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INFO: task hung in f2fs_file_write_iter (6)

Status: auto-obsoleted due to no activity on 2025/12/30 22:07
Subsystems: f2fs
[Documentation on labels]
First crash: 100d, last: 100d
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in f2fs_file_write_iter (3) f2fs 1 4 621d 685d 0/29 auto-obsoleted due to no activity on 2024/07/28 01:00
upstream INFO: task hung in f2fs_file_write_iter (4) f2fs 1 2 482d 486d 0/29 auto-obsoleted due to no activity on 2024/12/14 14:52
linux-4.19 INFO: task hung in f2fs_file_write_iter f2fs 1 5 1043d 1147d 0/1 upstream: reported on 2022/11/20 07:00
upstream INFO: task hung in f2fs_file_write_iter f2fs 1 5 946d 1043d 0/29 auto-obsoleted due to no activity on 2023/09/06 20:28
upstream INFO: task hung in f2fs_file_write_iter (2) f2fs 1 1 785d 785d 0/29 auto-obsoleted due to no activity on 2024/02/14 19:21
upstream INFO: task hung in f2fs_file_write_iter (5) f2fs 1 3 194d 263d 0/29 auto-obsoleted due to no activity on 2025/09/28 14:58

Sample crash report:
INF
INFO: task syz.2.73:7055 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.73        state:D stack:0     pid:7055  tgid:7054  ppid:6534   task_flags:0x400140 flags:0x00000001
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7115
 rwsem_down_write_slowpath+0x6b4/0x10f4 kernel/locking/rwsem.c:1185
 __down_write_common kernel/locking/rwsem.c:1317 [inline]
 __down_write kernel/locking/rwsem.c:1326 [inline]
 down_write+0xb4/0xc0 kernel/locking/rwsem.c:1591
 inode_lock include/linux/fs.h:870 [inline]
 f2fs_file_write_iter+0x1d0/0x1cf4 fs/f2fs/file.c:5200
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x540/0xa3c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
1 lock held by khungtaskd/32:
 #0: ffff80008f9d9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
4 locks held by kworker/u8:3/42:
 #0: ffff0000c1f7a948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3210
 #1: ffff8000992e7be0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3210
 #2: ffff0000daf240e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x24/0xdc fs/super.c:563
 #3: ffff0000d5dd5410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2234 [inline]
 #3: ffff0000d5dd5410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x4b8/0x6ec fs/f2fs/segment.c:464
2 locks held by pr/ttyAMA-1/43:
2 locks held by getty/6317:
 #0: ffff0000d393d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff8000994042f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
3 locks held by syz.2.73/7055:
 #0: ffff0000da21a7f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x1fc/0x2a0 fs/file.c:1232
 #1: ffff0000daf24428 (sb_writers#14){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline]
 #1: ffff0000daf24428 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x24c/0xa3c fs/read_write.c:682
 #2: ffff0000f8920148 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline]
 #2: ffff0000f8920148 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: f2fs_file_write_iter+0x1d0/0x1cf4 fs/f2fs/file.c:5200
4 locks held by syz.2.73/7076:

=============================================


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/01 22:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2213e57a69f0 a1859138 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in f2fs_file_write_iter
* Struck through repros no longer work on HEAD.