On Mon, Dec 01, 2014 at 10:04:50AM -0500, Theodore Ts'o wrote:

On Mon, Dec 01, 2014 at 01:28:10AM -0800, Christoph Hellwig wrote:

quoted

The ->is_readonly method seems like a clear winner to me, I'm all for
adding it, and thus suggested moving it first in the series.

It's a real winner for me as well, but the reason why I dropped it is
because if btrfs() has to keep its ->update_time function, we wouldn't
actually have a user for is_readonly().  I suppose we could have
update_time() call ->is_readonly() and then ->update_time() if they
exist, but it only seemed to add an extra call and a bit of extra
overhead without really simplifying things for btrfs.

We would use is_readonly in order to remove some extra checks from btrfs
(setxattr, removexattr, possibly setsize).

If there were other users of ->is_readonly, then it would make sense,
but it seemed better to move into a separate code refactoring series.

Yeah it would be better addressed separately as it's not the point of
lazytime patchset and only turned out to be a good idea during the
iterations.