Re: 2.5.1-pre2 does not compile

[Paul Mackerras]

Linus Torvalds writes:

> The next-generation block-layer support is starting to be merged into
> the 2.5.x tree, and that breaks old drivers that haven't been updated to
> the new locking.
> 
> In particular, there used to be _one_ lock for the whole IO system
> ("io_request_lock"), and these days it's a per-block-queue lock.
> 
> In many cases the fix is as simple as just replacing the
> "io_request_lock" with "host->host_lock", but sometimes this is
> complicated by the need to pass the right data structures down far
> enough..

Is there a description of the new block layer and its interface to
block device drivers somewhere?  That would be helpful, since Ben
Herrenschmidt and I are going to have to convert several
powermac-specific drivers.

Thanks,
Paul.