warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow ====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc6-next-20221122 #1 Not tainted ------------------------------------------------------ syz-executor.3/75394 is trying to acquire lock: ffff88800c9b8400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x52/0x470 but task is already holding lock: ffff88801088a3f8 (&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+0x9b0/0x4340 __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+0x183/0x540 ext4_fileattr_set+0x142b/0x18c0 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/0x830 ext4_fileattr_set+0x1452/0x18c0 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+0x1a6/0x530 down_read+0x9c/0x450 ext4_bmap+0x52/0x470 bmap+0xb0/0x130 jbd2_journal_bmap+0xac/0x190 jbd2_journal_flush+0x857/0xc10 __ext4_ioctl+0x9b0/0x4340 __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.3/75394: #0: ffff88801088a170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x162/0x310 #1: ffff88801088a3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48f/0xc10 stack backtrace: CPU: 0 PID: 75394 Comm: syz-executor.3 Not tainted 6.1.0-rc6-next-20221122 #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+0x1a6/0x530 down_read+0x9c/0x450 ext4_bmap+0x52/0x470 bmap+0xb0/0x130 jbd2_journal_bmap+0xac/0x190 jbd2_journal_flush+0x857/0xc10 __ext4_ioctl+0x9b0/0x4340 __x64_sys_ioctl+0x19e/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7ffb2b401b19 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:00007ffb28956188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffb2b515020 RCX: 00007ffb2b401b19 RDX: 0000000020000000 RSI: 000000004004662b RDI: 0000000000000006 RBP: 00007ffb2b45bf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6d72c4af R14: 00007ffb28956300 R15: 0000000000022000 hpet: Lost 3 RTC interrupts Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed Process accounting resumed