From b56be87ffda890f7b9c0af385f29fd79597aa552 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 7 May 2010 15:50:15 -0300 Subject: [PATCH 08/11] block: bdrv_has_zero_init RH-Author: Christoph Hellwig Message-id: <1273247415-28118-8-git-send-email-chellwig@redhat.com> Patchwork-id: 9107 O-Subject: [RHEL6 qemu PATCH 8/8] block: bdrv_has_zero_init Bugzilla: 580363 RH-Acked-by: Gleb Natapov RH-Acked-by: Juan Quintela RH-Acked-by: Kevin Wolf From: Kevin Wolf This fixes the problem that qemu-img's use of no_zero_init only considered the no_zero_init flag of the format driver, but not of the underlying protocols. Between the raw/file split and this fix, converting to host devices is broken. Signed-off-by: Kevin Wolf Upstream commit: f2feebbd93c251ec0098a9ccf808f7cb1da7f67c Bugzilla: 580363 Signed-off-by: Eduardo Habkost --- block.c | 13 +++++++++++++ block.h | 1 + qemu-img.c | 6 ++++-- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index f7b6033..e551ddb 100644 --- a/block.c +++ b/block.c @@ -1279,6 +1279,19 @@ void bdrv_flush_all(void) bdrv_flush(bs); } +int bdrv_has_zero_init(BlockDriverState *bs) +{ + assert(bs->drv); + + if (bs->drv->no_zero_init) { + return 0; + } else if (bs->file) { + return bdrv_has_zero_init(bs->file); + } + + return 1; +} + /* * Returns true iff the specified sector is present in the disk image. Drivers * not implementing the functionality are assumed to not support backing files, diff --git a/block.h b/block.h index 9deee98..223caf7 100644 --- a/block.h +++ b/block.h @@ -127,6 +127,7 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, void bdrv_flush(BlockDriverState *bs); void bdrv_flush_all(void); +int bdrv_has_zero_init(BlockDriverState *bs); int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum); diff --git a/qemu-img.c b/qemu-img.c index 9569d96..7d2a4f2 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -761,6 +761,8 @@ static int img_convert(int argc, char **argv) /* signal EOF to align */ bdrv_write_compressed(out_bs, 0, NULL, 0); } else { + int has_zero_init = bdrv_has_zero_init(out_bs); + sector_num = 0; // total number of sectors converted so far for(;;) { nb_sectors = total_sectors - sector_num; @@ -784,7 +786,7 @@ static int img_convert(int argc, char **argv) if (n > bs_offset + bs_sectors - sector_num) n = bs_offset + bs_sectors - sector_num; - if (!drv->no_zero_init) { + if (has_zero_init) { /* If the output image is being created as a copy on write image, assume that sectors which are unallocated in the input image are present in both the output's and input's base images (no @@ -817,7 +819,7 @@ static int img_convert(int argc, char **argv) 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 (drv->no_zero_init || out_baseimg || + if (!has_zero_init || out_baseimg || is_allocated_sectors(buf1, n, &n1)) { if (bdrv_write(out_bs, sector_num, buf1, n1) < 0) error("error while writing"); -- 1.7.0.3