someone is willing to put all the fastmap fixes together, add the
> "stable tags" with the right kernel version "markings", and test for few
> older kernels, then I will recommend them to be included to the stable.
> Although I am not sure the stable maintainers would like accept them.
> 
> But I do not recommend adding this single patch to the stable queue.
> 
> But better, if people started paying more attention to "fastmap", we may
> agree that from now on we are careful about the sending the fixes to the
> stable queue.

Personally, I think that whatever feature provided in a kernel release is
subject to being used and deserves its fixes. There are some cases where
we *know* that some features are not used (eg: when they don't work without
a lot of patching or tweaking), but if they seem to work for end users, they
are likely to be used.

Just my two cents,
Willy