From 33d075d8a2d5c6f22aaefb5fcfbee61e0c46586b Mon Sep 17 00:00:00 2001 Message-Id: <33d075d8a2d5c6f22aaefb5fcfbee61e0c46586b.1389014116.git.minovotn@redhat.com> In-Reply-To: References: From: Paolo Bonzini Date: Mon, 9 Dec 2013 14:09:10 +0100 Subject: [PATCH 22/50] qemu-img: conditionally zero out target on convert RH-Author: Paolo Bonzini Message-id: <1386598178-11845-25-git-send-email-pbonzini@redhat.com> Patchwork-id: 56061 O-Subject: [RHEL 7.0 qemu-kvm PATCH 24/52] qemu-img: conditionally zero out target on convert Bugzilla: 1007815 RH-Acked-by: Jeffrey Cody RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi From: Peter Lieven If the target has_zero_init = 0, but supports efficiently writing zeroes by unmapping we call bdrv_make_zero to avoid fully allocating the target. This currently works only for iscsi. It can be extended to raw with BLKDISCARDZEROES for example. Reviewed-by: Eric Blake Signed-off-by: Peter Lieven Signed-off-by: Stefan Hajnoczi (cherry picked from commit 5a37b60a61c4c334e3b194758871f41494317d42) --- qemu-img.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) Signed-off-by: Michal Novotny --- qemu-img.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/qemu-img.c b/qemu-img.c index dfd8a92..3dacbec 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1353,7 +1353,7 @@ static int img_convert(int argc, char **argv) } } - flags = BDRV_O_RDWR; + flags = min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR; ret = bdrv_parse_cache_flags(cache, &flags); if (ret < 0) { error_report("Invalid cache option: %s", cache); @@ -1469,6 +1469,14 @@ static int img_convert(int argc, char **argv) } else { int has_zero_init = min_sparse ? bdrv_has_zero_init(out_bs) : 0; + if (!has_zero_init && bdrv_can_write_zeroes_with_unmap(out_bs)) { + ret = bdrv_make_zero(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) { -- 1.7.11.7