Re: [Qemu-devel] [PATCH V18 4/6] rename qcow2-cache.c to block-cache.c

[Dong Xu Wang <wdongxu@linux.vnet.ibm.com>]

On 2013/4/18 16:54, Stefan Hajnoczi wrote:
> On Wed, Apr 10, 2013 at 04:11:51PM +0800, Dong Xu Wang wrote:
>
> This patch does two things:
> 1. Rename and move qcow2-cache to block-cache.
> 2. Add a type enum to parameterize BLKDEBUG_EVENT() for L2, refcount,
>     and bitmaps.
>
> It's hard to review #2 since all lines are changed in the diff by #1.
> In the future, please split patches that move code into two.
>
> The first patch should simply move and rename - it should not include
> code changes.
>
> The second patch should contain code changes (i.e. adding the cache type
> enum and parameterizing BLKDEBUG_EVENT()).
>
> BTW, when splitting the patch into two for easy reviewing it also
> becomes questionable whether to reassign authorship since 90+% of the
> code is unchanged and simply moved.
>
Okay.
>> +    if (c->table_type == BLOCK_TABLE_REF) {
>> +        BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART);
>> +    } else if (c->table_type == BLOCK_TABLE_L2) {
>> +        BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
>> +    } else if (c->table_type == BLOCK_TABLE_BITMAP) {
>> +        BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
>
> BLKDBG_COW_WRITE is for writing out sectors from the backing file.  It
> is not for updating the allocation bitmap.
>
Okay.
> Please pick an appropriate constant or define your own if none exists.
>
>> +    if (read_from_disk) {
>> +        if (c->table_type == BLOCK_TABLE_L2) {
>> +            BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
>> +        } else if (c->table_type == BLOCK_TABLE_BITMAP) {
>> +            BLKDBG_EVENT(bs->file, BLKDBG_COW_READ);
>
> Same here.
>
>