====================================================== WARNING: possible circular locking dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted ------------------------------------------------------ kswapd1/112 is trying to acquire lock: ffff888029494e98 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_ilock+0x2ef/0x3e0 fs/xfs/xfs_inode.c:206 but task is already holding lock: ffffffff8d92fb40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x15f/0x1a90 mm/vmscan.c:6774 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:3692 [inline] fs_reclaim_acquire+0x102/0x150 mm/page_alloc.c:3706 might_alloc include/linux/sched/mm.h:303 [inline] slab_pre_alloc_hook mm/slub.c:3746 [inline] slab_alloc_node mm/slub.c:3827 [inline] kmem_cache_alloc+0x4f/0x320 mm/slub.c:3852 radix_tree_node_alloc.constprop.0+0x7c/0x350 lib/radix-tree.c:276 radix_tree_extend+0x1a2/0x4d0 lib/radix-tree.c:425 __radix_tree_create lib/radix-tree.c:613 [inline] radix_tree_insert+0x499/0x630 lib/radix-tree.c:712 xfs_qm_dqget_cache_insert.constprop.0+0x38/0x2c0 fs/xfs/xfs_dquot.c:826 xfs_qm_dqget+0x182/0x4a0 fs/xfs/xfs_dquot.c:901 xfs_qm_vop_dqalloc+0x899/0xe10 fs/xfs/xfs_qm.c:1730 xfs_setattr_nonsize+0x8ca/0xca0 fs/xfs/xfs_iops.c:707 xfs_vn_setattr+0x209/0x260 fs/xfs/xfs_iops.c:1027 notify_change+0x742/0x11c0 fs/attr.c:497 chown_common+0x598/0x660 fs/open.c:790 do_fchownat+0x1af/0x210 fs/open.c:821 ksys_chown include/linux/syscalls.h:1237 [inline] __do_sys_chown16 kernel/uid16.c:25 [inline] __se_sys_chown16 kernel/uid16.c:23 [inline] __ia32_sys_chown16+0xe3/0x110 kernel/uid16.c:23 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 -> #1 (&qinf->qi_tree_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 xfs_qm_dqget_cache_lookup+0x66/0x820 fs/xfs/xfs_dquot.c:784 xfs_qm_dqget_inode+0x1e7/0x6d0 fs/xfs/xfs_dquot.c:986 xfs_qm_dqattach_one+0x26f/0x530 fs/xfs/xfs_qm.c:278 xfs_qm_dqattach_locked+0x226/0x2d0 fs/xfs/xfs_qm.c:329 xfs_qm_vop_dqalloc+0x344/0xe10 fs/xfs/xfs_qm.c:1710 xfs_setattr_nonsize+0x8ca/0xca0 fs/xfs/xfs_iops.c:707 xfs_vn_setattr+0x209/0x260 fs/xfs/xfs_iops.c:1027 notify_change+0x742/0x11c0 fs/attr.c:497 chown_common+0x598/0x660 fs/open.c:790 do_fchownat+0x1af/0x210 fs/open.c:821 ksys_chown include/linux/syscalls.h:1237 [inline] __do_sys_chown16 kernel/uid16.c:25 [inline] __se_sys_chown16 kernel/uid16.c:23 [inline] __ia32_sys_chown16+0xe3/0x110 kernel/uid16.c:23 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 -> #0 (&xfs_nondir_ilock_class#3){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_ilock+0x2ef/0x3e0 fs/xfs/xfs_inode.c:206 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0xca6/0x1740 fs/xfs/xfs_icache.c:1713 xfs_icwalk+0x57/0x100 fs/xfs/xfs_icache.c:1762 xfs_reclaim_inodes_nr+0x182/0x250 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x409/0x550 fs/super.c:227 do_shrink_slab+0x44f/0x1160 mm/shrinker.c:435 shrink_slab+0x18a/0x1310 mm/shrinker.c:662 shrink_one+0x493/0x7b0 mm/vmscan.c:4767 shrink_many mm/vmscan.c:4828 [inline] lru_gen_shrink_node mm/vmscan.c:4929 [inline] shrink_node+0x2191/0x3770 mm/vmscan.c:5888 kswapd_shrink_node mm/vmscan.c:6696 [inline] balance_pgdat+0x9d0/0x1a90 mm/vmscan.c:6886 kswapd+0x5c1/0xc10 mm/vmscan.c:7146 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 other info that might help us debug this: Chain exists of: &xfs_nondir_ilock_class#3 --> &qinf->qi_tree_lock --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&qinf->qi_tree_lock); lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); *** DEADLOCK *** 2 locks held by kswapd1/112: #0: ffffffff8d92fb40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x15f/0x1a90 mm/vmscan.c:6774 #1: ffff8880506f00e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline] #1: ffff8880506f00e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_cache_scan+0x96/0x550 fs/super.c:196 stack backtrace: CPU: 3 PID: 112 Comm: kswapd1 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_ilock+0x2ef/0x3e0 fs/xfs/xfs_inode.c:206 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0xca6/0x1740 fs/xfs/xfs_icache.c:1713 xfs_icwalk+0x57/0x100 fs/xfs/xfs_icache.c:1762 xfs_reclaim_inodes_nr+0x182/0x250 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x409/0x550 fs/super.c:227 do_shrink_slab+0x44f/0x1160 mm/shrinker.c:435 shrink_slab+0x18a/0x1310 mm/shrinker.c:662 shrink_one+0x493/0x7b0 mm/vmscan.c:4767 shrink_many mm/vmscan.c:4828 [inline] lru_gen_shrink_node mm/vmscan.c:4929 [inline] shrink_node+0x2191/0x3770 mm/vmscan.c:5888 kswapd_shrink_node mm/vmscan.c:6696 [inline] balance_pgdat+0x9d0/0x1a90 mm/vmscan.c:6886 kswapd+0x5c1/0xc10 mm/vmscan.c:7146 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243