On Thu, 18 Sep 2014 12:12:45 +0200, Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com> wrote:
> Hi there!
> 
> I remember I reported a similar OOPs some time ago.
> 
> This is what I'm having now, while compiling a new kernel.
> Is a VM, with the ext4 over a LVS volume from the virtualization server (kvm).
Error is pretty obvious.
EIO provokes journal abort, jbd2_journal_dirty_metadata return -EROFS
non zero error code provokes this WARN_ON
if (ext4_handle_valid(handle)) {
   err = jbd2_journal_dirty_metadata(handle, bh);
   /* Errors can only happen if there is a bug */
   if (WARN_ON_ONCE(err)) {
This code was introduced by Jack@ here (91aa11fae1cf8c2)
So this WARN_ON is false positive.
IMHO we can interpret aborted journal as special but valid case.