Re: [Lse-tech] SCSI io_request_lock patch

Jens Axboe (axboe@suse.de)
Thu, 15 Nov 2001 11:23:00 +0100


On Wed, Nov 14 2001, Jonathan Lahr wrote:
> > It's absolutely worthless. Look, it ties in with the points I made
> > below. You are exporting the merge functions for instance, and setting
> > them in the queue. This will cause scsi_merge not to use it's own
> > functions, broken.
>
> As in the baseline, initialize_merge_fn overwrites these pointers:
> q->back_merge_fn = scsi_back_merge_fn_;
> q->front_merge_fn = scsi_front_merge_fn_;
> q->merge_requests_fn = scsi_merge_requests_fn_;

I had forgotten I had #if 0 out the check for already set back_merge etc
in scsi_merge -- however that's still beside the point. _Why_ are you
exporting the ll_rw_blk functions and setting them just to have them
overridden? Makes no sense.

Don't export the merge functions ever, define your own if you really
need them. You don't, though.

As I've mentioned before, go ahead with the make_request_fn replacement.
That is indeed what it is there for.

-- 
Jens Axboe

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