From: Eric Blake <eblake@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-block@nongnu.org
Cc: kwolf@redhat.com, den@openvz.org, qemu-devel@nongnu.org,
mreitz@redhat.com
Subject: Re: [PATCH 2/3] block/nbd: on shutdown terminate connection attempt
Date: Thu, 23 Jul 2020 13:52:19 -0500 [thread overview]
Message-ID: <98cebab5-c0a4-11fd-2582-dc7210f3a622@redhat.com> (raw)
In-Reply-To: <20200720090024.18186-3-vsementsov@virtuozzo.com>
On 7/20/20 4:00 AM, Vladimir Sementsov-Ogievskiy wrote:
> On shutdown nbd driver may be in a connecting state. We should shutdown
> it as well, otherwise we may hang in
> nbd_teardown_connection, waiting for conneciton_co to finish in
> BDRV_POLL_WHILE(bs, s->connection_co) loop if remote server is down.
>
> How to reproduce the dead lock:
>
Same reproducer as in the previous patch (again, where a temporary sleep
or well-placed gdb breakpoint may be more reliable than running two
process loops).
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
> block/nbd.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
Reviewed-by: Eric Blake <eblake@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
next prev parent reply other threads:[~2020-07-23 18:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 9:00 [PATCH for-5.1? 0/3] Fix nbd reconnect dead-locks Vladimir Sementsov-Ogievskiy
2020-07-20 9:00 ` [PATCH 1/3] block/nbd: allow drain during reconnect attempt Vladimir Sementsov-Ogievskiy
2020-07-20 9:02 ` Vladimir Sementsov-Ogievskiy
2020-07-23 18:47 ` Eric Blake
2020-07-24 10:04 ` Vladimir Sementsov-Ogievskiy
2020-07-24 11:50 ` Vladimir Sementsov-Ogievskiy
2020-07-24 9:49 ` Vladimir Sementsov-Ogievskiy
2020-07-24 10:21 ` Vladimir Sementsov-Ogievskiy
2020-07-20 9:00 ` [PATCH 2/3] block/nbd: on shutdown terminate connection attempt Vladimir Sementsov-Ogievskiy
2020-07-23 18:52 ` Eric Blake [this message]
2020-07-20 9:00 ` [PATCH 3/3] block/nbd: nbd_co_reconnect_loop(): don't sleep if drained Vladimir Sementsov-Ogievskiy
2020-07-23 18:55 ` Eric Blake
2020-07-27 18:42 ` Vladimir Sementsov-Ogievskiy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=98cebab5-c0a4-11fd-2582-dc7210f3a622@redhat.com \
--to=eblake@redhat.com \
--cc=den@openvz.org \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=vsementsov@virtuozzo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).