Andrew Morton wrote:
> Andrew Morton <akpm@osdl.org> wrote:
> 
>> buffer_error() was always supposed to be temporary.  Once per month someone
>> reports the one in __find_get_block_slow(), but that's all.  The only
>> reason for keeping it around is as a debug aid to filesystem developers.
>>
>> We could make it a no-op if !CONFIG_BUFFER_DEBUG.
> 
> 
> But even if we do that, the compiler cannot optimise away things like:
> 
> 	if (atomic_read(&bh->b_count) == 0 &&
> 			!PageLocked(bh->b_page) &&
> 			!PageWriteback(bh->b_page))
> 		do {} while (0);

Nod.


> so if it offends you, go kill the thing outright.

If you like config variables, here's a second patch (untested but should 
be obvious).  As a side note, we need a Kconfig for generic debugging 
options...

I would rather not kill the code in submit_bh() outright, just disable 
it for non-filesystem developers.

For me, buffer_error() definition is secondary to disabling these 
checks-that-noone-hits in the submit_bh() fast path.

	Jeff