xfs_efi_item slab corruption. (v3.9-10936-g51a26ae)

[Mark Tinguely]

On 05/07/13 08:37, Dave Jones wrote:
>    172.233570] Bytes b4 ffff8800aaac4e28: 07 a2 fd ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a  ........ZZZZZZZZ
> [  172.233573] Object ffff8800aaac4e38: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233575] Object ffff8800aaac4e48: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233577] Object ffff8800aaac4e58: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233579] Object ffff8800aaac4e68: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233581] Object ffff8800aaac4e78: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233583] Object ffff8800aaac4e88: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233586] Object ffff8800aaac4e98: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
> [  172.233588] Object ffff8800aaac4ea8: 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  jkkkkkkkkkkkkkkk
                                           ^^

xfs_efi_log_item.efi_refcount being decremented on the xfs_efi_release()
CAI Qian had the same thing in his May 6 "3.9.0: XFS rootfs corruption" 
email.

I have not reproduced it yet.

--Mark.