Ian Kent [off-list ref] wrote:

quoted

I'm changing it so that the fields are 64-bit, but initialised with the
existing mount ID in the notifications set.  The fsinfo set changes that
to a unique ID.  I'm tempted to make the unique IDs start at UINT_MAX+1 to
disambiguate them.

Mmm ... so what would I use as a mount id that's not used, like NULL
for strings?

Zero is skipped, so you could use that.

I'm using -1 now but changing this will mean I need something
different.

It's 64-bits, so you're not likely to see it reach -1, even if it does start
at UINT_MAX+1.

David