From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 778B46B025E for ; Tue, 23 Aug 2016 18:04:34 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id h186so277439649pfg.2 for ; Tue, 23 Aug 2016 15:04:34 -0700 (PDT) Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id hm6si5740071pac.254.2016.08.23.15.04.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Aug 2016 15:04:32 -0700 (PDT) From: Ross Zwisler 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> In-Reply-To: <20160823220419.11717-1-ross.zwisler@linux.intel.com> References: <20160823220419.11717-1-ross.zwisler@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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@lists.01.org, Matthew Wilcox 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org