[syzbot] [btrfs?] WARNING in btrfs_force_cow_block

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9ecfb2f7287a Merge tag 'trace-ring-buffer-v7.2' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16a15b7a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=41904f685679d171
dashboard link: https://syzkaller.appspot.com/bug?extid=d950c6ba09b79f6e1864
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-9ecfb2f7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e769c7b13970/vmlinux-9ecfb2f7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1e58f90eb1c5/bzImage-9ecfb2f7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d950c6...@syzkaller.appspotmail.com

extent compression 0
item 18 key (258 EXTENT_DATA 421888) itemoff 2800 itemsize 53
generation 16 type 1
extent data disk bytenr 8777728 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 19 key (258 EXTENT_DATA 438272) itemoff 2747 itemsize 53
generation 16 type 1
extent data disk bytenr 8790016 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 20 key (258 EXTENT_DATA 479232) itemoff 2694 itemsize 53
generation 16 type 1
extent data disk bytenr 8794112 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 21 key (258 EXTENT_DATA 552960) itemoff 2641 itemsize 53
generation 16 type 1
extent data disk bytenr 8798208 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 22 key (258 EXTENT_DATA 593920) itemoff 2588 itemsize 53
generation 16 type 1
extent data disk bytenr 8802304 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 23 key (258 EXTENT_DATA 638976) itemoff 2535 itemsize 53
generation 16 type 1
extent data disk bytenr 8818688 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 24 key (258 EXTENT_DATA 667648) itemoff 2482 itemsize 53
generation 16 type 1
extent data disk bytenr 8843264 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 25 key (258 EXTENT_DATA 700416) itemoff 2429 itemsize 53
generation 16 type 1
extent data disk bytenr 8851456 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 26 key (258 EXTENT_DATA 729088) itemoff 2376 itemsize 53
generation 16 type 1
extent data disk bytenr 8884224 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0
item 27 key (18446744073709551611 ORPHAN_ITEM 258) itemoff 2376 itemsize 0
BTRFS error (device loop0): unexpected non-zero offset in file extent item for data reloc inode 258 key offset 0 offset 9277520992061368337
------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/ctree.c:531 at btrfs_force_cow_block+0x1a3a/0x1bf0 fs/btrfs/ctree.c:531, CPU#0: syz.0.0/5346
Modules linked in:
CPU: 0 UID: 0 PID: 5346 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
RIP: 0010:btrfs_force_cow_block+0x1a3a/0x1bf0 fs/btrfs/ctree.c:531
Code: 82 d9 fd 90 0f 0b 90 44 89 f1 f7 d9 4c 8b 6c 24 08 e9 d8 f7 ff ff e8 b5 82 d9 fd eb 10 e8 ae 82 d9 fd eb 09 e8 a7 82 d9 fd 90 <0f> 0b 90 44 89 f1 f7 d9 4c 8b 6c 24 08 e9 1e f8 ff ff e8 8f 82 d9
RSP: 0018:ffffc9000f7ff0e0 EFLAGS: 00010287
RAX: ffffffff83ecb219 RBX: ffff888041980001 RCX: 0000000000100000
RDX: ffffc90020802000 RSI: 00000000000e8c21 RDI: 00000000000e8c22
RBP: ffffc9000f7ff260 R08: ffff888040818000 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000002 R12: dffffc0000000000
R13: ffff88800010e2f0 R14: 00000000ffffff8b R15: ffff888056ac103f
FS: 00007fecbea066c0(0000) GS:ffff88808c84f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54c062f120 CR3: 0000000043809000 CR4: 0000000000352ef0
Call Trace:
<TASK>
btrfs_cow_block+0x3f1/0xaf0 fs/btrfs/ctree.c:696
do_relocation+0xd1c/0x17a0 fs/btrfs/relocation.c:2350
relocate_tree_block fs/btrfs/relocation.c:2600 [inline]
relocate_tree_blocks+0x11a3/0x1fc0 fs/btrfs/relocation.c:2707
relocate_block_group+0x77c/0xe90 fs/btrfs/relocation.c:3635
do_nonremap_reloc+0xa7/0x560 fs/btrfs/relocation.c:5323
btrfs_relocate_block_group+0x6e2/0xaf0 fs/btrfs/relocation.c:5490
btrfs_relocate_chunk+0x114/0x810 fs/btrfs/volumes.c:3647
__btrfs_balance+0x1b5f/0x29d0 fs/btrfs/volumes.c:4586
btrfs_balance+0xaa6/0x1180 fs/btrfs/volumes.c:4973
btrfs_ioctl_balance+0x3da/0x640 fs/btrfs/ioctl.c:3474
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
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: 0033:0x7fecbdb9ce59
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:00007fecbea05fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fecbde16180 RCX: 00007fecbdb9ce59
RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 000000000000000a
RBP: 00007fecbdc32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fecbde16218 R14: 00007fecbde16180 R15: 00007ffc571bd148
</TASK>


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