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
5.15.185-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor428/4166 is trying to acquire lock:
ffffc90002e910f0 (&journal->j_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
ffffc90002e910f0 (&journal->j_mutex){+.+.}-{3:3}, at: lock_journal fs/reiserfs/journal.c:534 [inline]
ffffc90002e910f0 (&journal->j_mutex){+.+.}-{3:3}, at: do_journal_begin_r+0x37a/0x1010 fs/reiserfs/journal.c:3045

but task is already holding lock:
ffff88801abd0460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:421

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (sb_writers#9){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1811 [inline]
       sb_start_write+0x4f/0x1c0 include/linux/fs.h:1881
       mnt_want_write_file+0x5c/0x200 fs/namespace.c:421
       reiserfs_ioctl+0x10a/0x330 fs/reiserfs/ioctl.c:103
       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 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       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+0x385/0x1010 fs/reiserfs/journal.c:3045
       journal_begin+0x148/0x350 fs/reiserfs/journal.c:3253
       reiserfs_fill_super+0x1654/0x23e0 fs/reiserfs/super.c:2108
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3010
       do_mount fs/namespace.c:3353 [inline]
       __do_sys_mount fs/namespace.c:3561 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3538
       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_mutex){+.+.}-{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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
       lock_journal fs/reiserfs/journal.c:534 [inline]
       do_journal_begin_r+0x37a/0x1010 fs/reiserfs/journal.c:3045
       journal_begin+0x148/0x350 fs/reiserfs/journal.c:3253
       reiserfs_dirty_inode+0x119/0x240 fs/reiserfs/super.c:710
       __mark_inode_dirty+0x2b0/0xc60 fs/fs-writeback.c:2464
       mark_inode_dirty include/linux/fs.h:2467 [inline]
       reiserfs_ioctl+0x286/0x330 fs/reiserfs/ioctl.c:111
       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

other info that might help us debug this:

Chain exists of:
  &journal->j_mutex --> &sbi->lock --> sb_writers#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#9);
                               lock(&sbi->lock);
                               lock(sb_writers#9);
  lock(&journal->j_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor428/4166:
 #0: ffff88801abd0460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write_file+0x5c/0x200 fs/namespace.c:421

stack backtrace:
CPU: 0 PID: 4166 Comm: syz-executor428 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:814 [inline]
 lock_journal fs/reiserfs/journal.c:534 [inline]
 do_journal_begin_r+0x37a/0x1010 fs/reiserfs/journal.c:3045
 journal_begin+0x148/0x350 fs/reiserfs/journal.c:3253
 reiserfs_dirty_inode+0x119/0x240 fs/reiserfs/super.c:710
 __mark_inode_dirty+0x2b0/0xc60 fs/fs-writeback.c:2464
 mark_inode_dirty include/linux/fs.h:2467 [inline]
 reiserfs_ioctl+0x286/0x330 fs/reiserfs/ioctl.c:111
 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
RIP: 0033:0x7f524e0f9649
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 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:00007ffd83229dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffd83229f98 RCX: 00007f524e0f9649
RDX: 0000200000000000 RSI: 0000000040087602 RDI: 0000000000000003