From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx4-phx2.redhat.com ([209.132.183.25]:36625 "EHLO mx4-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752284AbcEERcS (ORCPT ); Thu, 5 May 2016 13:32:18 -0400 Date: Thu, 5 May 2016 13:32:08 -0400 (EDT) From: Bob Peterson To: Christoph Hellwig Cc: xfs@oss.sgi.com, linux-fsdevel@vger.kernel.org Message-ID: <1926435280.1998700.1462469528484.JavaMail.zimbra@redhat.com> In-Reply-To: <1462310947-16132-3-git-send-email-hch@lst.de> References: <1462310947-16132-1-git-send-email-hch@lst.de> <1462310947-16132-3-git-send-email-hch@lst.de> Subject: Re: [PATCH 02/14] fs: introduce iomap infrastructure MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: ----- Original Message ----- > Add infrastructure for multipage buffered writes. This is implemented > using an main iterator that applies an actor function to a range that > can be written. > > This infrastucture is used to implement a buffered write helper, one > to zero file ranges and one to implement the ->page_mkwrite VM > operations. All of them borrow a fair amount of code from fs/buffers. > for now by using an internal version of __block_write_begin that > gets passed an iomap and builds the corresponding buffer head. > > The file system is gets a set of paired ->iomap_begin and ->iomap_end > calls which allow it to map/reserve a range and get a notification > once the write code is finished with it. > > Based on earlier code from Dave Chinner. > > Signed-off-by: Christoph Hellwig > --- > + /* > + * For unwritten regions, we always need to ensure that > + * sub-block writes cause the regions in the block we are not > + * writing to are zeroed. Set the buffer as new to ensre this. Minor typo: s/ensre/ensure/ above. Reviewed-off-by: Bob Peterson