2009/387 [Pathname Reparse Points]

[Garrett D'Amore]

Robert Thurlow wrote:
> Garrett D'Amore wrote:
>
>> I'm confused.  Brian says that archivers Just Work with the current 
>> form, because the attributes are retained.  Yet, you're saying that 
>> the attributes are not necessarily retained.  Which is it?  Right 
>> now, either way, you have an attribute... which I *think* means that 
>> the you need support (which may or may not be present) in the archivers.
>
> I know that some archivers in use today will not create a different
> bitstream for a reparse point than for a regular symlink, but I
> believe our intent to set the bit on restore or create means that
> we don't have to teach all archivers about the new bit.  If any
> Sun-maintained archivers are aware, that's fine, but this should
> work with GNU tar, too.

Okay, that's an important detail that I missed somewhere.  (Was it in 
the original spec?)

>
> Logically, that bit is only a way for the NFS/CIFS server
> code to avoid having to read the symlink data to understand
> that it's touched a reparse point.  We want this because the
> referral is a two-part deal - we return an "it's not here"
> error to the client first, and then respond to a followup
> query later.  The sysattr makes an NFSv4 READDIR op able to
> avoid N accesses to symlink data.

OK.

    -- Garrett
>
> Rob T