[syzbot] [ext4?] [nilfs?] INFO: task hung in migrate_pages_batch
From: syzbot
Date: Sun Jan 28 2024 - 12:15:50 EST
Hello,
syzbot found the following issue on:
HEAD commit: 0802e17d9aca Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=10832107e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9616b7e180577ba
dashboard link: https://syzkaller.appspot.com/bug?extid=ee2ae68da3b22d04cd8d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=163043bfe80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1306c1e3e80000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e84e45f27a78/disk-0802e17d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a8b16d2fc3b1/vmlinux-0802e17d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4c7ac36b3de1/Image-0802e17d.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e31cee0eb927/mount_10.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee2ae68da3b22d04cd8d@xxxxxxxxxxxxxxxxxxxxxxxxx
INFO: task syz-executor439:7446 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7446 tgid:7429 ppid:6155 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
io_schedule+0x8c/0x12c kernel/sched/core.c:8998
folio_wait_bit_common+0x65c/0xb90 mm/filemap.c:1273
folio_wait_bit+0x30/0x40 mm/filemap.c:1412
folio_wait_writeback+0x14c/0x3bc mm/page-writeback.c:3065
migrate_folio_unmap mm/migrate.c:1191 [inline]
migrate_pages_batch+0xc1c/0x25b0 mm/migrate.c:1680
migrate_pages_sync mm/migrate.c:1873 [inline]
migrate_pages+0x1bf8/0x3114 mm/migrate.c:1955
do_mbind mm/mempolicy.c:1344 [inline]
kernel_mbind mm/mempolicy.c:1486 [inline]
__do_sys_mbind mm/mempolicy.c:1560 [inline]
__se_sys_mbind mm/mempolicy.c:1556 [inline]
__arm64_sys_mbind+0x1410/0x18e8 mm/mempolicy.c:1556
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
INFO: task segctord:7440 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:segctord state:D stack:0 pid:7440 tgid:7440 ppid:2 flags:0x00000008
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
io_schedule+0x8c/0x12c kernel/sched/core.c:8998
folio_wait_bit_common+0x65c/0xb90 mm/filemap.c:1273
__folio_lock+0x2c/0x3c mm/filemap.c:1611
folio_lock include/linux/pagemap.h:1031 [inline]
nilfs_lookup_dirty_data_buffers+0x2b0/0x7e8 fs/nilfs2/segment.c:727
nilfs_segctor_scan_file+0x1e4/0xcdc fs/nilfs2/segment.c:1084
nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1206 [inline]
nilfs_segctor_collect fs/nilfs2/segment.c:1533 [inline]
nilfs_segctor_do_construct+0x16ec/0x6560 fs/nilfs2/segment.c:2081
nilfs_segctor_construct+0x110/0x768 fs/nilfs2/segment.c:2415
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2523 [inline]
nilfs_segctor_thread+0x3d4/0xd74 fs/nilfs2/segment.c:2606
kthread+0x288/0x310 kernel/kthread.c:388
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
INFO: task syz-executor439:7442 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7442 tgid:7441 ppid:6156 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
wb_wait_for_completion+0x154/0x29c fs/fs-writeback.c:192
sync_inodes_sb+0x220/0x944 fs/fs-writeback.c:2758
sync_inodes_one_sb+0x58/0x70 fs/sync.c:77
iterate_supers+0xd4/0x188 fs/super.c:971
ksys_sync+0xb4/0x1cc fs/sync.c:102
__arm64_sys_sync+0x14/0x24 fs/sync.c:113
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
INFO: task syz-executor439:7445 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7445 tgid:7444 ppid:6160 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835
rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
sync_inodes_one_sb+0x58/0x70 fs/sync.c:77
iterate_supers+0xd4/0x188 fs/super.c:971
ksys_sync+0xb4/0x1cc fs/sync.c:102
__arm64_sys_sync+0x14/0x24 fs/sync.c:113
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
INFO: task syz-executor439:7450 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7450 tgid:7448 ppid:6153 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835
rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
sync_inodes_one_sb+0x58/0x70 fs/sync.c:77
iterate_supers+0xd4/0x188 fs/super.c:971
ksys_sync+0xb4/0x1cc fs/sync.c:102
__arm64_sys_sync+0x14/0x24 fs/sync.c:113
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
INFO: task syz-executor439:7451 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7451 tgid:7449 ppid:6154 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835
rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
sync_inodes_one_sb+0x58/0x70 fs/sync.c:77
iterate_supers+0xd4/0x188 fs/super.c:971
ksys_sync+0xb4/0x1cc fs/sync.c:102
__arm64_sys_sync+0x14/0x24 fs/sync.c:113
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
INFO: task syz-executor439:7460 blocked for more than 143 seconds.
Not tainted 6.7.0-rc8-syzkaller-g0802e17d9aca #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor439 state:D stack:0 pid:7460 tgid:7456 ppid:6161 flags:0x0000000d
Call trace:
__switch_to+0x314/0x560 arch/arm64/kernel/process.c:556
context_switch kernel/sched/core.c:5376 [inline]
__schedule+0x1354/0x2360 kernel/sched/core.c:6688
__schedule_loop kernel/sched/core.c:6763 [inline]
schedule+0xb8/0x19c kernel/sched/core.c:6778
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6835
rwsem_down_write_slowpath+0xcfc/0x1aa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0xb4/0xc0 kernel/locking/rwsem.c:1580
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
sync_inodes_one_sb+0x58/0x70 fs/sync.c:77
iterate_supers+0xd4/0x188 fs/super.c:971
ksys_sync+0xb4/0x1cc fs/sync.c:102
__arm64_sys_sync+0x14/0x24 fs/sync.c:113
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffff80008e6c48c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:300
2 locks held by kworker/u4:3/41:
#0: ffff0000c1c3a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x560/0x1204 kernel/workqueue.c:2600
#1: ffff8000943f7c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x5a0/0x1204 kernel/workqueue.c:2602
2 locks held by getty/5863:
#0: ffff0000d255f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1: ffff800094e702f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41c/0x1228 drivers/tty/n_tty.c:2201
1 lock held by segctord/7440:
#0: ffff0000c7ade2a0 (&nilfs->ns_segctor_sem){++++}-{3:3}, at: nilfs_transaction_lock+0x178/0x33c fs/nilfs2/segment.c:357
2 locks held by syz-executor439/7442:
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
2 locks held by syz-executor439/7445:
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
2 locks held by syz-executor439/7450:
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
2 locks held by syz-executor439/7451:
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
2 locks held by syz-executor439/7460:
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff0000c5e920e0 (&type->s_umount_key#64){++++}-{3:3}, at: super_lock+0x160/0x328 fs/super.c:117
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff0000c9d147d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x208/0x944 fs/fs-writeback.c:2756
=============================================
---
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If the report is already addressed, let syzbot know by replying with:
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