On Fri, Apr 20, 2018 at 10:07:16AM +1000, Dave Chinner wrote: > On Thu, Apr 19, 2018 at 02:57:23PM -0400, Brian Foster wrote: > > On Thu, Apr 19, 2018 at 10:25:48AM -0700, Darrick J. Wong wrote: > > > On Thu, Apr 19, 2018 at 08:55:47AM -0400, Brian Foster wrote: > > > > On Tue, Apr 17, 2018 at 07:40:20PM -0700, Darrick J. Wong wrote: > > > > > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > > > > > > > We've never cached buffers when reading or writing superblocks, so we > > > > > need to change scrub to do likewise or risk screwing up the uncached sb > > > > > buffer usage everywhere else. > > > > > > > > > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > > > > --- > > > > > > > > Hmm, so this goes back to this[1] thread, right? > > > > > > Yep. > > > > > > > IIRC, we wanted to end up with an lru-bypassing uncached buffer lookup > > > > mechanism to provide uncached behavior for resource-saving purposes > > > > but without introducing serialization issues between multiple users of > > > > uncached buffers. > > > > > > Right. > > > > > > > On a quick look back, growfs currently uses cached buffers for secondary > > > > superblocks and the associated patch was looking to change that to > > > > something like the above. Don't we have the same requirement here (since > > > > growfs currently still uses cached buffers)? > > > > > > Correct, this patch is contingent on landing Dave's "tableise growfs" > > > series that converts growfs to use uncached buffers for writing out the > > > new secondary supers. If I manage to land Dave's growfs thing before > > > repair then I'll keep this; if repair goes first I'll defer it to that > > > series. > > > > > > > Ok, though I'm not sure I see the need for the higher level series > > dependency. Don't one of these patches just need to fold in a helper[1] > > to set the lru reference appropriately and start to use it? > > Yes, that would work. :P Ok, I'll fold that into my patch and I'll fix things up depending on who wins the race. I changed the ASSERT to trip on agno == 0, btw. --D > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
