Re: fuse: kernel BUG at mm/truncate.c:763!

Luis Henriques
2021-05-03T08:50:40Z

Matthew Wilcox <willy@infradead.org> writes:

> On Mon, Mar 29, 2021 at 10:01:58AM +0100, Luis Henriques wrote:
>> On Fri, Mar 19, 2021 at 09:02:33AM +0000, Luis Henriques wrote:
>> > On Thu, Mar 18, 2021 at 11:55:43AM +0000, Matthew Wilcox wrote:
>> > > On Thu, Mar 18, 2021 at 11:29:28AM +0000, Luis Henriques wrote:
>> > > > On Thu, Mar 18, 2021 at 02:03:02PM +0300, Kirill A. Shutemov wrote:
>> > > > > On Thu, Mar 18, 2021 at 11:59:59AM +0100, Miklos Szeredi wrote:
>> > > > > > > [16247.536348] page:00000000dfe36ab1 refcount:673 mapcount:0 mapping:00000000f982a7f8 index:0x1400 pfn:0x4c65e00
>> > > > > > > [16247.536359] head:00000000dfe36ab1 order:9 compound_mapcount:0 compound_pincount:0
>> > > > > >
>> > > > > > This is a compound page alright. Have no idea how it got into fuse's
>> > > > > > pagecache.
>> > > > >
>> > > > >
>> > > > > Luis, do you have CONFIG_READ_ONLY_THP_FOR_FS enabled?
>> > > >
>> > > > Yes, it looks like Tumbleweed kernels have that config option enabled by
>> > > > default. And it this feature was introduced in 5.4 (the bug doesn't seem
>> > > > to be reproducible in 5.3).
>> > >
>> > > Can you try adding this patch?
>> > >
>> > > https://git.infradead.org/users/willy/pagecache.git/commitdiff/369a4fcd78369b7a026bdef465af9669bde98ef4
>> >
>> > Good news, looks like this patch fixes the issue[1]. Thanks a lot
>> > everyone. Is this already queued somewhere for 5.12? Also, it would be
>> > nice to have it Cc'ed for stable kernels >= 5.4.
>>
>> Ping. Are you planning to push this for 5.12, or is that queued for the
>> 5.13 merged window? Or "none of the above"? :)
>
> Sorry, dropped the ball on this one. This patch is good for that point
> in the patch series, but I'm not sure it works against upstream in all
> cases. I need to spend some time evaluating it. Thanks for the reminder.

Gentle ping :-)

Any chances of getting this into 5.13? (And tagged for stable kernels.)

Cheers,
--
Luis