diff options
| -rw-r--r-- | block.c | 13 | ||||
| -rw-r--r-- | block.h | 1 | ||||
| -rw-r--r-- | qemu-img.c | 6 |
3 files changed, 18 insertions, 2 deletions
@@ -1282,6 +1282,19 @@ void bdrv_flush_all(void) } } +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, @@ -122,6 +122,7 @@ 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 7203b8bc72..74311a5215 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -732,6 +732,8 @@ 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; @@ -755,7 +757,7 @@ 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 @@ -788,7 +790,7 @@ 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"); |