From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.128.54 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793859612; b=w/ffp4WBmBbGRYVO16xBW03pFwBwUqP8JP4+goPdI2C9VLWk7pWC0qAOLkOa2u0EseM5 wckDFxTnPv2aHMpYuMTSt3cHQO6k0I5ACL5V4OWQq8mhB64G7xUs/UvcJAj9EUl8tVyqj M3niY05KOmqBcpGRTu3Meh/9efPtVjZc2jWC97AaHoOrkoTo6pSImNU5lScGfhl7ox3ui Hy7FVoBab58XPx+TxjKwO3j6RNfl1BTC3aEXUg6JZ0WgDx4Z1iGymb3JGKQt0M4Zb1Kvg 5g1E8MC1k4D61XWwNNUtFCkpmC8B2ikhcgBzTdP/7WEBHiB3RWZA8xNb8vX3XuwRuQg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793859612; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Message-ID:Date:MIME-Version:User-Agent:Subject:To:Cc:References: Content-Language:From:Autocrypt:In-Reply-To:Content-Type: Content-Transfer-Encoding; bh=WS3SIbAjQ99dz8XPsd+erMN3YcHpcAqp19dH18JDaKw=; b=ARoiY/Id9YCpVy3aE7orcwYjV7WtV8zkh0BClYx6OgBCO32k88BcOqOsa0CBDEWeSakQ cez1Xze1U8yVBs0+KKET8BSgfMSV2UkWZuPLySLJEMWSfKcXhHGzNmI4gbZ/teWvjk/Bq gOCMAYOLUd39S9YGDeK9DJJGPfNw5tNQdpfDMdWBK5BgetVguUTsI6jzHp4WwIWW6E1xo ZxxQfSRYA6kriNAHOP5UeRoNwoIEVnAo5h8dXRf8LE+xlEgElk14eiCXGX+MFOSaYbGbb qTyxEaRARELyhl7eOeJutDNl3vyB7kEIQErs0f4l1jf7pZBfmsX6DQTIhkndkbhQg6w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass header.d=suse.com header.i=@suse.com header.a=rsa-sha256 header.s=google header.b=CSQx8Wh8; arc=none smtp.remote-ip=209.85.128.54 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (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 AB951606A32F for ; Thu, 5 Nov 2026 06:20:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org AB951606A32F Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=suse.com header.i=@suse.com header.a=rsa-sha256 header.s=google header.b=CSQx8Wh8 Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-4a214c5c4c0so13135185e9.3 for ; Wed, 04 Nov 2026 22:20:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1793859610; x=1794464410; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=WS3SIbAjQ99dz8XPsd+erMN3YcHpcAqp19dH18JDaKw=; b=CSQx8Wh8TfNl7SGoqVtHcqsq8PsiFxWxfkOnHd+TaEyg28sNrNiVICGMa8MtQz/iiT /WK0QhqCA0fKIxqJ/W1D3vGd6GwN+axsQLKJkE2B32X/JZAqeELwO5liY2EfUi0C2/2D AkMVg8CUB2154GQx/N98N3L553DNJbfXFcfN9++RfFt4v1wdLvCkF0r+FnNxUnbvRsuG Yl7ylOSBt4ulUuDdbOEp9U9hgE9royvbz9XtP8KptjvnSQs8PkjyKqiaGWl5b5CbYUh7 w3ShAujrBY3SlxPI37vdAgKPmQOuHb6PKpKRulB434LPuGfW5dpI9trKa88ArTh0qLPr LqMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793859610; x=1794464410; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=WS3SIbAjQ99dz8XPsd+erMN3YcHpcAqp19dH18JDaKw=; b=FdLDTWoEB5NUt+XPA0B3TF+9rHbFE9IKWIREzBzXhyZrihdfOvThysEqvVH1s/Svv2 rbjpnz+1fODBgJWTiLuPt8YOne8FTSkhQWzhs8SwCkJ9wQNZMdhgklKInEB86JTDKdFY C70tjHiUWNNcown8/hinKUIfGi27ea+SFnDpKYTzq465Z3m5GsA+fjMA/hpACKst7sGM frUUMSa0oke4qIOVzPaVJeXUALTS8l2YDw8peRdVh7O12drYYQAEYV5/IX/iNq3Er2R1 8qj0XjKDcZ/Wjva7o5dztwZ7Bp3TmmAzzr2z57P+lPIyG8TPj5F/Fh4Xd9ug8x6GDg4i /4ow== X-Forwarded-Encrypted: i=1; AKwUvBxVqdOUvqLLvJAHo4FLhUz/3DUU7I0++2lxOMZkFRnQU+1QpVju3Y2hnLJgYTt9vs/juMv88PQaGNyFo6Y=@vger.kernel.org X-Gm-Message-State: APuU4Z8qpqHLtSiAeHZxTnbRtPCjOD4LxbnILdWq/whXzNo6ky75Gidn LXggwtUmHwmjMoJhmLVt8oiGZK38wCpUgf+9JGe1lIk4wR1R4G5cMJw8djv2An69k6A= X-Gm-Gg: AYBFou0CNJRkbwq86qwk/7jPRbcefzihsdCXcp9UsA0KQuiiVM39cURJlmRUXT0kH9V J1YiuinGzt0rIWpGn9wDOBszyHSwQBEcERgxYLvgCfpNFtcOhWPO+X8l8c8+mGRoF/OTK4c5C/V 1ODw8X6OTcXPqv6m24h26MIk2qEFipnunACehz75I0MXSB2bf0BgOYRSXJnjmcemi5EhZ8wcFCr tALOmQOdKFMIqXw2ZAjFwtGlt0uX2zpMgkSrFhtBvHmL+9815tZ4kbjwaHg8oXkfYicnNAm4dVP 5cNcHoXv2Sx8wATIAAnMIkAo0yf7e2kW63rRFOR3IzeNyDicY9uboZrFphrw0FEzYx8jklG0MGY 8xrcOaEGh0RYUYnzZaZKgBREuAgY79EXGuvcj5l75JoHZDeFVe+lRo3RQulDKQQehzpODGDYXwg bNfZo/4eAtPMLj8xC5kTZUqFdiam+4o8ArU233Y1kyF3lu87l02h2PqL4QDPTv2tTli07+TKK97 elnZxCw2elC8SYskWvrp69zjSe++P7lgrerBqdnTyP2FcMrr5OrXQqj4EJH7vfobzvmu/vJxHoc 8E3kdPNJ9P3N1Ai5TgfW X-Received: by 2002:a05:600c:4e13:b0:49c:d019:70c5 with SMTP id 5b1f17b1804b1-4ac1228978cmr375296395e9.0.1793859609978; Wed, 04 Nov 2026 22:20:09 -0800 (PST) Received: from [172.16.0.229] ([159.196.52.54]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b0b323c18fsm2077495a91.4.2026.11.04.22.20.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Nov 2026 22:20:09 -0800 (PST) Message-ID: <0313641d-567c-4615-ba14-7662a533b793@suse.com> Date: Thu, 5 Nov 2026 16:50:04 +1030 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [BUG] btrfs: WARNING in invalidate_and_check_btree_folios, during unmount on 7.4-rc1 To: =?UTF-8?B?6ZOu?= , dsterba@suse.com Cc: mason@kernel.org, linux-btrfs@vger.kernel.org, syzkaller@googlegroups.com, linux-kernel@vger.kernel.org References: Content-Language: en-US From: Qu Wenruo Autocrypt: addr=wqu@suse.com; keydata= xsBNBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAHNGFF1IFdlbnJ1byA8d3F1QHN1c2UuY29tPsLAlAQTAQgAPgIbAwULCQgHAgYVCAkKCwIE FgIDAQIeAQIXgBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJq3ujyBQkUpLw5AAoJEMI9kfOh Jf6o8OIH/0mqW+TQM4m2x3hCsnK+oB4yJH1qnGvIhFF/Lhs48wI02sGh6/4aA0hkCDfd9LHQ +ci4FUepZ9y4VS01+oIExbg/8ytzGYTzLtb44jK2GBOBVSJkMiha6jp22XFt7WUkT/tvbreu WWdGsaJIRQaZChy7xsMI8lqQ2WdmluZJ4LT0wD3l/l6QU1ZseMGySebdY9sVOQEOJNV7Qj92 /KOAFNmeZshV/qDI8Iw1RTs6TvLqCcqmlZLCmJkYSVhT1RonWRren8xIRcFEgMe004IDnt7V qdQhk/nhTS9x9MBAhMRl0TTE1VKDLvVALsud3iZLrmmtYvwPApzGJk052f0m28vOwE0EWdWB rwEIAKpT62HgSzL9zwGe+WIUCMB+nOEjXAfvoUPUwk+YCEDcOdfkkM5FyBoJs8TCEuPXGXBO Cl5P5B8OYYnkHkGWutAVlUTV8KESOIm/KJIA7jJA+Ss9VhMjtePfgWexw+P8itFRSRrrwyUf E+0WcAevblUi45LjWWZgpg3A80tHP0iToOZ5MbdYk7YFBE29cDSleskfV80ZKxFv6koQocq0 vXzTfHvXNDELAuH7Ms/WJcdUzmPyBf3Oq6mKBBH8J6XZc9LjjNZwNbyvsHSrV5bgmu/THX2n g/3be+iqf6OggCiy3I1NSMJ5KtR0q2H2Nx2Vqb1fYPOID8McMV9Ll6rh8S8AEQEAAcLAfAQY AQgAJgIbDBYhBC3fcuWlpVuonapC4cI9kfOhJf6oBQJq3ukKBQkUzDspAAoJEMI9kfOhJf6o SNsH/1ysUWOKmzY0rGS3ZdS61QgqMGhSWD/EJ4UiPw+xO4l4+GtX0fOAqxqsmBKqje3vyhBa Z5o/1Y+gNiN+E6RBcSz4b1TAd78sQ2bvT5DWOvBjeeVxHdiuQMIn4S8xk5ZpySBw5ifjoiuL 0M33UVtJOzM8yfAeL+d/Rp4leJw72SutjkLyZTG/gJIp4pJGD/kFHn24OLL0IxEcO0gOekNZ os5e1R6jAJ2ILk7+MDnvU8wXHcCiVzuDhJLI1tih1uUIE50muHQJWbYuVBbdJeu8WlIDDssx UOCxLylNG3gDXV5MhLubPTOpp9OiFc/XC37nvkgEcrlmlOFBv4/NJCbECpo= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit 在 2026/11/5 16:12, 铮 写道: > Hi Btrfs maintainers, > [...] > > We also reproduced the warning with panic_on_warn=0, allowing the > kernel to print the extent buffer diagnostics following the WARN. > > Four instances were captured: > > BTRFS warning (device loop4 state I): unable to release extent > buffer 6881280 owner 5 gen 9 refs 2 flags 0xd 0xd means UPTODATE | TREE_REF | STALE. Meaning the eb is already being released, so this means there are some races. > BTRFS warning (device loop0 state I): unable to release extent > buffer 6885376 owner 5 gen 9 refs 2 flags 0x1d This is UPTODATE | TREE_REF | STALE | WRITEBACK, which is also stale but also under writeback. Exactly what the check is supposed to catch. > BTRFS warning (device loop8 state I): unable to release extent > buffer 6885376 owner 5 gen 9 refs 2 flags 0x1d > BTRFS warning (device loop1 state I): unable to release extent > buffer 6885376 owner 5 gen 9 refs 2 flags 0x5 This is UPTODATE | TREE_REF. Combined with the 0xd one, I guess someone else is holding the eb, not yet reached the releasing part. I guess you have already passed all the info into an LLM, and no obvious cause can be pinned down. So far I'd say finding a minimal reproducer would be the best way to continue. No human will be happy waiting over 1000s just for one single triggering. > > In all four instances, the recorded reference count was 2, > corresponding to the expected baseline references described in > invalidate_and_check_btree_folios(). > > Two instances had EXTENT_BUFFER_WRITEBACK set (flags 0x1d), indicating > that the extent buffer was marked as under writeback when its flags > were printed. > > The other two instances (flags 0xd and 0x5) did not have > EXTENT_BUFFER_DIRTY or EXTENT_BUFFER_WRITEBACK set at print time. > > Since WARN_ON_ONCE() is executed before the diagnostic message and the > flags are read later, these observations may reflect changes in the > extent buffer state between the initial condition check and the > diagnostic print. This is definitely something we can improve. We should ensure the message is before WARNING/ASSERT/BUG_ON to make sure syzbot can catch the problem. I can easily craft a patch re-ordering those call sites. Thanks, Qu