Mailing List Archive: Linux-HA: Dev

[PATCH 0 of 2] [updated] iSCSITarget, iSCSILogicalUnit: support graceful stop, add tgt support

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florian.haas at linbit

Jun 16, 2009, 12:09 AM

Post #1 of 4 (428 views)
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[PATCH 0 of 2] [updated] iSCSITarget, iSCSILogicalUnit: support graceful stop, add tgt support

Hello everyone,

a couple of patches for the freshly merged iSCSITarget and
iSCSILogicalUnit RAs. This is an updated version of the patch set I
submitted yesterday.

The first patch adds support for graceful "stop" operations for the
iSCSITarget RA. It now looks for active sessions/connections on the
target, and shuts them down. Many thanks to lge for the sed magic.

Also in the first patch, there is a generic do_cmd command wrapper
that captures command output and exit codes, which is particularly
helpful on IET as ietadm is notoriously terse (thanks to lmb -- I
stole the idea from your drbd OCF RA).

The second patch adds tgt support to both resource agents (including
graceful connection shutdown for iSCSITarget, again many thanks to
lge).

What's changed versus yesterday's patch set is that the "stop"
operation for iSCSILogicalUnit now loops on LU removal. tgt will not
allow an LU to be removed while it has pending I/O, so we'll have to
wait for I/O on that LU to drain before it can be deleted. This should
complete well within the 10-second stop timeout.

I also ran into an ugly bug in tgtadm where, upon iSCSITarget "stop",
connection removal may seemingly complete successfully when really it
doesn't. The only way to remove such a "dangling" connection seems to
be sending a KILL signal to tgtd and then restarting it -- TERM won't
do it. I am cc'ing Hannes Reinecke from SUSE here; maybe Hannes can
share some insight.

As always, feedback and comments are much appreciated.

Cheers,
Florian

_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev[at]lists.linux-ha.org
http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
Home Page: http://linux-ha.org/

dejanmm at fastmail

Jun 17, 2009, 7:18 AM

Post #2 of 4 (372 views)
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Re: [PATCH 0 of 2] [updated] iSCSITarget, iSCSILogicalUnit: support graceful stop, add tgt support [In reply to]

Hi,

On Tue, Jun 16, 2009 at 09:09:55AM +0200, Florian Haas wrote:
> Hello everyone,
>
> a couple of patches for the freshly merged iSCSITarget and
> iSCSILogicalUnit RAs. This is an updated version of the patch set I
> submitted yesterday.
>
> The first patch adds support for graceful "stop" operations for the
> iSCSITarget RA. It now looks for active sessions/connections on the
> target, and shuts them down. Many thanks to lge for the sed magic.
>
> Also in the first patch, there is a generic do_cmd command wrapper
> that captures command output and exit codes, which is particularly
> helpful on IET as ietadm is notoriously terse (thanks to lmb -- I
> stole the idea from your drbd OCF RA).
>
> The second patch adds tgt support to both resource agents (including
> graceful connection shutdown for iSCSITarget, again many thanks to
> lge).
>
> What's changed versus yesterday's patch set is that the "stop"
> operation for iSCSILogicalUnit now loops on LU removal. tgt will not
> allow an LU to be removed while it has pending I/O, so we'll have to
> wait for I/O on that LU to drain before it can be deleted. This should
> complete well within the 10-second stop timeout.

Good.

> I also ran into an ugly bug in tgtadm where, upon iSCSITarget "stop",
> connection removal may seemingly complete successfully when really it
> doesn't.

Oops.

> The only way to remove such a "dangling" connection seems to
> be sending a KILL signal to tgtd and then restarting it -- TERM won't
> do it. I am cc'ing Hannes Reinecke from SUSE here; maybe Hannes can
> share some insight.

Well, hard to cover such bugs in an RA. Should be fixed upstream.

Both patches applied.

Cheers,

Dejan

> As always, feedback and comments are much appreciated.
>
> Cheers,
> Florian
>
>
>
>
> _______________________________________________________
> Linux-HA-Dev: Linux-HA-Dev[at]lists.linux-ha.org
> http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> Home Page: http://linux-ha.org/
_______________________________________________________
Linux-HA-Dev: Linux-HA-Dev[at]lists.linux-ha.org
http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
Home Page: http://linux-ha.org/

florian.haas at linbit

Jun 22, 2009, 11:29 AM

Post #3 of 4 (333 views)
Permalink

Re: [PATCH 0 of 2] [updated] iSCSITarget, iSCSILogicalUnit: support graceful stop, add tgt support [In reply to]

Dejan,

I just noticed that you applied the original (June 15) version of this
patch, not the updated one I submitted on 6/16. Would you mind applying
the 6/16 version of this patch?

Thanks!
Cheers,
Florian

On 06/17/2009 04:18 PM, Dejan Muhamedagic wrote:
> Hi,
>
> On Tue, Jun 16, 2009 at 09:09:55AM +0200, Florian Haas wrote:
>> Hello everyone,
>>
>> a couple of patches for the freshly merged iSCSITarget and
>> iSCSILogicalUnit RAs. This is an updated version of the patch set I
>> submitted yesterday.
>>
>> The first patch adds support for graceful "stop" operations for the
>> iSCSITarget RA. It now looks for active sessions/connections on the
>> target, and shuts them down. Many thanks to lge for the sed magic.
>>
>> Also in the first patch, there is a generic do_cmd command wrapper
>> that captures command output and exit codes, which is particularly
>> helpful on IET as ietadm is notoriously terse (thanks to lmb -- I
>> stole the idea from your drbd OCF RA).
>>
>> The second patch adds tgt support to both resource agents (including
>> graceful connection shutdown for iSCSITarget, again many thanks to
>> lge).
>>
>> What's changed versus yesterday's patch set is that the "stop"
>> operation for iSCSILogicalUnit now loops on LU removal. tgt will not
>> allow an LU to be removed while it has pending I/O, so we'll have to
>> wait for I/O on that LU to drain before it can be deleted. This should
>> complete well within the 10-second stop timeout.
>
> Good.
>
>> I also ran into an ugly bug in tgtadm where, upon iSCSITarget "stop",
>> connection removal may seemingly complete successfully when really it
>> doesn't.
>
> Oops.
>
>> The only way to remove such a "dangling" connection seems to
>> be sending a KILL signal to tgtd and then restarting it -- TERM won't
>> do it. I am cc'ing Hannes Reinecke from SUSE here; maybe Hannes can
>> share some insight.
>
> Well, hard to cover such bugs in an RA. Should be fixed upstream.
>
> Both patches applied.
>
> Cheers,
>
> Dejan
>
>> As always, feedback and comments are much appreciated.
>>
>> Cheers,
>> Florian

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florian.haas at linbit

Jun 22, 2009, 11:37 AM

Post #4 of 4 (332 views)
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Re: [PATCH 0 of 2] [updated] iSCSITarget, iSCSILogicalUnit: support graceful stop, add tgt support [In reply to]

Eh, stupid me. My bad, disregard earlier message. Turns out I forgot to
submit one patch I thought I had submitted. :(

Florian

On 06/22/2009 08:29 PM, Florian Haas wrote:
> Dejan,
>
> I just noticed that you applied the original (June 15) version of this
> patch, not the updated one I submitted on 6/16. Would you mind applying
> the 6/16 version of this patch?
>
> Thanks!
> Cheers,
> Florian

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signature.asc (0.25 KB)

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