ZFS and pathconf(_PC_NO_TRUNC)

[Mark Blackman]

On 11 Nov 2010, at 14:17, Bruce Evans wrote:
>  where zfs seems to succeed for a lot
> of features that shouldn't apply to fifos, and then falls back to
> vop_stdpathconf() which succeeds for even more features where it shouldn't.
> fifo_pathconf() only succeeds for _PC_LINK_MAX, _PC_PIPE_BUF and
> _PC_CHOWN_RESTRICTED.  Its setting of _PC_LINK_MAX is wrong, since the
> value of this is fs-dependent.  _PC_PIPE_BUF is of course pipe+fifo-dependent
> so its setting belongs here and somewhere for pipes (I can't see where it
> is supported for fpathconf() on pipes).  _PC_CHOWN_RESTRICTED also shouldn't
> be set here, but perhaps fifos can know a system-wide setting and repeat it,
> as other file systems do.
> 
> Correct layering would probably result in vop_stdpathconf() not existing.
> It is currently more or less correct only for devfs, and is only used by
> zfs, coda, devfs, fdescfs and portalfs.
> 
> Bruce

Ok, I'll file that bug then. I wonder how Solaris handles pathconf, but that's
another question.

Cheers,
Mark