====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-10553-gb86545e02e8c #0 Not tainted ------------------------------------------------------ kswapd1/81 is trying to acquire lock: ffff888043f27758 (&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: ffffffff8ea3f620 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6864 [inline] ffffffff8ea3f620 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7246 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:3851 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3865 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4055 [inline] slab_alloc_node mm/slub.c:4133 [inline] __kmalloc_cache_noprof+0x41/0x390 mm/slub.c:4309 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:233 [inline] loop_set_status+0x5f0/0x8f0 drivers/block/loop.c:1285 lo_ioctl+0xcbc/0x1f50 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:75 [inline] blk_mq_submit_bio+0x1536/0x23a0 block/blk-mq.c:3092 __submit_bio+0x2c6/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 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/0x7f0 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+0x431/0xa60 fs/xfs/xfs_buf.c:873 xfs_trans_read_buf_map+0x260/0xad0 fs/xfs/xfs_trans_buf.c:304 xfs_trans_read_buf fs/xfs/xfs_trans.h:213 [inline] xfs_read_agf+0x2dc/0x630 fs/xfs/libxfs/xfs_alloc.c:3378 xfs_alloc_read_agf+0x196/0xbe0 fs/xfs/libxfs/xfs_alloc.c:3413 xfs_alloc_fix_freelist+0x608/0x1bd0 fs/xfs/libxfs/xfs_alloc.c:2877 xfs_alloc_vextent_prepare_ag+0xf9/0x6b0 fs/xfs/libxfs/xfs_alloc.c:3543 xfs_alloc_vextent_iterate_ags+0x141/0x960 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:3768 [inline] xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3813 [inline] xfs_bmapi_allocate+0x18fa/0x3450 fs/xfs/libxfs/xfs_bmap.c:4226 xfs_bmapi_write+0xbac/0x1b40 fs/xfs/libxfs/xfs_bmap.c:4555 xfs_dquot_disk_alloc+0x5f4/0xe20 fs/xfs/xfs_dquot.c:355 xfs_qm_dqread+0x1a3/0x650 fs/xfs/xfs_dquot.c:694 xfs_qm_dqget+0x2bb/0x6f0 fs/xfs/xfs_dquot.c:906 xfs_qm_quotacheck_dqadjust+0xea/0x5a0 fs/xfs/xfs_qm.c:1297 xfs_qm_dqusage_adjust+0x5e1/0x850 fs/xfs/xfs_qm.c:1419 xfs_iwalk_ag_recs+0x4e1/0x820 fs/xfs/xfs_iwalk.c:209 xfs_iwalk_run_callbacks+0x218/0x470 fs/xfs/xfs_iwalk.c:370 xfs_iwalk_ag+0xa9a/0xbb0 fs/xfs/xfs_iwalk.c:476 xfs_iwalk_ag_work+0xfb/0x1b0 fs/xfs/xfs_iwalk.c:625 xfs_pwork_work+0x7f/0x190 fs/xfs/xfs_pwork.c:47 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 -> #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/0xf60 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+0x701/0x1160 mm/shrinker.c:437 shrink_slab+0x1093/0x14d0 mm/shrinker.c:664 shrink_one+0x43b/0x850 mm/vmscan.c:4836 shrink_many mm/vmscan.c:4897 [inline] lru_gen_shrink_node mm/vmscan.c:4975 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5956 kswapd_shrink_node mm/vmscan.c:6785 [inline] balance_pgdat mm/vmscan.c:6977 [inline] kswapd+0x1ca9/0x3700 mm/vmscan.c:7246 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 kswapd1/81: #0: ffffffff8ea3f620 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6864 [inline] #0: ffffffff8ea3f620 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x3700 mm/vmscan.c:7246 #1: ffff88805460c0e0 (&type->s_umount_key#46){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff88805460c0e0 (&type->s_umount_key#46){.+.+}-{4:4}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 81 Comm: kswapd1 Not tainted 6.12.0-syzkaller-10553-gb86545e02e8c #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/0xf60 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+0x701/0x1160 mm/shrinker.c:437 shrink_slab+0x1093/0x14d0 mm/shrinker.c:664 shrink_one+0x43b/0x850 mm/vmscan.c:4836 shrink_many mm/vmscan.c:4897 [inline] lru_gen_shrink_node mm/vmscan.c:4975 [inline] shrink_node+0x37c5/0x3e50 mm/vmscan.c:5956 kswapd_shrink_node mm/vmscan.c:6785 [inline] balance_pgdat mm/vmscan.c:6977 [inline] kswapd+0x1ca9/0x3700 mm/vmscan.c:7246 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