Re: CD writing in future Linux (stirring up a hornets' nest)

["Christopher Friesen" <cfriesen@nortel.com>]

Joerg Schilling wrote:
> "Christopher Friesen" <cfriesen@nortel.com> wrote:

> > There's nothing there that says the mapping cannot change with 
> > time...just that it has to be unique.
>
>
> If it changes over the runtime of a program, it is not unique from the
> view of that program.

That depends on what "uniquely identified" actually means.

One possible definition is that at any time, a particular path maps to a 
single unique st_ino/st_dev tuple.

The other possibility (and this is what you seem to be advocating) is 
that a st_ino/st_dev tuple always maps to the same file over the entire 
runtime of the system.

This second possibility seems easily disproved.  If you delete and 
recreate files on a filesystem (assuming nobody has open files in the 
filesystem), at some point a new file will end up with the same inode as 
an old (deleted) file.  The two files are different, but have the same 
st_ino/st_dev tuple.

This leaves the first possibility as the only choice...

Chris
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