syzbot

         option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/6106 is trying to acquire lock:
ffff8880291b18d0 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xb0/0x130 mm/memory.c:6958

but task is already holding lock:
ffff888047fd07d0 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_fiemap+0x2b0/0xc90 fs/ocfs2/extent_map.c:765

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&oi->ip_alloc_sem){++++}-{4:4}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
       ocfs2_page_mkwrite+0x301/0xc50 fs/ocfs2/mmap.c:142
       do_page_mkwrite+0x14d/0x310 mm/memory.c:3361
       do_shared_fault mm/memory.c:5649 [inline]
       do_fault mm/memory.c:5711 [inline]
       do_pte_missing mm/memory.c:4234 [inline]
       handle_pte_fault mm/memory.c:6052 [inline]
       __handle_mm_fault mm/memory.c:6195 [inline]
       handle_mm_fault+0x124b/0x3400 mm/memory.c:6364
       do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
       handle_page_fault arch/x86/mm/fault.c:1476 [inline]
       exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #1 (sb_pagefaults#2){.+.+}-{0:0}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
       __sb_start_write include/linux/fs.h:1798 [inline]
       sb_start_pagefault include/linux/fs.h:1963 [inline]
       ocfs2_page_mkwrite+0x1dc/0xc50 fs/ocfs2/mmap.c:122
       do_page_mkwrite+0x14d/0x310 mm/memory.c:3361
       do_shared_fault mm/memory.c:5649 [inline]
       do_fault mm/memory.c:5711 [inline]
       do_pte_missing mm/memory.c:4234 [inline]
       handle_pte_fault mm/memory.c:6052 [inline]
       __handle_mm_fault mm/memory.c:6195 [inline]
       handle_mm_fault+0x124b/0x3400 mm/memory.c:6364
       do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387
       handle_page_fault arch/x86/mm/fault.c:1476 [inline]
       exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __might_fault+0xcc/0x130 mm/memory.c:6958
       _inline_copy_to_user include/linux/uaccess.h:192 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:225 [inline]
       fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145
       ocfs2_fiemap+0x888/0xc90 fs/ocfs2/extent_map.c:806
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x1188/0x1440 fs/ioctl.c:532
       __do_sys_ioctl fs/ioctl.c:596 [inline]
       __se_sys_ioctl+0x82/0x170 fs/ioctl.c:584
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> sb_pagefaults#2 --> &oi->ip_alloc_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&oi->ip_alloc_sem);
                               lock(sb_pagefaults#2);
                               lock(&oi->ip_alloc_sem);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz.0.17/6106:
 #0: ffff888047fd07d0 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_fiemap+0x2b0/0xc90 fs/ocfs2/extent_map.c:765

stack backtrace:
CPU: 1 UID: 0 PID: 6106 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __might_fault+0xcc/0x130 mm/memory.c:6958
 _inline_copy_to_user include/linux/uaccess.h:192 [inline]
 _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145
 ocfs2_fiemap+0x888/0xc90 fs/ocfs2/extent_map.c:806
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x1188/0x1440 fs/ioctl.c:532
 __do_sys_ioctl fs/ioctl.c:596 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe5624debe9
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:00007ffe7d0ee8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe562705fa0 RCX: 00007fe5624debe9
RDX: 0000200000000380 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007fe562561e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe562705fa0 R14: 00007fe562705fa0 R15: 0000000000000003
 </TASK>