Re: [PATCH 3/5] xfs: separate the dqrele_all inode grab logic from xfs_inode_walk_ag_grab

From: Dave Chinner <david@fromorbit.com>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: linux-xfs@vger.kernel.org, hch@infradead.org
Subject: Re: [PATCH 3/5] xfs: separate the dqrele_all inode grab logic from xfs_inode_walk_ag_grab
Date: Wed, 2 Jun 2021 07:40:27 +1000	[thread overview]
Message-ID: <20210601214027.GD664593@dread.disaster.area> (raw)
In-Reply-To: <20210601195051.GB26380@locust>

On Tue, Jun 01, 2021 at 12:50:51PM -0700, Darrick J. Wong wrote:
> On Tue, Jun 01, 2021 at 10:20:23AM +1000, Dave Chinner wrote:
> > On Mon, May 31, 2021 at 03:41:07PM -0700, Darrick J. Wong wrote:
> > > From: Darrick J. Wong <djwong@kernel.org>
> > > 
> > > Disentangle the dqrele_all inode grab code from the "generic" inode walk
> > > grabbing code, and and use the opportunity to document why the dqrele
> > > grab function does what it does.
> > > 
> > > Since dqrele_all is the only user of XFS_ICI_NO_TAG, rename it to
> > > something more specific for what we're doing.
> > > 
> > > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > > ---
> > >  fs/xfs/xfs_icache.c |   64 ++++++++++++++++++++++++++++++++++++++++++++++++---
> > >  fs/xfs/xfs_icache.h |    4 ++-
> > >  2 files changed, 62 insertions(+), 6 deletions(-)
> > > 
> > > 
> > > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > > index 34b8b5fbd60d..5501318b5db0 100644
> > > --- a/fs/xfs/xfs_icache.c
> > > +++ b/fs/xfs/xfs_icache.c
> > > @@ -26,6 +26,8 @@
> > >  
> > >  #include <linux/iversion.h>
> > >  
> > > +static bool xfs_dqrele_inode_grab(struct xfs_inode *ip);
> > > +
> > 
> > Just mov the function higher up in the file rather than add forward
> > declarations....
> 
> Ugh, this will cause churn that will ripple through this and the next
> iwalk refactoring patchsets and deferred inactivation.  Can I please
> please please defer the churn cleanup until the end of all that?

Yes, by all means. I don't want to make it harder to get stuff done,
so moving stuff around at the end of the series is fine...

....

> > This is basically just duplication of xfs_inode_walk_ag_grab()
> > without the XFS_INODE_WALK_INEW_WAIT check in it. At this point I
> > just don't see a reason for this function or the
> > XFS_ICI_DQRELE_NONTAG rename just to use this grab function...
> 
> Ugh.  I should have sent the /next/ iwalk refactoring series along with
> this one so that it would become more obvious that the end goal is to
> seal all the incore inode walk code in xfs_icache.c, since there are
> only four of them (reclaim, inodegc, blockgc, quotaoff) and the grab
> functions for all four are just different enough that it's not really
> worth it to keep them combined in one function full of conditionals.
> 
> Once that's done, the only user of xfs_inode_walk_ag_grab is the blockgc
> code and I can rename it.

Ok, that context is missing from the patch series. :/

> Ofc the reason I held back is that the next series adds 8 more iwalk
> cleanup patches, and the more patches I send all at once the longer it
> takes for anyone to start looking at it.  I /still/ can't figure out the
> balance between risking overwhelming everyone with too many patches vs.
> sending insufficient patches to convey where I'm really going with
> something.

Yeah, can be difficult. I prefer to err on the side of "complete
change" rather than splitting two parts of a larger work
arbitrarily...

> <shrug> I might just ping you on irc so that we can have a conversation
> about this and summarize whatever we come up with for the list.

You've got a branch with the full series in it somewhere, I'm
guessing? point me at it so I can see where this ends up....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com