Re: [PATCH] Use ida_simple for SCSI iSCSI transport session id

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Fri, 2016-02-12 at 09:38 -0800, Lee Duncan wrote:
> The scsi_transport_iscsi module already uses the ida_simple
> routines for managing the target ID, if requested to do
> so. This change replaces an ever-increasing atomic integer
> that tracks the session ID itself with the ida_simple
> family of routines. This means that the session ID
> will be reclaimed and can be reused when the session
> is freed.

Is reusing session ID's really a good idea?  For sequential sessions it
means that the ID of the next session will be re-used, i.e. the same as
the previous sessions, which could lead to target confusion.  I think
local uniqueness of session IDs is more important than wrap around
because sessions are short lived entities and the chances of the same
session being alive by the time we've wrapped is pretty tiny.

If you can demostrate a multi-target problem, perhaps we should rather
fix this by making the next session id a target local quantity?

James