Re: [PATCH v2 2/3] block: don't hide inode from block_device users

[Pavel Begunkov]

On 10/14/21 05:51, Christoph Hellwig wrote:
> On Wed, Oct 13, 2021 at 07:44:20PM +0100, Pavel Begunkov wrote:
> > Mildly hot in io_uring w/o fixed files, but that's not peak perf,
> > but would also be great to get rid of bdev->bd_inode dereference,
> > e.g. lots of in fops.c.
> >
> > Are you going to just hid the dereference in helpers or kill it
> > with some offseting magic?
>
> The only real hot path uses I found is the size (which you and Jens
> already seem to have moved to use something out of the inode for the
> fast path),  and maybe the blkbits for which we could do the same.
>
> So basically the idea is to not touch the inode in the hot path,
> and use accessors helpers in bdev.c that could do the offsetof trick.

I see, sounds good

--
Pavel Begunkov