syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.189-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.71/4623 is trying to acquire lock:
ffff888079223898 (&new->rf_sem){+.+.}-{3:3}, at: __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
ffff888079223898 (&new->rf_sem){+.+.}-{3:3}, at: ocfs2_lock_refcount_tree+0x1c0/0x980 fs/ocfs2/refcounttree.c:463

but task is already holding lock:
ffff88805e14b120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x326/0x13b0 fs/ocfs2/file.c:467

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ocfs2_read_virt_blocks+0x23f/0x8a0 fs/ocfs2/extent_map.c:976
       ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
       ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
       ocfs2_find_entry+0x3d1/0x1f90 fs/ocfs2/dir.c:1091
       ocfs2_find_files_on_disk+0xdb/0x2f0 fs/ocfs2/dir.c:1995
       ocfs2_lookup_ino_from_name+0x4f/0xf0 fs/ocfs2/dir.c:2017
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x319/0x760 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x316/0x650 fs/ocfs2/super.c:458
       ocfs2_initialize_super fs/ocfs2/super.c:2279 [inline]
       ocfs2_fill_super+0x3dbf/0x4d80 fs/ocfs2/super.c:995
       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:3014
       do_mount fs/namespace.c:3357 [inline]
       __do_sys_mount fs/namespace.c:3565 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3542
       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 (&osb->system_file_mutex){+.+.}-{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
       ocfs2_get_system_file_inode+0x1b5/0x760 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_suballoc_bits+0x139/0x4350 fs/ocfs2/suballoc.c:776
       ocfs2_reserve_new_metadata_blocks+0x400/0x940 fs/ocfs2/suballoc.c:978
       ocfs2_add_refcount_flag+0x36e/0xd80 fs/ocfs2/refcounttree.c:3711
       ocfs2_reflink_remap_extent fs/ocfs2/refcounttree.c:4591 [inline]
       ocfs2_reflink_remap_blocks+0xd2c/0x1930 fs/ocfs2/refcounttree.c:4718
       ocfs2_remap_file_range+0x4aa/0x720 fs/ocfs2/file.c:2706
       vfs_copy_file_range+0xce7/0x1470 fs/read_write.c:1510
       __do_sys_copy_file_range fs/read_write.c:1588 [inline]
       __se_sys_copy_file_range+0x31d/0x480 fs/read_write.c:1551
       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 (&new->rf_sem){+.+.}-{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
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
       ocfs2_lock_refcount_tree+0x1c0/0x980 fs/ocfs2/refcounttree.c:463
       ocfs2_commit_truncate+0xa61/0x1b30 fs/ocfs2/alloc.c:7339
       ocfs2_truncate_file+0xca4/0x13b0 fs/ocfs2/file.c:505
       ocfs2_setattr+0x143b/0x1a10 fs/ocfs2/file.c:1215
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x197/0x220 fs/open.c:65
       handle_truncate fs/namei.c:3265 [inline]
       do_open fs/namei.c:3612 [inline]
       path_openat+0x28af/0x2f30 fs/namei.c:3742
       do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
       do_sys_openat2+0x142/0x4a0 fs/open.c:1253
       do_sys_open fs/open.c:1269 [inline]
       __do_sys_creat fs/open.c:1345 [inline]
       __se_sys_creat fs/open.c:1339 [inline]
       __x64_sys_creat+0x8c/0xb0 fs/open.c:1339
       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:
  &new->rf_sem --> &osb->system_file_mutex --> &ocfs2_file_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_file_ip_alloc_sem_key);
                               lock(&osb->system_file_mutex);
                               lock(&ocfs2_file_ip_alloc_sem_key);
  lock(&new->rf_sem);

 *** DEADLOCK ***

3 locks held by syz.0.71/4623:
 #0: ffff888024570460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377
 #1: ffff88805e14b488 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805e14b488 (&sb->s_type->i_mutex_key#27){+.+.}-{3:3}, at: do_truncate+0x183/0x220 fs/open.c:63
 #2: ffff88805e14b120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_truncate_file+0x326/0x13b0 fs/ocfs2/file.c:467

stack backtrace:
CPU: 0 PID: 4623 Comm: syz.0.71 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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
 down_write+0x38/0x60 kernel/locking/rwsem.c:1551
 __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
 ocfs2_lock_refcount_tree+0x1c0/0x980 fs/ocfs2/refcounttree.c:463
 ocfs2_commit_truncate+0xa61/0x1b30 fs/ocfs2/alloc.c:7339
 ocfs2_truncate_file+0xca4/0x13b0 fs/ocfs2/file.c:505
 ocfs2_setattr+0x143b/0x1a10 fs/ocfs2/file.c:1215
 notify_change+0xbcd/0xee0 fs/attr.c:505
 do_truncate+0x197/0x220 fs/open.c:65
 handle_truncate fs/namei.c:3265 [inline]
 do_open fs/namei.c:3612 [inline]
 path_openat+0x28af/0x2f30 fs/namei.c:3742
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_creat fs/open.c:1345 [inline]
 __se_sys_creat fs/open.c:1339 [inline]
 __x64_sys_creat+0x8c/0xb0 fs/open.c:1339
 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: 0033:0x7f40378bebe9
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:00007f4035ae4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f4037ae6180 RCX: 00007f40378bebe9
RDX: 0000000000000000 RSI: 000000000000000d RDI: 0000200000000240
RBP: 00007f4037941e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4037ae6218 R14: 00007f4037ae6180 R15: 00007ffffb157ac8
 </TASK>