When a partition is not aligned by 4KB, mount -o dax succeeds, but any read/write access to the filesystem fails, except for metadata update. Call bdev_dax_supported() to perform proper precondition checks which includes this partition alignment check. Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Boaz Harrosh <boaz@xxxxxxxxxxxxx> --- fs/xfs/xfs_super.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 187e14b..39f4e6a 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1558,14 +1558,12 @@ xfs_fs_fill_super( if (mp->m_flags & XFS_MOUNT_DAX) { xfs_warn(mp, - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); - if (sb->s_blocksize != PAGE_SIZE) { - xfs_alert(mp, - "Filesystem block size invalid for DAX Turning DAX off."); - mp->m_flags &= ~XFS_MOUNT_DAX; - } else if (!sb->s_bdev->bd_disk->fops->direct_access) { + "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); + + error = bdev_dax_supported(sb, sb->s_blocksize); + if (error) { xfs_alert(mp, - "Block device does not support DAX Turning DAX off."); + "DAX unsupported by block device. Turning off DAX."); mp->m_flags &= ~XFS_MOUNT_DAX; } } -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html