From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45036 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PTCGQ-0005ls-BM for qemu-devel@nongnu.org; Thu, 16 Dec 2010 06:44:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PTCGN-00072q-H0 for qemu-devel@nongnu.org; Thu, 16 Dec 2010 06:44:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2471) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PTCGN-00072X-6X for qemu-devel@nongnu.org; Thu, 16 Dec 2010 06:44:47 -0500 Message-ID: <4D09FBEB.6020608@redhat.com> Date: Thu, 16 Dec 2010 12:45:47 +0100 From: Kevin Wolf MIME-Version: 1.0 References: <1292497454-32573-1-git-send-email-Jes.Sorensen@redhat.com> <1292497454-32573-3-git-send-email-Jes.Sorensen@redhat.com> In-Reply-To: <1292497454-32573-3-git-send-email-Jes.Sorensen@redhat.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH 2/3] Introduce do_snapshot_blkdev() and monitor command to handle it. List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jes.Sorensen@redhat.com Cc: qemu-devel@nongnu.org, armbru@redhat.com, stefanha@linux.vnet.ibm.com Am 16.12.2010 12:04, schrieb Jes.Sorensen@redhat.com: > From: Jes Sorensen > > The monitor command is: > snapshot_blkdev [snapshot-file] [format] > > Default format is qcow2. For now snapshots without a snapshot-file, eg > internal snapshots, are not supported. > > Signed-off-by: Jes Sorensen > --- > blockdev.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > blockdev.h | 1 + > hmp-commands.hx | 19 +++++++++++++++++ > 3 files changed, 81 insertions(+), 0 deletions(-) > > diff --git a/blockdev.c b/blockdev.c > index 3b3b82d..9d6f72c 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -516,6 +516,67 @@ void do_commit(Monitor *mon, const QDict *qdict) > } > } > > +int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data) > +{ > + const char *device = qdict_get_str(qdict, "device"); > + const char *filename = qdict_get_try_str(qdict, "snapshot_file"); > + const char *format = qdict_get_try_str(qdict, "format"); > + const char format_qcow2[] = "qcow2"; > + BlockDriverState *bs; > + BlockDriver *drv, *proto_drv; > + int ret = 0; > + int flags; > + > + bs = bdrv_find(device); > + if (!bs) { > + qerror_report(QERR_DEVICE_NOT_FOUND, device); > + ret = -1; > + goto out; > + } > + > + if (!format) { > + format = format_qcow2; Why introducing format_qcow2 instead of directly using the string literal here? > + } > + > + drv = bdrv_find_format(format); > + if (!drv) { > + qerror_report(QERR_INVALID_BLOCK_FORMAT, format); > + ret = -1; > + goto out; > + } > + > + proto_drv = bdrv_find_protocol(filename); > + if (!proto_drv) { > + qerror_report(QERR_INVALID_BLOCK_FORMAT, format); > + ret = -1; > + goto out; > + } > + > + ret = bdrv_img_create(filename, format, bs->filename, > + bs->drv->format_name, NULL, -1, bs->open_flags); > + if (ret) { > + goto out; > + } > + > + qemu_aio_flush(); > + bdrv_flush(bs); > + > + flags = bs->open_flags; > + bdrv_close(bs); > + ret = bdrv_open(bs, filename, flags, drv); > + /* > + * If reopening the image file we just created fails, we really > + * are in trouble :( > + */ > + assert(ret == 0); bdrv_commit handles this case by setting bs->drv = NULL. After this the device will fail all requests with -ENOMEDIUM, but at least you don't lose your VM immediately. Kevin