[Btrfs-devel] kernel BUG at volumes.c:1404!

[Peter Teoh]

I keep  getting the following whenever I did a  "mount -t btrfs
/dev/sdc1 /mnt/btrfs".   The partition was mountable the last  time
round.   As shown below, it is just a  1GB thumbdrive.

scsi 3:0:0:0: Direct-Access     TREK     TDMINIG4         1.00 PQ: 0 ANSI: 2
sd 3:0:0:0: [sdc] 2015231 512-byte hardware sectors (1032 MB)
sd 3:0:0:0: [sdc] Write Protect is off
sd 3:0:0:0: [sdc] Mode Sense: 00 00 00 00
sd 3:0:0:0: [sdc] Assuming drive cache: write through
sd 3:0:0:0: [sdc] 2015231 512-byte hardware sectors (1032 MB)
sd 3:0:0:0: [sdc] Write Protect is off
sd 3:0:0:0: [sdc] Mode Sense: 00 00 00 00
sd 3:0:0:0: [sdc] Assuming drive cache: write through
 sdc: sdc1
sd 3:0:0:0: [sdc] Attached SCSI removable disk
sd 3:0:0:0: Attached scsi generic sg3 type 0
device fsid d54e88dfe7045a33-5c0a895e8fb74296 devid 1 transid 19 /dev/sdc1
------------[ cut here ]------------
kernel BUG at /sda4/download/linux_linus/btrfs-unstable/volumes.c:1404!
invalid opcode: 0000 [#1] SMP
Modules linked in: btrfs nls_utf8 loop ipt_MASQUERADE iptable_nat
nf_nat bridge autofs4 hidp rfcomm l2cap bluetooth sunrpc
nf_conntrack_netbios_ns nf_conntrack_ipv4 xt_state nf_conntrack
ipt_REJECT iptable_filter ip_tables xt_tcpudp ip6t_REJECT
ip6table_filter ip6_tables x_tables cpufreq_ondemand acpi_cpufreq
dm_mirror dm_multipath dm_mod sbs sbshc radeon drm ipv6 snd_intel8x0
snd_seq_dummy snd_intel8x0m snd_ac97_codec ac97_bus snd_seq_oss
snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss
snd_pcm snd_timer snd firewire_ohci firewire_core soundcore ipw2200
ieee80211 sdhci mmc_core video b44 button iTCO_wdt iTCO_vendor_support
output ssb crc_itu_t mii i2c_i801 battery joydev snd_page_alloc
ieee80211_crypt dcdbas i2c_core pcspkr ac sr_mod sg cdrom usb_storage
ata_generic ahci ata_piix libata sd_mod scsi_mod ext3 jbd ehci_hcd
ohci_hcd uhci_hcd [last unloaded: microcode]

Pid: 8018, comm: mount Not tainted (2.6.25-rc9 #5)
EIP: 0060:[<f8bf0b70>] EFLAGS: 00010a16 CPU: 0
EIP is at btrfs_read_sys_array+0x97/0xaa [btrfs]
EAX: 000000c5 EBX: 000001d8 ECX: cdb80000 EDX: 00000000
ESI: f170a32c EDI: 00000000 EBP: d63f7dfc ESP: d63f7dd0
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process mount (pid: 8018, ti=d63f7000 task=c6ade6e0 task.ti=d63f7000)
Stack: c6a86200 ed745188 00000047 ed745188 00000246 c570abc4 000000bf 04854f00
       00000001 00001000 f170a154 d63f7e3c f8bdb4e2 f14698a0 e1f2f600 f170abc4
       00001000 00001000 00001000 c6a86c00 c6a86200 f16ee600 f170a000 f16eee00
Call Trace:
 [<f8bdb4e2>] ? open_ctree+0x5bf/0x7c7 [btrfs]
 [<f8bcd4d2>] ? btrfs_get_sb_bdev+0x134/0x2d8 [btrfs]
 [<c04288c4>] ? irq_exit+0x53/0x6b
 [<f8bcd6ba>] ? btrfs_get_sb+0x44/0x5f [btrfs]
 [<c0475821>] ? vfs_kern_mount+0x81/0xf7
 [<c04758db>] ? do_kern_mount+0x32/0xb9
 [<c048794c>] ? do_new_mount+0x46/0x74
 [<c0487b03>] ? do_mount+0x189/0x1a7
 [<c045a2ed>] ? __get_free_pages+0x45/0x4c
 [<c0485f40>] ? copy_mount_options+0x27/0x10b
 [<c0487b85>] ? sys_mount+0x64/0x9b
 [<c04048c6>] ? sysenter_past_esp+0x5f/0x85
 =======================
Code: 0b eb fe 8b 45 d8 89 da e8 30 68 ff ff 0f b7 c0 85 c0 75 04 0f
0b eb fe c1 e0 05 83 c0 30 8d 74 06 11 8d 1c 18 8d 7c 07 11 eb 04 <0f>
0b eb fe 3b 7d dc 72 93 8d 65 f4 31 c0 5b 5e 5f 5d c3 55 89
EIP: [<f8bf0b70>] btrfs_read_sys_array+0x97/0xaa [btrfs] SS:ESP 0068:d63f7dd0


uname -r:

2.6.25-rc9

lsmod:

btrfs                 208952  2

My tip is:

changeset:   513:1c4e9af4dfe7
tag:         tip
user:        Chris Mason <chris.mason at oracle.com>
date:        Tue Apr 22 13:26:47 2008 -0400
summary:     Fix the unplug_io_fn to grab a consistent copy of page->mapping

Even after reboot the  kernel, the same thing happened.   And the
second time of issuing the same mount command, will result in mount
blocking, but not the first time.

Any clue?

-- 
Regards,
Peter Teoh