From patchwork Wed May 11 21:08:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 621276 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3r4pgp1vjbz9t41 for ; Thu, 12 May 2016 07:11:02 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752666AbcEKVKk (ORCPT ); Wed, 11 May 2016 17:10:40 -0400 Received: from mga09.intel.com ([134.134.136.24]:47806 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752198AbcEKVJi (ORCPT ); Wed, 11 May 2016 17:09:38 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP; 11 May 2016 14:09:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,609,1455004800"; d="scan'208";a="977838225" Received: from omniknight.lm.intel.com ([10.232.112.171]) by fmsmga002.fm.intel.com with ESMTP; 11 May 2016 14:09:20 -0700 From: Vishal Verma To: linux-nvdimm@lists.01.org Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Ross Zwisler , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Andrew Morton , linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Moyer , Boaz Harrosh Subject: [PATCH v7 4/6] dax: export a low-level __dax_zero_page_range helper Date: Wed, 11 May 2016 15:08:50 -0600 Message-Id: <1463000932-31680-5-git-send-email-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1463000932-31680-1-git-send-email-vishal.l.verma@intel.com> References: <1463000932-31680-1-git-send-email-vishal.l.verma@intel.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Christoph Hellwig This allows XFS to perform zeroing using the iomap infrastructure and avoid buffer heads. [vishal: fix conflicts with dax-error-handling] Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara --- fs/dax.c | 35 ++++++++++++++++++++--------------- include/linux/dax.h | 7 +++++++ 2 files changed, 27 insertions(+), 15 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 0abbbb6..651d4b1 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -947,6 +947,23 @@ int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +int __dax_zero_page_range(struct block_device *bdev, sector_t sector, + unsigned int offset, unsigned int length) +{ + struct blk_dax_ctl dax = { + .sector = sector, + .size = PAGE_SIZE, + }; + + if (dax_map_atomic(bdev, &dax) < 0) + return PTR_ERR(dax.addr); + clear_pmem(dax.addr + offset, length); + wmb_pmem(); + dax_unmap_atomic(bdev, &dax); + return 0; +} +EXPORT_SYMBOL_GPL(__dax_zero_page_range); + /** * dax_zero_page_range - zero a range within a page of a DAX file * @inode: The file being truncated @@ -982,23 +999,11 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, bh.b_bdev = inode->i_sb->s_bdev; bh.b_size = PAGE_SIZE; err = get_block(inode, index, &bh, 0); - if (err < 0) + if (err < 0 || !buffer_written(&bh)) return err; - if (buffer_written(&bh)) { - struct block_device *bdev = bh.b_bdev; - struct blk_dax_ctl dax = { - .sector = to_sector(&bh, inode), - .size = PAGE_SIZE, - }; - if (dax_map_atomic(bdev, &dax) < 0) - return PTR_ERR(dax.addr); - clear_pmem(dax.addr + offset, length); - wmb_pmem(); - dax_unmap_atomic(bdev, &dax); - } - - return 0; + return __dax_zero_page_range(bh.b_bdev, to_sector(&bh, inode), + offset, length); } EXPORT_SYMBOL_GPL(dax_zero_page_range); diff --git a/include/linux/dax.h b/include/linux/dax.h index 7f853ff..90fbc99 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -14,12 +14,19 @@ int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); #ifdef CONFIG_FS_DAX struct page *read_dax_sector(struct block_device *bdev, sector_t n); +int __dax_zero_page_range(struct block_device *bdev, sector_t sector, + unsigned int offset, unsigned int length); #else static inline struct page *read_dax_sector(struct block_device *bdev, sector_t n) { return ERR_PTR(-ENXIO); } +static inline int __dax_zero_page_range(struct block_device *bdev, + sector_t sector, unsigned int offset, unsigned int length) +{ + return -ENXIO; +} #endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE