====================================================== WARNING: possible circular locking dependency detected 6.1.0-next-20221219 #1 Not tainted ------------------------------------------------------ syz-executor.4/5470 is trying to acquire lock: ffff88800b580400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x52/0x470 but task is already holding lock: ffff88800ffee3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: mutex_lock_io_nested+0x14c/0x1330 jbd2_journal_flush+0x19e/0xc10 __ext4_ioctl+0x9be/0x4560 __x64_sys_ioctl+0x19e/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #2 (&journal->j_barrier){+.+.}-{3:3}: __mutex_lock+0x136/0x14e0 jbd2_journal_lock_updates+0x162/0x310 ext4_change_inode_journal_flag+0x187/0x550 ext4_fileattr_set+0x14fa/0x19f0 vfs_fileattr_set+0x780/0xb90 do_vfs_ioctl+0xa6c/0x1af0 __x64_sys_ioctl+0x110/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_write+0x51/0x350 ext4_ind_migrate+0x23b/0x840 ext4_fileattr_set+0x1521/0x19f0 vfs_fileattr_set+0x780/0xb90 do_vfs_ioctl+0xa6c/0x1af0 __x64_sys_ioctl+0x110/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #0 (&sb->s_type->i_mutex_key#6){++++}-{3:3}: __lock_acquire+0x2a02/0x5e70 lock_acquire.part.0+0x11e/0x340 down_read+0x9c/0x450 ext4_bmap+0x52/0x470 bmap+0xb0/0x130 jbd2_journal_bmap+0xac/0x190 jbd2_journal_flush+0x857/0xc10 __ext4_ioctl+0x9be/0x4560 __x64_sys_ioctl+0x19e/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#6 --> &journal->j_barrier --> &journal->j_checkpoint_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&journal->j_checkpoint_mutex); lock(&journal->j_barrier); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#6); *** DEADLOCK *** 2 locks held by syz-executor.4/5470: #0: ffff88800ffee170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x162/0x310 #1: ffff88800ffee3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10 stack backtrace: CPU: 0 PID: 5470 Comm: syz-executor.4 Not tainted 6.1.0-next-20221219 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x8f/0xb7 check_noncircular+0x263/0x2e0 __lock_acquire+0x2a02/0x5e70 lock_acquire.part.0+0x11e/0x340 down_read+0x9c/0x450 ext4_bmap+0x52/0x470 bmap+0xb0/0x130 jbd2_journal_bmap+0xac/0x190 jbd2_journal_flush+0x857/0xc10 __ext4_ioctl+0x9be/0x4560 __x64_sys_ioctl+0x19e/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f20d2a94b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f20d000a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f20d2ba7f60 RCX: 00007f20d2a94b19 RDX: 0000000020000340 RSI: 000000004004662b RDI: 0000000000000006 RBP: 00007f20d2aeef6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff8862152f R14: 00007f20d000a300 R15: 0000000000022000 random: crng reseeded on system resumption random: crng reseeded on system resumption random: crng reseeded on system resumption