BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents
BTRFS error (device loop3): bad tree block start 0 1052672
BTRFS error (device loop3): failed to read chunk root
======================================================
WARNING: possible circular locking dependency detected
4.14.221-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/9706 is trying to acquire lock:
(&p->lock){+.+.}, at: [<ffffffff818e5eaa>] seq_read+0xba/0x1120 fs/seq_file.c:165
but task is already holding lock:
(sb_writers#3){.+.+}, at: [<ffffffff81867bdf>] file_start_write include/linux/fs.h:2712 [inline]
(sb_writers#3){.+.+}, at: [<ffffffff81867bdf>] do_sendfile+0x84f/0xb30 fs/read_write.c:1440
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (sb_writers#3){.+.+}:
percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
__sb_start_write+0x64/0x260 fs/super.c:1342
sb_start_write include/linux/fs.h:1549 [inline]
mnt_want_write+0x3a/0xb0 fs/namespace.c:386
ovl_do_remove+0x67/0xb90 fs/overlayfs/dir.c:759
vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3908
vfs_rmdir fs/namei.c:3893 [inline]
do_rmdir+0x334/0x3c0 fs/namei.c:3968
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
batman_adv: batadv0: Interface deactivated: batadv_slave_0
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #3 (&ovl_i_mutex_dir_key[depth]){++++}:
down_read+0x36/0x80 kernel/locking/rwsem.c:24
inode_lock_shared include/linux/fs.h:729 [inline]
lookup_slow+0x129/0x400 fs/namei.c:1674
lookup_one_len_unlocked+0x3a0/0x410 fs/namei.c:2595
batman_adv: batadv0: Removing interface: batadv_slave_0
ovl_lookup_single+0x33/0x6d0 fs/overlayfs/namei.c:208
ovl_lookup_layer+0x2ef/0x3d0 fs/overlayfs/namei.c:265
ovl_lookup+0x5d9/0x1120 fs/overlayfs/namei.c:670
lookup_slow+0x20a/0x400 fs/namei.c:1696
walk_component+0x6a1/0xbc0 fs/namei.c:1825
link_path_walk+0x823/0x10a0 fs/namei.c:2154
path_parentat+0x41/0x120 fs/namei.c:2398
filename_parentat+0x176/0x520 fs/namei.c:2420
SYSC_renameat2 fs/namei.c:4562 [inline]
SyS_renameat2+0x159/0xad0 fs/namei.c:4533
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #2 (&ovl_i_mutex_dir_key[depth]#2){++++}:
down_read+0x36/0x80 kernel/locking/rwsem.c:24
inode_lock_shared include/linux/fs.h:729 [inline]
do_last fs/namei.c:3333 [inline]
path_openat+0x149b/0x2970 fs/namei.c:3569
do_filp_open+0x179/0x3c0 fs/namei.c:3603
do_open_execat+0xd3/0x450 fs/exec.c:849
do_execveat_common+0x711/0x1f30 fs/exec.c:1755
do_execve fs/exec.c:1860 [inline]
SYSC_execve fs/exec.c:1941 [inline]
SyS_execve+0x3b/0x50 fs/exec.c:1936
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #1 (&sig->cred_guard_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
lock_trace fs/proc/base.c:407 [inline]
proc_pid_stack+0x13f/0x2f0 fs/proc/base.c:457
proc_single_show+0xe7/0x150 fs/proc/base.c:761
seq_read+0x4cf/0x1120 fs/seq_file.c:237
do_loop_readv_writev fs/read_write.c:695 [inline]
do_loop_readv_writev fs/read_write.c:682 [inline]
do_iter_read+0x3eb/0x5b0 fs/read_write.c:919
vfs_readv+0xc8/0x120 fs/read_write.c:981
do_preadv fs/read_write.c:1065 [inline]
SYSC_preadv fs/read_write.c:1115 [inline]
SyS_preadv+0x15a/0x200 fs/read_write.c:1110
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #0 (&p->lock){+.+.}:
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
seq_read+0xba/0x1120 fs/seq_file.c:165
proc_reg_read+0xee/0x1a0 fs/proc/inode.c:217
do_loop_readv_writev fs/read_write.c:695 [inline]
do_loop_readv_writev fs/read_write.c:682 [inline]
do_iter_read+0x3eb/0x5b0 fs/read_write.c:919
vfs_readv+0xc8/0x120 fs/read_write.c:981
kernel_readv fs/splice.c:361 [inline]
default_file_splice_read+0x418/0x910 fs/splice.c:416
do_splice_to+0xfb/0x140 fs/splice.c:880
splice_direct_to_actor+0x207/0x730 fs/splice.c:952
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x47f/0xb30 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
other info that might help us debug this:
Chain exists of:
&p->lock --> &ovl_i_mutex_dir_key[depth] --> sb_writers#3
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sb_writers#3);
lock(&ovl_i_mutex_dir_key[depth]);
lock(sb_writers#3);
lock(&p->lock);
*** DEADLOCK ***
1 lock held by syz-executor.5/9706:
#0: (sb_writers#3){.+.+}, at: [<ffffffff81867bdf>] file_start_write include/linux/fs.h:2712 [inline]
#0: (sb_writers#3){.+.+}, at: [<ffffffff81867bdf>] do_sendfile+0x84f/0xb30 fs/read_write.c:1440
stack backtrace:
CPU: 1 PID: 9706 Comm: syz-executor.5 Not tainted 4.14.221-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258
check_prev_add kernel/locking/lockdep.c:1905 [inline]
check_prevs_add kernel/locking/lockdep.c:2022 [inline]
validate_chain kernel/locking/lockdep.c:2464 [inline]
__lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
seq_read+0xba/0x1120 fs/seq_file.c:165
proc_reg_read+0xee/0x1a0 fs/proc/inode.c:217
do_loop_readv_writev fs/read_write.c:695 [inline]
do_loop_readv_writev fs/read_write.c:682 [inline]
do_iter_read+0x3eb/0x5b0 fs/read_write.c:919
vfs_readv+0xc8/0x120 fs/read_write.c:981
kernel_readv fs/splice.c:361 [inline]
default_file_splice_read+0x418/0x910 fs/splice.c:416
do_splice_to+0xfb/0x140 fs/splice.c:880
splice_direct_to_actor+0x207/0x730 fs/splice.c:952
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x47f/0xb30 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465ef9
RSP: 002b:00007fe15f503188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465ef9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00000000004bcd1c R08: 0000000000000000 R09: 0000000000000000
R10: 4000000000010044 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffebb3b53df R14: 00007fe15f503300 R15: 0000000000022000
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): setting 8 feature flag
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
BTRFS info (device loop3): force lzo compression
device veth1_macvtap left promiscuous mode
BTRFS info (device loop3): turning on flush-on-commit
device veth0_macvtap left promiscuous mode
device veth1_vlan left promiscuous mode
BTRFS info (device loop3): disk space caching is enabled
device veth0_vlan left promiscuous mode
BTRFS info (device loop3): has skinny extents
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): setting 8 feature flag
BTRFS info (device loop3): force lzo compression
BTRFS info (device loop3): turning on flush-on-commit
BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents
BTRFS error (device loop3): open_ctree failed
device hsr_slave_1 left promiscuous mode
device hsr_slave_0 left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
IPVS: ftp: loaded support on port[0] = 21
chnl_net:caif_netlink_parms(): no params data found
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
device bridge_slave_0 entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_1 entered promiscuous mode
bond0: Enslaving bond_slave_0 as an active interface with an up link
bond0: Enslaving bond_slave_1 as an active interface with an up link
IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready
team0: Port device team_slave_0 added
IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready
team0: Port device team_slave_1 added
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready
device hsr_slave_0 entered promiscuous mode
device hsr_slave_1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready
8021q: adding VLAN 0 to HW filter on device bond0
IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
bridge0: port 1(bridge_slave_0) entered disabled state
bridge0: port 2(bridge_slave_1) entered disabled state
IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready
8021q: adding VLAN 0 to HW filter on device team0
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready
hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network
IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
8021q: adding VLAN 0 to HW filter on device batadv0
IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_vlan: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready
device veth0_vlan entered promiscuous mode
device veth1_vlan entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macvlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): macvlan1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_macvtap: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
device veth0_macvtap entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready
device veth1_macvtap entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macsec0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_0
IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
audit: type=1804 audit(1613995016.837:86): pid=10071 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/0/bus" dev="sda1" ino=16209 res=1
Bluetooth: hci3 command 0x0409 tx timeout
audit: type=1804 audit(1613995017.567:87): pid=10074 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/0/bus" dev="sda1" ino=16209 res=1
audit: type=1804 audit(1613995017.597:88): pid=10074 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/0/bus" dev="sda1" ino=16209 res=1
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS info (device loop3): setting 8 feature flag
BTRFS info (device loop3): force lzo compression
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents
IPVS: ftp: loaded support on port[0] = 21
audit: type=1804 audit(1613995018.037:89): pid=10124 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/1/bus" dev="sda1" ino=16177 res=1
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS error (device loop3): bad tree block start 0 1052672
BTRFS error (device loop3): failed to read chunk root
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): unrecognized mount option 'compress-�orce=lo'
BTRFS error (device loop3): open_ctree failed
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS info (device loop3): setting 8 feature flag
BTRFS info (device loop3): force lzo compression
BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
Bluetooth: hci3 command 0x041b tx timeout
audit: type=1804 audit(1613995019.007:90): pid=10245 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/2/bus" dev="sda1" ino=16257 res=1
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS error (device loop3): bad tree block start 0 1052672
BTRFS error (device loop3): failed to read chunk root
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): unrecognized mount option 'treelog'
netlink: 32 bytes leftover after parsing attributes in process `syz-executor.5'.
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): setting 8 feature flag
BTRFS info (device loop3): force lzo compression
BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents
IPVS: ftp: loaded support on port[0] = 21
BTRFS error (device loop3): bad tree block start 0 1052672
BTRFS error (device loop3): failed to read chunk root
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): unrecognized mount option 'treelog'
audit: type=1804 audit(1613995020.017:91): pid=10365 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir422944373/syzkaller.98c8A2/3/bus" dev="sda1" ino=16180 res=1
BTRFS error (device loop3): open_ctree failed
BTRFS info (device loop3): setting 8 feature flag
BTRFS info (device loop3): force lzo compression
BTRFS info (device loop3): disk space caching is enabled
BTRFS info (device loop3): has skinny extents