syzbot


possible deadlock in ocfs2_run_deallocs

Status: upstream: reported on 2026/04/30 09:11
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+407d2fec3cdeb646c8f3@syzkaller.appspotmail.com
First crash: 20d, last: 6d03h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in ocfs2_run_deallocs 0 (1) 2026/04/30 09:11

Sample crash report:
loop0: detected capacity change from 0 to 32768
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.0.0/5324 is trying to acquire lock:
ffff88800bbcc1a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
ffff88800bbcc1a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_free_cached_blocks fs/ocfs2/alloc.c:6445 [inline]
ffff88800bbcc1a0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_run_deallocs+0x2c4/0x1570 fs/ocfs2/alloc.c:6588

but task is already holding lock:
ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x43b0 fs/ocfs2/inode.c:1299

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}:
       down_write+0x96/0x200 kernel/locking/rwsem.c:1625
       inode_lock include/linux/fs.h:1029 [inline]
       ocfs2_del_inode_from_orphan+0x12e/0x7a0 fs/ocfs2/namei.c:2728
       ocfs2_dio_end_io_write fs/ocfs2/aops.c:2379 [inline]
       ocfs2_dio_end_io+0xf9c/0x1370 fs/ocfs2/aops.c:2418
       dio_complete+0x25b/0x790 fs/direct-io.c:281
       __blockdev_direct_IO+0x2e5d/0x34e0 fs/direct-io.c:1303
       ocfs2_direct_IO+0x251/0x2c0 fs/ocfs2/aops.c:2455
       generic_file_direct_write+0x1db/0x3e0 mm/filemap.c:4259
       __generic_file_write_iter+0x11d/0x230 mm/filemap.c:4428
       ocfs2_file_write_iter+0x1663/0x1e70 fs/ocfs2/file.c:2476
       iter_file_splice_write+0x9a1/0x10f0 fs/splice.c:736
       do_splice_from fs/splice.c:936 [inline]
       direct_splice_actor+0x101/0x160 fs/splice.c:1159
       splice_direct_to_actor+0x53a/0xc70 fs/splice.c:1103
       do_splice_direct_actor fs/splice.c:1202 [inline]
       do_splice_direct+0x195/0x290 fs/splice.c:1228
       do_sendfile+0x535/0x7d0 fs/read_write.c:1372
       __do_sys_sendfile64 fs/read_write.c:1433 [inline]
       __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       down_write+0x96/0x200 kernel/locking/rwsem.c:1625
       inode_lock include/linux/fs.h:1029 [inline]
       ocfs2_free_cached_blocks fs/ocfs2/alloc.c:6445 [inline]
       ocfs2_run_deallocs+0x2c4/0x1570 fs/ocfs2/alloc.c:6588
       ocfs2_commit_truncate+0x1d26/0x2310 fs/ocfs2/alloc.c:7405
       ocfs2_truncate_for_delete fs/ocfs2/inode.c:701 [inline]
       ocfs2_wipe_inode fs/ocfs2/inode.c:868 [inline]
       ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
       ocfs2_evict_inode+0x1023/0x43b0 fs/ocfs2/inode.c:1299
       evict+0x61e/0xb10 fs/inode.c:841
       ocfs2_dentry_iput+0x24d/0x390 fs/ocfs2/dcache.c:407
       __dentry_kill+0x1a2/0x690 fs/dcache.c:718
       finish_dput+0xc9/0x480 fs/dcache.c:927
       __fput+0x691/0xa60 fs/file_table.c:518
       task_work_run+0x1d9/0x270 kernel/task_work.c:233
       exit_task_work include/linux/task_work.h:40 [inline]
       do_exit+0x70f/0x22c0 kernel/exit.c:975
       do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
       get_signal+0x1284/0x1330 kernel/signal.c:3037
       arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
       __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
       exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
       do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
                               lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);
                               lock(&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
  lock(&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);

 *** DEADLOCK ***

2 locks held by syz.0.0/5324:
 #0: ffff888012408bc0 (&osb->nfs_sync_rwlock){.+.+}-{4:4}, at: ocfs2_nfs_sync_lock+0x106/0x270 fs/ocfs2/dlmglue.c:2875
 #1: ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #1: ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_wipe_inode fs/ocfs2/inode.c:854 [inline]
 #1: ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 #1: ffff88800bbccfa0 (&ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_evict_inode+0xe97/0x43b0 fs/ocfs2/inode.c:1299

stack backtrace:
CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 down_write+0x96/0x200 kernel/locking/rwsem.c:1625
 inode_lock include/linux/fs.h:1029 [inline]
 ocfs2_free_cached_blocks fs/ocfs2/alloc.c:6445 [inline]
 ocfs2_run_deallocs+0x2c4/0x1570 fs/ocfs2/alloc.c:6588
 ocfs2_commit_truncate+0x1d26/0x2310 fs/ocfs2/alloc.c:7405
 ocfs2_truncate_for_delete fs/ocfs2/inode.c:701 [inline]
 ocfs2_wipe_inode fs/ocfs2/inode.c:868 [inline]
 ocfs2_delete_inode fs/ocfs2/inode.c:1157 [inline]
 ocfs2_evict_inode+0x1023/0x43b0 fs/ocfs2/inode.c:1299
 evict+0x61e/0xb10 fs/inode.c:841
 ocfs2_dentry_iput+0x24d/0x390 fs/ocfs2/dcache.c:407
 __dentry_kill+0x1a2/0x690 fs/dcache.c:718
 finish_dput+0xc9/0x480 fs/dcache.c:927
 __fput+0x691/0xa60 fs/file_table.c:518
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x70f/0x22c0 kernel/exit.c:975
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
 get_signal+0x1284/0x1330 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbae539cdd9
Code: Unable to access opcode bytes at 0x7fbae539cdaf.
RSP: 002b:00007fbae61f3fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 000000000014c000 RBX: 00007fbae5615fa0 RCX: 00007fbae539cdd9
RDX: 00000000fffffceb RSI: 00002000000001c0 RDI: 0000000000000007
RBP: 00007fbae5432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbae5616038 R14: 00007fbae5615fa0 R15: 00007ffc31b11578
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/11 01:37 upstream aa54b1d27fe0 29233ece .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_run_deallocs
2026/04/26 09:10 upstream 897d54018cc9 9c2d0995 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_run_deallocs
* Struck through repros no longer work on HEAD.