INFO: task khugepaged:904 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D23240 904 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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 collapse_huge_page+0x2b9/0x2140 mm/khugepaged.c:1006 khugepaged_scan_pmd mm/khugepaged.c:1215 [inline] khugepaged_scan_mm_slot+0x2096/0x3200 mm/khugepaged.c:1701 khugepaged_do_scan mm/khugepaged.c:1782 [inline] khugepaged+0x9aa/0xce0 mm/khugepaged.c:1827 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 INFO: task syz-fuzzer:4464 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-fuzzer D19984 4464 4447 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_pagefault include/linux/fs.h:1610 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6127 do_page_mkwrite+0x14e/0x520 mm/memory.c:2386 wp_page_shared mm/memory.c:2682 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2782 handle_pte_fault mm/memory.c:3994 [inline] __handle_mm_fault+0x2aab/0x4480 mm/memory.c:4102 handle_mm_fault+0x53e/0xc80 mm/memory.c:4139 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1397 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1472 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1164 RIP: 0033:0x70b5e1 Code: 48 89 6c 24 10 48 8d 6c 24 10 48 8b 44 24 20 48 8b 48 08 48 8b 50 10 48 8d 58 08 48 83 fa 08 0f 8c 1e 01 00 00 48 8b 54 24 28 <88> 11 48 8b 48 08 48 8b 70 10 48 83 fe 01 0f 86 44 01 00 00 48 89 RSP: 002b:000000c427477538 EFLAGS: 00010212 RAX: 000000c427477878 RBX: 000000c427477880 RCX: 00007fd39b6a5000 RDX: 0000000000000745 RSI: 0000000000000000 RDI: 00000000000008d8 RBP: 000000c427477548 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000095bf8a R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 000000c427477a00 INFO: task syz-executor2:4478 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D21232 4478 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_write include/linux/fs.h:1581 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:364 filename_create+0x13e/0x5b0 fs/namei.c:3687 user_path_create fs/namei.c:3750 [inline] do_mkdirat+0xda/0x310 fs/namei.c:3889 __do_sys_mkdir fs/namei.c:3913 [inline] __se_sys_mkdir fs/namei.c:3911 [inline] __x64_sys_mkdir+0x5c/0x80 fs/namei.c:3911 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455267 Code: 00 00 48 8b 4c 24 78 8b 44 01 04 89 44 24 08 48 8b 84 24 c8 00 00 00 48 89 04 24 e8 53 e7 ff ff 48 8b 44 24 10 48 89 84 24 d0 <00> 00 00 48 8b 8c 24 f8 00 00 00 48 8b 54 24 78 8b 4c 0a 04 89 4c RSP: 002b:00007ffc6a210698 EFLAGS: 00000202 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffc6a2106c0 RCX: 0000000000455267 RDX: 00007ffc6a211375 RSI: 00000000000001ff RDI: 00007ffc6a211370 RBP: 0000000000000013 R08: 0000000000000000 R09: 0000000000000005 R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000001380 R14: 00007ffc6a210d40 R15: 00000000007034c0 INFO: task syz-executor7:4479 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D21232 4479 4469 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_write include/linux/fs.h:1581 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:364 do_unlinkat+0x2b7/0xa30 fs/namei.c:4102 __do_sys_unlink fs/namei.c:4167 [inline] __se_sys_unlink fs/namei.c:4165 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4165 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: c0 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 8d 7e 20 40 80 10 73 64 48 83 fa 02 7e c2 0f b6 54 0b 01 8d 7a 80 40 80 ff 3f RSP: 002b:00007ffda6857498 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffda68574a0 RSI: 00007ffda6857530 RDI: 00007ffda6857530 RBP: 00007ffda6859240 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000006 R11: 0000000000000202 R12: 000000000219b940 R13: 0000000000000000 R14: 00007ffda6858c10 R15: 0000000000702140 INFO: task syz-executor3:27845 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21352 27845 27813 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_write include/linux/fs.h:1581 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:364 do_unlinkat+0x2b7/0xa30 fs/namei.c:4102 __do_sys_unlink fs/namei.c:4167 [inline] __se_sys_unlink fs/namei.c:4165 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4165 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b77 Code: c0 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 48 83 c4 08 c3 8d 7e 20 40 80 10 73 64 48 83 fa 02 7e c2 0f b6 54 0b 01 8d 7a 80 40 80 ff 3f RSP: 002b:00007ffd6be976f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000455b77 RDX: 00007ffd6be97700 RSI: 00007ffd6be97790 RDI: 00007ffd6be97790 RBP: 00007ffd6be994a0 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000006 R11: 0000000000000202 R12: 00000000027f8940 R13: 0000000000000000 R14: 00007ffd6be98e70 R15: 0000000000702140 INFO: task syz-executor1:31419 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D24880 31419 4475 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_pagefault include/linux/fs.h:1610 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6127 do_page_mkwrite+0x14e/0x520 mm/memory.c:2386 wp_page_shared mm/memory.c:2682 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2782 handle_pte_fault mm/memory.c:3994 [inline] __handle_mm_fault+0x2aab/0x4480 mm/memory.c:4102 handle_mm_fault+0x53e/0xc80 mm/memory.c:4139 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1397 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1472 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1164 RIP: 0033:0x4084b0 Code: 24 1f e9 d2 00 00 00 48 ff c2 48 83 fa 08 0f 83 ad 00 00 00 84 01 0f b6 1c 11 38 d8 75 e9 48 89 54 24 20 48 8b 5c 24 48 0f b6 <73> 50 48 0f af f2 0f b6 5b 51 48 89 cf 48 8d 74 3e 08 84 db 74 7c RSP: 002b:00007fff9315e260 EFLAGS: 00010283 RAX: 0000001b33021cc8 RBX: 0000000000000000 RCX: 0000001b34020000 RDX: 0000001b33021ccc RSI: 0000000000730a90 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fff9315e2a0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bf48 R15: 000000000072bf48 INFO: task syz-executor5:31469 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D23336 31469 4482 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_pagefault include/linux/fs.h:1610 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6127 do_page_mkwrite+0x14e/0x520 mm/memory.c:2386 wp_page_shared mm/memory.c:2682 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2782 handle_pte_fault mm/memory.c:3994 [inline] __handle_mm_fault+0x2aab/0x4480 mm/memory.c:4102 handle_mm_fault+0x53e/0xc80 mm/memory.c:4139 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1397 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1472 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1164 RIP: 0033:0x4084b0 Code: 24 1f e9 d2 00 00 00 48 ff c2 48 83 fa 08 0f 83 ad 00 00 00 84 01 0f b6 1c 11 38 d8 75 e9 48 89 54 24 20 48 8b 5c 24 48 0f b6 <73> 50 48 0f af f2 0f b6 5b 51 48 89 cf 48 8d 74 3e 08 84 db 74 7c RSP: 002b:00007ffe8fbe6f80 EFLAGS: 00010283 RAX: 0000001b33620004 RBX: 0000000000000000 RCX: 0000001b34620000 RDX: 0000001b33620008 RSI: 0000000000730108 RDI: 0000000000000001 RBP: 0000000000000000 R08: 00007ffe8fbe0000 R09: 0000000000000000 R10: 00007ffe8fbe6fc0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bf48 R15: 000000000072bf48 INFO: task syz-executor5:31478 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25464 31478 4482 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_write include/linux/fs.h:1581 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:364 do_last fs/namei.c:3339 [inline] path_openat+0x2878/0x5620 fs/namei.c:3587 do_filp_open+0x255/0x380 fs/namei.c:3621 do_sys_open+0x584/0x720 fs/open.c:1106 ksys_open include/linux/syscalls.h:1285 [inline] __do_sys_creat fs/open.c:1164 [inline] __se_sys_creat fs/open.c:1162 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 ab 04 00 00 48 83 ec 58 48 89 6c 24 50 48 8d 6c 24 50 48 8b 44 24 60 c6 00 00 <48> 8b 4c 24 68 48 89 ca 48 89 50 08 48 8b 59 20 48 01 da 31 db 31 RSP: 002b:00007f0c22e37c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f0c22e386d4 RCX: 0000000000455e29 RDX: 0000000000000000 RSI: fffffffffffffffd RDI: 000000002002bff8 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bbd75 R14: 00000000004c9188 R15: 0000000000000000 INFO: task syz-executor6:31474 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D25120 31474 4477 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_pagefault include/linux/fs.h:1610 [inline] ext4_page_mkwrite+0x1d0/0x1430 fs/ext4/inode.c:6127 do_page_mkwrite+0x14e/0x520 mm/memory.c:2386 wp_page_shared mm/memory.c:2682 [inline] do_wp_page+0xf78/0x19b0 mm/memory.c:2782 handle_pte_fault mm/memory.c:3994 [inline] __handle_mm_fault+0x2aab/0x4480 mm/memory.c:4102 handle_mm_fault+0x53e/0xc80 mm/memory.c:4139 __do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1397 do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1472 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1164 RIP: 0033:0x4084b0 Code: 24 1f e9 d2 00 00 00 48 ff c2 48 83 fa 08 0f 83 ad 00 00 00 84 01 0f b6 1c 11 38 d8 75 e9 48 89 54 24 20 48 8b 5c 24 48 0f b6 <73> 50 48 0f af f2 0f b6 5b 51 48 89 cf 48 8d 74 3e 08 84 db 74 7c RSP: 002b:00007ffe73195c00 EFLAGS: 00010287 RAX: 0000001b33322b60 RBX: 0000000000000000 RCX: 0000001b34320000 RDX: 0000001b33322b64 RSI: 00000000007302d0 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe73195c40 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000072bea0 R15: 000000000072bea0 INFO: task syz-executor4:31475 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D25544 31475 7322 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 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] __percpu_down_read+0x16e/0x210 kernel/locking/percpu-rwsem.c:85 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x2d7/0x300 fs/super.c:1520 sb_start_write include/linux/fs.h:1581 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:364 filename_create+0x13e/0x5b0 fs/namei.c:3687 user_path_create fs/namei.c:3750 [inline] do_symlinkat+0xfe/0x2d0 fs/namei.c:4204 __do_sys_symlink fs/namei.c:4230 [inline] __se_sys_symlink fs/namei.c:4228 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4228 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b57 Code: 80 80 fa 3f 77 10 83 e6 1f c1 e6 06 83 e1 3f 09 ce 83 fe 7f 7f 19 c7 44 24 28 fd ff 00 00 48 ff c0 48 89 44 24 30 48 8b 2c 24 <48> 83 c4 08 c3 89 74 24 28 48 83 c0 02 48 89 44 24 30 48 8b 2c 24 RSP: 002b:00007ffc57b823d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000455b57 RDX: 0000000000000000 RSI: 00000000004bb387 RDI: 00007ffc57b83150 RBP: 0000000000000013 R08: 0000000000000000 R09: 00000000011f6940 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffc57b82a80 R15: 00000000007034c0 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 PID: 898 Comm: khungtaskd Not tainted 4.18.0-rc3-next-20180709+ #2 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.5+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:143 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x10b0 kernel/hung_task.c:265 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 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