On Tue, Jul 03, 2007 at 10:18:55AM -0400, Stephen M. Rumble wrote:
>
> In any event, I'd either like to fix this so it behaves as expected,  

What is "as expected"?  It works the way the Unix buffer cache always has.

> A few related questions: If the buffer cache expects fixed-sized  
> buffers, does that mean for some filesystems there could be a 124-byte  
> struct buf for each block of cached data? Also, do we not have any  
> filesystems with extents where this sort of thing would have cropped  
> up before?

You understand that actual file data is not cached through the buffer
cache, yes?  If EFS is doing so, EFS is buggy.  The buffer cache is only
used for metadata now -- the page cache handles all else.

We don't have any filesystems that use extents -- the clustering done by
FFS is the closest thing to that, really, and that's now handled by the
paging code.  When it was done through the buffer cache... sigh... do
you _really_ want to know?

Thor