Re: [Qemu-devel] [PATCH 4/4] ISCSI: If the device we open is a SMC device, then force the use of sg. We dont have any medium changer emulation so only passthrough via real sg or scsi-generic via iscsi would work anyway.

[ronnie sahlberg]

Paolo


I think I have seen a problem inside libiscsi that could be triggered
by the shortcut.

Can you remove this shortcut completely :

-    /* Try to write as much as we can to the socket
-     * without setting up an event.
-     * Only do this if we are completely logged in, so we know that
-     * the socket is in connected state.
-     */
-    if (iscsi_is_logged_in(iscsi)) {
-        if (iscsi_which_events(iscsi) & POLLOUT) {
-            iscsi_process_write(iscsilun);
-        }
-    }

I think there is a problem inside libiscsi if the socket becomes full
and is no longer writeable and we try to write via this shortcurcuit.
It will take a while until I can verify or fix that issue and before a
new version of libiscsi can be available
so I would feel most comfortable with if we just remove this
optimization from QEMU for now.

It can be added back later once libiscsi is fixed.



regards
ronnie sahlberg


On Mon, May 28, 2012 at 4:48 PM, Paolo Bonzini <address@hidden> wrote:
> Il 27/05/2012 15:12, Andreas Färber ha scritto:
>>> > Modified to also do the same for tapes, applied to scsi-next branch for 
>>> > 1.2.
>> Paolo, it seems you haven't pushed scsi-next since then.
>
> Yeah, I have a pending push request for scsi-next, so I'm waiting till
> Anthony applies it before pushing 1.2-only patches (I wasn't expecting
> parallel 1.1/1.2 development for SCSI).
>
>> I hope you've
>> also shortened the subject to a humanly bearable length?
>
> Yes. :)
>
> Paolo