====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc4-syzkaller-00266-g977b1ef51866 #0 Not tainted ------------------------------------------------------ kswapd0/87 is trying to acquire lock: ffff888061c665d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] ffff888061c665d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] ffff888061c665d8 (&xfs_nondir_ilock_class#3){++++}-{3:3}, at: xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 but task is already holding lock: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline] ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb20/0x30c0 mm/vmscan.c:7164 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3698 [inline] fs_reclaim_acquire+0x88/0x140 mm/page_alloc.c:3712 might_alloc include/linux/sched/mm.h:312 [inline] prepare_alloc_pages+0x147/0x5d0 mm/page_alloc.c:4346 __alloc_pages+0x166/0x6c0 mm/page_alloc.c:4564 alloc_pages_mpol+0x3e8/0x680 mm/mempolicy.c:2264 stack_depot_save_flags+0x666/0x830 lib/stackdepot.c:635 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x51/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1db/0x360 mm/slub.c:3997 kmalloc include/linux/slab.h:628 [inline] kzalloc include/linux/slab.h:749 [inline] xfs_iext_alloc_node fs/xfs/libxfs/xfs_iext_tree.c:401 [inline] xfs_iext_alloc_root fs/xfs/libxfs/xfs_iext_tree.c:593 [inline] xfs_iext_insert_raw+0x206/0x23d0 fs/xfs/libxfs/xfs_iext_tree.c:645 xfs_iext_insert+0x38/0x250 fs/xfs/libxfs/xfs_iext_tree.c:684 xfs_bmap_add_extent_hole_delay+0x573/0xc20 fs/xfs/libxfs/xfs_bmap.c:2686 xfs_bmapi_reserve_delalloc+0x897/0x9b0 fs/xfs/libxfs/xfs_bmap.c:4128 xfs_buffered_write_iomap_begin+0x1243/0x1b40 fs/xfs/xfs_iomap.c:1130 iomap_iter+0x691/0xf60 fs/iomap/iter.c:91 iomap_file_buffered_write+0x26c/0xa60 fs/iomap/buffered-io.c:1014 xfs_file_buffered_write+0x2e4/0xad0 fs/xfs/xfs_file.c:786 call_write_iter include/linux/fs.h:2110 [inline] iter_file_splice_write+0xbd7/0x14e0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11e/0x220 fs/splice.c:1164 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x28c/0x3e0 fs/splice.c:1233 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&xfs_nondir_ilock_class#3){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 xfs_icwalk fs/xfs/xfs_icache.c:1762 [inline] xfs_reclaim_inodes_nr+0x257/0x360 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab+0x1092/0x14d0 mm/shrinker.c:662 shrink_node_memcgs mm/vmscan.c:5875 [inline] shrink_node+0x11f5/0x2d60 mm/vmscan.c:5908 kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat mm/vmscan.c:6895 [inline] kswapd+0x1a25/0x30c0 mm/vmscan.c:7164 kthread+0x2f0/0x390 kernel/kthread.c:388 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); lock(fs_reclaim); lock(&xfs_nondir_ilock_class#3); *** DEADLOCK *** 2 locks held by kswapd0/87: #0: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6782 [inline] #0: ffffffff8e428e80 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xb20/0x30c0 mm/vmscan.c:7164 #1: ffff8881fa6600e0 (&type->s_umount_key#63){++++}-{3:3}, at: super_trylock_shared fs/super.c:561 [inline] #1: ffff8881fa6600e0 (&type->s_umount_key#63){++++}-{3:3}, at: super_cache_scan+0x94/0x4b0 fs/super.c:196 stack backtrace: CPU: 1 PID: 87 Comm: kswapd0 Not tainted 6.9.0-rc4-syzkaller-00266-g977b1ef51866 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1695 xfs_reclaim_inode fs/xfs/xfs_icache.c:945 [inline] xfs_icwalk_process_inode fs/xfs/xfs_icache.c:1631 [inline] xfs_icwalk_ag+0x120e/0x1ad0 fs/xfs/xfs_icache.c:1713 xfs_icwalk fs/xfs/xfs_icache.c:1762 [inline] xfs_reclaim_inodes_nr+0x257/0x360 fs/xfs/xfs_icache.c:1011 super_cache_scan+0x40f/0x4b0 fs/super.c:227 do_shrink_slab+0x705/0x1160 mm/shrinker.c:435 shrink_slab+0x1092/0x14d0 mm/shrinker.c:662 shrink_node_memcgs mm/vmscan.c:5875 [inline] shrink_node+0x11f5/0x2d60 mm/vmscan.c:5908 kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat mm/vmscan.c:6895 [inline] kswapd+0x1a25/0x30c0 mm/vmscan.c:7164 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244