From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
Subject: Re: Deadlock in ceph journal
Date: Sat, 23 Aug 2014 10:18:43 +1200
Message-ID: <53F7C1C3.8000303@catalyst.net.nz>
References: <755F6B91B3BE364F9BCA11EA3F9E0C6F2646AE7B@SACMBXIP02.sdcorp.global.sandisk.com> <alpine.DEB.2.00.1408192052530.28244@cobra.newdream.net> <755F6B91B3BE364F9BCA11EA3F9E0C6F2646AF1D@SACMBXIP02.sdcorp.global.sandisk.com> <alpine.DEB.2.00.1408192149330.28244@cobra.newdream.net> <755F6B91B3BE364F9BCA11EA3F9E0C6F2646AF69@SACMBXIP02.sdcorp.global.sandisk.com> <alpine.DEB.2.00.1408200832440.28244@cobra.newdream.net> <6AA21C22F0A5DA478922644AD2EC308C8B7FF7@SHSMSX101.ccr.corp.intel.com> <alpine.DEB.2.00.1408202051540.28244@cobra.newdream.net> <6AA21C22F0A5DA478922644AD2EC308C8B8342@SHSMSX101.ccr.corp.intel.com> <alpine.DEB.2.00.1408210822430.31169@cobra.newdream.net> <53F692AE.90007@catalyst.net.nz> <alpine.DEB.2.00.1408211749040.31169@cobra.newdream.net>
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To: Sage Weil <sweil@redhat.com>
Cc: "Ma, Jianpeng" <jianpeng.ma@intel.com>, Somnath Roy <Somnath.Roy@sandisk.com>, "Samuel Just (sam.just@inktank.com)" <sam.just@inktank.com>, "ceph-devel@vger.kernel.org" <ceph-devel@vger.kernel.org>

On 22/08/14 12:49, Sage Weil wrote:
> On Fri, 22 Aug 2014, Mark Kirkwood wrote:
>> On 22/08/14 03:23, Sage Weil wrote:
>>> I've pushed the patch to wip-filejournal.  Mark, can you test please?
>>>
>>
>> I've tested wip-filejournal and looks good (25 test runs, good journal header
>> each time).
>
> Thanks!  Merged.
>

Excellent.

One thing that does still concern me - if I understand what is happening 
here correctly: we write to the journal using aio until we want to stop 
doing writes (presumably pre closing it), then use normal io to write at 
that point.

Given that we appear to be using direct io whenever we use aio, does 
this mean we end up mixing direct and buffered io to the journal [1] (or 
is the normal i.e non aio write still using direct io)?

Cheers

Mark

[1] which I understand is bad...