From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 BBB8F253932 for ; Tue, 11 Nov 2025 08:54:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762851266; cv=none; b=C0JYQ4XRPYIeWGoy1hHccZ6IEJB16qL80+O+J0XW+FlAl3E7K9VeORwePJNAgm1zRrCgXl6iNgDtPEbwvFUSv839c/SHqBbofcudkik4K1oP2C7cFHH+T24pI+V++nNo2g+pEpA6kR+jIdZGMgDZDtxAaZ72kTjSflN494ZYiKs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762851266; c=relaxed/simple; bh=DhiMOr8uROXptEMu2gl3xMmZcEv5y0qXexHRreDYgDA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DN6JYWAxvds7faE9PvW4VaBrXyVx/i+2Y0ZSRgEBx8hO5I/TE6kH7PZYvQgrq9MDdCvHScRoreHLu2CNiMnXfR20zAAZJRtbxwqtwK5JXs2iynYuPj6OtFA52rabSlD9F9szqr6e8MlBPTy6gKPD1fIyJhMOXXAQgzcUM0ct408= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 9F3F2227A87; Tue, 11 Nov 2025 09:54:20 +0100 (CET) Date: Tue, 11 Nov 2025 09:54:20 +0100 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Christoph Hellwig , Carlos Maiolino , linux-xfs@vger.kernel.org Subject: Re: [PATCH 18/18] xfs: reduce ilock roundtrips in xfs_qm_vop_dqalloc Message-ID: <20251111085420.GA11611@lst.de> References: <20251110132335.409466-1-hch@lst.de> <20251110132335.409466-19-hch@lst.de> <20251110181930.GW196370@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20251110181930.GW196370@frogsfrogsfrogs> User-Agent: Mutt/1.5.17 (2007-11-01) On Mon, Nov 10, 2025 at 10:19:30AM -0800, Darrick J. Wong wrote: > Zooming out a bit: As far as taking the ILOCK is concerned -- I think we > still need to do that to prevent [ugp]id changes to the inode while > we're doing a potentially expensive ondisk dquot allocation, right? That's my assumption, and it was how things historically worked. That being said Linux calls all VFЅ operations that could change them under i_rwsem aka the IOLOCK, so maybe we don't even need it at all, but that would require a more indepth audit.