Regression? Cannot remount a loop device from ro to rw

[Carl S. Gutekunst]

I recently upgraded BusyBox from 1.18.1 to 1.23.2, and now I find I 
cannot change the read-write mode on a loop mount. That is, if the 
original mount is something like:

     mount -o loop,ro /private/myopt.ext2 /opt

and I then remount this this:

     mount -o remount,rw /opt

With 1.18.1 the filesystem is remounted as read-write as expected, but 
in 1.23.2 the command has no effect and the filesystem remains read-only.

At first glance, it looks like the problem was introduced in BusyBox 
1.21.0 when the set_loop() function in libbb/loop.c was modified to 
accept the ro argument. But I haven't yet narrowed down exactly what's 
going wrong.

Has anyone else seen this problem? I'm happy to work out a fix, but 
wanted to check with the list first.

<csg>