[syzbot] [btrfs?] WARNING in create_pending_snapshot

From: syzbot
Date: Thu Nov 09 2023 - 12:16:29 EST


Hello,

syzbot found the following issue on:

HEAD commit: 305230142ae0 Merge tag 'pm-6.7-rc1-2' of git://git.kernel...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11777b60e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=beb32a598fd79db9
dashboard link: https://syzkaller.appspot.com/bug?extid=4d81015bc10889fd12ea
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14900138e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10907197680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0aab25a831ba/disk-30523014.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9d1b7b8fdf8a/vmlinux-30523014.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e9b6822fcd5f/bzImage-30523014.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/82e806de5984/mount_0.gz

The issue was bisected to:

commit 6ed05643ddb166c0fddabac8ee092659006214a9
Author: Boris Burkov <boris@xxxxxx>
Date: Wed Jun 28 18:00:05 2023 +0000

btrfs: create qgroup earlier in snapshot creation

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=117a7050e80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=137a7050e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=157a7050e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4d81015bc10889fd12ea@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 6ed05643ddb1 ("btrfs: create qgroup earlier in snapshot creation")

------------[ cut here ]------------
BTRFS: Transaction aborted (error -17)
WARNING: CPU: 0 PID: 5057 at fs/btrfs/transaction.c:1778 create_pending_snapshot+0x25f4/0x2b70 fs/btrfs/transaction.c:1778
Modules linked in:
CPU: 0 PID: 5057 Comm: syz-executor225 Not tainted 6.6.0-syzkaller-15365-g305230142ae0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:create_pending_snapshot+0x25f4/0x2b70 fs/btrfs/transaction.c:1778
Code: f8 fd 48 c7 c7 00 43 ab 8b 89 de e8 76 4b be fd 0f 0b e9 30 f3 ff ff e8 7a 8d f8 fd 48 c7 c7 00 43 ab 8b 89 de e8 5c 4b be fd <0f> 0b e9 f8 f6 ff ff e8 60 8d f8 fd 48 c7 c7 00 43 ab 8b 89 de e8
RSP: 0018:ffffc90003abf580 EFLAGS: 00010246
RAX: 10fb7cf24e10ea00 RBX: 00000000ffffffef RCX: ffff888023ea9dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003abf870 R08: ffffffff81547c82 R09: 1ffff11017305172
R10: dffffc0000000000 R11: ffffed1017305173 R12: ffff888078ae2878
R13: 00000000ffffffef R14: 0000000000000000 R15: ffff888078ae2818
FS: 000055555667d380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6ff7bf2304 CR3: 0000000079f17000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1967
btrfs_commit_transaction+0xf1c/0x3730 fs/btrfs/transaction.c:2440
create_snapshot+0x4a5/0x7e0 fs/btrfs/ioctl.c:845
btrfs_mksubvol+0x5d0/0x750 fs/btrfs/ioctl.c:995
btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1041
__btrfs_ioctl_snap_create+0x344/0x460 fs/btrfs/ioctl.c:1294
btrfs_ioctl_snap_create+0x13c/0x190 fs/btrfs/ioctl.c:1321
btrfs_ioctl+0xbbf/0xd40
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f2f791127b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc5dc597b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f2f791127b9
RDX: 0000000020000a80 RSI: 0000000050009401 RDI: 0000000000000004
RBP: 00007f2f7918b610 R08: 00007ffc5dc59988 R09: 00007ffc5dc59988
R10: 00007ffc5dc59988 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc5dc59978 R14: 0000000000000001 R15: 0000000000000001
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup