diff options
| -rw-r--r-- | qemu-img.c | 44 |
1 files changed, 14 insertions, 30 deletions
diff --git a/qemu-img.c b/qemu-img.c index 9b6e72893a..c7196362df 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1649,6 +1649,8 @@ static int coroutine_fn convert_co_write(ImgConvertState *s, int64_t sector_num, while (nb_sectors > 0) { int n = nb_sectors; + BdrvRequestFlags flags = s->compressed ? BDRV_REQ_WRITE_COMPRESSED : 0; + switch (status) { case BLK_BACKING_FILE: /* If we have a backing file, leave clusters unallocated that are @@ -1658,43 +1660,24 @@ static int coroutine_fn convert_co_write(ImgConvertState *s, int64_t sector_num, break; case BLK_DATA: - /* We must always write compressed clusters as a whole, so don't - * try to find zeroed parts in the buffer. We can only save the - * write if the buffer is completely zeroed and we're allowed to - * keep the target sparse. */ - if (s->compressed) { - if (s->has_zero_init && s->min_sparse && - buffer_is_zero(buf, n * BDRV_SECTOR_SIZE)) - { - assert(!s->target_has_backing); - break; - } - - iov.iov_base = buf; - iov.iov_len = n << BDRV_SECTOR_BITS; - qemu_iovec_init_external(&qiov, &iov, 1); - - ret = blk_co_pwritev(s->target, sector_num << BDRV_SECTOR_BITS, - n << BDRV_SECTOR_BITS, &qiov, - BDRV_REQ_WRITE_COMPRESSED); - if (ret < 0) { - return ret; - } - break; - } - - /* If there is real non-zero data or we're told to keep the target - * fully allocated (-S 0), we must write it. Otherwise we can treat - * it as zero sectors. */ + /* If we're told to keep the target fully allocated (-S 0) or there + * is real non-zero data, we must write it. Otherwise we can treat + * it as zero sectors. + * Compressed clusters need to be written as a whole, so in that + * case we can only save the write if the buffer is completely + * zeroed. */ if (!s->min_sparse || - is_allocated_sectors_min(buf, n, &n, s->min_sparse)) + (!s->compressed && + is_allocated_sectors_min(buf, n, &n, s->min_sparse)) || + (s->compressed && + !buffer_is_zero(buf, n * BDRV_SECTOR_SIZE))) { iov.iov_base = buf; iov.iov_len = n << BDRV_SECTOR_BITS; qemu_iovec_init_external(&qiov, &iov, 1); ret = blk_co_pwritev(s->target, sector_num << BDRV_SECTOR_BITS, - n << BDRV_SECTOR_BITS, &qiov, 0); + n << BDRV_SECTOR_BITS, &qiov, flags); if (ret < 0) { return ret; } @@ -1704,6 +1687,7 @@ static int coroutine_fn convert_co_write(ImgConvertState *s, int64_t sector_num, case BLK_ZERO: if (s->has_zero_init) { + assert(!s->target_has_backing); break; } ret = blk_co_pwrite_zeroes(s->target, |