From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38495) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1csKyJ-0004sg-2c for qemu-devel@nongnu.org; Sun, 26 Mar 2017 23:05:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1csKyG-00042B-AK for qemu-devel@nongnu.org; Sun, 26 Mar 2017 23:05:31 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43202 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1csKyG-00041Z-4Z for qemu-devel@nongnu.org; Sun, 26 Mar 2017 23:05:28 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v2R33Y6p013104 for ; Sun, 26 Mar 2017 23:05:26 -0400 Received: from e18.ny.us.ibm.com (e18.ny.us.ibm.com [129.33.205.208]) by mx0b-001b2d01.pphosted.com with ESMTP id 29dn2ts8qc-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 26 Mar 2017 23:05:26 -0400 Received: from localhost by e18.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 26 Mar 2017 23:05:25 -0400 From: Dong Jia Shi Date: Mon, 27 Mar 2017 05:05:17 +0200 Message-Id: <20170327030518.37268-1-bjsdjshi@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH RFC v2 0/1] block: pass the right options for BlockDriver.bdrv_open List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, kwolf@redhat.com, mreitz@redhat.com Cc: qemu-devel@nongnu.org, bjsdjshi@linux.vnet.ibm.com, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com Trying to restore rbd image on ceph cluster from snapshot with qemu-img could trigger a calling to raw_open with a NULL @options, and that will lead to a failure of the snapshot applying. [root@s8345007 ~]# gdb --args qemu-img snapshot -a snap1 rbd:test_pool/dj_image ... ... Program received signal SIGSEGV, Segmentation fault. 0x00000000801395a8 in qdict_next_entry (qdict=0x0, first_bucket=0) at qobject/qdict.c:327 327 if (!QLIST_EMPTY(&qdict->table[i])) { (gdb) bt #0 0x00000000801395a8 in qdict_next_entry (qdict=0x0, first_bucket=0) at qobject/qdict.c:327 #1 0x0000000080139626 in qdict_first (qdict=0x0) at qobject/qdict.c:340 #2 0x000000008013a00c in qdict_extract_subqdict (src=0x0, dst=0x3ffffffec50, start=0x80698260 "file.") at qobject/qdict.c:576 #3 0x0000000080019c26 in bdrv_open_child_bs (filename=0x0, options=0x0, bdref_key=0x8017ab38 "file", parent=0x80630300, child_role=0x80176108 , allow_none=false, errp=0x0) at block.c:2018 #4 0x0000000080019dfa in bdrv_open_child (filename=0x0, options=0x0, bdref_key=0x8017ab38 "file", parent=0x80630300, child_role=0x80176108 , allow_none=false, errp=0x0) at block.c:2065 #5 0x000000008002b9a0 in raw_open (bs=0x80630300, options=0x0, flags=8194, errp=0x0) at block/raw-format.c:387 #6 0x0000000080087516 in bdrv_snapshot_goto (bs=0x80630300, snapshot_id=0x3fffffff75c "snap1") at block/snapshot.c:194 #7 0x0000000080010b8c in img_snapshot (argc=4, argv=0x3fffffff4c0) at qemu-img.c:2937 #8 0x00000000800140e4 in main (argc=4, argv=0x3fffffff4c0) at qemu-img.c:4373 The problematic code is /block/snapshot.c:194: 178 int bdrv_snapshot_goto(BlockDriverState *bs, 179 const char *snapshot_id) 180 { 181 BlockDriver *drv = bs->drv; 182 int ret, open_ret; 183 184 if (!drv) { 185 return -ENOMEDIUM; 186 } 187 if (drv->bdrv_snapshot_goto) { 188 return drv->bdrv_snapshot_goto(bs, snapshot_id); 189 } 190 191 if (bs->file) { 192 drv->bdrv_close(bs); 193 ret = bdrv_snapshot_goto(bs->file->bs, snapshot_id); 194 open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL); 195 if (open_ret < 0) { 196 bdrv_unref(bs->file->bs); 197 bs->drv = NULL; 198 return open_ret; 199 } 200 return ret; 201 } 202 203 return -ENOTSUP; 204 } After a chat with Kevin, now my understanding is that's because NULL @options is not a valid parameter value for the bdrv_open callback of the BlockDriver. We shoule prepare a @options by adding the "file" key-value pair to the actual options that were given for the node (i.e. bs->options), and pass it to the callback. Dong Jia Shi (1): block: pass the right options for BlockDriver.bdrv_open block/snapshot.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 2.8.4