From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Boaz Harrosh , Jeff Moyer , Dan Williams Subject: [PATCH 4.2 052/258] blockdev: dont set S_DAX for misaligned partitions Date: Sat, 17 Oct 2015 18:56:05 -0700 Message-Id: <20151018014732.678447898@linuxfoundation.org> In-Reply-To: <20151018014729.976101177@linuxfoundation.org> References: <20151018014729.976101177@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Moyer commit f0b2e563bc419df7c1b3d2f494574c25125f6aed upstream. 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 Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- fs/block_dev.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1241,6 +1241,13 @@ static int __blkdev_get(struct block_dev 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) {