abrt version: 2.0.3
architecture:   x86_64
cmdline:        ro pcie_aspm=force root=/dev/mapper/sheep-root.f15 rd_LVM_LV=sheep/root.f15 rd_LVM_LV=sheep/swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_GB.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=uk rhgb quiet
comment:        This just happened, I don't think I was doing anything special except, perhaps, running VirtualBox.
component:      kernel
kernel:         2.6.38.8-35.fc15.x86_64
kernel_tainted: 512
kernel_tainted_long: Taint on warning.
os_release:     Fedora release 15 (Lovelock)
package:        kernel
reason:         WARNING: at fs/btrfs/extent-tree.c:5695 btrfs_alloc_free_block+0xca/0x27c [btrfs]()
time:           Wed Jul 13 11:36:55 2011

backtrace:
:WARNING: at fs/btrfs/extent-tree.c:5695 btrfs_alloc_free_block+0xca/0x27c [btrfs]()
:Hardware name: Latitude E6410
:Modules linked in: tcp_lp nfs lockd fscache nfs_acl auth_rpcgss fuse hidp ipt_REDIRECT iptable_nat nf_nat vboxnetadp vboxnetflt sunrpc vboxdrv cpufreq_ondemand acpi_cpufreq freq_table mperf rfcomm sco bnep l2cap ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables xts gf128mul dm_crypt arc4 snd_hda_codec_hdmi snd_hda_codec_idt joydev snd_hda_intel snd_hda_codec iwlagn btusb bluetooth iwlcore dell_laptop dell_wmi ppdev snd_hwdep sparse_keymap intel_ips snd_seq snd_seq_device dcdbas i2c_i801 snd_pcm iTCO_wdt iTCO_vendor_support e1000e snd_timer parport_pc mac80211 snd soundcore wmi parport cfg80211 microcode rfkill snd_page_alloc ipv6 btrfs zlib_deflate libcrc32c sdhci_pci sdhci mmc_core firewire_ohci firewire_core crc_itu_t i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
:Pid: 19203, comm: btrfs-endio-wri Not tainted 2.6.38.8-35.fc15.x86_64 #1
:Call Trace:
: [<ffffffff8105511a>] warn_slowpath_common+0x83/0x9b
: [<ffffffff8105514c>] warn_slowpath_null+0x1a/0x1c
: [<ffffffffa010db54>] btrfs_alloc_free_block+0xca/0x27c [btrfs]
: [<ffffffffa0100df9>] __btrfs_cow_block+0xfc/0x31d [btrfs]
: [<ffffffffa010111b>] btrfs_cow_block+0x101/0x110 [btrfs]
: [<ffffffffa010408e>] btrfs_search_slot+0x13f/0x505 [btrfs]
: [<ffffffffa0111984>] btrfs_lookup_file_extent+0x38/0x3a [btrfs]
: [<ffffffffa0125547>] btrfs_drop_extents+0xdd/0x6f8 [btrfs]
: [<ffffffff8104127e>] ? should_resched+0xe/0x2d
: [<ffffffff81111763>] ? kmem_cache_alloc+0x90/0x105
: [<ffffffffa011d019>] insert_reserved_file_extent.constprop.8+0x70/0x1f9 [btrfs]
: [<ffffffffa01193a2>] ? start_transaction+0x1b0/0x1f1 [btrfs]
: [<ffffffffa011db77>] btrfs_finish_ordered_io+0x1c7/0x2a1 [btrfs]
: [<ffffffff810e06c9>] ? test_clear_page_writeback+0xc1/0xd4
: [<ffffffff81478402>] ? _raw_spin_lock_irqsave+0x12/0x2f
: [<ffffffffa011dc6b>] btrfs_writepage_end_io_hook+0x1a/0x1c [btrfs]
: [<ffffffffa0132d2f>] end_bio_extent_writepage+0xa4/0x152 [btrfs]
: [<ffffffffa0113cb8>] ? end_workqueue_fn+0xf1/0x108 [btrfs]
: [<ffffffff81147141>] bio_endio+0x2d/0x2f
: [<ffffffffa0113cc3>] end_workqueue_fn+0xfc/0x108 [btrfs]
: [<ffffffffa013cdfb>] worker_loop+0x145/0x46e [btrfs]
: [<ffffffffa013ccb6>] ? worker_loop+0x0/0x46e [btrfs]
: [<ffffffff8106ebaf>] kthread+0x84/0x8c
: [<ffffffff8100a9e4>] kernel_thread_helper+0x4/0x10
: [<ffffffff8106eb2b>] ? kthread+0x0/0x8c
: [<ffffffff8100a9e0>] ? kernel_thread_helper+0x0/0x10