linux-kernel - Re: [PATCH] ext2: Avoid WARN() messages when failing to write to the superblock

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Message-ID: <20091026075645.GA22625@elf.ucw.cz>
Date:	Mon, 26 Oct 2009 08:56:45 +0100
From:	Pavel Machek <pavel@....cz>
To:	Theodore Tso <tytso@....edu>,
	Linux Kernel Developers List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ext2: Avoid WARN() messages when failing to write to
 the superblock

On Mon 2009-10-26 00:08:10, Theodore Tso wrote:
> On Sun, Oct 25, 2009 at 07:21:28AM +0100, Pavel Machek wrote:
> > > +	if (buffer_write_io_error(sbh)) {
> > > +		/*
> > > +		 * Oh, dear.  A previous attempt to write the
> > > +		 * superblock failed.  This could happen because the
> > > +		 * USB device was yanked out.  Or it could happen to
> > > +		 * be a transient write error and maybe the block will
> > > +		 * be remapped.  Nothing we can do but to retry the
> > > +		 * write and hope for the best.
> > > +		 */
> > > +		printk(KERN_ERR "EXT2-fs: %s previous I/O error to "
> > > +		       "superblock detected", sb->s_id);
> > 
> > KERN_ALERT/KERN_CRITICAL?
> 
> Based on kerneloops.org logs, it's apparently very frequent that
> clueless lusers rip out USB drives without bothering to unmount them
> first.  (Or people by crappy laptops where the SD cards sticks out
> slightly and is easily jostled.)  It's not clear we really want to be
> issueing KERN_ALERT or KERN_CRITICAL messages when this very common
> event happens.

I'd say that frequency of the message should not determine the
priority. (If this happens on your root filesystem you are in deep
trouble, and it _should_ be broadcast on all consoles).

OTOH filesystem should be handle device unplug just fine, so not
issuing this in that case would be nice...
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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