02.06.2021 22:14, Eric Blake wrote:
On Fri, Apr 16, 2021 at 11:08:47AM +0300, Vladimir Sementsov-Ogievskiy wrote:
We are going to split connection code to separate file. Now we are
to a separate
ready to give nbd_co_establish_connection() clean and bs-independent
interface.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Roman Kagan <rvka...@yandex-team.ru>
---
block/nbd.c | 49 +++++++++++++++++++++++++++++++------------------
1 file changed, 31 insertions(+), 18 deletions(-)
-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 the thread is running,...
+ * if thread is already succeeded in background, and user didn't get the
if the thread already succeeded in the background,...
+ * result, just return it now
+ * otherwise if thread is not running, start a thread and wait for completion
otherwise, the thread is not running, so start...
+ */
+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);
Worth using QEMU_LOCK_GUARD() here?
Refactored together with other critical sections in patch 15
+
+ return sioc;
}
+
thr->running = true;
error_free(thr->err);
thr->err = NULL;
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Best regards,
Vladimir
