From: Sergio Lopez <slp@redhat.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
Sergio Lopez <slp@redhat.com>,
qemu-block@nongnu.org, Max Reitz <mreitz@redhat.com>,
Nir Soffer <nsoffer@redhat.com>
Subject: [PATCH 0/2] nbd/server: Quiesce server on drained section
Date: Tue, 1 Jun 2021 07:57:26 +0200 [thread overview]
Message-ID: <20210601055728.90849-1-slp@redhat.com> (raw)
Before switching between AioContexts we need to make sure that we're
fully quiesced ("nb_requests == 0" for every client) when entering the
drained section. Otherwise, coroutines may be run in the wrong context
after the switch, leading to a number of critical issues.
To accomplish this, we add ".drained_poll" to BlockDevOps and use it
in the NBD server, along with ".drained_being" and "drained_end", to
coordinate the quiescing of the server while entering a drained
section.
Sergio Lopez (2):
block-backend: add drained_poll
nbd/server: Use drained block ops to quiesce the server
block/block-backend.c | 7 ++-
include/sysemu/block-backend.h | 4 ++
nbd/server.c | 99 +++++++++++++++++++++++++---------
3 files changed, 85 insertions(+), 25 deletions(-)
--
2.26.2
next reply other threads:[~2021-06-01 5:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 5:57 Sergio Lopez [this message]
2021-06-01 5:57 ` [PATCH 1/2] block-backend: add drained_poll Sergio Lopez
2021-06-01 15:59 ` Kevin Wolf
2021-06-01 16:32 ` Sergio Lopez
2021-06-01 21:24 ` Eric Blake
2021-06-01 5:57 ` [PATCH 2/2] nbd/server: Use drained block ops to quiesce the server Sergio Lopez
2021-06-01 16:08 ` Kevin Wolf
2021-06-01 16:31 ` Sergio Lopez
2021-06-01 21:31 ` Eric Blake
2021-06-01 21:29 ` Eric Blake
2021-06-02 5:52 ` Sergio Lopez
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