I have TW install which used to have a ext4 / partition. Using a rescue TW USB
stick ( created about 2-3 weeks ago ) I converted that partition to btrfs. I
did a balance and defrag ( in that order ) , both when the fs was mounted.
After logging in to KDE I quickly get a read-only filesystem. I've pasted the
backtrace below
Jun 11 23:13:08 mars kernel: WARNING: CPU: 2 PID: 2777 at
../fs/btrfs/super.c:260 __btrfs_abort_transaction+0x4b/0x120 [btrfs]()
Jun 11 23:13:08 mars kernel: BTRFS: Transaction aborted (error -95)
Jun 11 23:13:08 mars kernel: Modules linked in: bnep bluetooth rfkill fuse
vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) af_packet nf_log_ipv6
xt_pkttype nf_log_ip
v4 nf_log_common xt_LOG xt_limit ip6t_REJECT xt_tcpudp nf_conntrack_ipv6
nf_defrag_ipv6 ip6table_raw ipt_REJECT iptable_raw xt_CT iptable_filter
ip6table_mangle nf_con
ntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_ipv4 nf_defrag_ipv4
ip_tables xt_conntrack nf_conntrack ip6table_filter ip6_tables x_tables xfs
libcrc32c snd_hda
_codec_hdmi raid1 md_mod gpio_ich ppdev iTCO_wdt iTCO_vendor_support coretemp
snd_hda_codec_realtek snd_hda_codec_generic kvm_intel snd_hda_intel dm_mod kvm
snd_hda_co
ntroller snd_hda_codec snd_hwdep serio_raw pcspkr snd_pcm i2c_i801 snd_seq
joydev snd_seq_device snd_timer snd 8250_fintek parport_pc parport acpi_cpufreq
lpc_ich
Jun 11 23:13:08 mars kernel: soundcore mfd_core shpchp processor ata_generic
btrfs hid_logitech_hidpp xor raid6_pq sr_mod cdrom nvidia_uvm(PO) nvidia(PO)
firewire_ohc
i firewire_core crc_itu_t uas usb_storage r8169 mii pata_jmicron
hid_logitech_dj drm button sg
Jun 11 23:13:08 mars kernel: CPU: 2 PID: 2777 Comm: kworker/u8:0 Tainted: P
O 4.0.4-3-desktop #1
Jun 11 23:13:08 mars kernel: Hardware name: Gigabyte Technology Co., Ltd.
EP35-DS4/EP35-DS4, BIOS F6d 01/08/2009
Jun 11 23:13:08 mars kernel: Workqueue: btrfs-endio-write
btrfs_endio_write_helper [btrfs]
Jun 11 23:13:08 mars kernel: 0000000000000000 ffffffffa0a92832
ffffffff8167c4aa ffff880128513ca8
Jun 11 23:13:08 mars kernel: ffffffff81063bb1 ffff880031929d28
ffff880221e71800 00000000ffffffa1
Jun 11 23:13:08 mars kernel: ffffffffa0a914e0 0000000000000b50
ffffffff81063c2a ffffffffa0a95928
Jun 11 23:13:08 mars kernel: Call Trace:
Jun 11 23:13:08 mars kernel: [<ffffffff8100574c>] dump_trace+0x8c/0x340
Jun 11 23:13:08 mars kernel: [<ffffffff81005aa3>]
show_stack_log_lvl+0xa3/0x190
Jun 11 23:13:08 mars kernel: [<ffffffff81007201>] show_stack+0x21/0x50
Jun 11 23:13:08 mars kernel: [<ffffffff8167c4aa>] dump_stack+0x47/0x67
Jun 11 23:13:08 mars kernel: [<ffffffff81063bb1>]
warn_slowpath_common+0x81/0xb0
Jun 11 23:13:08 mars kernel: [<ffffffff81063c2a>] warn_slowpath_fmt+0x4a/0x50
Jun 11 23:13:08 mars kernel: [<ffffffffa09e598b>]
__btrfs_abort_transaction+0x4b/0x120 [btrfs]
Jun 11 23:13:08 mars kernel: [<ffffffffa0a1d18a>]
btrfs_finish_ordered_io+0x5aa/0x620 [btrfs]
Jun 11 23:13:08 mars kernel: [<ffffffffa0a43253>]
normal_work_helper+0xc3/0x320 [btrfs]
Jun 11 23:13:08 mars kernel: [<ffffffff8107bcf2>] process_one_work+0x142/0x420
Jun 11 23:13:08 mars kernel: [<ffffffff8107c0e4>] worker_thread+0x114/0x460
Jun 11 23:13:08 mars kernel: [<ffffffff81081261>] kthread+0xc1/0xe0
Jun 11 23:13:08 mars kernel: [<ffffffff81682d58>] ret_from_fork+0x58/0x90
Jun 11 23:13:08 mars kernel: ---[ end trace 4c4eb7d6e98afa91 ]---
Jun 11 23:13:08 mars kernel: BTRFS: error (device sda1) in
btrfs_finish_ordered_io:2896: errno=-95 unknown
Jun 11 23:13:08 mars kernel: BTRFS info (device sda1): forced readonly
I've only found one reference to this problem online, and it also seems to be
related to partitions converted from ext4:
http://comments.gmane.org/gmane.comp.file-systems.btrfs/45297