Re: [PATCH STABLE 5.10 5.11] swap: fix swapfile page to sector mapping

[Greg Kroah-Hartman]

On Thu, Mar 04, 2021 at 05:30:00PM +0100, Anthony Iliopoulos wrote:
> On Thu, Mar 04, 2021 at 04:16:26PM +0100, Greg Kroah-Hartman wrote:
> > On Thu, Mar 04, 2021 at 04:08:24PM +0100, Anthony Iliopoulos wrote:
> > > commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream.
> > 
> > No, this does not look like that commit.
> > 
> > Why can I not just take caf6912f3f4a ("swap: fix swapfile read/write
> > offset") directly for 5.10 and 5.11?  WHat has changed to prevent that?
> 
> You're right of course, the upstream fix applies even on v5.4 so you
> could just take it directly for those branches if this is preferable.

But, that commit says it fixes 48d15436fde6 ("mm: remove get_swap_bio"),
which is NOT what you are saying here in these patches.

So which is it?  Is there a problem in 5.11 and older kernels
(48d15436fde6 ("mm: remove get_swap_bio") showed up in 5.12-rc1), that
requires this fix, or is there nothing needed to be backported?

As a note, I've been running swapfiles on 5.11 and earlier just fine for
a very long time now, so is this really an issue?

confused,

greg k-h