Kernel bug: possible deadlock in ocfs2_try_remove_refcount_tree
Subsystem: ocfs2
Status: open

Crash report:
         option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5994 is trying to acquire lock:
ffff888049705b90 (&oi->ip_alloc_sem){+.+.}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xb6/0x320 fs/ocfs2/refcounttree.c:933

but task is already holding lock:
ffff888049705c18 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xa4/0x320 fs/ocfs2/refcounttree.c:932

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&oi->ip_xattr_sem){++++}-{4:4}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
       ocfs2_xattr_set_handle+0x3b0/0x7a0 fs/ocfs2/xattr.c:3531
       ocfs2_init_security_set+0xbd/0xe0 fs/ocfs2/xattr.c:7337
       ocfs2_mknod+0x135d/0x2030 fs/ocfs2/namei.c:423
       ocfs2_create+0x195/0x420 fs/ocfs2/namei.c:677
       lookup_open fs/namei.c:4440 [inline]
       open_last_lookups fs/namei.c:4540 [inline]
       path_openat+0x18d1/0x3df0 fs/namei.c:4784
       do_filp_open+0x1fa/0x410 fs/namei.c:4814
       do_sys_openat2+0x121/0x200 fs/open.c:1430
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_openat fs/open.c:1452 [inline]
       __se_sys_openat fs/open.c:1447 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1447
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
       down_read+0x97/0x1f0 kernel/locking/rwsem.c:1537
       ocfs2_start_trans+0x36b/0x6d0 fs/ocfs2/journal.c:372
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:686 [inline]
       ocfs2_reserve_suballoc_bits+0x722/0x4600 fs/ocfs2/suballoc.c:835
       ocfs2_reserve_new_metadata_blocks+0x403/0x940 fs/ocfs2/suballoc.c:985
       ocfs2_mknod+0xde6/0x2030 fs/ocfs2/namei.c:351
       ocfs2_create+0x195/0x420 fs/ocfs2/namei.c:677
       lookup_open fs/namei.c:4440 [inline]
       open_last_lookups fs/namei.c:4540 [inline]
       path_openat+0x18d1/0x3df0 fs/namei.c:4784
       do_filp_open+0x1fa/0x410 fs/namei.c:4814
       do_sys_openat2+0x121/0x200 fs/open.c:1430
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_openat fs/open.c:1452 [inline]
       __se_sys_openat fs/open.c:1447 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1447
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (sb_internal#2){.+.+}-{0:0}:
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
       __sb_start_write include/linux/fs/super.h:19 [inline]
       sb_start_intwrite include/linux/fs/super.h:177 [inline]
       ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:370
       ocfs2_orphan_for_truncate fs/ocfs2/file.c:396 [inline]
       ocfs2_truncate_file+0x611/0x13e0 fs/ocfs2/file.c:500
       ocfs2_setattr+0x155e/0x1bb0 fs/ocfs2/file.c:1218
       notify_change+0xc18/0xf60 fs/attr.c:546
       do_truncate+0x1a4/0x220 fs/open.c:68
       handle_truncate fs/namei.c:4235 [inline]
       do_open fs/namei.c:4632 [inline]
       path_openat+0x35b9/0x3df0 fs/namei.c:4787
       do_filp_open+0x1fa/0x410 fs/namei.c:4814
       do_sys_openat2+0x121/0x200 fs/open.c:1430
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_openat fs/open.c:1452 [inline]
       __se_sys_openat fs/open.c:1447 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1447
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&oi->ip_alloc_sem){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
       ocfs2_try_remove_refcount_tree+0xb6/0x320 fs/ocfs2/refcounttree.c:933
       ocfs2_truncate_file+0xd92/0x13e0 fs/ocfs2/file.c:521
       ocfs2_setattr+0x155e/0x1bb0 fs/ocfs2/file.c:1218
       notify_change+0xc18/0xf60 fs/attr.c:546
       do_truncate+0x1a4/0x220 fs/open.c:68
       handle_truncate fs/namei.c:4235 [inline]
       do_open fs/namei.c:4632 [inline]
       path_openat+0x35b9/0x3df0 fs/namei.c:4787
       do_filp_open+0x1fa/0x410 fs/namei.c:4814
       do_sys_openat2+0x121/0x200 fs/open.c:1430
       do_sys_open fs/open.c:1436 [inline]
       __do_sys_openat fs/open.c:1452 [inline]
       __se_sys_openat fs/open.c:1447 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1447
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &oi->ip_alloc_sem --> &journal->j_trans_barrier --> &oi->ip_xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&oi->ip_xattr_sem);
                               lock(&journal->j_trans_barrier);
                               lock(&oi->ip_xattr_sem);
  lock(&oi->ip_alloc_sem);

 *** DEADLOCK ***

3 locks held by syz.0.17/5994:
 #0: ffff88803cd74480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
 #1: ffff888049705f40 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1032 [inline]
 #1: ffff888049705f40 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: do_truncate+0x171/0x220 fs/open.c:63
 #2: ffff888049705c18 (&oi->ip_xattr_sem){++++}-{4:4}, at: ocfs2_try_remove_refcount_tree+0xa4/0x320 fs/ocfs2/refcounttree.c:932

stack backtrace:
CPU: 1 UID: 0 PID: 5994 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
 down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
 ocfs2_try_remove_refcount_tree+0xb6/0x320 fs/ocfs2/refcounttree.c:933
 ocfs2_truncate_file+0xd92/0x13e0 fs/ocfs2/file.c:521
 ocfs2_setattr+0x155e/0x1bb0 fs/ocfs2/file.c:1218
 notify_change+0xc18/0xf60 fs/attr.c:546
 do_truncate+0x1a4/0x220 fs/open.c:68
 handle_truncate fs/namei.c:4235 [inline]
 do_open fs/namei.c:4632 [inline]
 path_openat+0x35b9/0x3df0 fs/namei.c:4787
 do_filp_open+0x1fa/0x410 fs/namei.c:4814
 do_sys_openat2+0x121/0x200 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9ceccf749
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:00007ffc78374c28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff9cef25fa0 RCX: 00007ff9ceccf749
RDX: 0000000000007a05 RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007ff9ced53f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001700 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff9cef25fa0 R14: 00007ff9cef25fa0 R15: 0000000000000004
 </TASK>