Re: [PATCH] 1/1: Device-Mapper: Remove 1024 devices limitation

From: Alasdair G Kergon
Date: Tue Jul 06 2004 - 17:06:19 EST


On Tue, Jul 06, 2004 at 10:35:52PM +0100, Alasdair G Kergon wrote:
> Yes, but the comments imply that the thing it found might in some
> circumstances not be the thing you asked it to look for

To clarify, we make two sorts of requests for ids [minor numbers]:
(a) What is the lowest unused id number?
(b) Is id number N used or not?

If I interpret things correctly, in case (b) if N is larger than the
the highest id number currently stored it might still return non-NULL
(if lower order bits match lower order bits of a different stored id).

[Would it be sufficient for the caller to keep track of the highest
allocated ID and check before calling, or is the masking sometimes
stronger than that?]

Alasdair
--
agk@xxxxxxxxxx
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/