On Mon, 07/02 14:35, Max Reitz wrote: > On 2018-07-02 04:58, Fam Zheng wrote: > > These are the low priority ones spotted by Kevin and Max last week. > > > > Fam Zheng (4): > > qcow2: Drop unused cluster_data > > file-posix: Fix fd_open check in raw_co_copy_range_to > > qcow2: Drop unreachable break > > raw: Drop superfluous semicolon > > > > block/file-posix.c | 2 +- > > block/qcow2.c | 3 --- > > block/raw-format.c | 2 +- > > 3 files changed, 2 insertions(+), 5 deletions(-) > > Thanks, applied to my block branch: > > https://git.xanclic.moe/XanClic/qemu/commits/branch/block > > > Do you want to make qcow2_co_copy_range_to() do something special on > BDRV_REQ_ZERO_WRITE? To me, it seems natural, but on the other hand > maybe it wouldn't bring anything. If the protocol layer supports copy > offloading, then it'll probably do that zero write efficiently anyway. > If it doesn't, qemu-img convert will just fall back to the usual > implementation which involves writing zeroes when zeroes are read, so... > What's your opinion?
In bdrv_co_copy_range_internal() there is if (flags & BDRV_REQ_ZERO_WRITE) { return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags); } before calling driver .bdrv_co_copy_range_to() callback. I think this is enough? Fam