From: Eric Blake <eblake@redhat.com>
To: qemu-devel@nongnu.org
Cc: Roman Kagan <rvkagan@yandex-team.ru>,
Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
"open list:Network Block Dev..." <qemu-block@nongnu.org>,
Max Reitz <mreitz@redhat.com>
Subject: [PULL 14/34] block/nbd: bs-independent interface for nbd_co_establish_connection()
Date: Tue, 15 Jun 2021 15:47:36 -0500 [thread overview]
Message-ID: <20210615204756.281505-15-eblake@redhat.com> (raw)
In-Reply-To: <20210615204756.281505-1-eblake@redhat.com>
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
We are going to split connection code to a separate file. Now we are
ready to give nbd_co_establish_connection() clean and bs-independent
interface.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-13-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
block/nbd.c | 50 ++++++++++++++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 18 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index f2d5b47026a3..15b569a899fd 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -130,7 +130,8 @@ typedef struct BDRVNBDState {
static void nbd_free_connect_thread(NBDConnectThread *thr);
static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr,
Error **errp);
-static int nbd_co_establish_connection(BlockDriverState *bs, Error **errp);
+static coroutine_fn QIOChannelSocket *
+nbd_co_establish_connection(NBDConnectThread *thr, Error **errp);
static void nbd_co_establish_connection_cancel(BlockDriverState *bs);
static int nbd_client_handshake(BlockDriverState *bs, Error **errp);
static void nbd_yank(void *opaque);
@@ -416,22 +417,37 @@ static void *connect_thread_func(void *opaque)
return NULL;
}
-static int coroutine_fn
-nbd_co_establish_connection(BlockDriverState *bs, Error **errp)
+/*
+ * Get a new connection in context of @thr:
+ * if the thread is running, wait for completion
+ * if the thread already succeeded in the background, and user didn't get the
+ * result, just return it now
+ * otherwise the thread is not running, so start a thread and wait for
+ * completion
+ */
+static coroutine_fn QIOChannelSocket *
+nbd_co_establish_connection(NBDConnectThread *thr, Error **errp)
{
+ QIOChannelSocket *sioc = NULL;
QemuThread thread;
- BDRVNBDState *s = bs->opaque;
- NBDConnectThread *thr = s->connect_thread;
-
- assert(!s->sioc);
qemu_mutex_lock(&thr->mutex);
+ /*
+ * Don't call nbd_co_establish_connection() in several coroutines in
+ * parallel. Only one call at once is supported.
+ */
+ assert(!thr->wait_co);
+
if (!thr->running) {
if (thr->sioc) {
/* Previous attempt finally succeeded in background */
- goto out;
+ sioc = g_steal_pointer(&thr->sioc);
+ qemu_mutex_unlock(&thr->mutex);
+
+ return sioc;
}
+
thr->running = true;
error_free(thr->err);
thr->err = NULL;
@@ -445,13 +461,12 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp)
/*
* We are going to wait for connect-thread finish, but
- * nbd_client_co_drain_begin() can interrupt.
+ * nbd_co_establish_connection_cancel() can interrupt.
*/
qemu_coroutine_yield();
qemu_mutex_lock(&thr->mutex);
-out:
if (thr->running) {
/*
* The connection attempt was canceled and the coroutine resumed
@@ -463,17 +478,12 @@ out:
} else {
error_propagate(errp, thr->err);
thr->err = NULL;
- s->sioc = thr->sioc;
- thr->sioc = NULL;
- if (s->sioc) {
- yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name),
- nbd_yank, bs);
- }
+ sioc = g_steal_pointer(&thr->sioc);
}
qemu_mutex_unlock(&thr->mutex);
- return s->sioc ? 0 : -1;
+ return sioc;
}
/*
@@ -541,11 +551,15 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
s->ioc = NULL;
}
- if (nbd_co_establish_connection(s->bs, NULL) < 0) {
+ s->sioc = nbd_co_establish_connection(s->connect_thread, NULL);
+ if (!s->sioc) {
ret = -ECONNREFUSED;
goto out;
}
+ yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank,
+ s->bs);
+
bdrv_dec_in_flight(s->bs);
ret = nbd_client_handshake(s->bs, NULL);
--
2.31.1
next prev parent reply other threads:[~2021-06-15 20:53 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-15 20:47 [PULL 00/34] NBD patches for 2021-06-15 Eric Blake
2021-06-15 20:47 ` [PULL 01/34] async: the main AioContext is only "current" if under the BQL Eric Blake
2021-06-15 20:47 ` [PULL 02/34] tests: cover aio_co_enter from a worker thread without BQL taken Eric Blake
2021-06-15 20:47 ` [PULL 03/34] co-queue: drop extra coroutine_fn marks Eric Blake
2021-06-15 20:47 ` [PULL 04/34] block/nbd: fix channel object leak Eric Blake
2021-06-15 20:47 ` [PULL 05/34] block/nbd: fix how state is cleared on nbd_open() failure paths Eric Blake
2021-06-15 20:47 ` [PULL 06/34] block/nbd: connect_thread_func(): do qio_channel_set_delay(false) Eric Blake
2021-06-15 20:47 ` [PULL 07/34] qemu-sockets: introduce socket_address_parse_named_fd() Eric Blake
2021-06-15 20:47 ` [PULL 08/34] block/nbd: call socket_address_parse_named_fd() in advance Eric Blake
2021-06-15 20:47 ` [PULL 09/34] block/nbd: ensure ->connection_thread is always valid Eric Blake
2021-06-15 20:47 ` [PULL 10/34] block/nbd: nbd_client_handshake(): fix leak of s->ioc Eric Blake
2021-06-15 20:47 ` [PULL 11/34] block/nbd: BDRVNBDState: drop unused connect_err and connect_status Eric Blake
2021-06-15 20:47 ` [PULL 12/34] block/nbd: simplify waking of nbd_co_establish_connection() Eric Blake
2021-06-15 20:47 ` [PULL 13/34] block/nbd: drop thr->state Eric Blake
2021-06-15 20:47 ` Eric Blake [this message]
2021-06-15 20:47 ` [PULL 15/34] block/nbd: make nbd_co_establish_connection_cancel() bs-independent Eric Blake
2021-06-15 20:47 ` [PULL 16/34] block/nbd: rename NBDConnectThread to NBDClientConnection Eric Blake
2021-06-15 20:47 ` [PULL 17/34] block/nbd: introduce nbd_client_connection_new() Eric Blake
2021-06-15 20:47 ` [PULL 18/34] block/nbd: introduce nbd_client_connection_release() Eric Blake
2021-06-15 20:47 ` [PULL 19/34] nbd: move connection code from block/nbd to nbd/client-connection Eric Blake
2021-06-15 20:47 ` [PULL 20/34] nbd/client-connection: use QEMU_LOCK_GUARD Eric Blake
2021-06-15 20:47 ` [PULL 21/34] nbd/client-connection: add possibility of negotiation Eric Blake
2021-06-15 20:47 ` [PULL 22/34] nbd/client-connection: implement connection retry Eric Blake
2021-06-15 20:47 ` [PULL 23/34] nbd/client-connection: shutdown connection on release Eric Blake
2021-06-15 20:47 ` [PULL 24/34] block/nbd: split nbd_handle_updated_info out of nbd_client_handshake() Eric Blake
2021-06-15 20:47 ` [PULL 25/34] block/nbd: use negotiation of NBDClientConnection Eric Blake
2021-06-15 20:47 ` [PULL 26/34] block/nbd: don't touch s->sioc in nbd_teardown_connection() Eric Blake
2021-06-15 20:47 ` [PULL 27/34] block/nbd: drop BDRVNBDState::sioc Eric Blake
2021-06-15 20:47 ` [PULL 28/34] nbd/client-connection: return only one io channel Eric Blake
2021-06-17 18:32 ` Vladimir Sementsov-Ogievskiy
2021-06-18 15:55 ` Eric Blake
2021-06-15 20:47 ` [PULL 29/34] block-coroutine-wrapper: allow non bdrv_ prefix Eric Blake
2021-06-15 20:47 ` [PULL 30/34] block/nbd: split nbd_co_do_establish_connection out of nbd_reconnect_attempt Eric Blake
2021-06-15 20:47 ` [PULL 31/34] nbd/client-connection: add option for non-blocking connection attempt Eric Blake
2021-06-15 20:47 ` [PULL 32/34] block/nbd: reuse nbd_co_do_establish_connection() in nbd_open() Eric Blake
2021-06-15 20:47 ` [PULL 33/34] block/nbd: add nbd_client_connected() helper Eric Blake
2021-06-15 20:47 ` [PULL 34/34] block/nbd: safer transition to receiving request Eric Blake
2021-06-17 9:42 ` [PULL 00/34] NBD patches for 2021-06-15 Peter Maydell
2021-06-17 18:35 ` Vladimir Sementsov-Ogievskiy
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