From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51935) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Un3Sf-0006iK-Mp for qemu-devel@nongnu.org; Thu, 13 Jun 2013 05:04:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Un3Sb-0003eG-3P for qemu-devel@nongnu.org; Thu, 13 Jun 2013 05:04:53 -0400 Received: from mail-ie0-x229.google.com ([2607:f8b0:4001:c03::229]:32774) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Un3Sa-0003e4-VU for qemu-devel@nongnu.org; Thu, 13 Jun 2013 05:04:49 -0400 Received: by mail-ie0-f169.google.com with SMTP id 10so12340257ied.0 for ; Thu, 13 Jun 2013 02:04:48 -0700 (PDT) From: Liu Ping Fan Date: Thu, 13 Jun 2013 17:03:05 +0800 Message-Id: <1371114186-8854-6-git-send-email-qemulist@gmail.com> In-Reply-To: <1371114186-8854-1-git-send-email-qemulist@gmail.com> References: <1371114186-8854-1-git-send-email-qemulist@gmail.com> Subject: [Qemu-devel] [PATCH v2 5/6] net: defer nested call to BH List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mdroth , Stefan Hajnoczi From: Liu Ping Fan Nested call caused by ->receive() will raise issue like deadlock, so postphone it to BH. Signed-off-by: Liu Ping Fan --- net/queue.c | 40 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-) diff --git a/net/queue.c b/net/queue.c index 58222b0..9c343ab 100644 --- a/net/queue.c +++ b/net/queue.c @@ -24,6 +24,8 @@ #include "net/queue.h" #include "qemu/queue.h" #include "net/net.h" +#include "block/aio.h" +#include "qemu/main-loop.h" /* The delivery handler may only return zero if it will call * qemu_net_queue_flush() when it determines that it is once again able @@ -183,6 +185,22 @@ static ssize_t qemu_net_queue_deliver_iov(NetQueue *queue, return ret; } +typedef struct NetQueBH { + QEMUBH *bh; + NetClientState *nc; +} NetQueBH; + +static void qemu_net_queue_send_bh(void *opaque) +{ + NetQueBH *q_bh = opaque; + NetQueue *queue = q_bh->nc->send_queue; + + qemu_net_queue_flush(queue); + netclient_unref(q_bh->nc); + qemu_bh_delete(q_bh->bh); + g_slice_free(NetQueBH, q_bh); +} + ssize_t qemu_net_queue_send(NetQueue *queue, NetClientState *sender, unsigned flags, @@ -192,8 +210,17 @@ ssize_t qemu_net_queue_send(NetQueue *queue, { ssize_t ret; - if (queue->delivering || !qemu_can_send_packet_nolock(sender)) { + if (queue->delivering || !qemu_can_send_packet_nolock(sender) + || sender->send_queue->delivering) { qemu_net_queue_append(queue, sender, flags, data, size, sent_cb); + /* Nested call will be deferred to BH */ + if (sender->send_queue->delivering) { + NetQueBH *que_bh = g_slice_new(NetQueBH); + que_bh->bh = qemu_bh_new(qemu_net_queue_send_bh, que_bh); + que_bh->nc = queue->opaque; + netclient_ref(queue->opaque); + qemu_bh_schedule(que_bh->bh); + } return 0; } @@ -217,8 +244,17 @@ ssize_t qemu_net_queue_send_iov(NetQueue *queue, { ssize_t ret; - if (queue->delivering || !qemu_can_send_packet_nolock(sender)) { + if (queue->delivering || !qemu_can_send_packet_nolock(sender) + || sender->send_queue->delivering) { qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, sent_cb); + /* Nested call will be deferred to BH */ + if (sender->send_queue->delivering) { + NetQueBH *que_bh = g_slice_new(NetQueBH); + que_bh->bh = qemu_bh_new(qemu_net_queue_send_bh, que_bh); + que_bh->nc = queue->opaque; + netclient_ref(queue->opaque); + qemu_bh_schedule(que_bh->bh); + } return 0; } -- 1.8.1.4