syzbot


inconsistent lock state in btrfs_run_delayed_iputs

Status: fixed on 2023/10/12 12:48
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+da501a04be5ff533b102@syzkaller.appspotmail.com
Fix commit: 866e98a4d95d btrfs: use irq safe locking when running and adding delayed iputs
First crash: 238d, last: 238d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [btrfs?] inconsistent lock state in btrfs_run_delayed_iputs 0 (1) 2023/07/05 13:17

Sample crash report:
================================
WARNING: inconsistent lock state
6.4.0-syzkaller-09904-ga507db1d8fdc #0 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
btrfs-cleaner/16079 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888107804d20 (&fs_info->delayed_iput_lock){+.?.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff888107804d20 (&fs_info->delayed_iput_lock){+.?.}-{2:2}, at: btrfs_run_delayed_iputs+0x28/0xe0 fs/btrfs/inode.c:3523
{IN-SOFTIRQ-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5761 [inline]
  lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:350 [inline]
  btrfs_add_delayed_iput+0x128/0x390 fs/btrfs/inode.c:3490
  btrfs_put_ordered_extent fs/btrfs/ordered-data.c:559 [inline]
  btrfs_put_ordered_extent+0x2f6/0x610 fs/btrfs/ordered-data.c:547
  __btrfs_bio_end_io fs/btrfs/bio.c:118 [inline]
  __btrfs_bio_end_io+0x136/0x180 fs/btrfs/bio.c:112
  btrfs_orig_bbio_end_io+0x86/0x2b0 fs/btrfs/bio.c:163
  btrfs_simple_end_io+0x105/0x380 fs/btrfs/bio.c:378
  bio_endio+0x589/0x690 block/bio.c:1617
  req_bio_endio block/blk-mq.c:766 [inline]
  blk_update_request+0x5c5/0x1620 block/blk-mq.c:911
  blk_mq_end_request+0x59/0x680 block/blk-mq.c:1032
  lo_complete_rq+0x1c6/0x280 drivers/block/loop.c:370
  blk_complete_reqs+0xb3/0xf0 block/blk-mq.c:1110
  __do_softirq+0x1d4/0x905 kernel/softirq.c:553
  run_ksoftirqd kernel/softirq.c:921 [inline]
  run_ksoftirqd+0x31/0x60 kernel/softirq.c:913
  smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164
  kthread+0x344/0x440 kernel/kthread.c:389
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
irq event stamp: 39
hardirqs last  enabled at (39): [<ffffffff81d5ebc4>] __do_kmem_cache_free mm/slab.c:3558 [inline]
hardirqs last  enabled at (39): [<ffffffff81d5ebc4>] kmem_cache_free mm/slab.c:3582 [inline]
hardirqs last  enabled at (39): [<ffffffff81d5ebc4>] kmem_cache_free+0x244/0x370 mm/slab.c:3575
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] __do_kmem_cache_free mm/slab.c:3553 [inline]
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] kmem_cache_free mm/slab.c:3582 [inline]
hardirqs last disabled at (38): [<ffffffff81d5eb5e>] kmem_cache_free+0x1de/0x370 mm/slab.c:3575
softirqs last  enabled at (0): [<ffffffff814ac99f>] copy_process+0x227f/0x75c0 kernel/fork.c:2448
softirqs last disabled at (0): [<0000000000000000>] 0x0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&fs_info->delayed_iput_lock);
  <Interrupt>
    lock(&fs_info->delayed_iput_lock);

 *** DEADLOCK ***

1 lock held by btrfs-cleaner/16079:
 #0: ffff888107804860 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: cleaner_kthread+0x103/0x4b0 fs/btrfs/disk-io.c:1463

stack backtrace:
CPU: 3 PID: 16079 Comm: btrfs-cleaner Not tainted 6.4.0-syzkaller-09904-ga507db1d8fdc #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_usage_bug kernel/locking/lockdep.c:3978 [inline]
 valid_state kernel/locking/lockdep.c:4020 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4223 [inline]
 mark_lock.part.0+0x1102/0x1960 kernel/locking/lockdep.c:4685
 mark_lock kernel/locking/lockdep.c:4649 [inline]
 mark_usage kernel/locking/lockdep.c:4598 [inline]
 __lock_acquire+0x8e4/0x5e20 kernel/locking/lockdep.c:5098
 lock_acquire kernel/locking/lockdep.c:5761 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:350 [inline]
 btrfs_run_delayed_iputs+0x28/0xe0 fs/btrfs/inode.c:3523
 cleaner_kthread+0x2e5/0x4b0 fs/btrfs/disk-io.c:1478
 kthread+0x344/0x440 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/01 13:07 upstream a507db1d8fdc bfc47836 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream inconsistent lock state in btrfs_run_delayed_iputs
* Struck through repros no longer work on HEAD.