On 05/16/2017 10:07 PM, Bart Van Assche wrote:

On Tue, 2017-05-16 at 17:39 +0800, Anand Jain wrote:

quoted

BTRFS wanted a block device flush function which does not wait for
its completion, so that the flush for the next device can be called
in the same thread.

Here is a RFC patch to provide the function
'blkdev_issue_flush_no_wait()', which is based on the current device
flush function 'blkdev_issue_flush()', however it uses submit_bio()
instead of submit_bio_wait().

This patch is for review comments, will send out a final patch based
on the comments received.

Hello Anand,

Since the block layer can reorder requests, I think using
blkdev_issue_flush_no_wait() will only yield the intended result if
the caller waits until the requests that have to be flushed have completed.
Is that how you intend to use this function?

  Yes. The patch 2/2 did that. Sorry for no explanation though.

Thanks, Anand

Thanks,

Bart.N�����r��y���b�X��ǧv�^�)޺{.n�+����{�n�߲)���w*jg���

�����ݢj/���z�ޖ��2�ޙ���&�)ߡ�a����
�G���h��j:+v���w�٥