Re: [PATCH v13 0/7] fsdax: introduce fs query to support reflink

From: Shiyang Ruan <ruansy.fnst@fujitsu.com>
To: Dave Chinner <david@fromorbit.com>
Cc: <linux-kernel@vger.kernel.org>, <linux-xfs@vger.kernel.org>,
	<nvdimm@lists.linux.dev>, <linux-mm@kvack.org>,
	<linux-fsdevel@vger.kernel.org>, <djwong@kernel.org>,
	<dan.j.williams@intel.com>, <hch@infradead.org>,
	<jane.chu@oracle.com>
Subject: Re: [PATCH v13 0/7] fsdax: introduce fs query to support reflink
Date: Thu, 21 Apr 2022 09:48:00 +0800	[thread overview]
Message-ID: <86cb0ada-208c-02de-dbc9-53c6014892c3@fujitsu.com> (raw)
In-Reply-To: <20220421012045.GR1544202@dread.disaster.area>

Hi Dave,

在 2022/4/21 9:20, Dave Chinner 写道:
> Hi Ruan,
> 
> On Tue, Apr 19, 2022 at 12:50:38PM +0800, Shiyang Ruan wrote:
>> This patchset is aimed to support shared pages tracking for fsdax.
> 
> Now that this is largely reviewed, it's time to work out the
> logistics of merging it.

Thanks!

> 
>> Changes since V12:
>>    - Rebased onto next-20220414
> 
> What does this depend on that is in the linux-next kernel?
> 
> i.e. can this be applied successfully to a v5.18-rc2 kernel without
> needing to drag in any other patchsets/commits/trees?

Firstly, I tried to apply to v5.18-rc2 but it failed.

There are some changes in memory-failure.c, which besides my Patch-02
   "mm/hwpoison: fix race between hugetlb free/demotion and 
memory_failure_hugetlb()"

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=423228ce93c6a283132be38d442120c8e4cdb061

Then, why it is on linux-next is: I was told[1] there is a better fix 
about "pgoff_address()" in linux-next:
   "mm: rmap: introduce pfn_mkclean_range() to cleans PTEs"

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=65c9605009f8317bb3983519874d755a0b2ca746
so I rebased my patches to it and dropped one of mine.

[1] https://lore.kernel.org/linux-xfs/YkPuooGD139Wpg1v@infradead.org/

> 
> What are your plans for the followup patches that enable
> reflink+fsdax in XFS? AFAICT that patchset hasn't been posted for
> while so I don't know what it's status is. Is that patchset anywhere
> near ready for merge in this cycle?
> 
> If that patchset is not a candidate for this cycle, then it largely
> doesn't matter what tree this is merged through as there shouldn't
> be any major XFS or dax dependencies being built on top of it during
> this cycle. The filesystem side changes are isolated and won't
> conflict with other work in XFS, either, so this could easily go
> through Dan's tree.
> 
> However, if the reflink enablement is ready to go, then this all
> needs to be in the XFS tree so that we can run it through filesystem
> level DAX+reflink testing. That will mean we need this in a stable
> shared topic branch and tighter co-ordination between the trees.
> 
> So before we go any further we need to know if the dax+reflink
> enablement patchset is near being ready to merge....

The "reflink+fsdax" patchset is here:

https://lore.kernel.org/linux-xfs/20210928062311.4012070-1-ruansy.fnst@fujitsu.com/

It was based on v5.15-rc3, I think I should do a rebase.

--
Thanks,
Ruan.

> 
> Cheers,
> 
> Dave.