From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Tso Subject: Re: [Bug #14472] EXT4 corruption Date: Thu, 29 Oct 2009 18:23:35 -0400 Message-ID: <20091029222335.GJ18464@mit.edu> References: <6dRYo8ss7vL.A.haF.Are5KB@chimera> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Lutomirski Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Shawn Starr On Thu, Oct 29, 2009 at 03:57:32PM -0400, Andrew Lutomirski wrote: > > This but is *not* fixed. I just triggered it a few minutes ago by > abusing i915 and drm, which caused a panic. This is slightly newer > than 2.6.32-rc5, with a couple of i915 bugfixes thrown in. Andrew, can you test to see if this patch helps? Thanks, - Ted commit a8836b1d6f92273e001012c7705ae8f4c3d5fb65 Author: Aneesh Kumar K.V Date: Tue Oct 27 15:36:38 2009 +0530 ext4: discard preallocation during truncate We need to make sure when we drop and reacquire the inode's i_data_sem we discard the inode preallocation. Otherwise we could have blocks marked as free in bitmap but still belonging to prealloc space. Signed-off-by: Aneesh Kumar K.V diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5c5bc5d..a1ef1c3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -209,6 +209,12 @@ static int try_to_extend_transaction(handle_t *handle, struct inode *inode) up_write(&EXT4_I(inode)->i_data_sem); ret = ext4_journal_restart(handle, blocks_for_truncate(inode)); down_write(&EXT4_I(inode)->i_data_sem); + /* + * We have dropped i_data_sem. So somebody else could have done + * block allocation. So discard the prealloc space created as a + * part of block allocation + */ + ext4_discard_preallocations(inode); return ret; }