syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.116-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor246/4381 is trying to acquire lock:
ffff88806e0d22e0 (&ocfs2_file_ip_alloc_sem_key/1){+.+.}-{3:3}, at: ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2688

but task is already holding lock:
ffff88806e0bea20 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2686

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+0x436/0x28c0 fs/ocfs2/dir.c:1080
       ocfs2_find_files_on_disk+0x10d/0x3a0 fs/ocfs2/dir.c:1982
       ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x314/0x7b0 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+0x2f82/0x5730 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+0x1a1/0x7b0 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_create_refcount_tree+0x33c/0x15b0 fs/ocfs2/refcounttree.c:571
       ocfs2_reflink_remap_blocks+0x2f2/0x1f20 fs/ocfs2/refcounttree.c:4655
       ocfs2_remap_file_range+0x5f2/0x8d0 fs/ocfs2/file.c:2696
       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 (&ocfs2_file_ip_alloc_sem_key/1){+.+.}-{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_nested+0x39/0x60 kernel/locking/rwsem.c:1689
       ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2688
       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

other info that might help us debug this:

Chain exists of:
  &ocfs2_file_ip_alloc_sem_key/1 --> &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(&ocfs2_file_ip_alloc_sem_key/1);

 *** DEADLOCK ***

4 locks held by syz-executor246/4381:
 #0: ffff888073122460 (sb_writers#9){.+.+}-{0:0}, at: vfs_copy_file_range+0x981/0x1640 fs/read_write.c:1502
 #1: ffff88806e0bed88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88806e0bed88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: lock_two_nondirectories+0xde/0x130 fs/inode.c:1204
 #2: ffff88806e0d2648 (&sb->s_type->i_mutex_key#15/4){+.+.}-{3:3}, at: ocfs2_reflink_inodes_lock+0x164/0xec0 fs/ocfs2/refcounttree.c:4723
 #3: ffff88806e0bea20 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_remap_file_range+0x45c/0x8d0 fs/ocfs2/file.c:2686

stack backtrace:
CPU: 1 PID: 4381 Comm: syz-executor246 Not tainted 6.1.116-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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_nested+0x39/0x60 kernel/locking/rwsem.c:1689
 ocfs2_remap_file_range+0x488/0x8d0 fs/ocfs2/file.c:2688
 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
RIP: 0033:0x7fa8866491e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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:00007fffdd187398 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007fa8866491e9
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00007fffdd1873cc
R13: 000000000000002a R14: 431bde82d7b634db R15: 00007fffdd187400
 </TASK>
(syz-executor246,4381,1):ocfs2_get_clusters:606 ERROR: status = -34
(syz-executor246,4381,1):ocfs2_reflink_remap_extent:4534 ERROR: status = -34
(syz-executor246,4381,1):ocfs2_reflink_remap_blocks:4693 ERROR: status = -34
(syz-executor246,4381,1):ocfs2_remap_file_range:2703 ERROR: status = -34