INFO: task kworker/u4:5:1644 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack: 0 pid: 1644 ppid: 2 flags:0x00000008 Workqueue: writeback wb_workfn (flush-7:0) Call trace: __switch_to+0x2f4/0x540 arch/arm64/kernel/process.c:521 context_switch kernel/sched/core.c:5049 [inline] __schedule+0xdfc/0x1bc4 kernel/sched/core.c:6395 schedule+0x11c/0x1c8 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc34/0x145c kernel/locking/rwsem.c:1165 __down_write_common kernel/locking/rwsem.c:1292 [inline] __down_write kernel/locking/rwsem.c:1301 [inline] down_write+0xe8/0x12c kernel/locking/rwsem.c:1552 f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 f2fs_write_inode+0x3f4/0x598 fs/f2fs/inode.c:745 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x560/0x11c8 fs/fs-writeback.c:1715 writeback_sb_inodes+0x830/0x13a8 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x110/0x394 fs/fs-writeback.c:2011 wb_writeback+0x400/0xe64 fs/fs-writeback.c:2116 wb_check_background_flush fs/fs-writeback.c:2182 [inline] wb_do_writeback fs/fs-writeback.c:2270 [inline] wb_workfn+0xae8/0xe44 fs/fs-writeback.c:2298 process_one_work+0x79c/0x1138 kernel/workqueue.c:2310 worker_thread+0x8f4/0x1034 kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001b407c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000cf1800e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000db9c11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 1 lock held by khungtaskd/27: #0: ffff800014461360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:312 4 locks held by kworker/u4:2/148: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001bf57c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000c10a20e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000ec5551b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:3/347: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001f657c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000faca40e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d63f11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:4/437: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff80001f737c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000fba540e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff000102ec51b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:5/1644: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff800023f37c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000ce6080e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d31c11b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:6/1680: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff800024397c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000e8b9c0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d93191b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 2 locks held by getty/3805: #0: ffff0000d4de0098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340 #1: ffff80001be8b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158 5 locks held by syz.0.16/5001: 5 locks held by syz.1.17/5026: 6 locks held by syz.2.18/5052: 5 locks held by syz.3.19/5077: 4 locks held by kworker/u4:7/5081: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff8000200e7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000cf0d00e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000cf0991b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 4 locks held by kworker/u4:8/5109: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff8000203d7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0001069ec0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000d69b51b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 6 locks held by syz.4.20/5120: 4 locks held by kworker/u4:9/5145: #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283 #1: ffff8000204e7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285 #2: ffff0000c96e40e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418 #3: ffff0000c15fd1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x3b4/0x650 fs/f2fs/segment.c:528 5 locks held by syz.5.21/5157: 4 locks held by syz.6.22/5193: 4 locks held by syz.7.23/5229: 5 locks held by syz.8.24/5271: 1 lock held by syz-executor/5276: #0: ffff8000163bbce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffff8000163bbce8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6d0/0xd70 net/core/rtnetlink.c:5681 =============================================