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Date: Tue, 27 Feb 2024 10:34:23 +0000
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: John Groves <John@groves.net>
CC: John Groves <jgroves@micron.com>, Jonathan Corbet <corbet@lwn.net>, "Dan
 Williams" <dan.j.williams@intel.com>, Vishal Verma
	<vishal.l.verma@intel.com>, Dave Jiang <dave.jiang@intel.com>, "Alexander
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 Kara" <jack@suse.cz>, Matthew Wilcox <willy@infradead.org>,
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	<david@fromorbit.com>, Christoph Hellwig <hch@infradead.org>,
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Subject: Re: [RFC PATCH 09/20] famfs: Add super_operations
Message-ID: <20240227103423.0000510e@Huawei.com>
In-Reply-To: <z3tnfxbbvhtbyantbm3yr3yv2qsih7darbm3p5pwwdsknuxlqa@rvexwleaixiy>
References: <cover.1708709155.git.john@groves.net>
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	<20240226125136.00002e64@Huawei.com>
	<z3tnfxbbvhtbyantbm3yr3yv2qsih7darbm3p5pwwdsknuxlqa@rvexwleaixiy>
Organization: Huawei Technologies Research and Development (UK) Ltd.
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On Mon, 26 Feb 2024 15:47:53 -0600
John Groves <John@groves.net> wrote:

> On 24/02/26 12:51PM, Jonathan Cameron wrote:
> > On Fri, 23 Feb 2024 11:41:53 -0600
> > John Groves <John@Groves.net> wrote:
> >   
> > > Introduce the famfs superblock operations
> > > 
> > > Signed-off-by: John Groves <john@groves.net>
> > > ---
> > >  fs/famfs/famfs_inode.c | 72 ++++++++++++++++++++++++++++++++++++++++++
> > >  1 file changed, 72 insertions(+)
> > >  create mode 100644 fs/famfs/famfs_inode.c
> > > 
> > > diff --git a/fs/famfs/famfs_inode.c b/fs/famfs/famfs_inode.c
> > > new file mode 100644
> > > index 000000000000..3329aff000d1
> > > --- /dev/null
> > > +++ b/fs/famfs/famfs_inode.c
> > > @@ -0,0 +1,72 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * famfs - dax file system for shared fabric-attached memory
> > > + *
> > > + * Copyright 2023-2024 Micron Technology, inc
> > > + *
> > > + * This file system, originally based on ramfs the dax support from xfs,
> > > + * is intended to allow multiple host systems to mount a common file system
> > > + * view of dax files that map to shared memory.
> > > + */
> > > +
> > > +#include <linux/fs.h>
> > > +#include <linux/pagemap.h>
> > > +#include <linux/highmem.h>
> > > +#include <linux/time.h>
> > > +#include <linux/init.h>
> > > +#include <linux/string.h>
> > > +#include <linux/backing-dev.h>
> > > +#include <linux/sched.h>
> > > +#include <linux/parser.h>
> > > +#include <linux/magic.h>
> > > +#include <linux/slab.h>
> > > +#include <linux/uaccess.h>
> > > +#include <linux/fs_context.h>
> > > +#include <linux/fs_parser.h>
> > > +#include <linux/seq_file.h>
> > > +#include <linux/dax.h>
> > > +#include <linux/hugetlb.h>
> > > +#include <linux/uio.h>
> > > +#include <linux/iomap.h>
> > > +#include <linux/path.h>
> > > +#include <linux/namei.h>
> > > +#include <linux/pfn_t.h>
> > > +#include <linux/blkdev.h>  
> > 
> > That's a lot of header for such a small patch.. I'm going to guess
> > they aren't all used - bring them in as you need them - I hope
> > you never need some of these!  
> 
> I didn't phase in headers in this series. Based on these recommendations,
> the next version of this series is gonna have to be 100% constructed from
> scratch, but okay. My head hurts just thinking about it. I need a nap...
> 
> I've been rebasing for 3 weeks to get this series out, and it occurs to
> me that maybe there are tools I'm not aware of that make it eaiser? I'm
> just typing "rebase -i..." 200 times a day. Is there a less soul-crushing way?

Hmm. There are things that make it easier to pick and chose parts of a
big diff for different patches.  Some combination of 
git reset HEAD~1
and one of the 'graphical' tools like tig that let you pick lines.

That lets you quickly break up a patch where you want to move things, then
you can reorder the patches to put them next to where you want to move
changes to and rely on git rebase -i with f or s to squash them.

Figuring out optimum path to the eventual break up you want is
a skill though.  When doing this sort of mangling I tend to get it wrong
and shout at my computer a few times a day ;)
Then git rebase --abort and try again.

End result is that you end up with coherent series and it looks like
you wrote perfect code in nice steps from the start!

Jonathan