From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.167.197 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794191859; b=4c7rQ1/GaGFHlt0XmOhJA8/9i9WiGlboS/F75CF1Y7+eSkcNHl9LMHqDRKL/umA85v76 sK7IzZQX/nAOozE0R1ShgwOGeId+Uop+Za2qVUIZBUZDl49428MQ8PWKCbtkSh1gMsy4+ 7xrhsqUjO+w9lDfSi1yAGf2vu1bju+B8lXPs83FVeVQSDymKgFPLnjBDqcJoRjb8BqC8x j2QPmPMcr4Uv/Kl3eXXmOQmCO2bw7s5cKePjh6EsukbkCs9iKr4bT/wDIRr6l5jV4DVgc gwhEXNYL020IKpaLIrWGfEIpuUhfJ2kaJzLobj73O4i5lSbX3GrqgBwZ3F5uCBAbCbA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794191859; h=DMARC-Filter:Received:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:MIME-Version:X-Received:Date: X-Google-Appengine-App-Id:X-Google-Appengine-App-Id-Alias:Message-ID: Subject:From:To:Content-Type; bh=9rXEcNZzcZAe4iE0p0XDHsc0VjCCW/UujjQm/s4ivWE=; b=ZPKH3yNrvQglZOECZeldGn5UxzCEaM7HwWiwUjkNZ0XtiPipc3Jw7jFXcUvhFKZVdBa6 7cA6z6hnOHfNn5Ianeu9y/k8LZu9lAOrmfzUUx6LXUslRTLR4yqYhgguse7o5kwUlsoeZ om/f3YFaiTtJslBCoVeTLxHo2sCDp3pIqOexGH0gA9jrLW+EgaQX3ngi53llJ5TdR6DRJ OJC7XkpNbOzuiztLB4HszcI7h4u9rG1uR7m3iM3YEpJOz8F3F6dwlOAldqPhNL1B96Bw+ a6XZ8K9BnNZYMANabwv2hx0bAWpj4YjtFEya4I6ik9TjVUxscY6h5Ka8ywb4SBHgcfA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.remote-ip=209.85.167.197 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EC49606A320 for ; Mon, 9 Nov 2026 02:37:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 5EC49606A320 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f197.google.com with SMTP id 5614622812f47-4eb0b989f0eso555832b6e.0 for ; Sun, 08 Nov 2026 18:37:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794191858; x=1794796658; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9rXEcNZzcZAe4iE0p0XDHsc0VjCCW/UujjQm/s4ivWE=; b=VO7oIUCAclYa4VtVDmcojFDjd8uE4jQSeVX5euU2xD3uBf5bJkXuvbIb2LqWGl6zW3 I6uar4lripjNfQUvUy5H05G1Au/FIhSyuAppFGV0I2GccRQ+G7HqArS1twXTYhZKQGQW oCDz0wlDQVpq/60wZAbN25G+IJTUuvNfVJRdjlaBL903F1eD7FYzSE/jvmxjRcz92OWQ GO0vuiPZNJduOugInpV5taOHfr6A8S1ZTNeL8ovtx4orWGVwt2WiMayUBoQpm+X7V6Up +QcO7nVSjakSjk7Z9XuvECTK2zf+acFFmULvPAygsy85wLmth1yztrNEwCux8xqaYWSb szhA== X-Forwarded-Encrypted: i=1; AL+hErG7plDF2x/jP+hktlwzBt/2+orM6Ld+1sLzvzWnmwpaKoqiDvX0mJpv6QIxjViDufprTBbMaIIYgq4SFw==@vger.kernel.org X-Gm-Message-State: APuU4Z+Ty3ZLg7kgQBcECRnZLr33laypt/bP9njN+/SsgWDP1bAG7tEc MdtPUl5RKHoZo3NwU/UHkc0WkFqF7xk+WmS6qP9tiJcvNIQPxLMgw8yfjGvZRJcVe6jVmxkhdog RWFTvJB5ZDAV4c43c3v8s+5634rHBiAcJwGkHWH6ItzwCvy4js8BSxRP+Hak= X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Received: by 2002:a05:6808:518b:b0:495:f8a5:8797 with SMTP id 5614622812f47-567fcf350damr2647509b6e.0.1794191858336; Sun, 08 Nov 2026 18:37:38 -0800 (PST) Date: Sun, 08 Nov 2026 18:37:38 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6af131f2.44d55313.247daf.0001.GAE@google.com> Subject: [syzbot] [btrfs?] WARNING in btrfs_put_root From: syzbot To: dsterba@suse.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, mason@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: fa4ad798f6f6 Merge tag 'for-7.4-rc1-tag' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16f5af35580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d44b06612b68f56 dashboard link: https://syzkaller.appspot.com/bug?extid=55d1814e49f1fc0ba542 compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7a262c93f0a1/disk-fa4ad798.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/670f0137c169/vmlinux-fa4ad798.xz kernel image: https://storage.googleapis.com/syzbot-assets/7b5f342645af/bzImage-fa4ad798.xz AI-generated root cause summary: When a Btrfs filesystem encounters a transaction abort (reported in state EA), inodes being evicted during unmount (particularly via delayed iputs in close_ctree(), which runs after btrfs_error_commit_super()) fail to persist their delayed inode updates in btrfs_commit_inode_delayed_inode() because transaction joining fails. In btrfs_evict_inode(), this error causes execution to jump directly to the out label, bypassing btrfs_kill_delayed_inode_items(). Because the delayed items remain uncleaned, __btrfs_release_delayed_node() re-queues the delayed node into delayed_root->node_list and retains a reference, preventing refcount_dec_and_test() from hitting zero and skipping xa_erase(&root->delayed_nodes, ...). When the root is finally freed in btrfs_put_root(), root->delayed_nodes is still non-empty, triggering WARN_ON(!xa_empty(&root->delayed_nodes)). full analysis: https://syzkaller.appspot.com/x/ai_root_cause?x=55d1814e49f1fc0ba542 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+55d1814e49f1fc0ba542@syzkaller.appspotmail.com BTRFS info (device loop6 state EA): last unmount of filesystem 395ef67a-297e-477c-816d-cd80a5b93e5d ------------[ cut here ]------------ !xa_empty(&root->delayed_nodes) WARNING: fs/btrfs/disk-io.c:1844 at btrfs_put_root+0x1f9/0x250 fs/btrfs/disk-io.c:1844, CPU#1: syz-executor/6160 Modules linked in: CPU: 1 UID: 0 PID: 6160 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 RIP: 0010:btrfs_put_root+0x1f9/0x250 fs/btrfs/disk-io.c:1844 Code: c5 0e fe e8 b9 81 a3 fd 48 8d bb 40 05 00 00 90 0f 0b 90 e8 69 98 de 07 e9 9b fe ff ff e8 9f 81 a3 fd 48 8d bb 90 05 00 00 90 <0f> 0b 90 e8 4f 98 de 07 e9 ad fe ff ff e8 85 81 a3 fd 90 0f 0b 90 RSP: 0018:ffffc90006287d18 EFLAGS: 00010293 RAX: ffffffff84258d21 RBX: ffff888079a62000 RCX: ffff8880233e8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888079a62590 RBP: 0000000000000001 R08: ffff888079a6262b R09: 1ffff1100f34c4c5 R10: dffffc0000000000 R11: ffffed100f34c4c6 R12: dffffc0000000000 R13: ffff888069f06218 R14: ffff888079a625d8 R15: dffffc0000000000 FS: 000055556295c500(0000) GS:ffff888123509000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faacae5e000 CR3: 000000001ef0b000 CR4: 0000000000350ef0 Call Trace: btrfs_free_fs_info+0x252/0x360 fs/btrfs/disk-io.c:1257 deactivate_locked_super+0xbe/0x110 fs/super.c:558 cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396 task_work_run+0x1d9/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb8687a0d57 Code: a2 c7 05 9c a9 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffc6dae6688 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fb8687a0d57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc6dae6740 RBP: 00007ffc6dae6740 R08: 00007ffc6dae7740 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc6dae77d0 R13: 00007fb868836fb3 R14: 0000000000041ae3 R15: 00007ffc6dae7810 --- 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@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title 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