====================================================== WARNING: possible circular locking dependency detected 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Not tainted ------------------------------------------------------ kswapd0/74 is trying to acquire lock: ffff888011bc6018 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_can_free_eofblocks+0x604/0x890 fs/xfs/xfs_bmap_util.c:546 but task is already holding lock: ffffffff8ea39460 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6874 [inline] ffffffff8ea39460 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x36f0 mm/vmscan.c:7256 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:5849 __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:4070 [inline] slab_alloc_node mm/slub.c:4148 [inline] __kmalloc_cache_noprof+0x41/0x390 mm/slub.c:4324 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 set_capacity_and_notify+0x265/0x2d0 block/genhd.c:102 loop_set_size drivers/block/loop.c:234 [inline] loop_set_status+0x65d/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 -> #1 (&q->q_usage_counter(io)#17){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 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_ioapply_map+0x461/0x5d0 fs/xfs/xfs_buf.c:1586 _xfs_buf_ioapply+0x307/0x660 fs/xfs/xfs_buf.c:1674 __xfs_buf_submit+0x34f/0x7e0 fs/xfs/xfs_buf.c:1758 xfs_buf_submit fs/xfs/xfs_buf.c:61 [inline] _xfs_buf_read fs/xfs/xfs_buf.c:809 [inline] xfs_buf_read_map+0x431/0xa50 fs/xfs/xfs_buf.c:873 xfs_trans_read_buf_map+0x260/0xab0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:213 [inline] xfs_alloc_read_agfl+0x273/0x4c0 fs/xfs/libxfs/xfs_alloc.c:887 xfs_alloc_fix_freelist+0xd8c/0x1bc0 fs/xfs/libxfs/xfs_alloc.c:2963 xfs_alloc_vextent_prepare_ag+0xf9/0x6b0 fs/xfs/libxfs/xfs_alloc.c:3543 xfs_alloc_vextent_iterate_ags+0x141/0x950 fs/xfs/libxfs/xfs_alloc.c:3727 xfs_alloc_vextent_start_ag+0x3f6/0x950 fs/xfs/libxfs/xfs_alloc.c:3816 xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3766 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3811 [inline] xfs_bmapi_allocate+0x18fa/0x3450 fs/xfs/libxfs/xfs_bmap.c:4224 xfs_bmapi_write+0xbac/0x1b40 fs/xfs/libxfs/xfs_bmap.c:4553 xfs_alloc_file_space+0x5a9/0xab0 fs/xfs/xfs_bmap_util.c:734 xfs_falloc_zero_range+0x2f3/0x6a0 fs/xfs/xfs_file.c:1026 xfs_file_fallocate+0x2e5/0x3d0 fs/xfs/xfs_file.c:1136 vfs_fallocate+0x569/0x6e0 fs/open.c:327 do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x80/0x170 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 -> #0 (&xfs_nondir_ilock_class){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 xfs_can_free_eofblocks+0x604/0x890 fs/xfs/xfs_bmap_util.c:546 xfs_inode_mark_reclaimable+0x1bb/0xf40 fs/xfs/xfs_icache.c:2246 destroy_inode fs/inode.c:386 [inline] evict+0x7af/0x9a0 fs/inode.c:827 dispose_list fs/inode.c:845 [inline] prune_icache_sb+0x239/0x2f0 fs/inode.c:1033 super_cache_scan+0x38c/0x4b0 fs/super.c:223 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:4846 shrink_many mm/vmscan.c:4907 [inline] lru_gen_shrink_node mm/vmscan.c:4985 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5966 kswapd_shrink_node mm/vmscan.c:6795 [inline] balance_pgdat mm/vmscan.c:6987 [inline] kswapd+0x1ca9/0x36f0 mm/vmscan.c:7256 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: &xfs_nondir_ilock_class --> &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(&xfs_nondir_ilock_class); *** DEADLOCK *** 2 locks held by kswapd0/74: #0: ffffffff8ea39460 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6874 [inline] #0: ffffffff8ea39460 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x36f0 mm/vmscan.c:7256 #1: ffff888032c380e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff888032c380e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 74 Comm: kswapd0 Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #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:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 xfs_can_free_eofblocks+0x604/0x890 fs/xfs/xfs_bmap_util.c:546 xfs_inode_mark_reclaimable+0x1bb/0xf40 fs/xfs/xfs_icache.c:2246 destroy_inode fs/inode.c:386 [inline] evict+0x7af/0x9a0 fs/inode.c:827 dispose_list fs/inode.c:845 [inline] prune_icache_sb+0x239/0x2f0 fs/inode.c:1033 super_cache_scan+0x38c/0x4b0 fs/super.c:223 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:4846 shrink_many mm/vmscan.c:4907 [inline] lru_gen_shrink_node mm/vmscan.c:4985 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5966 kswapd_shrink_node mm/vmscan.c:6795 [inline] balance_pgdat mm/vmscan.c:6987 [inline] kswapd+0x1ca9/0x36f0 mm/vmscan.c:7256 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