[linux-lvm] Trim support on stripped volumes ?

[Mike Snitzer]

On Wed, May 25 2011 at  4:11am -0400,
Franck Routier (personnel) <alci at mecadu.org> wrote:

> Le mardi 24 mai 2011 à 09:14 -0400, Mike Snitzer a écrit :
> 
> > When using -o discard, ext4 will log a warning if a discard failed (and
> > will disable discards).
> > 
> > So ext4 is a great indicator for whether discards are working on your
> > striped LV volume.
> > 
> 
> Just out of curiosity, how does ext4 tell if discards is working or
> not ?

It checks the return code from ext4_issue_discard() -- which comes from
sb_issue_discard().  See: fs/ext4/mballoc.c:release_blocks_on_commit()