syzbot

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ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
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WARNING: possible circular locking dependency detected
5.15.189-syzkaller #0 Not tainted
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syz.0.17/4342 is trying to acquire lock:
ffff88807d9dd488 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x1b5/0x760 fs/ocfs2/sysfile.c:101

but task is already holding lock:
ffff88805c838660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2819 [inline]
ffff88805c838660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x64b/0x4870 fs/ocfs2/dir.c:3200

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&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

-> #0 (&osb->system_file_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
       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_expand_inline_dir fs/ocfs2/dir.c:2838 [inline]
       ocfs2_extend_dir+0xc5c/0x4870 fs/ocfs2/dir.c:3200
       ocfs2_prepare_dir_for_insert+0x2e0a/0x5240 fs/ocfs2/dir.c:4321
       ocfs2_mknod+0x864/0x22b0 fs/ocfs2/namei.c:294
       ocfs2_create+0x192/0x410 fs/ocfs2/namei.c:674
       vfs_create+0x2db/0x460 fs/namei.c:3162
       do_mknodat+0x39d/0x620 fs/namei.c:3994
       __do_sys_mknod fs/namei.c:4027 [inline]
       __se_sys_mknod fs/namei.c:4025 [inline]
       __x64_sys_mknod+0x8a/0xa0 fs/namei.c:4025
       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:

 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(&osb->system_file_mutex);

 *** DEADLOCK ***

3 locks held by syz.0.17/4342:
 #0: ffff888074c74460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377
 #1: ffff88805c8389c8 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88805c8389c8 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3835
 #2: ffff88805c838660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2819 [inline]
 #2: ffff88805c838660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x64b/0x4870 fs/ocfs2/dir.c:3200

stack backtrace:
CPU: 1 PID: 4342 Comm: syz.0.17 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
 __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_expand_inline_dir fs/ocfs2/dir.c:2838 [inline]
 ocfs2_extend_dir+0xc5c/0x4870 fs/ocfs2/dir.c:3200
 ocfs2_prepare_dir_for_insert+0x2e0a/0x5240 fs/ocfs2/dir.c:4321
 ocfs2_mknod+0x864/0x22b0 fs/ocfs2/namei.c:294
 ocfs2_create+0x192/0x410 fs/ocfs2/namei.c:674
 vfs_create+0x2db/0x460 fs/namei.c:3162
 do_mknodat+0x39d/0x620 fs/namei.c:3994
 __do_sys_mknod fs/namei.c:4027 [inline]
 __se_sys_mknod fs/namei.c:4025 [inline]
 __x64_sys_mknod+0x8a/0xa0 fs/namei.c:4025
 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: 0033:0x7f36ca6c3be9
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:00007fff0f2c7248 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f36ca8eafa0 RCX: 00007f36ca6c3be9
RDX: 0000000000000701 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f36ca746e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36ca8eafa0 R14: 00007f36ca8eafa0 R15: 0000000000000003
 </TASK>
syz.0.17 (4342) used greatest stack depth: 19056 bytes left