I2C Switch / bus interlocking

I have an embedded system using multiple I2C busses and on each of those busses are several PDA9546A switches. Does anyone have any efficient solutions to maintaining switch coherency when devices on the bus are accessed by multiple clients? Linux seems to want to use the /sys/class interface, but without some sort of mutual exclusion to each of the switches and devices on the segments that they control there will definitely be problems.

Should I create a semaphore (semget) for each switch and have the clients bracket accesses to devices on the segments of that switch with semop calls?

Or maybe I should create a semaphore for each bus?

Thanks,
D i c k