From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54955) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zc8D1-000077-Be for qemu-devel@nongnu.org; Wed, 16 Sep 2015 04:36:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zc8Cw-0004la-Nd for qemu-devel@nongnu.org; Wed, 16 Sep 2015 04:36:55 -0400 Received: from [59.151.112.132] (port=18640 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zc8Cw-0004kn-3b for qemu-devel@nongnu.org; Wed, 16 Sep 2015 04:36:50 -0400 From: Wen Congyang Message-ID: <55F929E2.1020501@cn.fujitsu.com> Date: Wed, 16 Sep 2015 16:35:46 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH v2] nbd: release exp->blk after all clients are closed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devl , Paolo Bonzini Cc: Li Zhijian If the socket fd is shutdown, there may be some data which is received before shutdown. We will read the data and do read/write in nbd_trip(). But the exp's blk is NULL, and it will cause qemu crashed. Reported-by: Li Zhijian Signed-off-by: Wen Congyang --- nbd.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/nbd.c b/nbd.c index 06b501b..07240bd 100644 --- a/nbd.c +++ b/nbd.c @@ -1131,12 +1131,6 @@ void nbd_export_close(NBDExport *exp) } nbd_export_set_name(exp, NULL); nbd_export_put(exp); - if (exp->blk) { - blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, - blk_aio_detach, exp); - blk_unref(exp->blk); - exp->blk = NULL; - } } void nbd_export_get(NBDExport *exp) @@ -1159,6 +1153,13 @@ void nbd_export_put(NBDExport *exp) exp->close(exp); } + if (exp->blk) { + blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, + blk_aio_detach, exp); + blk_unref(exp->blk); + exp->blk = NULL; + } + g_free(exp); } } @@ -1305,6 +1306,14 @@ static void nbd_trip(void *opaque) goto invalid_request; } + if (client->closing) { + /* + * The client may be closed when we are blocked in + * nbd_co_receive_request() + */ + goto done; + } + switch (command) { case NBD_CMD_READ: TRACE("Request type is READ"); -- 2.4.3