sorry, I made a typo in the testcase (the second mount)
Basically, it might be enough to mount two different btrfs filesystems
to two different locations, umount one of them and watch
/var/log/kern.log for the oops
dd if=/dev/zero of=mountme bs=4k count=10
dd if=/dev/zero of=mountme2 bs=4k count=10
mkfs.btrfs mountme
mkfs.btrfs mountme2
mkdir loop loop2
mount -o loop mountme loop
mount -o loop mountme2 loop2
umount loop
# wait a moment
On 7/24/08, Lukas Vacek [EMAIL PROTECTED] wrote:
Hi,
I tried very promising btrfs to test it a little and I experienced a
little bug in implementation. I'm not sure where the bug lies however
this works quite well to reproduce the problem:
dd if=/dev/zero of=mountme bs=4k count=10
dd if=/dev/zero of=mountme2 bs=4k count=10
mkfs.btrfs mountme
mkfs.btrfs mountme2
mkdir loop loop2
mount -o loop mountme loop
mount -o loop mountme loop2
umount loop
# wait a moment
maybe SMP machine will be necessary to experience the same
thanks for the (otherwise ;-)) grea work and have a nice day,
Lukas V.
the interesting part of log goes next:
Jul 24 22:44:00 minerva kernel: [ 1478.326985] device fsid
5442602040543dd1-d32561672012f7a2 devid 1 transid 12 /dev/loop1
Jul 24 22:44:54 minerva kernel: [ 1532.882212] Unable to handle kernel
paging request at 7effdc171f47 RIP:
Jul 24 22:44:54 minerva kernel: [ 1532.882256] [wq_per_cpu+0x15/0x20]
wq_per_cpu+0x15/0x20
Jul 24 22:44:54 minerva kernel: [ 1532.882405] PGD 0
Jul 24 22:44:54 minerva kernel: [ 1532.882476] Oops: [1] SMP
Jul 24 22:44:54 minerva kernel: [ 1532.882572] CPU 1
Jul 24 22:44:54 minerva kernel: [ 1532.882641] Modules linked in: loop
binfmt_misc af_packet i915 drm rfcomm l2cap bluetooth ppdev ipv6
acpi_cpufreq cpufreq_ondemand cpufreq_stats freq_table
cpufreq_userspace cpufreq_conservative cpufreq_powersave video output
container sbs sbshc dock battery iptable_filter ip_tables x_tables
aes_x86_64 dm_crypt dm_mod ac btrfs libcrc32c lp snd_hda_intel
snd_hwdep snd_pcm_oss snd_pcm snd_page_alloc snd_mixer_oss
snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event
snd_seq snd_timer iTCO_wdt iTCO_vendor_support snd_seq_device button
snd evdev shpchp pci_hotplug intel_agp soundcore parport_pc parport
pcspkr ext3 jbd mbcache usbhid hid sg sd_mod ata_piix pata_acpi floppy
ehci_hcd ata_generic libata scsi_mod r8169 uhci_hcd usbcore thermal
processor fan fbcon tileblit font bitblit softcursor fuse
Jul 24 22:44:54 minerva kernel: [ 1532.885056] Pid: 3959, comm:
btrfs-transacti Not tainted 2.6.24-19-generic #1
Jul 24 22:44:54 minerva kernel: [ 1532.885117] RIP:
0010:[wq_per_cpu+0x15/0x20] [wq_per_cpu+0x15/0x20]
wq_per_cpu+0x15/0x20
Jul 24 22:44:54 minerva kernel: [ 1532.885224] RSP:
0018:81003e6a1c08 EFLAGS: 00010246
Jul 24 22:44:54 minerva kernel: [ 1532.885281] RAX: 7effdc171f3f
RBX: 81003db0b770 RCX:
Jul 24 22:44:54 minerva kernel: [ 1532.885342] RDX:
RSI: 0001 RDI: 810023e8e940
Jul 24 22:44:54 minerva kernel: [ 1532.885404] RBP: 81003db0a000
R08: R09: 882c9d80
Jul 24 22:44:54 minerva kernel: [ 1532.885465] R10: 81003653ade0
R11: R12: 81003653ade0
Jul 24 22:44:54 minerva kernel: [ 1532.885526] R13: 0001
R14: 810014366680 R15:
Jul 24 22:44:54 minerva kernel: [ 1532.885588] FS:
() GS:81003e401700()
knlGS:
Jul 24 22:44:54 minerva kernel: [ 1532.885671] CS: 0010 DS: 0018 ES:
0018 CR0: 8005003b
Jul 24 22:44:54 minerva kernel: [ 1532.885728] CR2: 7effdc171f47
CR3: 225cc000 CR4: 06e0
Jul 24 22:44:54 minerva kernel: [ 1532.885789] DR0:
DR1: DR2:
Jul 24 22:44:54 minerva kernel: [ 1532.885851] DR3:
DR6: 0ff0 DR7: 0400
Jul 24 22:44:54 minerva kernel: [ 1532.885912] Process btrfs-transacti
(pid: 3959, threadinfo 81003e6a, task 81003c74c7e0)
Jul 24 22:44:54 minerva kernel: [ 1532.885996] Stack:
8024f97c 81001e3db480 882ca4ce 882c9d80
Jul 24 22:44:54 minerva kernel: [ 1532.886193] 01c08fff
810014366680 81003653ad40 1000
Jul 24 22:44:54 minerva kernel: [ 1532.886364] 81003ee140e8
0001 882e19cf 01c09000
Jul 24 22:44:54 minerva kernel: [ 1532.886495] Call Trace:
Jul 24 22:44:54 minerva kernel: [ 1532.886587]
[shpchp:queue_work+0x2c/0x50] queue_work+0x2c/0x50
Jul 24 22:44:54 minerva kernel: [ 1532.886665]
[btrfs:btrfs_wq_submit_bio+0xbe/0xf0]
:btrfs:btrfs_wq_submit_bio+0xbe/0xf0
Jul 24 22:44:54 minerva kernel: [ 1532.886743]
[btrfs:__btree_submit_bio_hook+0x0/0x60]
:btrfs:__btree_submit_bio_hook+0x0/0x60
Jul 24 22:44:54 minerva kernel: [ 1532.886826]
[btrfs:submit_one_bio+0xcf/0x120] :btrfs:submit_one_bio+0xcf/0x120
