Re: [RFC/PATCH] - revert generic_fillattr stat->blksize to PAGE_CACHE_SIZE

From: Eric Sandeen
Date: Mon Nov 06 2006 - 20:39:42 EST


Andreas Dilger wrote:
On Nov 06, 2006 17:15 -0600, Eric Sandeen wrote:
Christoph Hellwig wrote:
I agree with the conclusion, but the patch is incomplete. You went down
all the way to find out what the fileystems do in this messages, so add
the hunks to override the defaults for non-standard filesystems to the
patch aswell to restore the pre-inode diet state.
Well, agreed. I put 80% or more back to pre-patch state, but not all.
:) So it's less broken with my patch than without, so at least it's
moving forward. So... Ted's patches get in w/o fixing up all the other
filesystems (left as an exercise to the patch reader) but mine can't? :)

Actually, rather than blindly revert to pre-patch behaviour it would be
worthwhile to determine if PAGE_SIZE isn't the better value. In some
cases people don't understand that i_blksize is the "optimal IO size"
and instead assume it is the filesystem blocksize. I saw a few that were
e.g. 512 and that can't be very useful.

I'm willing to either revert everyting to pre-inode-diet behavior, or leave it at the (newly re-proposed) page size default and let the other fs maintainers sort it out for their own codebase, but I don't pretend to know what is best for, say, qnx4 etc... I'd be willing to cc: all maintainers asking them to take another long hard look at their code. :)

As we saw with cifs, these changes can have unintended consequences (not picking on cifs, it's just one that ran into issues with the broad-stroke change).

-Eric
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