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[PATCH v3 09/33] block/nbd: bs-independent interface for nbd_co_establis
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH v3 09/33] block/nbd: bs-independent interface for nbd_co_establish_connection() |
Date: |
Fri, 16 Apr 2021 11:08:47 +0300 |
We are going to split connection code to 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>
---
block/nbd.c | 49 +++++++++++++++++++++++++++++++------------------
1 file changed, 31 insertions(+), 18 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index 2b26a033a4..dd97ea0916 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -121,7 +121,8 @@ 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);
@@ -407,22 +408,36 @@ 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 thread is running, wait for completion
+ * if thread is already succeeded in background, and user didn't get the
+ * result, just return it now
+ * otherwise if thread is not running, 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;
@@ -436,13 +451,12 @@ 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) {
/*
* Obviously, drained section wants to start. Report the attempt as
@@ -453,17 +467,12 @@ 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;
}
/*
@@ -530,11 +539,15 @@ 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);
--
2.29.2
- [PATCH v3 06/33] util/async: aio_co_schedule(): support reschedule in same ctx, (continued)
- [PATCH v3 06/33] util/async: aio_co_schedule(): support reschedule in same ctx, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 04/33] block/nbd: nbd_client_handshake(): fix leak of s->ioc, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 07/33] block/nbd: simplify waking of nbd_co_establish_connection(), Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 08/33] block/nbd: drop thr->state, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 09/33] block/nbd: bs-independent interface for nbd_co_establish_connection(),
Vladimir Sementsov-Ogievskiy <=
- [PATCH v3 10/33] block/nbd: make nbd_co_establish_connection_cancel() bs-independent, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 11/33] block/nbd: rename NBDConnectThread to NBDClientConnection, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 12/33] block/nbd: introduce nbd_client_connection_new(), Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 15/33] nbd/client-connection: use QEMU_LOCK_GUARD, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 16/33] nbd/client-connection: add possibility of negotiation, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 23/33] block/nbd: nbd_teardown_connection() don't touch s->sioc, Vladimir Sementsov-Ogievskiy, 2021/04/16
- [PATCH v3 17/33] nbd/client-connection: implement connection retry, Vladimir Sementsov-Ogievskiy, 2021/04/16