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Date: Wed, 9 Dec 2015 06:45:42 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dominique Martinet <dominique.martinet@cea.fr>
Cc: Andy Lutomirski <luto@amacapital.net>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	V9FS Developers <v9fs-developer@lists.sourceforge.net>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: [V9fs-developer] Hang triggered by udev coldplug, looks like a
 race
Message-ID: <20151209064542.GW20997@ZenIV.linux.org.uk>
References: <CALCETrX89vL2PBew7MxaFysP=33J7NBaA=aw3JFwMVZyr36UQA@mail.gmail.com>
 <CALCETrX8ukASsKfTgmN6SzDVG5L61GrSc6i26SvKu1OQt7_xTA@mail.gmail.com>
 <20151207224643.GA10531@nautica>
 <CALCETrU7SOhTi0g0=tvcirn_C4s9oTkhaV8BfbDf2F90+himJA@mail.gmail.com>
 <20151208023331.GJ20997@ZenIV.linux.org.uk>
 <CALCETrU1GKGXsp4gmnWJXh2Lp=dBp7K--qt1ViUOKyxpVWBtMQ@mail.gmail.com>
 <20151209062316.GA29917@nautica>
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On Wed, Dec 09, 2015 at 07:23:16AM +0100, Dominique Martinet wrote:
> Andy Lutomirski wrote on Tue, Dec 08, 2015:
> > Trace attached.  I don't see anything wrong, but I also don't know
> > what I'm looking for.
> 
> Actually doesn't look good, not sure if trace could be missing messages
> but it looks like tags get reused...
> 
> Quick and dirty parse script (attached output, it doesn't handle TFLUSH
> but there are none in his message):

There's also not a single RCLUNK in there, which looks like missing packets.
AFAICS, all (apparent) tag reuses caught by your awk script are of that nature.
And all RERROR are plain "no such file" in response to TWALK; all those
TCLUNK in there get no reply whatsoever - neither success nor failure...