From: Dan Carpenter <dan.carpenter@oracle.com>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] ext2: do not sleep in ext2_error()
Date: Fri, 3 Sep 2021 16:09:24 +0300 [thread overview]
Message-ID: <20210903130924.GA1935@kadam> (raw)
In-Reply-To: <YTIZpijSZc+ykNUY@mit.edu>
On Fri, Sep 03, 2021 at 08:48:38AM -0400, Theodore Ts'o wrote:
> On Fri, Sep 03, 2021 at 12:05:38PM +0300, Dan Carpenter wrote:
> > No one expects error logging functions to sleep so sometimes they are
> > called with spinlocks held. In this case the problematic call tree is:
> >
> > ext2_statfs() <- disables preempt
> > -> ext2_count_free_inodes()
> > -> ext2_get_group_desc()
> > -> ext2_error()
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > This is just from static analysis. NOT TESTED!
> >
> > Probably a safer fix would be to just call pr_err() instead of
> > ext2_error() in ext2_get_group_desc(). I can send that fix instead if
> > people want.
>
> Looking at both of the ext2_error() calls in ext2_get_group_desc(),
> those are really more in the way of assertions rather than warning of
> an on-disk corruption issue. The second "group descriptor not loaded"
> should never happen, and the "block_group >= groups_count" should have
> been caught via an invalid block number or check by the caller (or an
> outright code bug in say ext2_statfs().
>
> So I suspect both of those would be more usefule as a WARN() rather
> than a call to ext2_error(), since stack trace would actually provide
> more useful data to root causing the issue. Jan, what do you think?
>
> - Ted
Thanks Ted,
I'll resend with the WARN() change.
regards,
dan carpenter
next prev parent reply other threads:[~2021-09-03 13:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-03 9:05 [PATCH] ext2: do not sleep in ext2_error() Dan Carpenter
2021-09-03 12:48 ` Theodore Ts'o
2021-09-03 13:09 ` Dan Carpenter [this message]
2021-09-16 9:48 ` Jan Kara
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