syzbot

loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Not tainted
------------------------------------------------------
syz-executor374/5119 is trying to acquire lock:
ffff88803cfbd5a8 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101

but task is already holding lock:
ffff888041af3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2800 [inline]
ffff888041af3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x7f4/0x53d0 fs/ocfs2/dir.c:3181

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}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
       ocfs2_read_virt_blocks+0x2ca/0xa50 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+0x43b/0x2780 fs/ocfs2/dir.c:1080
       ocfs2_find_files_on_disk+0xff/0x360 fs/ocfs2/dir.c:1980
       ocfs2_lookup_ino_from_name+0xb1/0x1e0 fs/ocfs2/dir.c:2002
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x305/0x7b0 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x32c/0x730 fs/ocfs2/super.c:457
       ocfs2_initialize_super fs/ocfs2/super.c:2250 [inline]
       ocfs2_fill_super+0x3068/0x5880 fs/ocfs2/super.c:994
       mount_bdev+0x20a/0x2d0 fs/super.c:1679
       legacy_get_tree+0xee/0x190 fs/fs_context.c:662
       vfs_get_tree+0x90/0x2b0 fs/super.c:1800
       do_new_mount+0x2be/0xb40 fs/namespace.c:3472
       do_mount fs/namespace.c:3812 [inline]
       __do_sys_mount fs/namespace.c:4020 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&osb->system_file_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
       __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_suballoc_bits+0x16f/0x4eb0 fs/ocfs2/suballoc.c:780
       ocfs2_reserve_new_metadata_blocks+0x41c/0x9c0 fs/ocfs2/suballoc.c:982
       ocfs2_expand_inline_dir fs/ocfs2/dir.c:2819 [inline]
       ocfs2_extend_dir+0xdef/0x53d0 fs/ocfs2/dir.c:3181
       ocfs2_prepare_dir_for_insert+0x33d1/0x5c70 fs/ocfs2/dir.c:4296
       ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3578 [inline]
       open_last_lookups fs/namei.c:3647 [inline]
       path_openat+0x1a9a/0x3470 fs/namei.c:3883
       do_filp_open+0x235/0x490 fs/namei.c:3913
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
       do_sys_open fs/open.c:1431 [inline]
       __do_sys_openat fs/open.c:1447 [inline]
       __se_sys_openat fs/open.c:1442 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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-executor374/5119:
 #0: ffff88801df7a420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
 #1: ffff888041af3480 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:800 [inline]
 #1: ffff888041af3480 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3644 [inline]
 #1: ffff888041af3480 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: path_openat+0x7fb/0x3470 fs/namei.c:3883
 #2: ffff888041af3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_expand_inline_dir fs/ocfs2/dir.c:2800 [inline]
 #2: ffff888041af3120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_extend_dir+0x7f4/0x53d0 fs/ocfs2/dir.c:3181

stack backtrace:
CPU: 0 UID: 0 PID: 5119 Comm: syz-executor374 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 ocfs2_get_system_file_inode+0x18f/0x7b0 fs/ocfs2/sysfile.c:101
 ocfs2_reserve_suballoc_bits+0x16f/0x4eb0 fs/ocfs2/suballoc.c:780
 ocfs2_reserve_new_metadata_blocks+0x41c/0x9c0 fs/ocfs2/suballoc.c:982
 ocfs2_expand_inline_dir fs/ocfs2/dir.c:2819 [inline]
 ocfs2_extend_dir+0xdef/0x53d0 fs/ocfs2/dir.c:3181
 ocfs2_prepare_dir_for_insert+0x33d1/0x5c70 fs/ocfs2/dir.c:4296
 ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
 ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
 lookup_open fs/namei.c:3578 [inline]
 open_last_lookups fs/namei.c:3647 [inline]
 path_openat+0x1a9a/0x3470 fs/namei.c:3883
 do_filp_open+0x235/0x490 fs/namei.c:3913
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f34dbe662e9
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:00007ffc417f6f18 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f34dbe662e9
RDX: 0000000000105042 RSI: 0000000020000340 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007ffc417f6f50 R09: 00007ffc417f6f50
R10: 00000000000001db R11: 0000000000000246 R12: 00007ffc417f6f3c
R13: 0000000000000006 R14: 431bde82d7b634db R15: 00007ffc417f6f70
 </TASK>