From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:38418) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1goN03-0007pP-14 for qemu-devel@nongnu.org; Tue, 29 Jan 2019 01:35:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1goN02-0005Q8-9S for qemu-devel@nongnu.org; Tue, 29 Jan 2019 01:35:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48640) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1goN02-0005Py-3c for qemu-devel@nongnu.org; Tue, 29 Jan 2019 01:35:58 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3121088E66 for ; Tue, 29 Jan 2019 06:28:10 +0000 (UTC) From: Pankaj Gupta Date: Tue, 29 Jan 2019 11:58:01 +0530 Message-Id: <20190129062801.15799-1-pagupta@redhat.com> Subject: [Qemu-devel] [PATCH v2] chardev: Avoid adding duplicate chardev List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, marcandre.lureau@redhat.com, eblake@redhat.com, xiaohli@redhat.com, pagupta@redhat.com Hotplugging existing char chardev with qmp, dereferences(removes) existing chardev. This patch avoids adding a chardev if a chardev with same id exists. RH BZ 1660831: # (host) ls -lt /tmp/helloworld* srwxr-xr-x. /tmp/helloworld1 srwxr-xr-x. /tmp/helloworld2 Before this patch: hotplug existed chardev(channel1) in qmp: {"execute":"chardev-add","arguments":{"id":"charchannel1","backend":{"type":"socket", "data":{"addr":{"type":"unix", "data": {"path": "/tmp/helloworld1"}}}}}} {"error": {"class": "GenericError", "desc": "attempt to add duplicate property 'charchannel1' to object (type 'container')"}} # ls -lt /tmp/helloworld* srwxr-xr-x. 1 root root 0 Dec 19 16:39 /tmp/helloworld2 After this patch: {"execute":"chardev-add","arguments":{"id":"charchannel1","backend":{"type":"socket", "data":{"addr":{"type":"unix", "data": {"path": "/tmp/helloworld1"}}}}}} {"error": {"class": "GenericError", "desc": "Chardev 'charchannel1' already exists"}} # ls -lt /tmp/helloworld* srwxr-xr-x. 1 /tmp/helloworld1 srwxr-xr-x. 1 /tmp/helloworld2 Reported-by: Xiaohui Li Signed-off-by: Pankaj Gupta --- v1->v2 Correct error message - Eric chardev/char.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/chardev/char.c b/chardev/char.c index ccba36bafb..cab0d3df16 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -985,6 +985,12 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend, ChardevReturn *ret; Chardev *chr; + chr = qemu_chr_find(id); + if (chr) { + error_setg(errp, "Chardev '%s' already exists", id); + return NULL; + } + cc = char_get_class(ChardevBackendKind_str(backend->type), errp); if (!cc) { return NULL; -- 2.14.3