====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc2-next-20240605-syzkaller #0 Tainted: G W ------------------------------------------------------ kswapd0/88 is trying to acquire lock: ffff888032d96610 (sb_internal#3){.+.+}-{0:0}, at: nilfs_evict_inode+0x167/0x500 fs/nilfs2/inode.c:924 but task is already holding lock: ffffffff8e42c480 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6852 [inline] ffffffff8e42c480 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbe8/0x3710 mm/vmscan.c:7234 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:5817 __fs_reclaim_acquire mm/page_alloc.c:3838 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3852 might_alloc include/linux/sched/mm.h:334 [inline] prepare_alloc_pages+0x147/0x5d0 mm/page_alloc.c:4486 __alloc_pages_noprof+0x166/0x6c0 mm/page_alloc.c:4704 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 alloc_pages_noprof mm/mempolicy.c:2340 [inline] folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2347 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008 __filemap_get_folio+0x413/0xbb0 mm/filemap.c:1950 pagecache_get_page+0x2c/0x200 mm/folio-compat.c:81 block_write_begin+0x31/0x1e0 fs/buffer.c:2229 nilfs_write_begin+0xa0/0x110 fs/nilfs2/inode.c:262 page_symlink+0x2a6/0x4a0 fs/namei.c:5240 nilfs_symlink+0x236/0x380 fs/nilfs2/namei.c:153 vfs_symlink+0x137/0x2e0 fs/namei.c:4493 do_symlinkat+0x222/0x3a0 fs/namei.c:4519 __do_sys_symlink fs/namei.c:4540 [inline] __se_sys_symlink fs/namei.c:4538 [inline] __x64_sys_symlink+0x7e/0x90 fs/namei.c:4538 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 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:5817 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:3509 [inline] open_last_lookups fs/namei.c:3578 [inline] path_openat+0x1425/0x3280 fs/namei.c:3808 do_filp_open+0x235/0x490 fs/namei.c:3838 do_sys_openat2+0x13e/0x1d0 fs/open.c:1409 do_sys_open fs/open.c:1424 [inline] __do_sys_open fs/open.c:1432 [inline] __se_sys_open fs/open.c:1428 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1428 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_internal#3){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3159 [inline] check_prevs_add kernel/locking/lockdep.c:3278 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3902 __lock_acquire+0x1359/0x2000 kernel/locking/lockdep.c:5194 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5817 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1671 [inline] sb_start_intwrite include/linux/fs.h:1854 [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 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+0x701/0x1160 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0x878/0x14c0 mm/shrinker.c:626 shrink_one+0x450/0x880 mm/vmscan.c:4806 shrink_many mm/vmscan.c:4867 [inline] lru_gen_shrink_node mm/vmscan.c:4967 [inline] shrink_node+0x3975/0x4160 mm/vmscan.c:5947 kswapd_shrink_node mm/vmscan.c:6774 [inline] balance_pgdat mm/vmscan.c:6965 [inline] kswapd+0x1882/0x3710 mm/vmscan.c:7234 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#3 --> &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#3); *** DEADLOCK *** 2 locks held by kswapd0/88: #0: ffffffff8e42c480 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6852 [inline] #0: ffffffff8e42c480 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbe8/0x3710 mm/vmscan.c:7234 #1: ffff888032d960e0 (&type->s_umount_key#76){++++}-{3:3}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff888032d960e0 (&type->s_umount_key#76){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 PID: 88 Comm: kswapd0 Tainted: G W 6.10.0-rc2-next-20240605-syzkaller #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:91 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2075 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2204 check_prev_add kernel/locking/lockdep.c:3159 [inline] check_prevs_add kernel/locking/lockdep.c:3278 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3902 __lock_acquire+0x1359/0x2000 kernel/locking/lockdep.c:5194 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5817 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1671 [inline] sb_start_intwrite include/linux/fs.h:1854 [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 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+0x701/0x1160 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0x878/0x14c0 mm/shrinker.c:626 shrink_one+0x450/0x880 mm/vmscan.c:4806 shrink_many mm/vmscan.c:4867 [inline] lru_gen_shrink_node mm/vmscan.c:4967 [inline] shrink_node+0x3975/0x4160 mm/vmscan.c:5947 kswapd_shrink_node mm/vmscan.c:6774 [inline] balance_pgdat mm/vmscan.c:6965 [inline] kswapd+0x1882/0x3710 mm/vmscan.c:7234 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