Re: [PATCH v11 04/14] block/backup: introduce BlockCopyState

[Vladimir Sementsov-Ogievskiy]

20.09.2019 15:56, Vladimir Sementsov-Ogievskiy wrote:
> 20.09.2019 15:46, Max Reitz wrote:
>> On 13.09.19 20:25, Vladimir Sementsov-Ogievskiy wrote:
>>> 10.09.2019 13:23, Vladimir Sementsov-Ogievskiy wrote:
>>>> Split copying code part from backup to "block-copy", including separate
>>>> state structure and function renaming. This is needed to share it with
>>>> backup-top filter driver in further commits.
>>>>
>>>> Notes:
>>>>
>>>> 1. As BlockCopyState keeps own BlockBackend objects, remaining
>>>> job->common.blk users only use it to get bs by blk_bs() call, so clear
>>>> job->commen.blk permissions set in block_job_create and add
>>>> job->source_bs to be used instead of blk_bs(job->common.blk), to keep
>>>> it more clear which bs we use when introduce backup-top filter in
>>>> further commit.
>>>>
>>>> 2. Rename s/initializing_bitmap/skip_unallocated/ to sound a bit better
>>>> as interface to BlockCopyState
>>>>
>>>> 3. Split is not very clean: there left some duplicated fields, backup
>>>> code uses some BlockCopyState fields directly, let's postpone it for
>>>> further improvements and keep this comment simpler for review.
>>>>
>>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
>>>> ---
>>>
>>>
>>> [..]
>>>
>>>> +
>>>> +static BlockCopyState *block_copy_state_new(
>>>> +        BlockDriverState *source, BlockDriverState *target,
>>>> +        int64_t cluster_size, BdrvRequestFlags write_flags,
>>>> +        ProgressBytesCallbackFunc progress_bytes_callback,
>>>> +        ProgressResetCallbackFunc progress_reset_callback,
>>>> +        void *progress_opaque, Error **errp)
>>>> +{
>>>> +    BlockCopyState *s;
>>>> +    int ret;
>>>> +    uint64_t no_resize = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE |
>>>> +                         BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD;
>>>> +    BdrvDirtyBitmap *copy_bitmap;
>>>> +
>>>> +    copy_bitmap = bdrv_create_dirty_bitmap(source, cluster_size, NULL, 
>>>> errp);
>>>> +    if (!copy_bitmap) {
>>>> +        return NULL;
>>>> +    }
>>>> +    bdrv_disable_dirty_bitmap(copy_bitmap);
>>>> +
>>>> +    s = g_new(BlockCopyState, 1);
>>>> +    *s = (BlockCopyState) {
>>>> +        .source = blk_new(bdrv_get_aio_context(source),
>>>> +                          BLK_PERM_CONSISTENT_READ, no_resize),
>>>> +        .target = blk_new(bdrv_get_aio_context(target),
>>>> +                          BLK_PERM_WRITE, no_resize),
>>>> +        .copy_bitmap = copy_bitmap,
>>>> +        .cluster_size = cluster_size,
>>>> +        .len = bdrv_dirty_bitmap_size(copy_bitmap),
>>>> +        .write_flags = write_flags,
>>>> +        .use_copy_range = !(write_flags & BDRV_REQ_WRITE_COMPRESSED),
>>>> +        .progress_bytes_callback = progress_bytes_callback,
>>>> +        .progress_reset_callback = progress_reset_callback,
>>>> +        .progress_opaque = progress_opaque,
>>>> +    };
>>>> +
>>>> +    s->copy_range_size = 
>>>> QEMU_ALIGN_UP(MIN(blk_get_max_transfer(s->source),
>>>> +                                           
>>>> blk_get_max_transfer(s->target)),
>>>> +                                       s->cluster_size);
>>>
>>> preexistent, but it obviously should be QEMU_ALIGN_DOWN. I can resend with 
>>> a separate
>>> fix, it may be fixed while queuing (if resend is not needed for other 
>>> reasons) or
>>> I'll send a follow-up fix later, whichever you prefer.
>>
>> Hm, true.  But then we’ll also need to handle the (unlikely, admittedly)
>> case where max_transfer < cluster_size so this would then return 0 (by
>> setting use_copy_range = false).  So how about this:
> 
> Done in [PATCH v12 0/2] backup: copy_range fixes.
> If it is convenient I'll rebase these series on "[PATCH v12 0/2] backup: 
> copy_range fixes"
> 

Or vice versa



-- 
Best regards,
Vladimir