====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kswapd0/78 is trying to acquire lock: ffff8880437fa610 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x960 fs/xfs/xfs_trans.c:256 but task is already holding lock: ffffffff8e0518a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6975 [inline] ffffffff8e0518a0 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x92a/0x2820 mm/vmscan.c:7354 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4301 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4315 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4904 [inline] slab_alloc_node mm/slub.c:5239 [inline] __kmalloc_cache_noprof+0x40/0x700 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] iomap_fill_dirty_folios+0xf4/0x260 fs/iomap/buffered-io.c:1557 xfs_buffered_write_iomap_begin+0xa23/0x1a70 fs/xfs/xfs_iomap.c:1857 iomap_iter+0x5ef/0xeb0 fs/iomap/iter.c:110 iomap_zero_range+0x1cc/0xa30 fs/iomap/buffered-io.c:1590 xfs_zero_range+0x9a/0x100 fs/xfs/xfs_iomap.c:2289 xfs_file_write_zero_eof fs/xfs/xfs_file.c:415 [inline] xfs_file_write_checks+0x63f/0x9f0 fs/xfs/xfs_file.c:482 xfs_file_buffered_write+0x19e/0x8a0 fs/xfs/xfs_file.c:972 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&xfs_nondir_ilock_class){++++}-{4:4}: down_write_nested+0x9d/0x200 kernel/locking/rwsem.c:1706 xfs_dquot_disk_alloc+0x2d7/0xb20 fs/xfs/xfs_dquot.c:363 xfs_qm_dqread+0xfe/0x4e0 fs/xfs/xfs_dquot.c:720 xfs_qm_dqget+0x18b/0x3d0 fs/xfs/xfs_dquot.c:922 xfs_qm_quotacheck_dqadjust+0xc6/0x550 fs/xfs/xfs_qm.c:1261 xfs_qm_dqusage_adjust+0x49e/0x640 fs/xfs/xfs_qm.c:1390 xfs_iwalk_ag_recs+0x4d3/0x7f0 fs/xfs/xfs_iwalk.c:209 xfs_iwalk_run_callbacks+0x236/0x4a0 fs/xfs/xfs_iwalk.c:370 xfs_iwalk_ag+0x938/0xa20 fs/xfs/xfs_iwalk.c:473 xfs_iwalk_ag_work+0xfc/0x1b0 fs/xfs/xfs_iwalk.c:620 xfs_pwork_work+0x82/0x190 fs/xfs/xfs_pwork.c:47 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] __xfs_trans_alloc+0xad/0x420 fs/xfs/xfs_trans.c:224 xfs_trans_alloc+0xd7/0x960 fs/xfs/xfs_trans.c:256 xfs_fs_dirty_inode+0x12f/0x1e0 fs/xfs/xfs_super.c:735 __mark_inode_dirty+0x390/0x1330 fs/fs-writeback.c:2587 mark_inode_dirty_sync include/linux/fs.h:2200 [inline] iput+0x3e8/0x1030 fs/inode.c:1984 __dentry_kill+0x209/0x660 fs/dcache.c:670 shrink_kill+0xa9/0x2c0 fs/dcache.c:1137 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164 prune_dcache_sb+0x10e/0x180 fs/dcache.c:1246 super_cache_scan+0x369/0x4b0 fs/super.c:222 do_shrink_slab+0x6df/0x10d0 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x2d9/0x720 mm/vmscan.c:4921 shrink_many mm/vmscan.c:4982 [inline] lru_gen_shrink_node mm/vmscan.c:5060 [inline] shrink_node+0x2f7d/0x35b0 mm/vmscan.c:6047 kswapd_shrink_node mm/vmscan.c:6901 [inline] balance_pgdat mm/vmscan.c:7084 [inline] kswapd+0x145a/0x2820 mm/vmscan.c:7354 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 other info that might help us debug this: Chain exists of: sb_internal#2 --> &xfs_nondir_ilock_class --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&xfs_nondir_ilock_class); lock(fs_reclaim); rlock(sb_internal#2); *** DEADLOCK *** 2 locks held by kswapd0/78: #0: ffffffff8e0518a0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6975 [inline] #0: ffffffff8e0518a0 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x92a/0x2820 mm/vmscan.c:7354 #1: ffff8880437fa0e0 (&type->s_umount_key#52){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:563 [inline] #1: ffff8880437fa0e0 (&type->s_umount_key#52){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197 stack backtrace: CPU: 0 UID: 0 PID: 78 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full) 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_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] __xfs_trans_alloc+0xad/0x420 fs/xfs/xfs_trans.c:224 xfs_trans_alloc+0xd7/0x960 fs/xfs/xfs_trans.c:256 xfs_fs_dirty_inode+0x12f/0x1e0 fs/xfs/xfs_super.c:735 __mark_inode_dirty+0x390/0x1330 fs/fs-writeback.c:2587 mark_inode_dirty_sync include/linux/fs.h:2200 [inline] iput+0x3e8/0x1030 fs/inode.c:1984 __dentry_kill+0x209/0x660 fs/dcache.c:670 shrink_kill+0xa9/0x2c0 fs/dcache.c:1137 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164 prune_dcache_sb+0x10e/0x180 fs/dcache.c:1246 super_cache_scan+0x369/0x4b0 fs/super.c:222 do_shrink_slab+0x6df/0x10d0 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x2d9/0x720 mm/vmscan.c:4921 shrink_many mm/vmscan.c:4982 [inline] lru_gen_shrink_node mm/vmscan.c:5060 [inline] shrink_node+0x2f7d/0x35b0 mm/vmscan.c:6047 kswapd_shrink_node mm/vmscan.c:6901 [inline] balance_pgdat mm/vmscan.c:7084 [inline] kswapd+0x145a/0x2820 mm/vmscan.c:7354 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246