syzbot

REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using tea hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/4436 is trying to acquire lock:
ffffc900034290f0 (&journal->j_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
ffffc900034290f0 (&journal->j_mutex){+.+.}-{3:3}, at: lock_journal fs/reiserfs/journal.c:534 [inline]
ffffc900034290f0 (&journal->j_mutex){+.+.}-{3:3}, at: do_journal_begin_r+0x37a/0x1040 fs/reiserfs/journal.c:3049

but task is already holding lock:
ffff888029522460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:446

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (sb_writers#13){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1891 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1966
       mnt_want_write_file+0x5c/0x200 fs/namespace.c:446
       reiserfs_ioctl+0x10a/0x330 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       reiserfs_write_lock_nested+0x5c/0xd0 fs/reiserfs/lock.c:78
       reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:815 [inline]
       lock_journal fs/reiserfs/journal.c:534 [inline]
       do_journal_begin_r+0x385/0x1040 fs/reiserfs/journal.c:3049
       journal_begin+0x148/0x350 fs/reiserfs/journal.c:3257
       reiserfs_fill_super+0x15e7/0x2340 fs/reiserfs/super.c:2104
       mount_bdev+0x287/0x3c0 fs/super.c:1443
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x24a/0xa40 fs/namespace.c:3078
       do_mount fs/namespace.c:3421 [inline]
       __do_sys_mount fs/namespace.c:3629 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3606
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&journal->j_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
       lock_journal fs/reiserfs/journal.c:534 [inline]
       do_journal_begin_r+0x37a/0x1040 fs/reiserfs/journal.c:3049
       journal_begin+0x148/0x350 fs/reiserfs/journal.c:3257
       reiserfs_dirty_inode+0x119/0x240 fs/reiserfs/super.c:710
       __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443
       mark_inode_dirty include/linux/fs.h:2546 [inline]
       reiserfs_ioctl+0x286/0x330 fs/reiserfs/ioctl.c:111
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &journal->j_mutex --> &sbi->lock --> sb_writers#13

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#13);
                               lock(&sbi->lock);
                               lock(sb_writers#13);
  lock(&journal->j_mutex);

 *** DEADLOCK ***

1 lock held by syz.0.17/4436:
 #0: ffff888029522460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:446

stack backtrace:
CPU: 1 PID: 4436 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
 reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
 lock_journal fs/reiserfs/journal.c:534 [inline]
 do_journal_begin_r+0x37a/0x1040 fs/reiserfs/journal.c:3049
 journal_begin+0x148/0x350 fs/reiserfs/journal.c:3257
 reiserfs_dirty_inode+0x119/0x240 fs/reiserfs/super.c:710
 __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443
 mark_inode_dirty include/linux/fs.h:2546 [inline]
 reiserfs_ioctl+0x286/0x330 fs/reiserfs/ioctl.c:111
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5cff18f6c9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc5d64a998 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5cff3e5fa0 RCX: 00007f5cff18f6c9
RDX: 0000200000000000 RSI: 0000000040087602 RDI: 0000000000000003
RBP: 00007f5cff211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5cff3e5fa0 R14: 00007f5cff3e5fa0 R15: 0000000000000003
 </TASK>