Kernel bug: possible deadlock in _ocfs2_free_suballoc_bits
Subsystem: ocfs2
Status: open

Crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/5944 is trying to acquire lock:
ffff88805a865100 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
ffff88805a865100 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: _ocfs2_reclaim_suballoc_to_main fs/ocfs2/suballoc.c:2757 [inline]
ffff88805a865100 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}, at: _ocfs2_free_suballoc_bits+0x13f1/0x2130 fs/ocfs2/suballoc.c:2911

but task is already holding lock:
ffff888032f57ce8 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:372

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&journal->j_trans_barrier){.+.+}-{4:4}:
       down_read+0x47/0x2e0 kernel/locking/rwsem.c:1537
       ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:372
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:754 [inline]
       ocfs2_reserve_suballoc_bits+0x722/0x4600 fs/ocfs2/suballoc.c:903
       ocfs2_reserve_new_inode+0x4f4/0xc90 fs/ocfs2/suballoc.c:1143
       ocfs2_mknod+0x831/0x2030 fs/ocfs2/namei.c:307
       ocfs2_mkdir+0x181/0x420 fs/ocfs2/namei.c:660
       vfs_mkdir+0x414/0x630 fs/namei.c:5196
       do_mkdirat+0x276/0x500 fs/namei.c:5230
       __do_sys_mkdirat fs/namei.c:5252 [inline]
       __se_sys_mkdirat fs/namei.c:5250 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5250
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (sb_internal#2){.+.+}-{0:0}:
       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/super.h:19 [inline]
       sb_start_intwrite include/linux/fs/super.h:177 [inline]
       ocfs2_start_trans+0x26b/0x6d0 fs/ocfs2/journal.c:370
       ocfs2_block_group_alloc fs/ocfs2/suballoc.c:754 [inline]
       ocfs2_reserve_suballoc_bits+0x722/0x4600 fs/ocfs2/suballoc.c:903
       ocfs2_reserve_new_inode+0x4f4/0xc90 fs/ocfs2/suballoc.c:1143
       ocfs2_mknod+0x831/0x2030 fs/ocfs2/namei.c:307
       ocfs2_mkdir+0x181/0x420 fs/ocfs2/namei.c:660
       vfs_mkdir+0x414/0x630 fs/namei.c:5196
       do_mkdirat+0x276/0x500 fs/namei.c:5230
       __do_sys_mkdirat fs/namei.c:5252 [inline]
       __se_sys_mkdirat fs/namei.c:5250 [inline]
       __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5250
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
       down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590
       inode_lock include/linux/fs.h:1028 [inline]
       _ocfs2_reclaim_suballoc_to_main fs/ocfs2/suballoc.c:2757 [inline]
       _ocfs2_free_suballoc_bits+0x13f1/0x2130 fs/ocfs2/suballoc.c:2911
       ocfs2_free_suballoc_bits fs/ocfs2/suballoc.c:2925 [inline]
       ocfs2_free_dinode+0xb1/0xe0 fs/ocfs2/suballoc.c:2940
       ocfs2_remove_inode fs/ocfs2/inode.c:774 [inline]
       ocfs2_wipe_inode fs/ocfs2/inode.c:896 [inline]
       ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
       ocfs2_evict_inode+0x1d84/0x4040 fs/ocfs2/inode.c:1299
       evict+0x5f4/0xae0 fs/inode.c:837
       d_delete_notify include/linux/fsnotify.h:377 [inline]
       vfs_rmdir+0x427/0x6e0 fs/namei.c:5315
       do_rmdir+0x281/0x500 fs/namei.c:5357
       __do_sys_unlinkat fs/namei.c:5534 [inline]
       __se_sys_unlinkat fs/namei.c:5528 [inline]
       __x64_sys_unlinkat+0xc2/0xf0 fs/namei.c:5528
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0xf80 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:
  &ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE] --> sb_internal#2 --> &journal->j_trans_barrier

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&journal->j_trans_barrier);
                               lock(sb_internal#2);
                               lock(&journal->j_trans_barrier);
  lock(&ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]);

 *** DEADLOCK ***

8 locks held by syz-executor/5944:
 #0: ffff888021f00420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
 #1: ffff88805a8609c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
 #1: ffff88805a8609c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
 #1: ffff88805a8609c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
 #1: ffff88805a8609c0 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: do_rmdir+0x1be/0x500 fs/namei.c:5350
 #2: ffff888032084bd0 (&osb->nfs_sync_rwlock){.+.+}-{4:4}, at: ocfs2_nfs_sync_lock+0x106/0x250 fs/ocfs2/dlmglue.c:2875
 #3: ffff88805a865f40 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #3: ffff88805a865f40 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
 #3: ffff88805a865f40 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 #3: ffff88805a865f40 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xf6c/0x4040 fs/ocfs2/inode.c:1299
 #4: ffff88805a8689c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #4: ffff88805a8689c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_remove_inode fs/ocfs2/inode.c:733 [inline]
 #4: ffff88805a8689c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:896 [inline]
 #4: ffff88805a8689c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 #4: ffff88805a8689c0 (&ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0x1507/0x4040 fs/ocfs2/inode.c:1299
 #5: ffff888021f00610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_remove_inode fs/ocfs2/inode.c:742 [inline]
 #5: ffff888021f00610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:896 [inline]
 #5: ffff888021f00610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 #5: ffff888021f00610 (sb_internal#2){.+.+}-{0:0}, at: ocfs2_evict_inode+0x15ea/0x4040 fs/ocfs2/inode.c:1299
 #6: ffff888032f57ce8 (&journal->j_trans_barrier){.+.+}-{4:4}, at: ocfs2_start_trans+0x36a/0x6d0 fs/ocfs2/journal.c:372
 #7: ffff888021f02950 (jbd2_handle#2){.+.+}-{0:0}, at: start_this_handle+0x1f87/0x21c0 fs/jbd2/transaction.c:444

stack backtrace:
CPU: 1 UID: 0 PID: 5944 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 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 kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868
 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590
 inode_lock include/linux/fs.h:1028 [inline]
 _ocfs2_reclaim_suballoc_to_main fs/ocfs2/suballoc.c:2757 [inline]
 _ocfs2_free_suballoc_bits+0x13f1/0x2130 fs/ocfs2/suballoc.c:2911
 ocfs2_free_suballoc_bits fs/ocfs2/suballoc.c:2925 [inline]
 ocfs2_free_dinode+0xb1/0xe0 fs/ocfs2/suballoc.c:2940
 ocfs2_remove_inode fs/ocfs2/inode.c:774 [inline]
 ocfs2_wipe_inode fs/ocfs2/inode.c:896 [inline]
 ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 ocfs2_evict_inode+0x1d84/0x4040 fs/ocfs2/inode.c:1299
 evict+0x5f4/0xae0 fs/inode.c:837
 d_delete_notify include/linux/fsnotify.h:377 [inline]
 vfs_rmdir+0x427/0x6e0 fs/namei.c:5315
 do_rmdir+0x281/0x500 fs/namei.c:5357
 __do_sys_unlinkat fs/namei.c:5534 [inline]
 __se_sys_unlinkat fs/namei.c:5528 [inline]
 __x64_sys_unlinkat+0xc2/0xf0 fs/namei.c:5528
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f877438ed27
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 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:00007ffe2ce25a58 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f877438ed27
RDX: 0000000000000200 RSI: 00007ffe2ce26c00 RDI: 00000000ffffff9c
RBP: 00007f8774413d7d R08: 0000555594caa66b R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000207 R12: 00007ffe2ce26c00
R13: 00007f8774413d7d R14: 000000000001e634 R15: 00007ffe2ce28dc0
 </TASK>
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)
ocfs2: Unmounting device (7,0) on (node local)