Date:   Fri, 12 Nov 2021 14:39:13 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Pavel Machek <pavel@ucw.cz>, Zubin Mithra <zsm@chromium.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Omar Sandoval <osandov@fb.com>, Ming Lei <ming.lei@redhat.com>,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 4.19 01/16] block: introduce multi-page bvec helpers
Message-ID: <YY5ugWtHt2e/aQLJ@kroah.com>
References: <20211110182001.994215976@linuxfoundation.org>
 <20211110182002.041203616@linuxfoundation.org>
 <20211111164754.GA29545@duo.ucw.cz>
 <YY1OHxpimjKYgxGR@google.com>
 <20211111185308.GA7933@duo.ucw.cz>
 <20211112054811.GD27605@lst.de>
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On Fri, Nov 12, 2021 at 06:48:11AM +0100, Christoph Hellwig wrote:
> On Thu, Nov 11, 2021 at 07:53:08PM +0100, Pavel Machek wrote:
> > > There is some more context on this at:
> > > https://lore.kernel.org/linux-block/YXweJ00CVsDLCI7b@google.com/T/#u
> > > and
> > > https://lore.kernel.org/stable/YYVZBuDaWBKT3vOS@google.com/T/#u
> > 
> > Thank you!
> 
> Honestly, this looks broken to me.  multipage-bvec was a big invasive
> series with a lot of latter fixups.  While taking this patch on it's
> own should be save by itself, but also useless.  So if it is needed
> to make a KASAN warning go away we need to dig deeper and back something
> else out that should not have been backported to rely on multipage
> bvec becasue without the other patches they don't exist and can't
> acually work.

Ok, let me drop this for now.

Zubin, can you provide a better report as to what driver is causing the
problem and what exactly resolves it?  Has this issue always been in
4.19 since 4.19.0?

thanks,

greg k-h