Re: [patch] scsi: revert "[SCSI] Get rid of scsi_cmnd->done"

[Linus Torvalds <torvalds@linux-foundation.org>]

On Wed, 2 Jan 2008, James Bottomley wrote:
> > 
> > To say that another way:
> > 
> >  "the code is functionally equivalent, EXCEPT IT ISN'T, and it's 
> >   known to be broken".
> > 
> > wouldn't you say my version is more honest and correct?
> 
> No.  Just because a bug appears when a particular piece of code is in
> and disappears when it is reverted doesn't automatically equate to the
> code in question being buggy.

But it *DOES* mean that it's not equivalent.

> Look at the taxonomy of the bug.  This is the form of the error:
> 
> buffer I/O error on device sr0, logical block 20304
> attempt to access beyond end of device
> sr0: rw=0, want=81224, limit=40944
> 
> The last limit is the most suggestive, that comes straight from
> bdev->bd_inode->i_size>>9 and is supposed to be the size of the block
> device in 512 byte blocks. For a 4.7GB DVD, it's a little small.
> Nothing in the sr code sets this directly (although it does come from
> get_blkdev() for the first opener).  pktcdvd does set it, though ... and
> probably wrongly if the drive in question isn't UDF formatted.

.. but you're ignoring the fact that if pktcdvd sets it wrong, then it 
should be visible with the pre-commit kernel *also*.

In other words, you continue to ignore the fact that BEHAVIOUR CHANGED.

Why?

		Linus