Re: [PATCH v3] zram: do not forget to endio for partial discard requests

Sergey Senozhatsky
2026-04-01T01:10:20Z

On (26/03/31 17:49), Andrew Morton wrote:
> On Tue, 31 Mar 2026 16:42:44 +0900 Sergey Senozhatsky <senozhatsky@chromium.org> wrote:
>
> > As reported by Qu Wenruo, the following
> >
> > getconf PAGESIZE
> > 65536
> > blkdiscard -p 4k /dev/zram0
> >
> > takes literally forever to complete.
>
> I'm wondering how you measured this interval ;)

:)

> > zram doesn't support
> > partial discards and just returns immediately w/o doing any
> > discard work in such cases. The problem is that we forget
> > to endio on our way out, so blkdiscard sleeps forever in
> > submit_bio_wait(). Fix this by jumping to end_bio label,
> > which does bio_endio().
> >
> > Fixes: 0120dd6e4e202 ("zram: make zram_bio_discard more self-contained")
> > Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> > Reported-by: Qu Wenruo <wqu@suse.com>
> > Closes: https://lore.kernel.org/linux-block/92361cd3-fb8b-482e-bc89-15ff1acb9a59@suse.com
> > Test-by: Qu Wenruo <wqu@suse.com>
> > Cc: Avinesh Kumar <avinesh.kumar@suse.com>
> > Cc: Christoph Hellwig <hch@lst.de>
>
> Thanks. I made several changes to the changelog from the earlier
> discussion (Anivesh Reported-by:/Closes:) and added a cc:stable.

Thank you, sir!

>
> 0120dd6e4e202 was a few years ago so no need to rush this into mainline
> - target this to the upcoming merge window.

Sounds good to me.