BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed BTRFS error (device loop4): unsupported checksum algorithm 3786 BTRFS error (device loop4): superblock checksum mismatch BTRFS error (device loop4): open_ctree failed INFO: task syz-executor0:18685 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #175 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D24104 18685 4400 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:715 [inline] vfs_setxattr+0x96/0x100 fs/xattr.c:219 setxattr+0x2ea/0x450 fs/xattr.c:451 path_setxattr+0x1e3/0x230 fs/xattr.c:470 __do_sys_setxattr fs/xattr.c:485 [inline] __se_sys_setxattr fs/xattr.c:481 [inline] __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:481 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456b29 Code: 42 08 84 00 48 83 c0 58 48 89 04 24 e8 00 8b fb ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 91 33 00 00 eb bf cc cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2b RSP: 002b:00007fe30d2c3c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007fe30d2c46d4 RCX: 0000000000456b29 RDX: 0000000020000300 RSI: 00000000200002c0 RDI: 0000000020000080 RBP: 00000000009301e0 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d4f70 R14: 00000000004c2d68 R15: 0000000000000002 INFO: task syz-executor0:18689 blocked for more than 140 seconds. Not tainted 4.18.0-rc7+ #175 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25408 18689 4400 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:725 [inline] lookup_slow+0x49/0x80 fs/namei.c:1646 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 user_path_at_empty+0x40/0x50 fs/namei.c:2584 user_path_at include/linux/namei.h:57 [inline] path_listxattr+0xbc/0x1a0 fs/xattr.c:639 __do_sys_listxattr fs/xattr.c:654 [inline] __se_sys_listxattr fs/xattr.c:651 [inline] __x64_sys_listxattr+0x78/0xb0 fs/xattr.c:651 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456b29 Code: 42 08 84 00 48 83 c0 58 48 89 04 24 e8 00 8b fb ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 91 33 00 00 eb bf cc cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 2b RSP: 002b:00007fe30d2a2c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000c2 RAX: ffffffffffffffda RBX: 00007fe30d2a36d4 RCX: 0000000000456b29 RDX: 0000000000000039 RSI: 0000000020000440 RDI: 0000000020000400 RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d1928 R14: 00000000004c2d4a R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 00000000821da74c (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4267: 2 locks held by getty/4359: #0: 000000006b2139c2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000009b909fb9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4360: #0: 00000000c6612908 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008056804e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4361: #0: 00000000702718a6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000af635d1f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4362: #0: 00000000d22db95e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000011ca1bc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4363: #0: 000000009832626f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001c6489ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4364: #0: 0000000086a45d16 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000101fc360 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4365: #0: 00000000d8791924 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c32a5df3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor0/18631: #0: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 2 locks held by syz-executor0/18685: #0: 00000000aab485fd (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 00000000aab485fd (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 1 lock held by syz-executor0/18689: #0: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 00000000eb80e9e7 (&sb->s_type->i_mutex_key#20){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc7+ #175 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54