From: Stefan Hajnoczi <stefanha@redhat.com>
To: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>,
slp@redhat.com, "Michael S . Tsirkin" <mst@redhat.com>,
QEMU <qemu-devel@nongnu.org>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
virtio-fs@redhat.com, "Xie Yongji" <xieyongji@bytedance.com>,
"Marc-André Lureau" <marcandre.lureau@gmail.com>
Subject: Re: [External] Re: [RFC PATCH 0/9] Support for Virtio-fs daemon crash reconnection
Date: Mon, 22 Mar 2021 11:00:52 +0000 [thread overview]
Message-ID: <YFh45AUkh1OzbE6H@stefanha-x1.localdomain> (raw)
In-Reply-To: <CAFQAk7ia5HsX0e4WBrhDtytGKnd5LsPrUSz9DJVFoo+ShDRP7Q@mail.gmail.com>
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On Wed, Mar 17, 2021 at 08:32:31PM +0800, Jiachen Zhang wrote:
> On Wed, Mar 17, 2021 at 6:05 PM Stefan Hajnoczi <stefanha@redhat.com> wrote:
> > On Fri, Dec 18, 2020 at 05:39:34PM +0800, Jiachen Zhang wrote:
> I agreed with you that a virtiofsd must be launched by a software like
> systemd. So we are planning to define more generic persist/restore
> interfaces (callbacks). Then anyone can implement their own persist/restore
> callbacks to store states to proper places. And I think in the next
> version we will implement default callbacks for the interfaces. Instead of
> vhost-user messages, systemd's sd_notify(3) will be the default method for
> storing fds, and several tmpfs files can be the default place to store the
> shm regions.
Okay, great!
I was thinking about how to make the crash recovery mechanism reusable
as a C library or Rust crate. The mechanism is a combination of:
1. sd_listen_fds(3) for restoring the fds on restart.
2. sd_notify(3) for storing the fds.
3. memfd or tmpfs for storing state (could be mmapped).
I'm not sure if there is enough common behavior to create a reusable API
or if this is quite application-specific.
Stefan
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next prev parent reply other threads:[~2021-03-22 11:04 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 16:21 [RFC PATCH 0/9] Support for Virtio-fs daemon crash reconnection Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 1/9] vhost-user-fs: Add support for reconnection of vhost-user-fs backend Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 2/9] vhost: Add vhost-user message types for sending shared memory and file fds Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 3/9] vhost-user-fs: Support virtiofsd crash reconnection Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 4/9] libvhost-user: Add vhost-user message types for sending shared memory and file fds Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 5/9] virtiofsd: Convert the struct lo_map array to a more flatten layout Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 6/9] virtiofsd: Add two new options for crash reconnection Jiachen Zhang
2021-02-04 12:08 ` Dr. David Alan Gilbert
2021-02-04 14:16 ` [External] " Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 7/9] virtiofsd: Persist/restore lo_map and opened fds to/from QEMU Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 8/9] virtiofsd: Ensure crash consistency after reconnection Jiachen Zhang
2020-12-15 16:21 ` [RFC PATCH 9/9] virtiofsd: (work around) Comment qsort in inflight I/O tracking Jiachen Zhang
2021-02-04 12:15 ` Dr. David Alan Gilbert
2021-02-04 14:20 ` [External] " Jiachen Zhang
2020-12-15 22:51 ` [RFC PATCH 0/9] Support for Virtio-fs daemon crash reconnection no-reply
2020-12-16 15:36 ` Marc-André Lureau
2020-12-18 9:39 ` [External] " Jiachen Zhang
2021-03-17 10:05 ` Stefan Hajnoczi
2021-03-17 11:49 ` Christian Schoenebeck
2021-03-17 12:57 ` Jiachen Zhang
2021-03-18 11:58 ` Christian Schoenebeck
2021-03-22 10:54 ` Stefan Hajnoczi
2021-03-23 12:54 ` Christian Schoenebeck
2021-03-23 14:25 ` Stefan Hajnoczi
2021-03-17 12:32 ` Jiachen Zhang
2021-03-22 11:00 ` Stefan Hajnoczi [this message]
2021-03-22 20:13 ` [Virtio-fs] " Vivek Goyal
2021-03-23 13:45 ` Stefan Hajnoczi
2021-05-10 14:38 ` Jiachen Zhang
2021-05-13 15:17 ` Stefan Hajnoczi
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