RE: [PATCH v2 1/2] block: add sync_blockdev_range()

[Yuezhang.Mo@xxxxxxxx]

> From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> > --- a/block/bdev.c
> > +++ b/block/bdev.c
> > @@ -200,6 +200,16 @@ int sync_blockdev(struct block_device *bdev)  }
> > EXPORT_SYMBOL(sync_blockdev);
> >
> > +int sync_blockdev_range(struct block_device *bdev, loff_t lstart,
> > +loff_t lend) {
> > +	if (!bdev)
> > +		return 0;
> 
> This check isn't really needed, and I don't think we need a !CONFIG_BLOCK
> stub for this either.

sync_blockdev() and related helpers have this check and a !CONFIG_BLOCK stub.
I would like to understand the background of your comment, could you explain a little more?

Thanks.