From f0b2e563bc419df7c1b3d2f494574c25125f6aed Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Fri, 14 Aug 2015 16:15:32 -0400 Subject: [PATCH] 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. Cc: Suggested-by: Boaz Harrosh Signed-off-by: Jeff Moyer Signed-off-by: Dan Williams --- fs/block_dev.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 22ea424ee741..073bb57adab1 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1242,6 +1242,13 @@ 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) { -- 2.20.1