linux-kernel - Re: WARNING in xfs_lwr.c, xfs

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20100523092344.0fcaab42@aaa.pulp.binarylife.net>
Date:	Sun, 23 May 2010 09:23:44 -0500
From:	Roman Kononov <roman@...arylife.net>
To:	Dave Chinner <david@...morbit.com>
Cc:	xfs@....sgi.com, linux-kernel@...r.kernel.org
Subject: Re: WARNING in xfs_lwr.c, xfs_write()

On 2010-05-23, 20:18:56 +1000, Dave Chinner <david@...morbit.com> wrote:
> You've got some workload that is mixing direct IO writes with some
> form of buffered or mmap IO on the same file and they are racing.
> Mixing different types of IO on the one inode is also known as A
> Really Bad Idea because there is no guarantee of coherency between
> them....
> 
> Can you find out what the application is triggering this?

This is severely modified Postgresql, which does mix direct IO with
buffered one.

You say "they are racing". Do you mean that this can cause file system
corruption? Doest it simply warn that direct user data races with
buffered user data and one of them wins? This warning "taints" the
kernel. Should it be safe to do different types of IOs on different
non-overlapping 4-KiB-aligned regions of the same file (I am unsure
if this is what the application really does)?

Thanks,

Roman
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/