linux-kernel - Re: Nasty regression from .27.7 to .27.8: idle samba goes crazy

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Message-Id: <200812080834.22924.rjw@sisk.pl>
Date:	Mon, 8 Dec 2008 08:34:22 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	"Holger Hoffstaette" <holger@...ards.de>
Cc:	linux-kernel@...r.kernel.org, Greg KH <greg@...ah.com>,
	stable@...nel.org
Subject: Re: Nasty regression from .27.7 to .27.8: idle samba goes crazy

On Monday, 8 of December 2008, Holger Hoffstaette wrote:
> 
> Hi,
> 
> I just encountered a nasty symptom for the second time that has started to
> occur after updating my home server from vanilla 2.6.27.7 to .8 (same
> config).
> 
> A while after disconnecting a samba client, the smbd samba server
> process goes crazy and consumes 100% CPU. From that time on it is
> unkillable (kill -9 returns but the process continues to run). The only
> recourse is reboot, which works without problem (i.e. unmounting the
> served filesystems is apparently possible?). I tried to attach to the
> process with gdb but that just hung.
> 
> The system is a generic old single-core P4 box with a single SATA drive,
> Gentoo userland and Samba is 3.0.33 (in async mode). The kernel has no
> patches or binary drivers. It has been rock solid before the update and
> shows no other signs of weirdness in logs or otherwise. I downgraded to .7
> for now and will see what happens, but since it worked before I am certain
> that this is a regression in the .8 release.
> 
> The only commonality is a log entry by samba that seems to correlate with
> both occurrences:
> 
> [2008/12/08 01:02:52, 0] lib/util_sock.c:read_data(534)
>   read_data: read failure for 4 bytes to client 192.168.100.128. Error = No route to host
> 
> .128 is the Windows client machine (connected via a stable GigE link),
> which I shut down pretty much exactly 30 minutes before that (any 30
> minute timeouts in the kernel/network stack?). Both instances of these log
> entries correlate with the CPU spikes which I noticed in my MRTG graphs.
> 
> Any suspects or ideas?

Please bisect.

Thanks,
Rafael
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