From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by kanga.kvack.org (Postfix) with ESMTP id 2F9D48E0002 for ; Sat, 15 Dec 2018 05:51:15 -0500 (EST) Received: by mail-wm1-f72.google.com with SMTP id y85so3081926wmc.7 for ; Sat, 15 Dec 2018 02:51:15 -0800 (PST) Received: from newverein.lst.de (verein.lst.de. [213.95.11.211]) by mx.google.com with ESMTPS id b1si4883554wrj.176.2018.12.15.02.51.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 15 Dec 2018 02:51:13 -0800 (PST) Date: Sat, 15 Dec 2018 11:51:12 +0100 From: Christoph Hellwig Subject: Re: [PATCH] fix page_count in ->iomap_migrate_page() Message-ID: <20181215105112.GC1575@lst.de> References: <1544766961-3492-1-git-send-email-openzhangj@gmail.com> <1618433.IpySj692Hd@blindfold> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1618433.IpySj692Hd@blindfold> Sender: owner-linux-mm@kvack.org List-ID: To: Richard Weinberger Cc: zhangjun , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Darrick J . Wong" , hch@lst.de, bfoster@redhat.com, Dave Chinner , akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, mhocko@suse.com, n-horiguchi@ah.jp.nec.com, mgorman@techsingularity.net, aarcange@redhat.com, willy@infradead.org, linux@dominikbrodowski.net, linux-mm@kvack.org, Gao Xiang FYI, for iomap we got a patch to just increment the page count when setting the private data, and it finally got merged into mainline after a while. Not that it totally makes sense to me, but it is what it is. It would just be nice if set_page_private took care of it and we had a clear_page_private to undo it, making the whole scheme at lot more obvious.