From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: [PATCH 2/2] blockdev: don't set S_DAX for misaligned partitions Date: Fri, 14 Aug 2015 16:15:32 -0400 Message-ID: <1439583332-13754-3-git-send-email-jmoyer@redhat.com> References: <1439583332-13754-1-git-send-email-jmoyer@redhat.com> Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@ml01.01.org To: matthew.r.wilcox@intel.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:47299 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbbHNUPi (ORCPT ); Fri, 14 Aug 2015 16:15:38 -0400 In-Reply-To: <1439583332-13754-1-git-send-email-jmoyer@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: The dax code doesn't currently support misaligned partitions, so disable O_DIRECT via dax until such time as that support materializes. Suggested-by: Boaz Harrosh Signed-off-by: Jeff Moyer --- fs/block_dev.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 1982437..1170f8c 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1241,6 +1241,13 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) goto out_clear; } bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); + /* + * If the partition is not aligned on a page + * boundary, we can't do dax I/O to it. + */ + if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512)) || + (bdev->bd_part->nr_sects % (PAGE_SIZE / 512))) + bdev->bd_inode->i_flags &= ~S_DAX; } } else { if (bdev->bd_contains == bdev) { -- 1.8.3.1