syzbot


INFO: task hung in extent_writepages

Status: upstream: reported on 2024/05/08 07:03
Reported-by: syzbot+0edec97573a554ba29a6@syzkaller.appspotmail.com
First crash: 41d, last: 15d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in extent_writepages btrfs C inconclusive done 30 133d 321d 0/27 auto-obsoleted due to no activity on 2024/05/17 02:53
linux-5.15 INFO: task hung in extent_writepages 1 421d 421d 0/3 auto-obsoleted due to no activity on 2023/08/22 08:46
linux-5.15 INFO: task hung in extent_writepages (2) 1 40d 40d 0/3 upstream: reported on 2024/05/10 00:52

Sample crash report:
INFO: task kworker/u4:7:3700 blocked for more than 143 seconds.
      Not tainted 6.1.92-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:7    state:D stack:21280 pid:3700  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-btrfs-9)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 io_schedule+0x88/0x100 kernel/sched/core.c:8786
 folio_wait_bit_common+0x878/0x1290 mm/filemap.c:1296
 extent_write_cache_pages fs/btrfs/extent_io.c:3171 [inline]
 extent_writepages+0x8de/0x17a0 fs/btrfs/extent_io.c:3313
 do_writepages+0x3a2/0x670 mm/page-writeback.c:2469
 __writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1612
 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903
 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1974
 wb_writeback+0x4b1/0xe10 fs/fs-writeback.c:2079
 wb_check_background_flush fs/fs-writeback.c:2145 [inline]
 wb_do_writeback fs/fs-writeback.c:2233 [inline]
 wb_workfn+0xc9e/0x1020 fs/fs-writeback.c:2260
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
INFO: task kworker/u4:10:3768 blocked for more than 144 seconds.
      Not tainted 6.1.92-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:10   state:D stack:19072 pid:3768  ppid:2      flags:0x00004000
Workqueue: events_unbound btrfs_async_reclaim_data_space
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/03 18:04 linux-6.1.y 88690811da69 0aba2352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in extent_writepages
2024/05/28 03:12 linux-6.1.y 88690811da69 f550015e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in extent_writepages
2024/05/08 07:02 linux-6.1.y 909ba1f1b414 4cf3f9b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in extent_writepages
* Struck through repros no longer work on HEAD.