From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755751Ab0IHVUo (ORCPT ); Wed, 8 Sep 2010 17:20:44 -0400 Received: from ns2.cypress.com ([157.95.67.5]:49083 "EHLO ns2.cypress.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755388Ab0IHVUl (ORCPT ); Wed, 8 Sep 2010 17:20:41 -0400 Reply-To: From: "David Cross" To: "'Christoph Hellwig'" Cc: , , , References: <1283888011.7250.17.camel@odc-laptop> <4313.1283956531@redhat.com> <9465F8A421744836B35704023ECA8253@stanford.edu> <20100908210553.GA22411@infradead.org> Subject: RE: [PATCH] Cachefiles, mpage_cleardirty addtition, west bridge related Date: Wed, 8 Sep 2010 14:20:06 -0700 Organization: Cypress Semiconductor Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: ActPmaNjVy1m5z4xRfaTMlOmvfkoZgAAPsFg In-Reply-To: <20100908210553.GA22411@infradead.org> X-Brightmail-Tracker: AAAAAA== X-Brightmail-Tracker: AAAAAA== X-MailScanner: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----Original Message----- From: Christoph Hellwig [mailto:hch@infradead.org] On Wed, Sep 08, 2010 at 09:51:22AM -0700, David Cross wrote: > > This is used by the current west bridge driver in the linux-next tree, > > marked as BROKEN at the moment. It is used in order to clear dirty pages > > from the page cache for a specific file after it has been allocated. This > > allows west bridge to transfer data from USB to storage directly without > > requiring that the file data path go through the CPU. The easiest way to > > think of this is that it allows for direct file based DMA. Please let me > > know if you have any additional questions or concerns on this. > It's sad enough that it was taken into any tree at all, but we're not > going to add incorrect crap into the kernel kernel for it. Can you elaborate on what you mean by "incorrect crap" in a constructive way if at all possible please? > mpage_* are pagecache manpipulation routines, and are only for use by > filesystems for inodes they manage. A driver may never access this > directly. Then what about a user space call such as falloc()? Is your objection to the existence of the code or the place where it is called from? > Is this the same piece of junk you wanted fat_get_block > exported for? It is the same driver code, but I removed the fat_get_block call in a patch that I submitted previously based on past inputs, instead adding a few lines to this function. --------------------------------------------------------------- This message and any attachments may contain Cypress (or its subsidiaries) confidential information. If it has been received in error, please advise the sender and immediately delete this message. ---------------------------------------------------------------