From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34090) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VrZ0F-0007dU-35 for qemu-devel@nongnu.org; Fri, 13 Dec 2013 15:06:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VrZ09-0003DF-3G for qemu-devel@nongnu.org; Fri, 13 Dec 2013 15:06:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34794) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VrZ08-0003DB-Qk for qemu-devel@nongnu.org; Fri, 13 Dec 2013 15:06:21 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBDK6JHM008796 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 13 Dec 2013 15:06:19 -0500 Date: Fri, 13 Dec 2013 21:06:14 +0100 From: Kevin Wolf Message-ID: <20131213200614.GY3916@dhcp-200-207.str.redhat.com> References: <1386954633-28905-1-git-send-email-mreitz@redhat.com> <1386954633-28905-12-git-send-email-mreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386954633-28905-12-git-send-email-mreitz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v5 11/22] block: Allow block devices without files List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: Fam Zheng , qemu-devel@nongnu.org, Stefan Hajnoczi Am 13.12.2013 um 18:10 hat Max Reitz geschrieben: > blkdebug and blkverify will, in order to retain compatibility, not > support the field "file" implicitly through bdrv_open(). In order to be > able to use those drivers without giving a filename anyway, it is > necessary to be able to have block devices without files implicitly > opened by bdrv_open(). This is the case, if there was neither a file > name, a reference to an existing block device to use as a file nor > options specific to the file. > > Signed-off-by: Max Reitz > --- > block.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/block.c b/block.c > index bef4f82..9659eb5 100644 > --- a/block.c > +++ b/block.c > @@ -1145,11 +1145,14 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, > qdict_extract_subqdict(options, &file_options, "file."); > file_reference = qdict_get_try_str(options, "file"); > > - ret = bdrv_file_open(&file, filename, file_reference, file_options, > - bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); > - qdict_del(options, "file"); > - if (ret < 0) { > - goto fail; > + if (filename || file_reference || qdict_size(file_options)) { > + ret = bdrv_file_open(&file, filename, file_reference, file_options, > + bdrv_open_flags(bs, flags | BDRV_O_UNMAP), > + &local_err); > + qdict_del(options, "file"); > + if (ret < 0) { > + goto fail; > + } > } > > /* Find the right image format driver */ > @@ -1178,7 +1181,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, Manually adding more context before the next hunk: > if (!drv) { > ret = find_image_format(file, filename, &drv, &local_err); > } We can get file == NULL now, which will cause a segfault in find_image_format. (For a reproducer of the segfault, try 'x86_64-softmmu/qemu-system-x86_64 -drive foo=bar') Kevin