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From: Kairui Song <ryncsn@gmail.com>
Date: Tue, 30 Apr 2024 23:40:43 +0800
Message-ID: <CAMgjq7ADnn+uEL0jY676rk6+9cFWgrZxMCZ2m2qf1GM87Eav9Q@mail.gmail.com>
Subject: Re: [EXTERNAL] [PATCH v3 05/12] cifs: drop usage of page_file_offset
To: Steven French <Steven.French@microsoft.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>, Andrew Morton <akpm@linux-foundation.org>, 
	"Huang, Ying" <ying.huang@intel.com>, Matthew Wilcox <willy@infradead.org>, Chris Li <chrisl@kernel.org>, 
	Barry Song <v-songbaohua@oppo.com>, Ryan Roberts <ryan.roberts@arm.com>, Neil Brown <neilb@suse.de>, 
	Minchan Kim <minchan@kernel.org>, Hugh Dickins <hughd@google.com>, 
	David Hildenbrand <david@redhat.com>, Yosry Ahmed <yosryahmed@google.com>, 
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Namjae Jeon <linkinjeon@kernel.org>, 
	"Paulo Alcantara (SUSE)" <pc@manguebit.com>, Shyam Prasad <Shyam.Prasad@microsoft.com>, 
	Bharath S M <bharathsm@microsoft.com>
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On Tue, Apr 30, 2024 at 4:19=E2=80=AFAM Steven French
<Steven.French@microsoft.com> wrote:
>
> Wouldn't this make it harder to fix the regression when swap file support=
 was temporarily removed from cifs.ko (due to the folio migration)?   I was=
 hoping to come back to fixing swapfile support for cifs.ko in 6.10-rc (whi=
ch used to pass the various xfstests for this but code got removed with fol=
ios/netfs changes).
>

Hi Steven,

I think this won't cause any trouble for that, the new swap_rw
interface should have splitted the swap cache from fs side, which made
the code struct cleaner, and I think that's the right path. NFS is
using that already. With this interface, .read_folio (cifs_read_folio)
should never be called for swap cache folios.