Re: [PATCH 2/2] blockdev: don't set S_DAX for misaligned partitions

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 <boaz(a)plexistor.com&gt; Signed-off-by: Jeff Moyer <jmoyer(a)redhat.com&gt; --- 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