[Patch 15/18] fs/logfs/super.c

[Jörn Engel]

On Sun, 10 June 2007 20:33:05 +0200, Arnd Bergmann wrote:
> 
> Then maybe the submit_bio logic should only be done for the ->write
> path, not for ->read. The data that gets written out should already
> be present in the page cache for the files, so there is not much point
> having again, while you can see the read path as blockdev readahead:
> When you read a physical block that contains a logical block, it's
> likely to also contain part of another logical block that is going
> to be read in the near future.

Makes a lot of sense, yes.

> This way, you would also get exclusively clean pages in the block
> device address_space, which can be easily discarded.
> 
> Also, maintaining correct ordering between write requests can be
> done easier if you insert the bios directly, instead of waiting
> for the lru writeback.

s/easier/only/ ?

I don't think logfs on block devices makes too much sense yet, so my
personal priority for this is low.  Still, an obvious improvement.

Jörn

-- 
...one more straw can't possibly matter...
-- Kirby Bakken