====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc1-syzkaller-00009-g7033999ecd7b #0 Not tainted ------------------------------------------------------ kswapd0/110 is trying to acquire lock: ffff88805409d658 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_ilock+0x2ef/0x420 fs/xfs/xfs_inode.c:206 but task is already holding lock: ffffffff8d9392c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x166/0x1a10 mm/vmscan.c:6782 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:3698 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712 might_alloc include/linux/sched/mm.h:312 [inline] prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4346 __alloc_pages+0x194/0x2460 mm/page_alloc.c:4564 alloc_pages_mpol+0x275/0x610 mm/mempolicy.c:2264 stack_depot_save_flags+0x566/0x900 lib/stackdepot.c:635 kasan_save_stack+0x42/0x60 mm/kasan/common.c:48 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3852 kmem_cache_zalloc include/linux/slab.h:739 [inline] xfs_btree_alloc_cursor fs/xfs/libxfs/xfs_btree.h:679 [inline] xfs_refcountbt_init_cursor+0x69/0x310 fs/xfs/libxfs/xfs_refcount_btree.c:367 xfs_reflink_find_shared+0x10e/0x170 fs/xfs/xfs_reflink.c:147 xfs_reflink_trim_around_shared+0x3ec/0x7b0 fs/xfs/xfs_reflink.c:194 xfs_bmap_trim_cow+0x15c/0x1b0 fs/xfs/xfs_reflink.c:242 xfs_buffered_write_iomap_begin+0xe40/0x2220 fs/xfs/xfs_iomap.c:1062 iomap_iter+0x61f/0x1080 fs/iomap/iter.c:91 iomap_file_buffered_write+0x202/0x9c0 fs/iomap/buffered-io.c:1014 xfs_file_buffered_write+0x20a/0xa70 fs/xfs/xfs_file.c:786 xfs_file_write_iter+0x548/0x740 fs/xfs/xfs_file.c:861 call_write_iter include/linux/fs.h:2108 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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+0x1b1/0x560 kernel/locking/lockdep.c:5719 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_ilock+0x2ef/0x420 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+0xca6/0x1780 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/0x11c0 mm/shrinker.c:435 shrink_slab+0x18a/0x1310 mm/shrinker.c:662 shrink_one+0x493/0x7c0 mm/vmscan.c:4774 shrink_many mm/vmscan.c:4835 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935 shrink_node mm/vmscan.c:5894 [inline] kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895 kswapd+0x5ea/0xbf0 mm/vmscan.c:7164 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); *** DEADLOCK *** 2 locks held by kswapd0/110: #0: ffffffff8d9392c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x166/0x1a10 mm/vmscan.c:6782 #1: ffff888045af40e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline] #1: ffff888045af40e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_cache_scan+0x96/0x550 fs/super.c:196 stack backtrace: CPU: 0 PID: 110 Comm: kswapd0 Not tainted 6.9.0-rc1-syzkaller-00009-g7033999ecd7b #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+0x1b1/0x560 kernel/locking/lockdep.c:5719 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_ilock+0x2ef/0x420 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+0xca6/0x1780 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/0x11c0 mm/shrinker.c:435 shrink_slab+0x18a/0x1310 mm/shrinker.c:662 shrink_one+0x493/0x7c0 mm/vmscan.c:4774 shrink_many mm/vmscan.c:4835 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935 shrink_node mm/vmscan.c:5894 [inline] kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895 kswapd+0x5ea/0xbf0 mm/vmscan.c:7164 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