Re: [PATCH 1/3] direct-io: add a hook for the fs to provide its ownbio merging check function

From: Miao Xie
Date: Wed Nov 17 2010 - 20:32:40 EST


On wed, 17 Nov 2010 20:24:39 -0500, Chris Mason wrote:
Excerpts from Miao Xie's message of 2010-11-17 20:18:18 -0500:
Right thats the idea, if we can't span chunks/stripes we should be doing that
limiting in our get_blocks call and that way we don't have to screw with the
generic direct io stuff too much. Thanks,

In this case we're adding complexity to the O_DIRECT mapping code, when
we really should be adding it to the btrfs submit bio hook. It can
easily break up the bio into smaller units, which will leave us with a
smaller number of get_blocks calls overall.

I'm working that out now.

Do you mean you are fixing this bug now?

I started on it this afternoon, but lost network due to high winds here.
So, I didn't make any real progress.

If you'd like to fix this in the btrfs direct-io bio submit call you're
welcome to continue working on it.

The idea is to just clone and split up the bio, which will keep us from
filling up fs/direct-io.c w/btrfs rules and allow us to take fewer
trips into the get_blocks call.

Ok, I'll do it.

Thanks
Miao
--
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/