From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 0C0C4341ADF; Mon, 20 Apr 2026 16:26:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776702383; cv=none; b=WyJTlX4Nf7ThEYiewAXMqiAZXJ2BzKl8CiJCpUmJrLcup1t2cqSImKQSUpZEs+mLf6si9PXfcq9hr+T3YR6xqZY5hKf7FNqgG9lkJwaYx6zi//bo1SgyEZ6K42dIEXVb64+vuQFEcbTv3Gz6W6OQpFxqt2E9MA3TCOecRFYhHfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776702383; c=relaxed/simple; bh=WCG/mn04EZT2PRnQNwFez5dDdE2fCsqKIJdB0Yt9OAs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SXv/fy7sbL/Hg70zml5gG84ug3e38iZNrBZbori9Qyq8iV4pHLpCtnArs9FiadG1INLfRKAvCWz0W/I7Q9p3yIXCXgq65/P1k6OCU+RAsrRBd9CNPkMSH+RWKL2A3jzXdFH8iGBI2V391Unq03fARwWdW8C5WoexRcM8mS+J0vw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=dDEIDvLa; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="dDEIDvLa" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=bfKBlctQH+DmmbUOLO8Xd/pZe8bt+P73byWQDYXv2Ho=; b=dDEIDvLaGT8anzdW64LzJBghhD bAMMg/WEt8K0RZLsWc3EGO07rUMbbVTP99T7SmkyttKSTLblp0v2+UPjQZb6AoVZuCj+t3td1GkK/ 9MdaSPhJhI7hBV6CZYP77X2Cv6ixpsI1oJighWOHGRKS/QIGzbqRCk67FYymmet8icBFObT2NWUzV KVaIbzEoLKtVPmG8yBZ4Mw4rMmd/sVwyjJx3abjOHmhIyKadJEQB9wsTXMjHMKt6Axq5yRAzaCx/p uhBDgM+Xb916WXQfHfUgDXr8OwBaXIoxONTxpbusAMQKjaH5zro6ib54iFW+RdMqq6QXmhzYYwJIF wbA1t39w==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wErRm-000DAP-3B; Mon, 20 Apr 2026 16:26:07 +0000 Date: Mon, 20 Apr 2026 09:26:02 -0700 From: Breno Leitao To: Dominique Martinet Cc: Eric Van Hensbergen , Latchesar Ionkov , Christian Schoenebeck , Andrew Morton , Eryu Guan , Yiwen Jiang , v9fs@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] 9p: fix WARN_ON when dropping nlink on files with nlink=0 Message-ID: References: <20260126-9p-v1-1-dc234d53ae87@debian.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Debian-User: leitao On Tue, Apr 21, 2026 at 12:59:51AM +0900, Dominique Martinet wrote: > Breno Leitao wrote on Mon, Apr 20, 2026 at 07:31:14AM -0700: > > In cacheless mode the server is authoritative and the inode is on its > > way out, so locally adjusting nlink buys nothing. Skip v9fs_dec_count() > > entirely when neither CACHE_META nor CACHE_LOOSE is set, which both > > avoids the warning and removes a class of nlink races (two concurrent > > unlinkers observing nlink > 0 and both calling drop_nlink()) that an > > nlink == 0 guard alone would only narrow rather than close. > > I need to check this doesn't actually leak memory or something but this > sounds better to me, thanks. > > Please send as a proper PATCH mail and I'll tentatively apply for 7.2 > (a bit too late for 7.1) Ack, 7.2 is more than fine. Thanks for your help, --breno