Investigate checking FAT dirty bit being cleared to trigger auto-reload

[dhalbert]

The FAT dirty bit (https://en.wikipedia.org/wiki/Design_of_the_FAT_file_system#BIOS_Parameter_Block) might be set to zero when a write transaction is complete, and could be used as an alternative to the 0.5-second time-based auto-reload detection.

On the other hand, this bit might not be set until an actual eject is done, in which case this won't work.

[jepler]

From reading the Linux kernel source, it appears to only clear the dirty bit on unmount. However, I didn't actually test this.

[dhalbert]

I think that's right, and is also true on Windows. There's a command-line utility (fsutil) which is supposed to report the state of the dirty bit, but I'm getting completely incorrect results from it.

[dhalbert]

Oh, well.