Re: [MI400] ACCESS to IFS

[Dave McKenzie <davemck@xxxxxxxxxxxxx>]

On Thursday 03 January 2002 16:13, jamesl wrote:

> But please note that in the IFS, hard links are symmetrical, i.e., a given
> *STMF physically exists in one place, yet can have dozens of hard links
> pointing to it from all over the directory tree, so long as they don't cross
> file system boundaries, any one of which can hold the *STMF in existence,
> and
> none of which (not even the original one created with the *STMF) is any
> more
> important than any other.

If there are multiple hard links to a *STMF, the *STMF's pointer to the DSI
is empty.  But the *STMF's pointer to the DS (Data Space) record is still
there (in fact pointing to the one for the 1st-established link).  In the
DS record is a pointer field which points to the DS record for the next hard
link to the same *STMF, thus forming a list of all the hard links from which
the DSI entries could be rebuilt.

> Also, note that symbolic links (unlike
> hard links) do not hold an object in
> existence, can legally point to
> nonexistent objects, and can legally cross file
> system
> boundaries.

Symbolic links are implemented as *STMF's containing the path they point to
as data, so recovery for them would be like any other *STMF.

--Dave