syzbot


INFO: task hung in writeback_iter

Status: moderation: reported on 2024/09/30 09:06
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+4f91c7b1d53f03e5a3f3@syzkaller.appspotmail.com
First crash: 279d, last: 33d

Sample crash report:
INFO: task kworker/u8:11:3583 blocked for more than 143 seconds.
      Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11   state:D stack:21200 pid:3583  tgid:3583  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-bcachefs-6)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 io_schedule+0x8d/0x110 kernel/sched/core.c:7681
 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1299
 folio_lock include/linux/pagemap.h:1151 [inline]
 writeback_get_folio mm/page-writeback.c:2521 [inline]
 writeback_iter+0x8ad/0x12b0 mm/page-writeback.c:2615
 write_cache_pages+0xb1/0x230 mm/page-writeback.c:2664
 bch2_writepages+0x156/0x390 fs/bcachefs/fs-io-buffered.c:639
 do_writepages+0x35f/0x880 mm/page-writeback.c:2708
 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047
 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158
 wb_check_background_flush fs/fs-writeback.c:2228 [inline]
 wb_do_writeback fs/fs-writeback.c:2316 [inline]
 wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task $ë:6195 blocked for more than 144 seconds.
      Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:$ë             state:D stack:28208 pid:6195  tgid:6102  ppid:5824   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:818 [inline]
 bch2_fallocate_dispatch+0x1e2/0x540 fs/bcachefs/fs-io.c:771
 vfs_fallocate+0x569/0x6e0 fs/open.c:327
 ksys_fallocate fs/open.c:351 [inline]
 __do_sys_fallocate fs/open.c:356 [inline]
 __se_sys_fallocate fs/open.c:354 [inline]
 __x64_sys_fallocate+0xbc/0x110 fs/open.c:354
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd423b85d29
RSP: 002b:00007fd424925038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fd423d76240 RCX: 00007fd423b85d29
RDX: 0000000000002000 RSI: 0000000000000008 RDI: 0000000000000009
RBP: 00007fd423c01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000007000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd423d76240 R15: 00007ffe84d975c8
 </TASK>
INFO: task $ë:6198 blocked for more than 144 seconds.
      Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:$ë             state:D stack:24688 pid:6198  tgid:6102  ppid:5824   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 io_schedule+0x8d/0x110 kernel/sched/core.c:7681
 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1299
 folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3200
 truncate_inode_partial_folio+0x169/0x5e0 mm/truncate.c:192
 truncate_inode_pages_range+0x6f3/0x10e0 mm/truncate.c:338
 bchfs_fpunch+0x1c1/0x780 fs/bcachefs/fs-io.c:514
 bch2_fallocate_dispatch+0x3e4/0x540 fs/bcachefs/fs-io.c:782
 vfs_fallocate+0x569/0x6e0 fs/open.c:327
 do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x80/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd423b85d29
RSP: 002b:00007fd424904038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd423d76320 RCX: 00007fd423b85d29
RDX: 00000000200003c0 RSI: 0000000040305829 RDI: 0000000000000007
RBP: 00007fd423c01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd423d76320 R15: 00007ffe84d975c8
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
 watchdog+0xff6/0x1040 kernel/hung_task.c:397
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7672 Comm: syz.8.173 Not tainted 6.13.0-rc7-syzkaller-00149-g9bffa1ad25b8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:dtSplitRoot+0x89f/0x1930 fs/jfs/jfs_dtree.c:1978
Code: 00 00 00 4c 8b 64 24 10 0f 84 aa 00 00 00 49 8d 5c 24 13 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 09 0f 00 00 44 88 3b <49> 0f be df 0f b6 f3 bf ff 00 00 00 e8 f0 17 70 fe 84 db 78 44 e8
RSP: 0018:ffffc900030874a0 EFLAGS: 00000246
RAX: ffffffff832f5d5e RBX: ffff888050fb6000 RCX: 0000000000080000
RDX: ffffc90004691000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90003087690 R08: ffffffff832f5d30 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888050fb6000
R13: dffffc0000000000 R14: ffff88805648b248 R15: 0000000000000000
FS:  00007f7df95da6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8974369160 CR3: 0000000068e16000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 dtSplitUp fs/jfs/jfs_dtree.c:992 [inline]
 dtInsert+0x12cd/0x6c10 fs/jfs/jfs_dtree.c:870
 jfs_mkdir+0x7fb/0xba0 fs/jfs/namei.c:270
 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4311
 do_mkdirat+0x264/0x3a0 fs/namei.c:4334
 __do_sys_mkdirat fs/namei.c:4349 [inline]
 __se_sys_mkdirat fs/namei.c:4347 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4347
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7df8784597
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7df95d9e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f7df95d9ef0 RCX: 00007f7df8784597
RDX: 00000000000001ff RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 0000000020000000 R08: 00000000200000c0 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000020000040
R13: 00007f7df95d9eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (145):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/17 08:53 upstream 9bffa1ad25b8 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2025/01/16 22:24 upstream ce69b4019001 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2025/01/02 12:04 upstream 56e6a3499e14 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in writeback_iter
2024/12/30 05:20 upstream 4099a71718b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/28 01:23 upstream 8379578b11d5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/27 13:54 upstream d6ef8b40d075 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/25 01:13 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/24 02:41 upstream f07044dd0df0 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/17 10:10 upstream f44d154d6e3d f93b2b55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/16 05:50 upstream 78d4f34e2115 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/12 18:39 upstream 231825b2e1ff 530e80f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/12 00:59 upstream 231825b2e1ff ff949d25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/11 20:20 upstream f92f4749861b ff949d25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/11 01:05 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/10 23:16 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/10 19:55 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/02 10:18 upstream f788b5ef1ca9 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/12/01 11:12 upstream bcc8eda6d349 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/11/20 18:14 upstream bf9aa14fc523 4fca1650 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/11/09 06:35 upstream f1dce1f09380 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/10/29 12:42 upstream e42b1a9a2557 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/10/23 15:02 upstream c2ee9f594da8 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/10/23 04:25 upstream c2ee9f594da8 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/10/22 19:22 upstream c2ee9f594da8 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 15:43 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 12:13 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 07:46 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 07:12 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 03:27 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 02:15 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/29 00:18 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 20:38 upstream 3efc57369a0c ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in writeback_iter
2024/09/28 17:28 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 16:41 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 15:01 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 13:29 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 10:32 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 08:07 upstream ad46e8f95e93 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 06:42 upstream ad46e8f95e93 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in writeback_iter
2024/09/28 04:33 upstream 3630400697a3 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 02:25 upstream 3630400697a3 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/27 20:53 upstream e477dba5442c 2b1784d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in writeback_iter
2024/09/27 19:13 upstream 3630400697a3 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/27 15:20 upstream 075dbe9f6e3c 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/27 13:22 upstream 075dbe9f6e3c 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/27 10:51 upstream 075dbe9f6e3c 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/27 10:47 upstream 075dbe9f6e3c 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/26 08:51 upstream aa486552a110 0d19f247 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in writeback_iter
2024/09/18 07:00 upstream 2f27fce67173 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in writeback_iter
2024/09/28 00:47 linux-next 40e0c9d414f5 2b1784d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in writeback_iter
2024/10/29 19:48 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 1bf329c696cf 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in writeback_iter
2024/10/01 21:59 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5f5673607153 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in writeback_iter
* Struck through repros no longer work on HEAD.