====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Not tainted ------------------------------------------------------ kswapd1/80 is trying to acquire lock: ffff88804305e610 (sb_internal#2){.+.+}-{0:0}, at: xfs_fs_dirty_inode+0x158/0x250 fs/xfs/xfs_super.c:695 but task is already holding lock: ffffffff8ea35b00 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6864 [inline] ffffffff8ea35b00 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x36f0 mm/vmscan.c:7246 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: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 -> #2 (&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+0x1536/0x2390 block/blk-mq.c:3091 __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/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: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_iomap_write_direct+0x427/0x780 fs/xfs/xfs_iomap.c:322 xfs_direct_write_iomap_begin+0x1123/0x1770 fs/xfs/xfs_iomap.c:933 iomap_iter+0x697/0xf60 fs/iomap/iter.c:90 __iomap_dio_rw+0x1870/0x25b0 fs/iomap/direct-io.c:702 iomap_dio_rw+0x46/0xa0 fs/iomap/direct-io.c:792 xfs_file_dio_write_aligned+0x1a0/0x2c0 fs/xfs/xfs_file.c:614 xfs_file_dio_write fs/xfs/xfs_file.c:726 [inline] xfs_file_write_iter+0x5db/0x720 fs/xfs/xfs_file.c:876 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11b/0x220 fs/splice.c:1164 splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x564/0x8a0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410 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_nondir_ilock_class){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693 xfs_vn_update_time+0x271/0x5f0 fs/xfs/xfs_iops.c:1107 inode_update_time fs/inode.c:2124 [inline] __file_update_time fs/inode.c:2353 [inline] file_modified_flags+0x399/0x4e0 fs/inode.c:2424 xfs_file_write_checks+0xa04/0xa70 fs/xfs/xfs_file.c:491 xfs_file_dio_write_aligned+0xe5/0x2c0 fs/xfs/xfs_file.c:600 xfs_file_dio_write fs/xfs/xfs_file.c:726 [inline] xfs_file_write_iter+0x5db/0x720 fs/xfs/xfs_file.c:876 iter_file_splice_write+0xbfa/0x1510 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11b/0x220 fs/splice.c:1164 splice_direct_to_actor+0x586/0xc80 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x564/0x8a0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410 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: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 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1725 [inline] sb_start_intwrite include/linux/fs.h:1908 [inline] xfs_trans_alloc+0xe5/0x830 fs/xfs/xfs_trans.c:266 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:2490 [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+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+0x1ca9/0x36f0 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: 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 kswapd1/80: #0: ffffffff8ea35b00 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6864 [inline] #0: ffffffff8ea35b00 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbf1/0x36f0 mm/vmscan.c:7246 #1: ffff88804305e0e0 (&type->s_umount_key#47){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff88804305e0e0 (&type->s_umount_key#47){.+.+}-{4:4}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 0 UID: 0 PID: 80 Comm: kswapd1 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #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 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1725 [inline] sb_start_intwrite include/linux/fs.h:1908 [inline] xfs_trans_alloc+0xe5/0x830 fs/xfs/xfs_trans.c:266 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:2490 [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+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+0x1ca9/0x36f0 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