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 DAF063DA5CE; Mon, 15 Jun 2026 08:51:42 +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=1781513506; cv=none; b=ENn+j0cVzxBFKNjl+ytIHkpgj3uiIg+1/ATQRrEKUP53NPfmD7dsS6mez8CFB9p9oZvGKHdkx3lIQDBvKFVgJ1N8HPCzZZ5E8bv3P4cQe51455f8eCxeDh+uUUoxt1rWWVUceRSBsrHdWMMK6sqMc9mnsLyr/ah/HePIZh/kLAw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781513506; c=relaxed/simple; bh=iB5iiAuuaaf4I/DCOhKKDpagC8tBIw10GFLuD3cYz2w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BZPUNYgLUgPl0Fs4Ky8kDTiFNpOOplAArVgzYYV/+jLMebr8RQgWL3QlFXl2ksAulHJHfQ2KteR2hNZ7YUiQEv8lznoq/upJhT00TEP7aLl4C1GMobQh1xLTpy0RPfe88gBK4oH86GcXZVpiNpZ/UU2IOU/MMSW0vpADKh5rva8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=gfCcJ1v+; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="gfCcJ1v+" 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=ERWHpm0rcxQI7VGqVOkDuXv6ZjP9THe81NYexLreENw=; b=gfCcJ1v+IuslnxVYW9JMXOKG3Z ztMtmfT0yJQHaT8NVF2RRqORdA7A+Ok4kST9gLLFpTPtkBT47/Bl7sesoTAymcYUsUB6phHZN9Kzw /LTGkaH388Y+jOMOXXo2FyQ+QCKdBc3dfSkE+I08CiSiuxlM7fqs0kTdtSHtVsRjTRiFzdDB8Jr+z GrL8b7SodDlSqof89Sst5vTamAQGQ3xHBv82awFm+TmE/NyQzt1xgURFBKu2Ms5UULwnALvV6EWa5 op0tsko5y7fioQOouBGZzZ503E2JAPqF/RcDivCF69MBK2Kn5XXaRSoCJMjlRZLxtti1sYPqr27Dn vgy+iSaA==; 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 1wZ32I-00Cx6I-1L; Mon, 15 Jun 2026 08:51:14 +0000 Date: Mon, 15 Jun 2026 01:51:09 -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: linux-kernel@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) Please, don't forget this one for 7.2. This is one is hurting me from time to time. Thanks, --breno