RE: XATTR structure for biosfs entries

[Ulrich Kuehn <kuehn@GOEDEL.UNI-MUENSTER.DE>]

Hello,

Torsten Scherer writes:

|> As the subject line says, I want to bring the topic of each "file"
|> in the bios device directory /dev having ownership, filemodes and
|> c/m/a-time fields, say, a complete XATTR structure, "on stage".
|> [...]
|> The problem is how to change mtime/atime for these drivers? Obviously
|> the change is best made in the read/write calls, but the biosfs can't
|> do it since it's not touched when an extra device driver does I/O. On
|> the other hand side the device driver has only _direct_ access to the
|> filepointer...
|> 

I think the best way to do it would be a new Dcntl on /dev which allows
the device driver to query the address of its supporting structure in
the kernel memory. As the device driver run in the kernel's address space,
there would be no problem with that. It would be backward compatible with
older device drivers, they simply dont set the values as they dont know
about it.
And it should be fairly straight forward to do without messing with some
dev or index members in some structures.

Regards,
Ulrich

--

+---------------+----------------------------+-----------------------+
| Ulrich Kuehn  | Internet:                  | Life is uncertain --  |
| Cand.Math.Inf | kuehn@math.uni-muenster.de | eat the dessert first |
+---------------+----------------------------+-----------------------+