[Unionfs] Kernel oops with 2.6.16

[Mike Hearn]

Hi, 

The 2.6.16-rc4-3-default kernel on OpenSUSE 10.1 doesn't work with the
latest unionfs snapshot. Mounting it with the following command:

  mount -t unionfs -o dirs=/snapshots/snap1=rw:/=ro,delete=whiteout unionfs workspace/

Mar  4 00:45:47 linux kernel:  <4>unionfs: branches 0 and 1 overlap
Mar  4 00:45:47 linux kernel: Unable to handle kernel paging request at virtual address 6b6b6b6b
Mar  4 00:45:47 linux kernel:  printing eip:
Mar  4 00:45:47 linux kernel: c01637f3
Mar  4 00:45:47 linux kernel: *pde = 00000000
Mar  4 00:45:47 linux kernel: Oops: 0000 [#2]
Mar  4 00:45:47 linux kernel: last sysfs file: /class/net/sit0/statistics/collisions
Mar  4 00:45:47 linux kernel: Modules linked in: unionfs nvidia af_packet snd_pcm_oss snd_mixer_oss ipv6 snd_seq_midi snd_seq_midi_event snd_seq edd button battery ac apparmor aamatch_pcre generic ns558 gameport nls_utf8 ntfs snd_mpu401 snd_mpu401_uart nls_iso8859_1 snd_intel8x0 snd_ac97_codec nls_cp437 snd_ac97_bus snd_rawmidi snd_pcm snd_timer snd_seq_device snd snd_page_alloc vfat fat soundcore loop ohci_hcd usbcore shpchp pci_hotplug i2c_sis630 ide_cd cdrom sis_agp agpgart i2c_sis96x i2c_core sis900 mii dm_mod parport_pc lp parport ext3 jbd fan thermal processor sis5513 ide_disk ide_core
Mar  4 00:45:47 linux kernel: CPU:    0
Mar  4 00:45:47 linux kernel: EIP:    0060:[<c01637f3>]    Tainted: P     U VLI
Mar  4 00:45:47 linux kernel: EFLAGS: 00210202   (2.6.16-rc4-3-default #1)
Mar  4 00:45:47 linux kernel: EIP is at dput+0xc/0x132
Mar  4 00:45:47 linux kernel: eax: 6b6b6b6b   ebx: 6b6b6b6b   ecx: 00000000   edx: ce242498
Mar  4 00:45:50 linux kernel: esi: 00000000   edi: 00000000   ebp: ffffffea   esp: c90e9d14
Mar  4 00:45:50 linux kernel: ds: 007b   es: 007b   ss: 0068
Mar  4 00:45:50 linux kernel: Process mount (pid: 13762, threadinfo=c90e8000 task=c050a6f0)
Mar  4 00:45:52 linux dhclient: DHCPREQUEST on eth1 to 129.234.4.86 port 67
Mar  4 00:45:52 linux kernel: Stack: <0>00000000 00000000 d13d2dc3 d13fffa0 00000000 00000001 00000004 d13ffef8
Mar  4 00:45:52 linux kernel:        ccb61019 00000072 0000002d 0000002d c90e9d60 ccb6101a ccb61012 ca2ead84
Mar  4 00:45:52 linux kernel:        ce242498 00000000 d1407c20 ca2eaefc 00000001 00000002 c01556df c0154e75
Mar  4 00:45:53 linux kernel: Call Trace:
Mar  4 00:45:53 linux kernel:  [<d13d2dc3>] unionfs_read_super+0x563/0x168d [unionfs]
Mar  4 00:45:55 linux kernel:  [<c01556df>] sget+0x459/0x463
Mar  4 00:45:56 linux kernel:  [<c0154e75>] set_anon_super+0x0/0x9b
Mar  4 00:45:56 linux kernel:  [<c0155bda>] get_sb_nodev+0x33/0x62
Mar  4 00:45:56 linux kernel:  [<c015596a>] do_kern_mount+0x86/0x12b
Mar  4 00:45:56 linux kernel:  [<d13d2860>] unionfs_read_super+0x0/0x168d [unionfs]
Mar  4 00:45:56 linux kernel:  [<c0168012>] do_mount+0x68d/0x6e7
Mar  4 00:45:56 linux kernel:  [<c01ab3ea>] _atomic_dec_and_lock+0x22/0x2c
Mar  4 00:45:56 linux kernel:  [<c0167256>] mntput_no_expire+0x11/0x6d
Mar  4 00:45:56 linux kernel:  [<c015d2ac>] link_path_walk+0xaf/0xb9
Mar  4 00:45:56 linux kernel:  [<c0140a98>] __handle_mm_fault+0x814/0x822
Mar  4 00:45:56 linux kernel:  [<c0282483>] _read_unlock_irq+0x5/0x7
Mar  4 00:45:56 linux kernel:  [<c01361a2>] find_get_page+0x39/0x3f
Mar  4 00:45:56 linux kernel:  [<c0139ff7>] get_page_from_freelist+0x6f/0x2c4
Mar  4 00:45:56 linux kernel:  [<c02830a9>] do_page_fault+0x17b/0x53c
Mar  4 00:45:56 linux kernel:  [<c0110089>] smp_apic_timer_interrupt+0x28/0x2d
Mar  4 00:45:56 linux kernel:  [<c0166efe>] copy_mount_options+0xa2/0x109
Mar  4 00:45:56 linux kernel:  [<c0134408>] audit_getname+0x79/0xd2
Mar  4 00:45:56 linux kernel:  [<c01680d0>] sys_mount+0x64/0x97
Mar  4 00:45:56 linux kernel:  [<c0102ab9>] syscall_call+0x7/0xb
Mar  4 00:45:56 linux kernel: Code: c0 89 c3 74 15 8b 86 c0 00 00 00 89 f2 89 5b 24 89 43 5c 89 d8 e8 60 f8 ff ff 89 d8 5b 5e c3 56 85
c0 53 89 c3 0f 84 23 01 00 00 <8b> 03 48 75 14 ba 99 00 00 00 b8 16 23 2a c0 e8 ca 11 fb ff e8


Anybody got any ideas?

thanks -mike