============================================ WARNING: possible recursive locking detected 6.4.0-rc4-syzkaller-g7877cb91f108 #0 Not tainted -------------------------------------------- kworker/u4:5/1023 is trying to acquire lock: ffff8880298ce0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0 but task is already holding lock: ffff8880298ce0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock/1); lock(&tree->tree_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by kworker/u4:5/1023: #0: ffff888019645938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77a/0x10c0 kernel/workqueue.c:2378 #1: ffffc900051efd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c0/0x10c0 kernel/workqueue.c:2380 #2: ffff88807e520108 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x8a/0x1f0 fs/hfsplus/extents.c:149 #3: ffff8880298ce0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0 #4: ffff88807aba0108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:457 stack backtrace: CPU: 0 PID: 1023 Comm: kworker/u4:5 Not tainted 6.4.0-rc4-syzkaller-g7877cb91f108 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:3006 [inline] check_deadlock kernel/locking/lockdep.c:3049 [inline] validate_chain+0x4736/0x58f0 kernel/locking/lockdep.c:3834 __lock_acquire+0x1316/0x2070 kernel/locking/lockdep.c:5088 lock_acquire+0x1df/0x520 kernel/locking/lockdep.c:5705 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 hfsplus_find_init+0x146/0x1c0 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline] hfsplus_file_extend+0x40a/0x1b10 fs/hfsplus/extents.c:461 hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:358 __hfsplus_ext_write_extent+0x2a4/0x5b0 fs/hfsplus/extents.c:104 hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:139 [inline] hfsplus_ext_write_extent+0x166/0x1f0 fs/hfsplus/extents.c:150 hfsplus_write_inode+0x1e/0x5c0 fs/hfsplus/super.c:154 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xf90 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8df/0x11d0 fs/fs-writeback.c:1894 wb_writeback+0x454/0xc60 fs/fs-writeback.c:2068 wb_do_writeback fs/fs-writeback.c:2211 [inline] wb_workfn+0x3fc/0xfe0 fs/fs-writeback.c:2251 process_one_work+0x894/0x10c0 kernel/workqueue.c:2405 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2552 kthread+0x2b0/0x340 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308