syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.131-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.225/5254 is trying to acquire lock:
ffff8880761da098 (&new->rf_sem){+.+.}-{3:3}, at: __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
ffff8880761da098 (&new->rf_sem){+.+.}-{3:3}, at: ocfs2_lock_refcount_tree+0x1fa/0xa60 fs/ocfs2/refcounttree.c:463

but task is already holding lock:
ffff8880716a3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_inode_lock_for_extent_tree+0x6d/0x180 fs/ocfs2/file.c:2208

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}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_read_virt_blocks+0x2dc/0xab0 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+0x45f/0x27a0 fs/ocfs2/dir.c:1091
       ocfs2_find_files_on_disk+0x10d/0x3a0 fs/ocfs2/dir.c:1995
       ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2017
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x35e/0x840 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x328/0x720 fs/ocfs2/super.c:457
       ocfs2_initialize_super fs/ocfs2/super.c:2250 [inline]
       ocfs2_fill_super+0x3022/0x5a60 fs/ocfs2/super.c:994
       mount_bdev+0x2c9/0x3f0 fs/super.c:1443
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
       do_mount fs/namespace.c:3399 [inline]
       __do_sys_mount fs/namespace.c:3607 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&osb->system_file_mutex){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       ocfs2_get_system_file_inode+0x1ac/0x840 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_suballoc_bits+0x167/0x5190 fs/ocfs2/suballoc.c:776
       ocfs2_reserve_new_metadata_blocks+0x418/0x9b0 fs/ocfs2/suballoc.c:978
       ocfs2_add_refcount_flag+0x4a9/0x1220 fs/ocfs2/refcounttree.c:3683
       ocfs2_reflink_remap_extent fs/ocfs2/refcounttree.c:4563 [inline]
       ocfs2_reflink_remap_blocks+0xe53/0x1f20 fs/ocfs2/refcounttree.c:4690
       ocfs2_remap_file_range+0x5f2/0x8d0 fs/ocfs2/file.c:2703
       vfs_copy_file_range+0x10d6/0x1640 fs/read_write.c:1518
       __do_sys_copy_file_range fs/read_write.c:1596 [inline]
       __se_sys_copy_file_range+0x3ea/0x5d0 fs/read_write.c:1559
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&new->rf_sem){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
       ocfs2_lock_refcount_tree+0x1fa/0xa60 fs/ocfs2/refcounttree.c:463
       ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3415 [inline]
       ocfs2_refcount_cow+0x798/0x1250 fs/ocfs2/refcounttree.c:3476
       ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline]
       ocfs2_file_write_iter+0x10c9/0x2280 fs/ocfs2/file.c:2451
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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 ***

4 locks held by syz.2.225/5254:
 #0: ffff888020fbb9e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1032
 #1: ffff888054998460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #2: ffff8880716a3488 (&sb->s_type->i_mutex_key#30){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff8880716a3488 (&sb->s_type->i_mutex_key#30){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x454/0x2280 fs/ocfs2/file.c:2399
 #3: ffff8880716a3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_inode_lock_for_extent_tree+0x6d/0x180 fs/ocfs2/file.c:2208

stack backtrace:
CPU: 1 PID: 5254 Comm: syz.2.225 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 __ocfs2_lock_refcount_tree fs/ocfs2/refcounttree.c:428 [inline]
 ocfs2_lock_refcount_tree+0x1fa/0xa60 fs/ocfs2/refcounttree.c:463
 ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3415 [inline]
 ocfs2_refcount_cow+0x798/0x1250 fs/ocfs2/refcounttree.c:3476
 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline]
 ocfs2_file_write_iter+0x10c9/0x2280 fs/ocfs2/file.c:2451
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5259b8d169
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:00007f525a9f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5259da5fa0 RCX: 00007f5259b8d169
RDX: 0000000000000002 RSI: 0000400000000080 RDI: 0000000000000004
RBP: 00007f5259c0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5259da5fa0 R15: 00007fffc1fa1ed8
 </TASK>