qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru>,
	qemu-devel@nongnu.org
Cc: eblake@redhat.com
Subject: Re: [PATCH for-7.1 0/8] nbd: actually make s->state thread-safe
Date: Wed, 13 Apr 2022 09:30:55 +0200	[thread overview]
Message-ID: <1e43d88e-e17d-52d4-7b62-4bda34108f7f@redhat.com> (raw)
In-Reply-To: <70776c6a-a171-6005-4fb6-e489534ef3b4@mail.ru>

On 4/12/22 20:26, Vladimir Sementsov-Ogievskiy wrote:
> 12.04.2022 20:32, Paolo Bonzini wrote:
>> The main point of this series is patch 6, which removes the dubious and
>> probably wrong use of atomics in block/nbd.c.  This in turn is enabled
>> mostly by the cleanups in patches 3-5.  Together, they introduce a
>> QemuMutex that synchronizes the NBD client coroutines, the 
>> reconnect_delay timer and nbd_cancel_in_flight() as well.
>>
>> The fixes happen to remove an incorrect use of qemu_co_queue_restart_all
>> and qemu_co_enter_next on the s->free_sema CoQueue, which was not guarded
>> by s->send_mutex.
>>
>> The rest is bugfixes, simplifying the code a bit, and extra 
>> documentation.
>>
>> Paolo Bonzini (8):
>>    nbd: actually implement reply_possible safeguard
>>    nbd: mark more coroutine_fns
>>    nbd: remove peppering of nbd_client_connected
>>    nbd: keep send_mutex/free_sema handling outside
>>      nbd_co_do_establish_connection
>>    nbd: use a QemuMutex to synchronize reconnection with coroutines
>>    nbd: move s->state under requests_lock
>>    nbd: take receive_mutex when reading requests[].receiving
>>    nbd: document what is protected by the CoMutexes
>>
>>   block/coroutines.h |   4 +-
>>   block/nbd.c        | 303 +++++++++++++++++++++++----------------------
>>   2 files changed, 157 insertions(+), 150 deletions(-)
>>
> 
> Hmm, no patches come to me except for cover-letter. Neither here: 
> https://patchew.org/QEMU/20220412173216.308065-1-pbonzini@redhat.com/

Network issue, I resent it a couple hours later (and forgot to Cc you, 
sorry about that).

Paolo



  reply	other threads:[~2022-04-13  7:34 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-12 17:32 [PATCH for-7.1 0/8] nbd: actually make s->state thread-safe Paolo Bonzini
2022-04-12 18:26 ` Vladimir Sementsov-Ogievskiy
2022-04-13  7:30   ` Paolo Bonzini [this message]
  -- strict thread matches above, loose matches on Subject: below --
2022-04-12 19:41 Paolo Bonzini

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=1e43d88e-e17d-52d4-7b62-4bda34108f7f@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=eblake@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=v.sementsov-og@mail.ru \
    /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).