syzbot

loop2: detected capacity change from 0 to 32768
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,2) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller-00097-g196145c606d0 #0 Not tainted
------------------------------------------------------
syz.2.80/5706 is trying to acquire lock:
ffff88807bfa9e18 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0xaa/0x120 mm/memory.c:6404

but task is already holding lock:
ffff88805e233120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_fiemap+0x377/0xf80 fs/ocfs2/extent_map.c:755

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&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

-> #3 (&osb->system_file_mutex){+.+.}-{3:3}:
       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_local_alloc_bits+0x107/0x2870 fs/ocfs2/localalloc.c:627
       ocfs2_reserve_clusters_with_limit+0x1b8/0xb60 fs/ocfs2/suballoc.c:1166
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1227 [inline]
       ocfs2_lock_allocators+0x30a/0x630 fs/ocfs2/suballoc.c:2746
       ocfs2_write_begin_nolock+0x2916/0x4d30 fs/ocfs2/aops.c:1739
       __ocfs2_page_mkwrite fs/ocfs2/mmap.c:93 [inline]
       ocfs2_page_mkwrite+0x756/0xed0 fs/ocfs2/mmap.c:144
       do_page_mkwrite+0x19b/0x480 mm/memory.c:3159
       do_shared_fault mm/memory.c:5150 [inline]
       do_fault mm/memory.c:5212 [inline]
       do_pte_missing mm/memory.c:3964 [inline]
       handle_pte_fault+0x126b/0x6fc0 mm/memory.c:5538
       __handle_mm_fault mm/memory.c:5681 [inline]
       handle_mm_fault+0x1056/0x1ad0 mm/memory.c:5849
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #2 (&oi->ip_alloc_sem){++++}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       down_write+0x99/0x220 kernel/locking/rwsem.c:1579
       ocfs2_page_mkwrite+0x347/0xed0 fs/ocfs2/mmap.c:142
       do_page_mkwrite+0x19b/0x480 mm/memory.c:3159
       do_shared_fault mm/memory.c:5150 [inline]
       do_fault mm/memory.c:5212 [inline]
       do_pte_missing mm/memory.c:3964 [inline]
       handle_pte_fault+0x126b/0x6fc0 mm/memory.c:5538
       __handle_mm_fault mm/memory.c:5681 [inline]
       handle_mm_fault+0x1056/0x1ad0 mm/memory.c:5849
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #1 (sb_pagefaults#2){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1676 [inline]
       sb_start_pagefault include/linux/fs.h:1841 [inline]
       ocfs2_page_mkwrite+0x223/0xed0 fs/ocfs2/mmap.c:122
       do_page_mkwrite+0x19b/0x480 mm/memory.c:3159
       do_shared_fault mm/memory.c:5150 [inline]
       do_fault mm/memory.c:5212 [inline]
       do_pte_missing mm/memory.c:3964 [inline]
       handle_pte_fault+0x126b/0x6fc0 mm/memory.c:5538
       __handle_mm_fault mm/memory.c:5681 [inline]
       handle_mm_fault+0x1056/0x1ad0 mm/memory.c:5849
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #0 (&mm->mmap_lock){++++}-{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
       __might_fault+0xc6/0x120 mm/memory.c:6404
       _inline_copy_to_user include/linux/uaccess.h:176 [inline]
       _copy_to_user+0x2a/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:209 [inline]
       fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
       ocfs2_fiemap_inline fs/ocfs2/extent_map.c:725 [inline]
       ocfs2_fiemap+0xc25/0xf80 fs/ocfs2/extent_map.c:762
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:841
       __do_sys_ioctl fs/ioctl.c:905 [inline]
       __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
       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:

Chain exists of:
  &mm->mmap_lock --> &osb->system_file_mutex --> &ocfs2_file_ip_alloc_sem_key

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&ocfs2_file_ip_alloc_sem_key);
                               lock(&osb->system_file_mutex);
                               lock(&ocfs2_file_ip_alloc_sem_key);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz.2.80/5706:
 #0: ffff88805e233120 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_fiemap+0x377/0xf80 fs/ocfs2/extent_map.c:755

stack backtrace:
CPU: 0 UID: 0 PID: 5706 Comm: syz.2.80 Not tainted 6.11.0-rc7-syzkaller-00097-g196145c606d0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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
 __might_fault+0xc6/0x120 mm/memory.c:6404
 _inline_copy_to_user include/linux/uaccess.h:176 [inline]
 _copy_to_user+0x2a/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:209 [inline]
 fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
 ocfs2_fiemap_inline fs/ocfs2/extent_map.c:725 [inline]
 ocfs2_fiemap+0xc25/0xf80 fs/ocfs2/extent_map.c:762
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:841
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 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: 0033:0x7f49fe37def9
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:00007f49fe1f8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f49fe535f80 RCX: 00007f49fe37def9
RDX: 0000000020000040 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007f49fe3f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f49fe535f80 R15: 00007fffe1da76f8
 </TASK>