From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:34630 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403789AbeLUOWD (ORCPT ); Fri, 21 Dec 2018 09:22:03 -0500 Received: by mail-pg1-f196.google.com with SMTP id j10so2599690pga.1 for ; Fri, 21 Dec 2018 06:22:02 -0800 (PST) Subject: Re: [PATCH 16/22] block: add BIO_HOLD_PAGES flag To: Christoph Hellwig Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, viro@zeniv.linux.org.uk References: <20181218154230.3120-1-axboe@kernel.dk> <20181218154230.3120-17-axboe@kernel.dk> <20181221113011.GE7319@lst.de> From: Jens Axboe Message-ID: <5096a164-66eb-b48b-e012-3814bc08605f@kernel.dk> Date: Fri, 21 Dec 2018 07:22:00 -0700 MIME-Version: 1.0 In-Reply-To: <20181221113011.GE7319@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 12/21/18 4:30 AM, Christoph Hellwig wrote: > On Tue, Dec 18, 2018 at 08:42:24AM -0700, Jens Axboe wrote: >> For user mapped IO, we do get_user_pages() upfront, and then do a >> put_page() on each page at end_io time to release the page reference. In >> preparation for having permanently mapped pages, add a BIO_HOLD_PAGES >> flag that tells us not to release the pages, the caller will do that. >> >> Signed-off-by: Jens Axboe > > This looks sensible, but I'm not sure it makes sense on its own. > The changes are a lot more obvious if merged into the next patch. I'll fold with the next one. -- Jens Axboe