From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mykola Golub <mgolub@mirantis.com>
Subject: Re: 7915 is not resolved
Date: Tue, 12 Jan 2016 08:53:06 +0200
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To: Boris Lukashev <blukashev@sempervictus.com>
Cc: ceph-devel@vger.kernel.org, Sage Weil <sage@newdream.net>

On Mon, Jan 11, 2016 at 09:00:18PM -0500, Boris Lukashev wrote:
> In case anyone is following the mailing list later on, we spoke in IRC
> and Sage provided a patch - http://fpaste.org/309609/52550203/

> diff --git a/src/osd/PG.cc b/src/osd/PG.cc
> index dc18aec..f9ee23c 100644
> --- a/src/osd/PG.cc
> +++ b/src/osd/PG.cc
> @@ -135,8 +135,16 @@ void PGPool::update(OSDMapRef map)
>    name = map->get_pool_name(id);
>    if (pi->get_snap_epoch() == map->get_epoch()) {
>      pi->build_removed_snaps(newly_removed_snaps);
> -    newly_removed_snaps.subtract(cached_removed_snaps);
> -    cached_removed_snaps.union_of(newly_removed_snaps);
> +    interval_set<snapid_t> intersection;
> +    intersection.intersection_of(newly_removed_snaps, cached_removed_snaps);
> +    if (!(intersection == cached_removed_snaps)) {
> +      newly_removed_snaps.subtract(cached_removed_snaps);

Sage, won't it still violate the assert?
"intersection != cached_removed_snaps" means that cached_removed_snaps
contains snapshots missed in newly_removed_snaps, and we can't subtract?

> +      cached_removed_snaps.union_of(newly_removed_snaps);
> +    } else {
> +      lgeneric_subdout(g_ceph_context, osd, 0) << __func__ << " cached_removed_snaps shrank from " << cached_removed_snaps << dendl;
> +      cached_removed_snaps = newly_removed_snaps;
> +      newly_removed_snaps.clear();
> +    }
>      snapc = pi->get_snap_context();
>    } else {
>      newly_removed_snaps.clear();

-- 
Mykola Golub