From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C481A16EC0D for ; Tue, 28 May 2024 13:28:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716902913; cv=none; b=MEQTCV8ny0yb0JfoZVsED62dAkDiTYLBbL0o0esLgrYutemBTEH+gIe9t2p4qXCZIE3H+0cq61dOxlkMG86Jpj18EoPu6rjiuuFUwyhfsjWHC5VBmr4gNKRyLP/s/yqAgS2PZuecyjRSEsfWEBEiSzt8rBIyX0GhXdkqjIbveKY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716902913; c=relaxed/simple; bh=PBBLOV4U2IFgFSKdFT4Y43aEoeT6Ow1hJwKRcZckZ7w=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=AI/v1+qhLXZSuHiL+dI3xBlo+TPMGpfWeWQuCgJBQvseSJR18q4TPkptYonDvjLavklzumeDqABLo/yYA8MpnD5vBlPXSqKPFLTaqhjaiTWsNhoFGt5MPtAFuq6d+TUVwBWp/fOsLiRZSa1KnzT4cdMT5jyUMqLQ1ebwX4yTLCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu; spf=pass smtp.mailfrom=szeredi.hu; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b=Wm1QN3Ry; arc=none smtp.client-ip=209.85.218.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="Wm1QN3Ry" Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-a6303e13ffeso98827266b.3 for ; Tue, 28 May 2024 06:28:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; t=1716902910; x=1717507710; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=PBBLOV4U2IFgFSKdFT4Y43aEoeT6Ow1hJwKRcZckZ7w=; b=Wm1QN3RyfSowp3OP685y93x0QSYnT927aLF6A0cd+Dr/PPr3kY9GeQaKnWyWwIqKEi kSOmSfvQGe/RlzTCV8BXz1hM78yQtJgcvRvsgU73ezbBBMY2GvU/lxelFVGj8Hm3F8R2 WtI+cRhoXatHfGMVm6zMu6kO2ofAGu6bZ0Hos= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1716902910; x=1717507710; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=PBBLOV4U2IFgFSKdFT4Y43aEoeT6Ow1hJwKRcZckZ7w=; b=Nlf14ifvJlO/tWPW9MsExLPT0Hqv4iCaXCuv1rm0vKmNZVngVFGIeR6AAeqGbAnUQC Drn31M783HkvZXBAIz0DG9JomHwIjt0jf0/i4LAimsu7MDDG95cVbYo8iitk3z0TDoY4 Dk/6npYm+jgCCkKTjSrATKb/B3IDcncySAmSuejdkkroh+VRfBXd6FoQuGrs9FwMs1vQ wXn7SaF56PTj2O9i8ttuV070lFug+H7Uiwd9DfwxAOkuZGuBf2sinLknWOmOBXhgDWpW TmeY6XW5YkoB0dZic3Uf71J4szUZJCGV8hDAkEYk2dh0cckdvL03OLrmKtcIq/G/hxzF GrPA== X-Forwarded-Encrypted: i=1; AJvYcCXjuF+CmY7ifEONdrlnxSvv+ZqqLv5XY2Koojf00f/NS3VsTazOWRTgSonybz+/qLPWJEua+LtZknnUzgTt2w0cABrqcpp0Qxa6 X-Gm-Message-State: AOJu0YwlMdVFh65cKyTUkYaVz7EVFSagXDBiWJwkRGAA0I7HO+d9NfCp c6RSIBpWun7WHcGCTtLwxMn+PBxSqdFKhPVg3vaWMKB6SGs/doFjTm3JBoPW3+3nj3IaPWit7Cd zrBbOX55Lb4LoZ9B0z6QWVIEeGnRB5qsuLKGFhA== X-Google-Smtp-Source: AGHT+IET1YleTWVR5AXg8CRN1Esbkyz90K8kriJOg4HbyfAsDwmoVK/cGg98h3bhg32ByJBXHFEIavMxNd8QwGr8f7g= X-Received: by 2002:a17:906:788:b0:a59:adf8:a6e1 with SMTP id a640c23a62f3a-a62651144f1mr794014566b.47.1716902909983; Tue, 28 May 2024 06:28:29 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240526.184753-detached.length.shallow.contents-jWkMukeD7VAC@cyphar.com> <20240527133430.ifjo2kksoehtuwrn@quack3> <20240528-wachdienst-weitreichend-42f8121bf764@brauner> <20240528-gesell-evakuieren-899c08cbfa06@brauner> <20240528-gipfel-dilemma-948a590a36fd@brauner> In-Reply-To: From: Miklos Szeredi Date: Tue, 28 May 2024 15:28:18 +0200 Message-ID: Subject: Re: [PATCH RFC v2] fhandle: expose u64 mount id to name_to_handle_at(2) To: Christoph Hellwig Cc: Christian Brauner , Jan Kara , Aleksa Sarai , Alexander Viro , Chuck Lever , Jeff Layton , Amir Goldstein , Alexander Aring , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Content-Type: text/plain; charset="UTF-8" On Tue, 28 May 2024 at 15:24, Christoph Hellwig wrote: > > On Tue, May 28, 2024 at 02:04:16PM +0200, Christian Brauner wrote: > > Can you please explain how opening an fd based on a handle returned from > > name_to_handle_at() and not using a mount file descriptor for > > open_by_handle_at() would work? > > Same as NFS file handles: > > name_to_handle_at returns a handle that includes a file system > identifier. > > open_by_handle_at looks up the superblock based on that identifier. The open file needs a specific mount, holding the superblock is not sufficient. Thanks, Miklos