From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50622) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uz88i-0001hh-P0 for qemu-devel@nongnu.org; Tue, 16 Jul 2013 12:30:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uz88d-0005go-Oc for qemu-devel@nongnu.org; Tue, 16 Jul 2013 12:30:12 -0400 Received: from mail-qe0-x234.google.com ([2607:f8b0:400d:c02::234]:63491) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uz88d-0005ge-LS for qemu-devel@nongnu.org; Tue, 16 Jul 2013 12:30:07 -0400 Received: by mail-qe0-f52.google.com with SMTP id i11so519354qej.11 for ; Tue, 16 Jul 2013 09:30:07 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 16 Jul 2013 18:29:19 +0200 Message-Id: <1373992168-26043-9-git-send-email-pbonzini@redhat.com> In-Reply-To: <1373992168-26043-1-git-send-email-pbonzini@redhat.com> References: <1373992168-26043-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH v2 08/17] block: make bdrv_has_zero_init return false for copy-on-write-images List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pl@kamp.de, famz@redhat.com, stefanha@redhat.com This helps implementing is_allocated on top of get_block_status. Signed-off-by: Paolo Bonzini --- block.c | 5 +++++ qemu-img.c | 9 +-------- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/block.c b/block.c index ae87cba..0fb409b 100644 --- a/block.c +++ b/block.c @@ -2934,6 +2934,11 @@ int bdrv_has_zero_init(BlockDriverState *bs) { assert(bs->drv); + /* If BS is a copy on write image, it is initialized to + the contents of the base image, which may not be zeroes. */ + if (bs->backing_hd) { + return 0; + } if (bs->drv->bdrv_has_zero_init) { return bs->drv->bdrv_has_zero_init(bs); } diff --git a/qemu-img.c b/qemu-img.c index 3faffee..c5c8ebc 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1504,14 +1504,7 @@ static int img_convert(int argc, char **argv) should add a specific call to have the info to go faster */ buf1 = buf; while (n > 0) { - /* If the output image is being created as a copy on write image, - copy all sectors even the ones containing only NUL bytes, - because they may differ from the sectors in the base image. - - If the output is to a host device, we also write out - sectors that are entirely 0, since whatever data was - already there is garbage, not 0s. */ - if (!has_zero_init || out_baseimg || + if (!has_zero_init || is_allocated_sectors_min(buf1, n, &n1, min_sparse)) { ret = bdrv_write(out_bs, sector_num, buf1, n1); if (ret < 0) { -- 1.8.3.1