[Dazuko-help] kernel 2.6.36.2 + dazukofs-3.1.4-rc[123]: kernel BUG at fs/dcache.c:677!

[Dustin Polke]

Dear all,

after upgrading my kernel to 2.6.36.2 and therefore using
dazukofs-3.1.4-rc, I observe the following with all release candidates
upto rc3:

legolas dustin # mount /dev/sdb1 /mnt/usb/

legolas dustin # mount -t dazukofs /mnt/usb /mnt/usb

legolas dustin # mount | grep /mnt/usb
/dev/sdb1 on /mnt/usb type ext2 (rw)
/mnt/usb on /mnt/usb type dazukofs (rw)

legolas dustin # umount /mnt/usb

legolas dustin # mount | grep /mnt/usb
/dev/sdb1 on /mnt/usb type ext2 (rw)

legolas dustin # umount /mnt/usb
Segmentation fault

legolas dustin #


BUG: Dentry ffff88013b802d80{i=2,n=/} still in use (618) [unmount of
ext3 loop5]
------------[ cut here ]------------
kernel BUG at fs/dcache.c:677!
invalid opcode: 0000 [#1] PREEMPT SMP
last sysfs
file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT0/status
CPU 1
Modules linked in: uvcvideo bluetooth xt_mac xt_limit xt_state xt_tcpmss
xt_tcpudp xt_pkttype iptable_raw xt_CLASSIFY xt_comment xt_length
xt_policy iptable_mangle ipt_ULOG ipt_REJECT ipt_REDIRECT ipt_NETMAP
ipt_MASQUERADE ipt_LOG ipt_ECN ipt_ecn ipt_CLUSTERIP ipt_ah iptable_nat
nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ipt_addrtype
xt_DSCP xt_dscp xt_string xt_NFQUEUE xt_multiport xt_mark xt_hashlimit
xt_conntrack xt_connmark nf_conntrack ip_tables x_tables nfs coretemp
nfsd lockd auth_rpcgss sunrpc exportfs aes_x86_64 aes_generic bridge stp
llc dazukofs webcamstudio vboxnetadp vboxnetflt vboxdrv nvidiafb fb_ddc
vgastate nvidia(P) arc4 ecb iwlagn usbhid iwlcore mac80211 videodev
cfg80211 firewire_ohci firewire_core v4l1_compat v4l2_compat_ioctl32
tifm_7xx1 sony_laptop iTCO_wdt uhci_hcd intel_agp iTCO_vendor_support
rfkill i2c_i801 tifm_core sky2 video pcspkr output loop ehci_hcd
usb_storage usb_libusual usbcore [last unloaded: uvcvideo]

Pid: 16377, comm: umount Tainted: P            2.6.36-gentoo-r5-stable
#3 VAIO/VGN-FZ38M
RIP: 0010:[<ffffffff810c2f39>]  [<ffffffff810c2f39>]
shrink_dcache_for_umount_subtree+0x1a3/0x28e
RSP: 0018:ffff880112537de8  EFLAGS: 00010296
RAX: 0000000000000057 RBX: ffff88013b802d80 RCX: 0000000000003d1e
RDX: 0000000000000000 RSI: 0000000000000046 RDI: ffffffff813fe153
RBP: ffff880112537e18 R08: 0000000000000002 R09: 000000000000000a
R10: ffff880112537cd8 R11: 0000000000000000 R12: 00000000000000cc
R13: ffff88013b802d80 R14: dead000000200200 R15: ffff880112537f28
FS:  00007ff390818740(0000) GS:ffff880001900000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff3900f9e60 CR3: 000000013a9bb000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process umount (pid: 16377, threadinfo ffff880112536000, task
ffff88012b56b200)
Stack:
 ffff880137f3a288 ffffffff81029d27 ffff880137f3a000 ffffffff814226b0
<0> ffff880137f3a000 ffffffff816147c8 ffff880112537e38 ffffffff810c305b
<0> ffff880112537e68 ffff880137f3a000 ffff880112537e58 ffffffff810b44d1
Call Trace:
 [<ffffffff81029d27>] ? get_parent_ip+0x11/0x42
 [<ffffffff810c305b>] shrink_dcache_for_umount+0x37/0x47
 [<ffffffff810b44d1>] generic_shutdown_super+0x1a/0xd2
 [<ffffffff810b45ab>] kill_block_super+0x22/0x3a
 [<ffffffff810b38fb>] deactivate_locked_super+0x21/0x41
 [<ffffffff810b3d75>] deactivate_super+0x40/0x45
 [<ffffffff810c8413>] mntput_no_expire+0xdd/0x10b
 [<ffffffff810c898a>] sys_umount+0x2d2/0x2fd
 [<ffffffff81001f6b>] system_call_fastpath+0x16/0x1b
Code: 0a 48 8b 4b 38 31 d2 48 85 f6 74 04 48 8b 56 40 48 05 88 02 00 00
48 89 de 48 89 04 24 48 c7 c7 7e da 4d 81 31 c0 e8 de b1 33 00 <0f> 0b
eb fe 4c 8b 6b 28 4c 39 eb 75 05 45 31 ed eb 05 f0 41 ff
RIP  [<ffffffff810c2f39>] shrink_dcache_for_umount_subtree+0x1a3/0x28e
 RSP <ffff880112537de8>
---[ end trace 9a587062f6ae989f ]---


Any idea what might be the reason for this?
I tried with vanilla kernel 2.6.36.2 as well with the same result, so it
is not related to patches applied additionally by Gentoo.
If you need more information, please let me know.