From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56014) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VKQjI-0001dQ-Bz for qemu-devel@nongnu.org; Fri, 13 Sep 2013 06:36:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VKQjD-0006ES-Fn for qemu-devel@nongnu.org; Fri, 13 Sep 2013 06:36:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58190) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VKQjD-0006EM-5G for qemu-devel@nongnu.org; Fri, 13 Sep 2013 06:35:55 -0400 Message-ID: <5232EA90.7030903@redhat.com> Date: Fri, 13 Sep 2013 12:36:00 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1379067909-22984-1-git-send-email-pl@kamp.de> <1379067909-22984-9-git-send-email-pl@kamp.de> In-Reply-To: <1379067909-22984-9-git-send-email-pl@kamp.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 08/12] qemu-img: conditionally zero out target on convert List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: kwolf@redhat.com, ronniesahlberg@gmail.com, stefanha@redhat.com, qemu-devel@nongnu.org, anthony@codemonkey.ws Il 13/09/2013 12:25, Peter Lieven ha scritto: > if the target has_zero_init = 0, but supports efficiently > writing zeroes by unmapping we call bdrv_zeroize to > avoid fully allocating the target. this currently > is designed especially for iscsi. > > Signed-off-by: Peter Lieven > --- > qemu-img.c | 22 ++++++++++++++++------ > 1 file changed, 16 insertions(+), 6 deletions(-) > > diff --git a/qemu-img.c b/qemu-img.c > index 3e5e388..6eaddc6 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -1354,7 +1354,8 @@ static int img_convert(int argc, char **argv) > } > } > > - flags = BDRV_O_RDWR; > + flags = BDRV_O_RDWR | BDRV_O_UNMAP; I think this should be a new command-line flag. Paolo > + > ret = bdrv_parse_cache_flags(cache, &flags); > if (ret < 0) { > error_report("Invalid cache option: %s", cache); > @@ -1386,12 +1387,13 @@ static int img_convert(int argc, char **argv) > } > } > > + ret = bdrv_get_info(out_bs, &bdi); > + if (ret < 0) { > + error_report("could not get block driver info"); > + goto out; > + } > + > if (compress) { > - ret = bdrv_get_info(out_bs, &bdi); > - if (ret < 0) { > - error_report("could not get block driver info"); > - goto out; > - } > cluster_size = bdi.cluster_size; > if (cluster_size <= 0 || cluster_size > IO_BUF_SIZE) { > error_report("invalid cluster size"); > @@ -1470,6 +1472,14 @@ static int img_convert(int argc, char **argv) > } else { > int has_zero_init = bdrv_has_zero_init(out_bs); > > + if (!has_zero_init && !out_baseimg && bdi.discard_write_zeroes) { > + ret = bdrv_zeroize(out_bs, BDRV_REQ_MAY_UNMAP); > + if (ret < 0) { > + goto out; > + } > + has_zero_init = 1; > + } > + > sector_num = 0; // total number of sectors converted so far > nb_sectors = total_sectors - sector_num; > if (nb_sectors != 0) { >