From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758309AbcHWWGc (ORCPT ); Tue, 23 Aug 2016 18:06:32 -0400 Received: from mga05.intel.com ([192.55.52.43]:17979 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755214AbcHWWEd (ORCPT ); Tue, 23 Aug 2016 18:04:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,567,1464678000"; d="scan'208";a="752634155" From: Ross Zwisler To: linux-kernel@vger.kernel.org Cc: Ross Zwisler , "Theodore Ts'o" , Alexander Viro , Andreas Dilger , Andrew Morton , Dan Williams , Dave Chinner , Jan Kara , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@ml01.01.org, Matthew Wilcox Subject: [PATCH v2 3/9] ext4: tell DAX the size of allocation holes Date: Tue, 23 Aug 2016 16:04:13 -0600 Message-Id: <20160823220419.11717-4-ross.zwisler@linux.intel.com> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160823220419.11717-1-ross.zwisler@linux.intel.com> References: <20160823220419.11717-1-ross.zwisler@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When DAX calls _ext4_get_block() and the file offset points to a hole we currently don't set bh->b_size. When we re-enable PMD faults DAX will need bh->b_size to tell it the size of the hole so it can decide whether to fault in a 4 KiB zero page or a 2 MiB zero page. _ext4_get_block() has the hole size information from ext4_map_blocks(), so populate bh->b_size. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara --- fs/ext4/inode.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 0900cb4..9075fac 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -759,6 +759,9 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock, ext4_update_bh_state(bh, map.m_flags); bh->b_size = inode->i_sb->s_blocksize * map.m_len; ret = 0; + } else if (ret == 0) { + /* hole case, need to fill in bh->b_size */ + bh->b_size = inode->i_sb->s_blocksize * map.m_len; } return ret; } -- 2.9.0