====================================================== WARNING: possible circular locking dependency detected 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Not tainted ------------------------------------------------------ kswapd0/89 is trying to acquire lock: ffff8881bbb7c610 (sb_internal#5){.+.+}-{0:0}, at: nilfs_evict_inode+0x167/0x500 fs/nilfs2/inode.c:924 but task is already holding lock: ffffffff8e429680 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6798 [inline] ffffffff8e429680 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb1e/0x2f30 mm/vmscan.c:7180 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3783 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3797 might_alloc include/linux/sched/mm.h:334 [inline] prepare_alloc_pages+0x147/0x5d0 mm/page_alloc.c:4431 __alloc_pages_noprof+0x166/0x6c0 mm/page_alloc.c:4649 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_pages_noprof mm/mempolicy.c:2336 [inline] folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2343 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008 __filemap_get_folio+0x41a/0xbb0 mm/filemap.c:1950 pagecache_get_page+0x2c/0x200 mm/folio-compat.c:87 block_write_begin+0x31/0x1e0 fs/buffer.c:2232 nilfs_write_begin+0xa0/0x110 fs/nilfs2/inode.c:262 page_symlink+0x2a6/0x4a0 fs/namei.c:5236 nilfs_symlink+0x236/0x380 fs/nilfs2/namei.c:153 vfs_symlink+0x137/0x2e0 fs/namei.c:4489 do_symlinkat+0x222/0x3a0 fs/namei.c:4515 __do_sys_symlink fs/namei.c:4536 [inline] __se_sys_symlink fs/namei.c:4534 [inline] __x64_sys_symlink+0x7e/0x90 fs/namei.c:4534 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&nilfs->ns_segctor_sem){++++}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 nilfs_transaction_begin+0x320/0x6e0 fs/nilfs2/segment.c:223 nilfs_create+0xc7/0x2d0 fs/nilfs2/namei.c:82 lookup_open fs/namei.c:3505 [inline] open_last_lookups fs/namei.c:3574 [inline] path_openat+0x1425/0x3280 fs/namei.c:3804 do_filp_open+0x235/0x490 fs/namei.c:3834 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_internal#5){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1655 [inline] sb_start_intwrite include/linux/fs.h:1838 [inline] nilfs_transaction_begin+0x216/0x6e0 fs/nilfs2/segment.c:220 nilfs_evict_inode+0x167/0x500 fs/nilfs2/inode.c:924 evict+0x2a8/0x630 fs/inode.c:667 __dentry_kill+0x20d/0x630 fs/dcache.c:603 dput+0x19f/0x2b0 fs/dcache.c:845 ovl_destroy_inode+0x44/0x160 fs/overlayfs/super.c:181 destroy_inode fs/inode.c:311 [inline] evict+0x549/0x630 fs/inode.c:682 __dentry_kill+0x20d/0x630 fs/dcache.c:603 shrink_kill+0xa9/0x2c0 fs/dcache.c:1048 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1075 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1156 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0x883/0x14d0 mm/shrinker.c:626 shrink_node_memcgs mm/vmscan.c:5891 [inline] shrink_node+0x10ec/0x2a30 mm/vmscan.c:5924 kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat mm/vmscan.c:6911 [inline] kswapd+0x19a4/0x2f30 mm/vmscan.c:7180 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Chain exists of: sb_internal#5 --> &nilfs->ns_segctor_sem --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&nilfs->ns_segctor_sem); lock(fs_reclaim); rlock(sb_internal#5); *** DEADLOCK *** 2 locks held by kswapd0/89: #0: ffffffff8e429680 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6798 [inline] #0: ffffffff8e429680 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb1e/0x2f30 mm/vmscan.c:7180 #1: ffff8881bc73c0e0 (&type->s_umount_key#103){++++}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8881bc73c0e0 (&type->s_umount_key#103){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 PID: 89 Comm: kswapd0 Not tainted 6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1655 [inline] sb_start_intwrite include/linux/fs.h:1838 [inline] nilfs_transaction_begin+0x216/0x6e0 fs/nilfs2/segment.c:220 nilfs_evict_inode+0x167/0x500 fs/nilfs2/inode.c:924 evict+0x2a8/0x630 fs/inode.c:667 __dentry_kill+0x20d/0x630 fs/dcache.c:603 dput+0x19f/0x2b0 fs/dcache.c:845 ovl_destroy_inode+0x44/0x160 fs/overlayfs/super.c:181 destroy_inode fs/inode.c:311 [inline] evict+0x549/0x630 fs/inode.c:682 __dentry_kill+0x20d/0x630 fs/dcache.c:603 shrink_kill+0xa9/0x2c0 fs/dcache.c:1048 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1075 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1156 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0x883/0x14d0 mm/shrinker.c:626 shrink_node_memcgs mm/vmscan.c:5891 [inline] shrink_node+0x10ec/0x2a30 mm/vmscan.c:5924 kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat mm/vmscan.c:6911 [inline] kswapd+0x19a4/0x2f30 mm/vmscan.c:7180 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244