warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow ====================================================== WARNING: possible circular locking dependency detected 6.2.0-syzkaller-13563-gf915322fe014 #0 Not tainted ------------------------------------------------------ syz-executor.2/14040 is trying to acquire lock: ffff88801bad8400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline] ffff88801bad8400 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_bmap+0x52/0x470 fs/ext4/inode.c:3242 but task is already holding lock: ffff88814b1743f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x47f/0xc90 fs/jbd2/journal.c:2473 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_common kernel/locking/mutex.c:603 [inline] mutex_lock_io_nested+0x143/0x11a0 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x238/0x4b0 fs/jbd2/checkpoint.c:110 add_transaction_credits+0xa2d/0xb70 fs/jbd2/transaction.c:298 start_this_handle+0x3ae/0x14e0 fs/jbd2/transaction.c:422 jbd2__journal_start+0x39d/0x9d0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x706/0x890 fs/ext4/ext4_jbd2.c:111 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0xa5/0x130 fs/ext4/inode.c:6105 __mark_inode_dirty+0x247/0x1250 fs/fs-writeback.c:2421 mark_inode_dirty include/linux/fs.h:2127 [inline] generic_write_end+0x354/0x440 fs/buffer.c:2227 ext4_da_write_end+0x1f5/0xa50 fs/ext4/inode.c:3174 generic_perform_write+0x316/0x570 mm/filemap.c:3937 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:289 ext4_file_write_iter+0xbe0/0x1740 fs/ext4/file.c:710 call_write_iter include/linux/fs.h:1851 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 iter_file_splice_write+0x743/0xc80 fs/splice.c:778 do_splice_from fs/splice.c:856 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:1023 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:978 do_splice_direct+0x1ab/0x280 fs/splice.c:1066 do_sendfile+0xb19/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x14d/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&sb->s_type->i_mutex_key#8){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634 down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:768 [inline] ext4_bmap+0x52/0x470 fs/ext4/inode.c:3242 bmap+0xae/0x120 fs/inode.c:1799 jbd2_journal_bmap+0xac/0x1c0 fs/jbd2/journal.c:976 __jbd2_journal_erase fs/jbd2/journal.c:1788 [inline] jbd2_journal_flush+0x87b/0xc90 fs/jbd2/journal.c:2491 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1079 [inline] __ext4_ioctl+0xb3f/0x4c90 fs/ext4/ioctl.c:1587 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 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#8); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#8); *** DEADLOCK *** 2 locks held by syz-executor.2/14040: #0: ffff88814b174170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x162/0x310 fs/jbd2/transaction.c:904 #1: ffff88814b1743f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x47f/0xc90 fs/jbd2/journal.c:2473 stack backtrace: CPU: 0 PID: 14040 Comm: syz-executor.2 Not tainted 6.2.0-syzkaller-13563-gf915322fe014 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634 down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:768 [inline] ext4_bmap+0x52/0x470 fs/ext4/inode.c:3242 bmap+0xae/0x120 fs/inode.c:1799 jbd2_journal_bmap+0xac/0x1c0 fs/jbd2/journal.c:976 __jbd2_journal_erase fs/jbd2/journal.c:1788 [inline] jbd2_journal_flush+0x87b/0xc90 fs/jbd2/journal.c:2491 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1079 [inline] __ext4_ioctl+0xb3f/0x4c90 fs/ext4/ioctl.c:1587 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f099d08c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f099de4f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f099d1ac050 RCX: 00007f099d08c0f9 RDX: 0000000020000080 RSI: 000000004004662b RDI: 0000000000000006 RBP: 00007f099d0e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffda7efffdf R14: 00007f099de4f300 R15: 0000000000022000