Re: [PATCH] fix readahead pipeline break caused by block plug

[Wu Fengguang]

On Tue, Jan 31, 2012 at 05:46:21AM -0500, Christoph Hellwig wrote:
> On Tue, Jan 31, 2012 at 06:34:16PM +0800, Wu Fengguang wrote:
> >  	}
> >  
> > +	blk_start_plug(&plug);
> >  	written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
> > +	blk_finish_plug(&plug);
> 
> Please move the plugging into ->direct_IO for both read and write, as
> that is the boundary between generic highlevel code, and low-level block
> code that should know about plugs.

The problem is, there are a dozen of ->direct_IO callback functions.
While there are only two ->direct_IO() callers, one for READ and
another for WRITE, which are much easier to deal with.

Thanks,
Fengguang
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/