Re: btrfs io errors on 3.4rc1

[Dave Jones <davej@redhat.com>]

On Tue, Apr 03, 2012 at 06:33:43PM +0200, David Sterba wrote:
 > On Tue, Apr 03, 2012 at 12:20:23PM -0400, Dave Jones wrote:
 > > I see a lot of these ..
 > > 
 > > btrfs: __btrfs_end_transaction -EIO abored=1802201963 (no super error)
 > 
 > 1802201963 == 0x6b6b6b6b
 > 
 > #define POISON_FREE     0x6b    /* for use-after-free poisoning */
 > 
 > hmm

wait, what...

 535         memset(trans, 0, sizeof(*trans));
 536         kmem_cache_free(btrfs_trans_handle_cachep, trans);
 537 
 538         if (throttle)
 539                 btrfs_run_delayed_iputs(root);
 540 
 541         if (trans->aborted ||
 542             root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
 543                 return -EIO;
 544         }

that looks like a pretty clear use-after-free.

	Dave