From patchwork Sun Aug 21 02:29:43 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Allison Henderson X-Patchwork-Id: 110794 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 3F7BBB6F7B for ; Sun, 21 Aug 2011 12:26:45 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754216Ab1HUC0n (ORCPT ); Sat, 20 Aug 2011 22:26:43 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:54120 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751302Ab1HUC0m (ORCPT ); Sat, 20 Aug 2011 22:26:42 -0400 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by e5.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p7L1umtG021095 for ; Sat, 20 Aug 2011 21:56:48 -0400 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p7L2Qf662904300 for ; Sat, 20 Aug 2011 22:26:41 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p7L2Qe8R008788 for ; Sat, 20 Aug 2011 22:26:40 -0400 Received: from elm3c80.beaverton.ibm.com ([9.47.69.80]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p7L2QcRl008765; Sat, 20 Aug 2011 22:26:40 -0400 From: Allison Henderson To: linux-ext4@vger.kernel.org Cc: Allison Henderson Subject: [PATCH 2/6 v5] ext4: fix xfstests 75, 112, 127 punch hole failure Date: Sat, 20 Aug 2011 19:29:43 -0700 Message-Id: <1313893787-25460-3-git-send-email-achender@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1313893787-25460-1-git-send-email-achender@linux.vnet.ibm.com> References: <1313893787-25460-1-git-send-email-achender@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org This patch addresses a bug found by xfstests 75, 112, 127 when blocksize = 1k This bug happens because the punch hole code only zeros out non block aligned regions of the page. This means that if the blocks are smaller than a page, then the block aligned regions of the page inside the hole are left un-zeroed, and their buffer heads are still mapped. This bug is corrected by using ext4_discard_partial_page_buffers to properly zero the partial page at the head and tail of the hole, and unmap the corresponding buffer heads Signed-off-by: Allison Henderson --- :100644 100644 4d73e11... cd58117... M fs/ext4/extents.c fs/ext4/extents.c | 48 ++++++++++++++++++++++++++++++------------------ 1 files changed, 30 insertions(+), 18 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4d73e11..cd58117 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4157,7 +4157,7 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) struct address_space *mapping = inode->i_mapping; struct ext4_map_blocks map; handle_t *handle; - loff_t first_block_offset, last_block_offset, block_len; + loff_t first_block_offset, last_block_offset, page_len; loff_t first_page, last_page, first_page_offset, last_page_offset; int ret, credits, blocks_released, err = 0; @@ -4206,24 +4206,36 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) goto out; /* - * Now we need to zero out the un block aligned data. - * If the file is smaller than a block, just - * zero out the middle + * Now we need to zero out the non-page-aligned data in the + * pages at the start and tail of the hole, and unmap the buffer + * heads for the block aligned regions of the page that were + * completely zeroed. */ - if (first_block > last_block) - ext4_block_zero_page_range(handle, mapping, offset, length); - else { - /* zero out the head of the hole before the first block */ - block_len = first_block_offset - offset; - if (block_len > 0) - ext4_block_zero_page_range(handle, mapping, - offset, block_len); - - /* zero out the tail of the hole after the last block */ - block_len = offset + length - last_block_offset; - if (block_len > 0) { - ext4_block_zero_page_range(handle, mapping, - last_block_offset, block_len); + if (first_page > last_page) { + /* + * If the file space being truncated is contained within a page + * just zero out and unmap the middle of that page + */ + ext4_discard_partial_page_buffers(handle, + mapping, offset, length, 0); + } else { + /* + * zero out and unmap the partial page that contains + * the start of the hole + */ + page_len = first_page_offset - offset; + if (page_len > 0) + ext4_discard_partial_page_buffers(handle, mapping, + offset, page_len, 0); + + /* + * zero out and unmap the partial page that contains + * the end of the hole + */ + page_len = offset + length - last_page_offset; + if (page_len > 0) { + ext4_discard_partial_page_buffers(handle, mapping, + last_page_offset, page_len, 0); } }