diff options
| author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2020-05-28 12:44:04 +0300 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2020-07-06 10:34:14 +0200 |
| commit | a2adbbf603cee443ca923f6e8546267a706567d5 (patch) | |
| tree | db3c6df1347a108d1a39791cf8a3a8b22c9fee6a /block/io.c | |
| parent | cdf9ebf18f32f4b29f99af58e154a9afe93bbc92 (diff) | |
block: drop unallocated_blocks_are_zero
Currently this field only set by qed and qcow2. But in fact, all
backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share
these semantics: on unallocated blocks, if there is no backing file they
just memset the buffer with zeroes.
So, document this behavior for .supports_backing and drop
.unallocated_blocks_are_zero
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/io.c')
| -rw-r--r-- | block/io.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/block/io.c b/block/io.c index 36d4d562a6..b6564e34c5 100644 --- a/block/io.c +++ b/block/io.c @@ -2406,7 +2406,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { ret |= BDRV_BLOCK_ALLOCATED; - } else if (want_zero) { + } else if (want_zero && bs->drv->supports_backing) { if (bs->backing) { BlockDriverState *bs2 = bs->backing->bs; int64_t size2 = bdrv_getlength(bs2); @@ -2415,12 +2415,7 @@ static int coroutine_fn bdrv_co_block_status(BlockDriverState *bs, ret |= BDRV_BLOCK_ZERO; } } else { - BlockDriverInfo bdi; - int ret2 = bdrv_get_info(bs, &bdi); - - if (ret2 == 0 && bdi.unallocated_blocks_are_zero) { - ret |= BDRV_BLOCK_ZERO; - } + ret |= BDRV_BLOCK_ZERO; } } |