warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc1-next-20220822 #1 Not tainted ------------------------------------------------------ syz-executor.3/16938 is trying to acquire lock: ffff88800c930400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x4e/0x470 but task is already holding lock: ffff88800fee83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: mutex_lock_io_nested+0x148/0x1310 __jbd2_log_wait_for_space+0x234/0x460 add_transaction_credits+0xa42/0xb80 start_this_handle+0x3ac/0x14c0 jbd2__journal_start+0x390/0x8d0 __ext4_journal_start_sb+0x391/0x470 ext4_dirty_inode+0x9d/0x110 __mark_inode_dirty+0x455/0xf00 generic_update_time+0x26b/0x410 file_modified_flags+0x2d4/0x330 ext4_buffered_write_iter+0xf9/0x460 ext4_file_write_iter+0x3d5/0x1820 vfs_write+0x9c3/0xd90 ksys_write+0x127/0x250 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&sb->s_type->i_mutex_key#6){++++}-{3:3}: __lock_acquire+0x2a02/0x5e70 lock_acquire+0x1a2/0x530 down_read+0x98/0x450 ext4_bmap+0x4e/0x470 bmap+0xac/0x120 jbd2_journal_bmap+0xa8/0x180 jbd2_journal_flush+0x853/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#6); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#6); *** DEADLOCK *** 2 locks held by syz-executor.3/16938: #0: ffff88800fee8170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x15e/0x310 #1: ffff88800fee83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00 stack backtrace: CPU: 1 PID: 16938 Comm: syz-executor.3 Not tainted 6.0.0-rc1-next-20220822 #1 BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1521 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 16938, name: syz-executor.3 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. irq event stamp: 5457 hardirqs last enabled at (5457): [] asm_sysvec_apic_timer_interrupt+0x16/0x20 hardirqs last disabled at (5456): [] sysvec_apic_timer_interrupt+0xb/0xc0 softirqs last enabled at (5436): [] __irq_exit_rcu+0x11b/0x180 softirqs last disabled at (5425): [] __irq_exit_rcu+0x11b/0x180 CPU: 1 PID: 16938 Comm: syz-executor.3 Not tainted 6.0.0-rc1-next-20220822 #1 syz-executor.3[16938] cmdline: /syz-executor.3 exec Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x8b/0xb3 __might_resched.cold+0x222/0x26b down_read_killable+0x75/0x490 __access_remote_vm+0xac/0x6f0 get_mm_cmdline.part.0+0x214/0x600 get_task_cmdline_kernel+0x1e9/0x230 dump_stack_print_cmdline.part.0+0x82/0x150 dump_stack_print_info+0x185/0x190 dump_stack_lvl+0x7f/0xb3 check_noncircular+0x263/0x2e0 __lock_acquire+0x2a02/0x5e70 lock_acquire+0x1a2/0x530 down_read+0x98/0x450 ext4_bmap+0x4e/0x470 bmap+0xac/0x120 jbd2_journal_bmap+0xa8/0x180 jbd2_journal_flush+0x853/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ffa8e15db19 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:00007ffa8b6d3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffa8e270f60 RCX: 00007ffa8e15db19 RDX: 0000000020000340 RSI: 000000004004662b RDI: 0000000000000004 RBP: 00007ffa8e1b7f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdab2d85ff R14: 00007ffa8b6d3300 R15: 0000000000022000 syz-executor.3[16938] cmdline: /syz-executor.3 exec Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x8b/0xb3 check_noncircular+0x263/0x2e0 __lock_acquire+0x2a02/0x5e70 lock_acquire+0x1a2/0x530 down_read+0x98/0x450 ext4_bmap+0x4e/0x470 bmap+0xac/0x120 jbd2_journal_bmap+0xa8/0x180 jbd2_journal_flush+0x853/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ffa8e15db19 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:00007ffa8b6d3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffa8e270f60 RCX: 00007ffa8e15db19 RDX: 0000000020000340 RSI: 000000004004662b RDI: 0000000000000004 RBP: 00007ffa8e1b7f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdab2d85ff R14: 00007ffa8b6d3300 R15: 0000000000022000 warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow serio: Serial port tty33 warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow serio: Serial port tty33 warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow serio: Serial port tty23 serio: Serial port tty29 warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow serio: Serial port tty33 warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow serio: Serial port tty23 serio: Serial port tty29 serio: Serial port tty33 serio: Serial port tty23 serio: Serial port tty29