syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.156-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor854/3498 is trying to acquire lock:
ffff8880122803f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline]
ffff8880122803f0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152

but task is already holding lock:
ffff88814b2723f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2478

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       mutex_lock_io_nested+0x45/0x60 kernel/locking/mutex.c:777
       jbd2_journal_flush+0x290/0xc90 fs/jbd2/journal.c:2468
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
       ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #3 (&journal->j_barrier){+.+.}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       jbd2_journal_lock_updates+0x2aa/0x370 fs/jbd2/transaction.c:905
       ext4_change_inode_journal_flag+0x1a8/0x6e0 fs/ext4/inode.c:6041
       ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline]
       ext4_fileattr_set+0xdf4/0x1750 fs/ext4/ioctl.c:765
       vfs_fileattr_set+0x8f3/0xd30 fs/ioctl.c:700
       ioctl_setflags fs/ioctl.c:732 [inline]
       do_vfs_ioctl+0x1d85/0x2b70 fs/ioctl.c:843
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #2 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       percpu_down_write+0x52/0x2d0 kernel/locking/percpu-rwsem.c:217
       ext4_change_inode_journal_flag+0x1a0/0x6e0 fs/ext4/inode.c:6040
       ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline]
       ext4_fileattr_set+0xdf4/0x1750 fs/ext4/ioctl.c:765
       vfs_fileattr_set+0x8f3/0xd30 fs/ioctl.c:700
       ioctl_setflags fs/ioctl.c:732 [inline]
       do_vfs_ioctl+0x1d85/0x2b70 fs/ioctl.c:843
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (mapping.invalidate_lock){++++}-{3:3}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       filemap_invalidate_lock include/linux/fs.h:834 [inline]
       ext4_setattr+0xd6c/0x1990 fs/ext4/inode.c:5459
       notify_change+0xc6d/0xf50 fs/attr.c:505
       do_truncate+0x21c/0x300 fs/open.c:65
       do_sys_ftruncate+0x2eb/0x390 fs/open.c:193
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
       inode_lock_shared include/linux/fs.h:799 [inline]
       ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152
       bmap+0xa1/0xd0 fs/inode.c:1756
       jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
       __jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
       jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2496
       ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
       ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#9 --> &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#9);

 *** DEADLOCK ***

2 locks held by syz-executor854/3498:
 #0: ffff88814b272170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x2aa/0x370 fs/jbd2/transaction.c:905
 #1: ffff88814b2723f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x31c/0xc90 fs/jbd2/journal.c:2478

stack backtrace:
CPU: 1 PID: 3498 Comm: syz-executor854 Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
 inode_lock_shared include/linux/fs.h:799 [inline]
 ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152
 bmap+0xa1/0xd0 fs/inode.c:1756
 jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
 __jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
 jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2496
 ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
 __ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
 ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2227d21369
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe6a728b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0073746e6576652e RCX: 00007f2227d21369
RDX: 0000000020000000 RSI: 000000004004662b RDI: 0000000000000005
RBP: 652e79726f6d656d R08: 00000000000ac5f8 R09: 00000000000ac5f8
R10: 00000000000ac5f8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe6a728d58 R14: 0000000000000001 R15: 0000000000000001