ext4: hard fail dax mount on unsupported devices

As dax inches closer to production use, an administrator should not
be surprised by silently disabling the feature they asked for.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a39726cc78bc52f13e1f74ea68c2d736443c7bcf..e862b82066abbcffad194077af01de212c61aa1e 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3864,12 +3864,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                if (ext4_has_feature_inline_data(sb)) {
                        ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
                                        " that may contain inline data");
-                       sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
+                       goto failed_mount;
                }
                if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
                        ext4_msg(sb, KERN_ERR,
-                               "DAX unsupported by block device. Turning off DAX.");
-                       sbi->s_mount_opt &= ~EXT4_MOUNT_DAX;
+                               "DAX unsupported by block device.");
+                       goto failed_mount;
                }
        }