Comment # 37
on bug 1017461
from Frederic Crozat
I'm seeing similar issue and they seem to have increased since I enabled
snapper (including quota) on my /home some days ago (btrfs-transaction takes
100% cpu for a while and blocks any IO on /home).
The issue seems to be correlated when resuming back from suspend, but I'm not
sure.
I noticed some potential interesting infos in my logs :
BTRFS info (device sda3): qgroup scan completed (inconsistency flag cleared)
and:
kernel: ------------[ cut here ]------------
kernel: WARNING: CPU: 3 PID: 3211 at ../fs/btrfs/qgroup.c:2923
btrfs_qgroup_free_meta+0x87/0x90 [btrfs]()
kernel: Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE
nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf
kernel: ptp mei_me iTCO_wdt ansi_cprng iTCO_vendor_support regmap_i2c
snd_timer parport_pc mei cfg80211 8250_fintek btrtl dell_laptop pcspkr pps_core
btbcm aesni_intel sn
kernel: i2c_algo_bit
kernel: usbcore drm_kms_helper usb_common syscopyarea sysfillrect sdhci_pci
sysimgblt fb_sys_fops drm i2c_hid video sdhci_acpi sdhci mmc_core button sg
dm_multipath dm_mo
kernel: CPU: 3 PID: 3211 Comm: snapperd Tainted: G W
4.4.36-8-default #1
kernel: Hardware name: Dell Inc. Latitude E7250/0TVD2T, BIOS A15 12/26/2016
kernel: 0000000000000000 ffffffff81327b17 0000000000000000 ffffffffa056a168
kernel: ffffffff8107e841
kernel: ffff8803fe76b800 0000000000008000 ffff8803f7089c0c
kernel: 00000000000c0000
kernel: ffff8803f7089db8
kernel: ffffffffa0552fd7 ffff8803fe76b800
kernel: Call Trace:
kernel: [<ffffffff81019ea9>] dump_trace+0x59/0x320
kernel: [<ffffffff8101a26a>] show_stack_log_lvl+0xfa/0x180
kernel: [<ffffffff8101b011>] show_stack+0x21/0x40
kernel: [<ffffffff81327b17>] dump_stack+0x5c/0x85
kernel: [<ffffffff8107e841>] warn_slowpath_common+0x81/0xb0
kernel: [<ffffffffa0552fd7>] btrfs_qgroup_free_meta+0x87/0x90 [btrfs]
kernel: [<ffffffffa04d5270>] btrfs_delalloc_reserve_metadata+0x200/0x4a0
[btrfs]
kernel: [<ffffffffa04fbb2a>] __btrfs_buffered_write+0x17a/0x5b0 [btrfs]
kernel: [<ffffffffa04ff376>] btrfs_file_write_iter+0x176/0x540 [btrfs]
kernel: [<ffffffff81204f39>] __vfs_write+0xa9/0x100
kernel: [<ffffffff8120562d>] vfs_write+0x9d/0x190
kernel: [<ffffffff812062f2>] SyS_write+0x42/0xa0
kernel: [<ffffffff8160a8f2>] entry_SYSCALL_64_fastpath+0x16/0x71
kernel: DWARF2 unwinder stuck at entry_SYSCALL_64_fastpath+0x16/0x71
kernel:
kernel: Leftover inexact backtrace:
kernel: ---[ end trace d4465d6cbfeeee27 ]---
kernel: ------------[ cut here ]------------
as well as:
kernel: ------------[ cut here ]------------
kernel: WARNING: CPU: 3 PID: 425 at ../fs/btrfs/qgroup.c:2923
btrfs_qgroup_free_meta+0x87/0x90 [btrfs]()
kernel: Modules linked in: xt_CHECKSUM iptable_mangle ipt_MASQUERADE
nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf
kernel: ptp mei_me iTCO_wdt ansi_cprng iTCO_vendor_support regmap_i2c
snd_timer parport_pc mei cfg80211 8250_fintek btrtl dell_laptop pcspkr pps_core
btbcm aesni_intel sn
kernel: i2c_algo_bit usbcore drm_kms_helper usb_common syscopyarea sysfillrect
sdhci_pci sysimgblt fb_sys_fops drm i2c_hid video sdhci_acpi sdhci mmc_core
button sg dm_mu
kernel: CPU: 3 PID: 425 Comm: systemd-journal Tainted: G W
4.4.36-8-default #1
Feb 04 13:25:17 latitude.par.novell.com kernel: Hardware name: Dell Inc.
Latitude E7250/0TVD2T, BIOS A15 12/26/2016
kernel: 0000000000000000 ffffffff81327b17 0000000000000000 ffffffffa056a168
kernel: ffffffff8107e841 ffff8803fe76b800 000000000002c000 ffff8803fe76b800
kernel: 000000000002c000 ffff8803fd4a81d0 ffffffffa0552fd7 ffffffffffffffe4
kernel: Call Trace:
kernel: [<ffffffff81019ea9>] dump_trace+0x59/0x320
kernel: [<ffffffff8101a26a>] show_stack_log_lvl+0xfa/0x180
kernel: [<ffffffff8101b011>] show_stack+0x21/0x40
kernel: [<ffffffff81327b17>] dump_stack+0x5c/0x85
kernel: [<ffffffff8107e841>] warn_slowpath_common+0x81/0xb0
kernel: [<ffffffffa0552fd7>] btrfs_qgroup_free_meta+0x87/0x90 [btrfs]
kernel: [<ffffffffa04e9997>] start_transaction+0x3c7/0x4e0 [btrfs]
kernel: [<ffffffffa04f72c7>] btrfs_rename2+0x157/0x7b0 [btrfs]
kernel: [<ffffffff81211783>] vfs_rename+0x4b3/0x810
kernel: [<ffffffff8121675e>] SyS_rename+0x35e/0x3c0
kernel: [<ffffffff8160a8f2>] entry_SYSCALL_64_fastpath+0x16/0x71
kernel: DWARF2 unwinder stuck at entry_SYSCALL_64_fastpath+0x16/0x71