qemu-img: Fix bdrv_has_zero_init() use in convert

bdrv_has_zero_init() only has meaning for newly created images or image
areas.  If qemu-img convert did not create the image itself, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-2-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2019-07-24 19:12:29 +02:00
parent 672de729a1
commit 4d7c487eac

View File

@ -1578,6 +1578,7 @@ typedef struct ImgConvertState {
bool has_zero_init;
bool compressed;
bool unallocated_blocks_are_zero;
bool target_is_new;
bool target_has_backing;
int64_t target_backing_sectors; /* negative if unknown */
bool wr_in_order;
@ -1975,9 +1976,11 @@ static int convert_do_copy(ImgConvertState *s)
int64_t sector_num = 0;
/* Check whether we have zero initialisation or can get it efficiently */
s->has_zero_init = s->min_sparse && !s->target_has_backing
? bdrv_has_zero_init(blk_bs(s->target))
: false;
if (s->target_is_new && s->min_sparse && !s->target_has_backing) {
s->has_zero_init = bdrv_has_zero_init(blk_bs(s->target));
} else {
s->has_zero_init = false;
}
if (!s->has_zero_init && !s->target_has_backing &&
bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)))
@ -2428,6 +2431,8 @@ static int img_convert(int argc, char **argv)
}
}
s.target_is_new = !skip_create;
flags = s.min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
if (ret < 0) {