====================================================== WARNING: possible circular locking dependency detected 6.13.0-syzkaller-09485-g72deda0abee6 #0 Not tainted ------------------------------------------------------ kswapd0/80 is trying to acquire lock: ffff8880333f8610 (sb_internal#2){.+.+}-{0:0}, at: xfs_fs_dirty_inode+0x158/0x250 fs/xfs/xfs_super.c:695 but task is already holding lock: ffffffff8ea39060 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6881 [inline] ffffffff8ea39060 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb9f/0x3b10 mm/vmscan.c:7259 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __fs_reclaim_acquire mm/page_alloc.c:3853 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3867 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4066 [inline] slab_alloc_node mm/slub.c:4144 [inline] __kmalloc_cache_noprof+0x41/0x390 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] kobject_uevent_env+0x28b/0x8e0 lib/kobject_uevent.c:540 loop_set_size drivers/block/loop.c:235 [inline] loop_set_status+0x6c2/0x940 drivers/block/loop.c:1291 lo_ioctl+0xcd3/0x23b0 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 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 -> #2 (&q->q_usage_counter(io)#17){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 bio_queue_enter block/blk.h:77 [inline] blk_mq_submit_bio+0x14e1/0x25a0 block/blk-mq.c:3091 __submit_bio+0x2cf/0x6a0 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:716 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:745 xfs_buf_submit_bio fs/xfs/xfs_buf.c:1560 [inline] xfs_buf_submit+0xa71/0xf40 fs/xfs/xfs_buf.c:1668 _xfs_buf_read fs/xfs/xfs_buf.c:805 [inline] xfs_buf_read_map+0x40f/0xa50 fs/xfs/xfs_buf.c:872 xfs_trans_read_buf_map+0x260/0xab0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline] xfs_btree_read_buf_block+0x36f/0x5b0 fs/xfs/libxfs/xfs_btree.c:1402 xfs_btree_lookup_get_block+0x316/0x5b0 fs/xfs/libxfs/xfs_btree.c:1907 xfs_btree_lookup+0x4eb/0x15f0 fs/xfs/libxfs/xfs_btree.c:2018 xfs_inobt_lookup fs/xfs/libxfs/xfs_ialloc.c:47 [inline] xfs_dialloc_ag_finobt_near+0x182/0x9c0 fs/xfs/libxfs/xfs_ialloc.c:1384 xfs_dialloc_ag fs/xfs/libxfs/xfs_ialloc.c:1606 [inline] xfs_dialloc_try_ag fs/xfs/libxfs/xfs_ialloc.c:1835 [inline] xfs_dialloc+0x10ac/0x1e20 fs/xfs/libxfs/xfs_ialloc.c:1945 xfs_create+0x7d7/0xf50 fs/xfs/xfs_inode.c:719 xfs_generic_create+0x5d5/0xf50 fs/xfs/xfs_iops.c:215 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x192f/0x3580 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 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 (&xfs_dir_ilock_class/5){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693 xfs_create+0x7bf/0xf50 fs/xfs/xfs_inode.c:711 xfs_generic_create+0x5d5/0xf50 fs/xfs/xfs_iops.c:215 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x192f/0x3580 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 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#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1773 [inline] sb_start_intwrite include/linux/fs.h:1956 [inline] xfs_trans_alloc+0xe5/0x7f0 fs/xfs/xfs_trans.c:265 xfs_fs_dirty_inode+0x158/0x250 fs/xfs/xfs_super.c:695 __mark_inode_dirty+0x2ee/0xe90 fs/fs-writeback.c:2515 mark_inode_dirty_sync include/linux/fs.h:2540 [inline] iput+0x1f1/0xa50 fs/inode.c:1969 __dentry_kill+0x20d/0x630 fs/dcache.c:625 shrink_kill+0xa9/0x2c0 fs/dcache.c:1070 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1097 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1178 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x72d/0x1160 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x878/0x14d0 mm/shrinker.c:628 shrink_one+0x43b/0x850 mm/vmscan.c:4863 shrink_many mm/vmscan.c:4924 [inline] lru_gen_shrink_node mm/vmscan.c:5002 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5973 kswapd_shrink_node mm/vmscan.c:6802 [inline] balance_pgdat mm/vmscan.c:6994 [inline] kswapd+0x20f3/0x3b10 mm/vmscan.c:7259 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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#2 --> &q->q_usage_counter(io)#17 --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&q->q_usage_counter(io)#17); lock(fs_reclaim); rlock(sb_internal#2); *** DEADLOCK *** 2 locks held by kswapd0/80: #0: ffffffff8ea39060 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6881 [inline] #0: ffffffff8ea39060 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb9f/0x3b10 mm/vmscan.c:7259 #1: ffff8880333f80e0 (&type->s_umount_key#49){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8880333f80e0 (&type->s_umount_key#49){.+.+}-{4:4}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 80 Comm: kswapd0 Not tainted 6.13.0-syzkaller-09485-g72deda0abee6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1773 [inline] sb_start_intwrite include/linux/fs.h:1956 [inline] xfs_trans_alloc+0xe5/0x7f0 fs/xfs/xfs_trans.c:265 xfs_fs_dirty_inode+0x158/0x250 fs/xfs/xfs_super.c:695 __mark_inode_dirty+0x2ee/0xe90 fs/fs-writeback.c:2515 mark_inode_dirty_sync include/linux/fs.h:2540 [inline] iput+0x1f1/0xa50 fs/inode.c:1969 __dentry_kill+0x20d/0x630 fs/dcache.c:625 shrink_kill+0xa9/0x2c0 fs/dcache.c:1070 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1097 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1178 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x72d/0x1160 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x878/0x14d0 mm/shrinker.c:628 shrink_one+0x43b/0x850 mm/vmscan.c:4863 shrink_many mm/vmscan.c:4924 [inline] lru_gen_shrink_node mm/vmscan.c:5002 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5973 kswapd_shrink_node mm/vmscan.c:6802 [inline] balance_pgdat mm/vmscan.c:6994 [inline] kswapd+0x20f3/0x3b10 mm/vmscan.c:7259 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244