linux-ext4 - Re: [Bug 13232] ext3/4 with synchronous writes gets wedged by Postfix

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20090513160724.GC6579@mit.edu>
Date:	Wed, 13 May 2009 12:07:24 -0400
From:	Theodore Tso <tytso@....edu>
To:	Jan Kara <jack@...e.cz>
Cc:	bugzilla-daemon@...zilla.kernel.org, linux-ext4@...r.kernel.org,
	Al Viro <viro@...iv.linux.org.uk>
Subject: Re: [Bug 13232] ext3/4 with synchronous writes gets wedged by
	Postfix

On Wed, May 13, 2009 at 03:48:02PM +0200, Jan Kara wrote:
>   OK, the deadlock has been introduced by ext3 variant of
> 261bca86ed4f7f391d1938167624e78da61dcc6b (adding Al to CC).

What do you mean by this?

I'm puzzled why we haven't hit this before.  This looks like
long-standing issue; what unmasked it now?

> The deadlock
> is really tough to avoid - we have to first allocate inode on disk so
> that we know the inode number.

Well, the simple thing to do is to have a way of quickly determining
that a particular inode number is in the I_FREEING state, and simply
try to avoid using that inode number.  If there are no inodes
available, it can simply close the handle (since nothing else has
changed at that point), wait for the current transaction to close, and
then try again.  That should fix the problem, I think.

     	 	      	     	     	      - Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html