On Thu, Jun 06, 2019 at 08:52:03AM -0700, Eric Biggers wrote:

+/*
+ * Format of ext4 verity xattr.  This points to the location of the verity
+ * descriptor within the file data rather than containing it directly because
+ * the verity descriptor *must* be encrypted when ext4 encryption is used.  But,
+ * ext4 encryption does not encrypt xattrs.
+ */
+struct fsverity_descriptor_location {
+	__le32 version;
+	__le32 size;
+	__le64 pos;
+};

What's the benefit of storing the location in an xattr as opposed to
just keying it off the end of i_size, rounded up to next page size (or
64k) as I had suggested earlier?

Using an xattr burns xattr space, which is a limited resource, and it
adds some additional code complexity.  Does the benefits outweigh the
added complexity?

						- Ted