From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 733916B0260 for ; Tue, 3 Oct 2017 11:40:31 -0400 (EDT) Received: by mail-qk0-f200.google.com with SMTP id r18so6477332qkh.9 for ; Tue, 03 Oct 2017 08:40:31 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id w17sor3663582qtw.102.2017.10.03.08.40.30 for (Google Transport Security); Tue, 03 Oct 2017 08:40:30 -0700 (PDT) Date: Tue, 3 Oct 2017 11:40:28 -0400 (EDT) From: Nicolas Pitre Subject: Re: [PATCH v4 4/5] cramfs: add mmap support In-Reply-To: <20171003153659.GA31600@infradead.org> Message-ID: References: <20170927233224.31676-1-nicolas.pitre@linaro.org> <20170927233224.31676-5-nicolas.pitre@linaro.org> <20171001083052.GB17116@infradead.org> <20171003145732.GA8890@infradead.org> <20171003153659.GA31600@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Richard Weinberger , Alexander Viro , "linux-mm@kvack.org" , linux-fsdevel , "linux-embedded@vger.kernel.org" , LKML , Chris Brandt On Tue, 3 Oct 2017, Christoph Hellwig wrote: > On Tue, Oct 03, 2017 at 11:30:50AM -0400, Nicolas Pitre wrote: > > Unless you have a better scheme altogether to suggest of course, given > > the existing constraints. > > I still can't understand why this convoluted fault path that finds > vma, attempts with all kinds of races and then tries to update things > like vm_ops is even nessecary. > > We have direct mappings of physical address perfectly working in the > DAX code (even with write support!) or in drivers using remap_pfn_range > so a really good explanation why neither scheme can be used is needed > first. I provided that explanation several times by now in my cover letter. And separately even to you directly at least once. What else should I do? Nicolas -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org