syzbot

ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
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kernel BUG at fs/ocfs2/refcounttree.c:2890!
CPU: 1 UID: 0 PID: 5940 Comm: syz.0.36 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:ocfs2_clear_cow_buffer+0x79/0x80 fs/ocfs2/refcounttree.c:2890
Code: 02 75 21 e8 a9 1e 01 fe 48 89 df be 08 00 00 00 e8 ec 26 6a fe f0 80 23 ef 31 c0 5b 41 5e e9 ce f3 5f 07 cc e8 88 1e 01 fe 90 <0f> 0b 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003fa6d58 EFLAGS: 00010293
RAX: ffffffff83c3c8d8 RBX: ffff888059d30120 RCX: ffff88802a683e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100b3a6025 R12: ffff888059d30120
R13: ffff888059d30000 R14: 0000000000000002 R15: 0000000000001000
FS:  00007fd052bf66c0(0000) GS:ffff888126250000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0535ea540 CR3: 0000000046414000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 walk_page_buffers+0x94/0x1e0 fs/ocfs2/aops.c:421
 ocfs2_duplicate_clusters_by_page+0x70b/0xcd0 fs/ocfs2/refcounttree.c:2969
 ocfs2_replace_clusters fs/ocfs2/refcounttree.c:3120 [inline]
 ocfs2_make_clusters_writable fs/ocfs2/refcounttree.c:3252 [inline]
 ocfs2_replace_cow+0xaf4/0x1c90 fs/ocfs2/refcounttree.c:3346
 ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3424 [inline]
 ocfs2_refcount_cow+0x790/0xd40 fs/ocfs2/refcounttree.c:3467
 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2347 [inline]
 ocfs2_file_write_iter+0xf29/0x1f20 fs/ocfs2/file.c:2458
 iter_file_splice_write+0xa36/0x1240 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x104/0x160 fs/splice.c:1159
 splice_direct_to_actor+0x586/0xcc0 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
 do_sendfile+0x540/0x7e0 fs/read_write.c:1371
 __do_sys_sendfile64 fs/read_write.c:1432 [inline]
 __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd05359ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd052bf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fd053815fa0 RCX: 00007fd05359ce59
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007fd053632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd053816038 R14: 00007fd053815fa0 R15: 00007fff6370ad38
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_clear_cow_buffer+0x79/0x80 fs/ocfs2/refcounttree.c:2890
Code: 02 75 21 e8 a9 1e 01 fe 48 89 df be 08 00 00 00 e8 ec 26 6a fe f0 80 23 ef 31 c0 5b 41 5e e9 ce f3 5f 07 cc e8 88 1e 01 fe 90 <0f> 0b 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003fa6d58 EFLAGS: 00010293
RAX: ffffffff83c3c8d8 RBX: ffff888059d30120 RCX: ffff88802a683e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100b3a6025 R12: ffff888059d30120
R13: ffff888059d30000 R14: 0000000000000002 R15: 0000000000001000
FS:  00007fd052bf66c0(0000) GS:ffff888126250000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0535ea540 CR3: 0000000046414000 CR4: 00000000003526f0