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From: Eric Blake <eblake@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: kwolf@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org,
	qemu-block@nongnu.org, mreitz@redhat.com
Subject: Re: [PATCH v4 11/32] block/nbd: drop thr->state
Date: Fri, 11 Jun 2021 09:25:44 -0500	[thread overview]
Message-ID: <20210611142544.7tgwkripjtdygetk@redhat.com> (raw)
In-Reply-To: <20210610100802.5888-12-vsementsov@virtuozzo.com>

On Thu, Jun 10, 2021 at 01:07:41PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> We don't need all these states. The code refactored to use two boolean
> variables looks simpler.
> 
> While moving the comment in nbd_co_establish_connection() rework it to
> give better information. Also, we are going to move the connection code
> to separate file and mentioning drained section would be confusing.
> 
> Improve also the comment in NBDConnectThread, while dropping removed
> state names from it.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  block/nbd.c | 139 +++++++++++++++++-----------------------------------
>  1 file changed, 44 insertions(+), 95 deletions(-)
> 

>  typedef struct NBDConnectThread {
>      /* Initialization constants */
>      SocketAddress *saddr; /* address to connect to */
>  
> +    QemuMutex mutex;
> +
>      /*
> -     * Result of last attempt. Valid in FAIL and SUCCESS states.
> -     * If you want to steal error, don't forget to set pointer to NULL.
> +     * @sioc and @err present a result of connection attempt.
> +     * While running is true, they are used only by thread, mutex locking is not
> +     * needed. When thread is finished nbd_co_establish_connection steal these
> +     * pointers under mutex.

@sioc and @err represent a connection attempt.  While running is true,
they are only used by the connection thread, and mutex locking is not
needed.  Once the thread finishes, nbd_co_establish_connection then
steals these pointers under mutex.

>       */
>      QIOChannelSocket *sioc;
>      Error *err;
>  
> -    QemuMutex mutex;
> -    /* All further fields are protected by mutex */
> -    NBDConnectThreadState state; /* current state of the thread */
> +    /* All further fields are accessed only under mutex */
> +    bool running; /* thread is running now */
> +    bool detached; /* thread is detached and should cleanup the state */
>

Okay, I'm understanding this better than I did in v3.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org



  reply	other threads:[~2021-06-11 14:26 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-10 10:07 [PATCH v4 00/32] block/nbd: rework client connection Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 01/32] co-queue: drop extra coroutine_fn marks Vladimir Sementsov-Ogievskiy
2021-06-10 17:22   ` Eric Blake
2021-06-10 17:37     ` Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 02/32] block/nbd: fix channel object leak Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 03/32] block/nbd: fix how state is cleared on nbd_open() failure paths Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 04/32] block/nbd: connect_thread_func(): do qio_channel_set_delay(false) Vladimir Sementsov-Ogievskiy
2021-06-10 18:37   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 05/32] qemu-sockets: introduce socket_address_parse_named_fd() Vladimir Sementsov-Ogievskiy
2021-06-11 13:22   ` Eric Blake
2021-06-11 14:10     ` Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 06/32] block/nbd: call socket_address_parse_named_fd() in advance Vladimir Sementsov-Ogievskiy
2021-06-11 13:54   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 07/32] block/nbd: ensure ->connection_thread is always valid Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 08/32] block/nbd: nbd_client_handshake(): fix leak of s->ioc Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 09/32] block/nbd: BDRVNBDState: drop unused connect_err and connect_status Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 10/32] block/nbd: simplify waking of nbd_co_establish_connection() Vladimir Sementsov-Ogievskiy
2021-06-11 14:06   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 11/32] block/nbd: drop thr->state Vladimir Sementsov-Ogievskiy
2021-06-11 14:25   ` Eric Blake [this message]
2021-06-10 10:07 ` [PATCH v4 12/32] block/nbd: bs-independent interface for nbd_co_establish_connection() Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 13/32] block/nbd: make nbd_co_establish_connection_cancel() bs-independent Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 14/32] block/nbd: rename NBDConnectThread to NBDClientConnection Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 15/32] block/nbd: introduce nbd_client_connection_new() Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 16/32] block/nbd: introduce nbd_client_connection_release() Vladimir Sementsov-Ogievskiy
2021-06-11 14:28   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 17/32] nbd: move connection code from block/nbd to nbd/client-connection Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 18/32] nbd/client-connection: use QEMU_LOCK_GUARD Vladimir Sementsov-Ogievskiy
2021-06-11 14:31   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 19/32] nbd/client-connection: add possibility of negotiation Vladimir Sementsov-Ogievskiy
2021-06-11 15:07   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 20/32] nbd/client-connection: implement connection retry Vladimir Sementsov-Ogievskiy
2021-06-11 15:12   ` Eric Blake
2021-11-22 16:30   ` Eric Blake
2021-11-22 17:17     ` Vladimir Sementsov-Ogievskiy
2021-11-22 21:51       ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 21/32] nbd/client-connection: shutdown connection on release Vladimir Sementsov-Ogievskiy
2021-06-11 15:27   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 22/32] block/nbd: split nbd_handle_updated_info out of nbd_client_handshake() Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 23/32] block/nbd: use negotiation of NBDClientConnection Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 24/32] block/nbd: don't touch s->sioc in nbd_teardown_connection() Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 25/32] block/nbd: drop BDRVNBDState::sioc Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 26/32] nbd/client-connection: return only one io channel Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 27/32] block-coroutine-wrapper: allow non bdrv_ prefix Vladimir Sementsov-Ogievskiy
2021-06-10 10:07 ` [PATCH v4 28/32] block/nbd: split nbd_co_do_establish_connection out of nbd_reconnect_attempt Vladimir Sementsov-Ogievskiy
2021-06-11 15:29   ` Eric Blake
2021-06-10 10:07 ` [PATCH v4 29/32] nbd/client-connection: add option for non-blocking connection attempt Vladimir Sementsov-Ogievskiy
2021-06-10 10:08 ` [PATCH v4 30/32] block/nbd: reuse nbd_co_do_establish_connection() in nbd_open() Vladimir Sementsov-Ogievskiy
2021-06-10 10:08 ` [PATCH v4 31/32] block/nbd: add nbd_client_connected() helper Vladimir Sementsov-Ogievskiy
2021-06-10 10:08 ` [PATCH v4 32/32] block/nbd: safer transition to receiving request Vladimir Sementsov-Ogievskiy
2021-06-11 15:55 ` [PATCH v4 00/32] block/nbd: rework client connection Eric Blake
2021-06-11 17:23   ` Vladimir Sementsov-Ogievskiy

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