From: Andres Freund <andres@anarazel.de>
Subject: Re: EXT4 ENOSPC Bug
Date: Tue, 17 Feb 2009 18:36:24 +0100
Message-ID: <499AF598.7080400@anarazel.de>
References: <20090216162028.3032666a@lithium.local.net> <200811291418.24672.andres@anarazel.de> <200812100108.04163.andres@anarazel.de> <49994FEF.2020908@anarazel.de> <20090216150156.GD22619@mini-me.lan> <499985C7.8010302@anarazel.de> <20090216190001.GB11788@mini-me.lan>
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To: Theodore Tso <tytso@mit.edu>,
	Alex Buell <alex.buell@munted.org.uk>, adilger@sun.com,
	LKML <linux-kernel@vger.kernel.org>, linux-ext4@vger.kernel.org,
	Jonathan Bastien-Filiatrault <jo
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On 02/16/2009 08:00 PM, Theodore Tso wrote:
> On Mon, Feb 16, 2009 at 04:27:03PM +0100, Andres Freund wrote:
>> So, yes, seems to be an inode allocation problem.

> I'm pretty sure the ENOSPC problem which you both found is an inode
> allocation problem.  Some of you seem to have an easier time
> reproducing it than others; could you try this patch, and periodically
> scan your system logs for the message "ext4: find_group_flex failed,
> fallback succeeded"?  If the problem goes away for you, and you find
> the occasional aforemention message in your system log, that will
> confirm what I suspect, which is the bug is in fs/ext4/inode.c's
> find_group_flex() function.  (If I'm wrong, the fallback code will
> activate only when the filesystem is genuinely out of inodes, which
> should be very rare.)
>
> More comments are in the patch header.  My current long-term plan for
> dealing with this is to enhance find_group_orlov() to and
> find_group_other() to understand about flex_bg's.
Ok. I am now running with the patch enabled on two machines - but as the 
issue occured only 2 times in nearly 2 months on two machines...

Andres