From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from submarine.notk.org (submarine.notk.org [62.210.214.84]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6E3B369D55 for ; Fri, 29 May 2026 03:11:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.210.214.84 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780024311; cv=none; b=o533HV62DaxqHq0Gr+SRxbdayKLe5cVvKEIgL51R93e4oi5o/vZ89C+xFof+ALFGgwaBWZzmjiwwl0GyThcBwEx6b7eFgx9ts/rLBZYwspBwwIxUaScq5kVbQ86loojqiYt/1X3+LIBxQMi7VM/lCkv1r/OMAK6Zdo1uR5Fh8Y8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780024311; c=relaxed/simple; bh=0oMSeB2GluYcxelP4breah5oEHpzkUULyVRc99mSCe8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hR5DvSX9K0woEZflA0QTclotSKrKarWFCjL9Jg2djYrUazhr+VcW8u3M6JlFBmfmH3V+HJNeIXv+K4o8H7g2jUmeBQN2I6FDRZemfBE03XDRJSy9P1T8cf6+2sxi6ix++QWMw5eKYrK7m1JywNeIQf/huMFRbLDbCULp8vXH0kU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codewreck.org; spf=pass smtp.mailfrom=codewreck.org; dkim=pass (2048-bit key) header.d=codewreck.org header.i=@codewreck.org header.b=wUaVcfyH; arc=none smtp.client-ip=62.210.214.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=codewreck.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=codewreck.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=codewreck.org header.i=@codewreck.org header.b="wUaVcfyH" Received: from gaia.codewreck.org (localhost [127.0.0.1]) by submarine.notk.org (Postfix) with ESMTPS id 04B9614C2D6; Fri, 29 May 2026 05:11:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codewreck.org; s=2; t=1780024308; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=RbpKW2TSgrCLa/K2Y0OoiDA6cDFrB+2d8wgaxfFfCMQ=; b=wUaVcfyHlqsOm7qzFSru6pWj4uFTfJkfxC3AcPdtLnXVLs08M36prU3XAqIfoKNxJezTRf 5xKwicpmB89UVg7+n0Jxc/dRUoemVjt4EhTub7rx0vpABjRV9OXhk13vuhmCl43X74UN6k t+XvuJWINXNYht6wBL8l0jPazM0SpVJbwtHSFggEvpt5+WMByFTkaNSRiEFqm+CM4Z1Vkw HU8qr5KQz+MgJ2Hl8reA7cjdflovyEpDvZETLtbc/c2wwQWsligIlECsOWqUgz0DVT+XvS ZRhSXaAc4wzROV/arM/ISB9AdeK6y5qGoI9hqFBN0o6fd8qk6yr1llkbQSjWWg== Received: from localhost (gaia.codewreck.org [local]) by gaia.codewreck.org (OpenSMTPD) with ESMTPA id 0c1f7306; Fri, 29 May 2026 03:11:45 +0000 (UTC) Date: Fri, 29 May 2026 12:11:30 +0900 From: Dominique Martinet To: Yifei Chu Cc: v9fs@lists.linux.dev, Eric Van Hensbergen , Latchesar Ionkov , Christian Schoenebeck , linux-kernel@vger.kernel.org Subject: Re: [BUG] 9p: unknown RLOCK status triggers WARN_ONCE panic with panic_on_warn Message-ID: References: Precedence: bulk X-Mailing-List: v9fs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Yifei Chu wrote on Sun, May 24, 2026 at 10:43:57AM -0400: > Short version: I found that a 9P2000.L server can return an unknown RLOCK > status byte and make the Linux 9P client hit a WARN_ONCE() in > v9fs_file_do_lock(). With panic_on_warn=1, that turns into a reproducible > kernel panic. You're right we should not WARN() due to server sending us bogus data (only on internal state bug) Please send a patch directly next time, especially since this is trivial I've saved us both time for this time: https://lore.kernel.org/r/20260529-lock-warn-v1-1-20c29580d61d@codewreck.org -- Dominique