[Pkg-iscsi-maintainers] Bug#850060: 2.0.874-2~exp1 issues

[Andrew Patterson]

On 01/04/2017 04:11 PM, Christian Seiler wrote:
> Control: reopen -1
> 
> Hi,
> (reopening the bug report since iscsiuio doesn't actually work
> according to what you're telling me)
> 
> On 01/04/2017 11:30 PM, Andrew Patterson wrote:
>> 1. In debian/extra/initramfs.local-top and
>> debian/extra/initramfs.local-bottom /sbin/iscsuio creates a pid file
>> in /run/iscsiuio.pid. You cannot override it on the command-line. The
>> --pidfile option for start-stop-daemon should point to this location
>> instead of /run/initramfs/iscsiuio.pid.
> 
> Gah. I thought I had fixed that before the upload. :-(
> A good thing there's experimental...
> 
> OTOH, initramfs should write to /run/initramfs only, so maybe
> we should pass -p /run/initramfs/iscsiuio.pid to iscsiuio
> instead as well.

Yes. I believe that will work. I wonder why this option is not in the
man-page.

> 
>> 2. The /sbin/iscsiuio deamon is trying to create a logfile in
>> /var/log/iscsiuio.log. The /var/log directory does not exist in the
>> initramfs.
> 
> Unfortunately that's hardcoded. OTOH from reading the code
> this shouldn't be an issue.
> 
>> 3. The iscsiuio daemon is dieing before or during iscsistart -b. I am
>> investigating why. It works fine when run after boot.
> 
> This is weird, on my test VM (no offloading NIC though) it
> does start (and shut down again).
> 
> Question: does the network card require firmware for offloading
> to work? If that's the case we might need to add the firmware
> to the initramfs or this to work properly...

Yes, the card requires firmware. But it has been loaded (according to
kernel output).

> 
>> 4. The commit 02c3051 "Don't ignore offloading NICs in iscsistart"
>> will cause the interface to be configured in both iscsistart -N and in
>> iscsistart -b for cards with iscsi hardware offload. I suspect we
>> instead need a flag in iscsistart to bring up the NIC in iscsistart
>> regardless if the NIC uses an offloadable driver. The local-top script
>> can use this flag if /sbin/iscsiuio is not present, e.g.,
>>
>> ISCSISTART_FLAGS=""
>> if [ ! -x /sbin/iscsiuio ] ; then
>>    ISCSISTART_FLAGS="-S"
>> fi
> 
> Hmm, now I see what you mean. I also dug up this commit which
> gives a little insight.
> 
> https://github.com/open-iscsi/open-iscsi/commit/ee115be828362653478e6fe7cd4c6ee3318223ff
> 
> However, I think the solution is different from what you suggest: the
> "fix" for #850057 is wrong I believe.
> 
> Debian sid package (w/o -DOFFLOAD_BOOT_SUPPORTED):
> 
>  - cxgb*i: iscsistart -N ignores interface
>            iscsistart -b doesn't configure offloading
>        => won't work
> 
>  - bnx2i (any mode): iscsistart -N ignores interface
>                      iscsistart -b doesn't configure offloading
>        => won't work
> 
> Current upstream situation (w/ -DOFFLOAD_BOOT_SUPPORTED):
> 
>  - cxgb*i: iscsistart -N ignores interface
>            iscsistart -b configures offloading 
>        => should work
>           (but don't have hardware)
>           (also: remind me to check whether we copy the
>           module into the initramfs)
> 
>  - bnx2i non-hba: iscsistart -N ignores it
>                   iscsistart -b doesn't configure offloading
>        => won't work
> 
>  - bnx2i hba: iscsistart -N ignores it
>               iscsistart -b configures offloading
>        => should work (once iscsiuio is running)
> 
> "Fix" for 850057 (in experimental):
> 
>  - cxgb*i: iscsistart -N configures interface on host
>            iscsistart -b configures offloading
>          => no idea what happens thereafter
>             (since MAC address is the same on these cards: is
>             this a problem if they have the same IP?)
> 
>  - bnx2i non-hba: iscsistart -N configures interface
>                   iscsistart -b doesn't configure offloading,
>                                 but enables software iSCSI
>           => should work
> 
>  - bnx2i hba: iscsistart -N configures interface
>               iscsistart -b configures offloading
>           => same IP, different MAC addresses
>           => will cause trouble
> 
> The ideal solution would be to mirror the check that is done
> for -b in -N. In that case we'd either configure the host
> interface (and use software iSCSI), or configure offloading
> (and use hardware iSCSI), but never both, and never neither.
> So instead of the current patch for #850057 I would suggest
> to do that instead. That should then also be upstream-able. I
> can prepare a patch for that tomorrow.

That was my thought. However, I don't think you can programaticaly
determine whether the card is configured for iscsi offload. We need to
use some sort of signal from the admin, hence my suggestion to check
for the presence of iscsiuio or to use a flag.

> 
> That still leaves us with the question why iscsiuio doesn't
> appear to work in the initramfs on your system. You could
> just add strace to your initramfs and call iscsiuio in a
> detached strace, a la
> 
> old:
> start-stop-daemon ... /sbin/iscsiuio
> 
> new:
> start-stop-daemon ... /bin/strace -- -D -f \
>    -o /run/initramfs/iscsiuio.trace  -- /sbin/iscsiuio
> 
> (The first -- is for start-stop-daemon, the second one for
> strace itself.)
>

It looks like iscsuio is complaining about a missing libgcc:

writev(2, [{"libgcc_s.so.1 must be installed "..., 59]], 1) = 59

which is indeed missing.  I think pthreads needs libgcc, but shouldn't
copy_exec take care of this?

-- 
Andrew Patterson
Hewlett-Packard Enterprise