warning: checkpointing journal with EXT4_IOC_CHECKPOINT_FLAG_ZEROOUT can be slow ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/4599 is trying to acquire lock: ffff88814caa8170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x2d1/0x390 fs/jbd2/transaction.c:905 but task is already holding lock: ffff88814caa6bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_change_inode_journal_flag+0x194/0x6b0 fs/ext4/inode.c:6105 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_write+0x52/0x2f0 kernel/locking/percpu-rwsem.c:217 ext4_change_inode_journal_flag+0x194/0x6b0 fs/ext4/inode.c:6105 ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline] ext4_fileattr_set+0xe5a/0x1750 fs/ext4/ioctl.c:765 vfs_fileattr_set+0x859/0xb10 fs/ioctl.c:700 ioctl_setflags fs/ioctl.c:732 [inline] do_vfs_ioctl+0x186a/0x1ef0 fs/ioctl.c:843 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x83/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #3 (mapping.invalidate_lock){++++}-{3:3}: down_write+0x38/0x60 kernel/locking/rwsem.c:1551 filemap_invalidate_lock include/linux/fs.h:832 [inline] ext4_setattr+0xdb6/0x19e0 fs/ext4/inode.c:5524 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (&sb->s_type->i_mutex_key#9){++++}-{3:3}: down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 inode_lock_shared include/linux/fs.h:797 [inline] ext4_bmap+0x4d/0x3f0 fs/ext4/inode.c:3164 bmap+0xa2/0xd0 fs/inode.c:1820 jbd2_journal_bmap fs/jbd2/journal.c:981 [inline] __jbd2_journal_erase fs/jbd2/journal.c:1795 [inline] jbd2_journal_flush+0x655/0xcc0 fs/jbd2/journal.c:2515 ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline] __ext4_ioctl fs/ext4/ioctl.c:1273 [inline] ext4_ioctl+0x3100/0x3820 fs/ext4/ioctl.c:1282 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 mutex_lock_io_nested+0x43/0x60 kernel/locking/mutex.c:777 jbd2_journal_flush+0x284/0xcc0 fs/jbd2/journal.c:2487 ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline] __ext4_ioctl fs/ext4/ioctl.c:1273 [inline] ext4_ioctl+0x3100/0x3820 fs/ext4/ioctl.c:1282 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&journal->j_barrier){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 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+0x2d1/0x390 fs/jbd2/transaction.c:905 ext4_change_inode_journal_flag+0x19c/0x6b0 fs/ext4/inode.c:6106 ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline] ext4_fileattr_set+0xe5a/0x1750 fs/ext4/ioctl.c:765 vfs_fileattr_set+0x859/0xb10 fs/ioctl.c:700 ioctl_setflags fs/ioctl.c:732 [inline] do_vfs_ioctl+0x186a/0x1ef0 fs/ioctl.c:843 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x83/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &journal->j_barrier --> mapping.invalidate_lock --> &sbi->s_writepages_rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(mapping.invalidate_lock); lock(&sbi->s_writepages_rwsem); lock(&journal->j_barrier); *** DEADLOCK *** 4 locks held by syz-executor.0/4599: #0: ffff88814caa4460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:430 #1: ffff8880668d97e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff8880668d97e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: vfs_fileattr_set+0x150/0xb10 fs/ioctl.c:685 #2: ffff8880668d9980 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:832 [inline] #2: ffff8880668d9980 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_change_inode_journal_flag+0x116/0x6b0 fs/ext4/inode.c:6097 #3: ffff88814caa6bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_change_inode_journal_flag+0x194/0x6b0 fs/ext4/inode.c:6105 stack backtrace: CPU: 0 PID: 4599 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 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 kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 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+0x2d1/0x390 fs/jbd2/transaction.c:905 ext4_change_inode_journal_flag+0x19c/0x6b0 fs/ext4/inode.c:6106 ext4_ioctl_setflags fs/ext4/ioctl.c:448 [inline] ext4_fileattr_set+0xe5a/0x1750 fs/ext4/ioctl.c:765 vfs_fileattr_set+0x859/0xb10 fs/ioctl.c:700 ioctl_setflags fs/ioctl.c:732 [inline] do_vfs_ioctl+0x186a/0x1ef0 fs/ioctl.c:843 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x83/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc7e78ed0f9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc7e6c7e0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc7e7a2bf80 RCX: 00007fc7e78ed0f9 RDX: 0000000020000380 RSI: 0000000040086602 RDI: 0000000000000004 RBP: 00007fc7e794e498 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc7e7a2bf80 R15: 00007ffe60e1b528