jfs2 log wrapping and monitoring log usage

I've got a whole bunch of JFS2 filesystems, all using the inline log. I just got the "J2_LOG_WRAP_START" error for one, and while I was able to fix it by making the log larger.

I was wondering if there was a command that could be used to determine just how much of the log for a given filesystem is used, and if it should be enlarged beforehand. Kind of like a "df" but for JFS2 logs.

-s-