From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, vsementsov@virtuozzo.com,
eblake@redhat.com, mreitz@redhat.com, kwolf@redhat.com,
pbonzini@redhat.com
Subject: [PATCH v4 32/32] block/nbd: safer transition to receiving request
Date: Thu, 10 Jun 2021 13:08:02 +0300 [thread overview]
Message-ID: <20210610100802.5888-33-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210610100802.5888-1-vsementsov@virtuozzo.com>
req->receiving is a flag of request being in one concrete yield point
in nbd_co_do_receive_one_chunk().
Such kind of boolean flag is always better to unset before scheduling
the coroutine, to avoid double scheduling. So, let's be more careful.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
block/nbd.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/nbd.c b/block/nbd.c
index 5cfb749e08..3cbee762de 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -150,6 +150,7 @@ static void nbd_recv_coroutines_wake_all(BDRVNBDState *s)
NBDClientRequest *req = &s->requests[i];
if (req->coroutine && req->receiving) {
+ req->receiving = false;
aio_co_wake(req->coroutine);
}
}
@@ -548,6 +549,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque)
* connection_co happens through a bottom half, which can only
* run after we yield.
*/
+ s->requests[i].receiving = false;
aio_co_wake(s->requests[i].coroutine);
qemu_coroutine_yield();
}
@@ -934,7 +936,7 @@ static coroutine_fn int nbd_co_do_receive_one_chunk(
/* Wait until we're woken up by nbd_connection_entry. */
s->requests[i].receiving = true;
qemu_coroutine_yield();
- s->requests[i].receiving = false;
+ assert(!s->requests[i].receiving);
if (!nbd_client_connected(s)) {
error_setg(errp, "Connection closed");
return -EIO;
--
2.29.2
next prev parent reply other threads:[~2021-06-10 10:37 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
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 ` Vladimir Sementsov-Ogievskiy [this message]
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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