abrt version: 2.0.1
architecture:   x86_64
cmdline:        ro root=UUID=b22e4265-9691-447d-8174-2a88a6226590 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us rhgb quiet
comment:        Usage of my Fedora 15, while operating a KVM based virtual machine, Fedora 15 as guest OS.
component:      kernel
kernel:         2.6.38.8-32.fc15.x86_64
kernel_tainted: 512
os_release:     Fedora release 15 (Lovelock)
package:        kernel
reason:         [168087.763378] WARNING: at fs/btrfs/disk-io.c:381 __btree_submit_bio_start+0x124/0x1aa [btrfs]()
reported_to:    kerneloops: URL=http://submit.kerneloops.org/submitoops.php
time:           Thu Jun 23 08:20:08 2011

backtrace:
:[168087.763378] WARNING: at fs/btrfs/disk-io.c:381 __btree_submit_bio_start+0x124/0x1aa [btrfs]()
:[168087.763423] Hardware name: 2241B38
:[168087.763428] Modules linked in: tcp_lp usb_storage uas tun fuse ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat xt_CHECKSUM iptable_mangle bridge sunrpc 8021q garp stp llc cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables arc4 iwlagn iwlcore mac80211 cfg80211 e1000e snd_usb_audio snd_usbmidi_lib snd_rawmidi uvcvideo snd_hda_codec_conexant microcode videodev ppdev snd_hda_intel snd_hda_codec snd_hwdep btusb snd_seq r852 sm_common nand snd_seq_device nand_ids bluetooth v4l2_compat_ioctl32 nand_ecc joydev mtd snd_pcm thinkpad_acpi snd_timer wmi snd soundcore rfkill iTCO_wdt iTCO_vendor_support i2c_i801 snd_page_alloc parport_pc parport virtio_net kvm_intel kvm ipv6 btrfs zlib_deflate libcrc32c firewire_ohci sdhci_pci firewire_core sdhci pata_acpi mmc_core yenta_socket crc_itu_t ata_generic i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
:[168087.763591] Pid: 1880, comm: btrfs-worker-1 Tainted: G        W   2.6.38.8-32.fc15.x86_64 #1
:[168087.763597] Call Trace:
:[168087.763614]  [<ffffffff8105511a>] warn_slowpath_common+0x83/0x9b
:[168087.763623]  [<ffffffff8105514c>] warn_slowpath_null+0x1a/0x1c
:[168087.763661]  [<ffffffffa013b3ea>] __btree_submit_bio_start+0x124/0x1aa [btrfs]
:[168087.763723]  [<ffffffffa0139e8c>] run_one_async_start+0x25/0x27 [btrfs]
:[168087.763764]  [<ffffffffa0163dfb>] worker_loop+0x145/0x46e [btrfs]
:[168087.763806]  [<ffffffffa0163cb6>] ? worker_loop+0x0/0x46e [btrfs]
:[168087.763841]  [<ffffffff8106ebaf>] kthread+0x84/0x8c
:[168087.763852]  [<ffffffff8100a9e4>] kernel_thread_helper+0x4/0x10
:[168087.763860]  [<ffffffff8106eb2b>] ? kthread+0x0/0x8c
:[168087.763869]  [<ffffffff8100a9e0>] ? kernel_thread_helper+0x0/0x10

event_log:
:2011-06-23-16:23:39> Submitting oops report to http://submit.kerneloops.org/submitoops.php
:2011-06-23-16:23:50  Kernel oops report was uploaded