Received: by 2002:a89:d88:0:b0:1fa:5c73:8e2d with SMTP id eb8csp2539938lqb; Tue, 28 May 2024 03:12:13 -0700 (PDT) X-Forwarded-Encrypted: i=3; AJvYcCVuR5kyN/AU51mAV0bplF0odk5IEVat+eOeKFjenEnN7ZhSCKuxTp+CXndsMzMOTeuT/KSnabGGjomAYY3nbRxouknNNAKr3Roz2jScDA== X-Google-Smtp-Source: AGHT+IGtNf8TP8A2l2gaz9h1ZzCovJvAAicPuoVjg2vLCGaj1/3j07HjaXX0Hb/BiFmoEyrYxeIg X-Received: by 2002:a37:e112:0:b0:794:b548:b848 with SMTP id af79cd13be357-794b548c3c4mr858754685a.5.1716891133517; Tue, 28 May 2024 03:12:13 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1716891133; cv=pass; d=google.com; s=arc-20160816; b=rYp9obBft6m26PkjZ11f48t8/fYHy7qyp7eLDLsNqamXOYdZPr4Q5aN+tkWpq0EUIG lDI2XyUKyB33lVowlPet2/WNFUlgjsf+jm1iMpfFgYmsxhXOJ+MPZPv+9QKlOI7uniyN mafiVsuD3yC1oCNnpdADoYaLUU2SjrnJVKRZExGRh9qmQotOvMIM8w5S5f8D+O5rtZo2 r1liG356h4yxZ+mbhvYHvH0vT9ni4Z6MzERIP+WBnby1sba4qNS07qte1fomCv1lKYTP zWjaQwdWLUeUrlV1pJ72cjLL3wgXyVPwinF39wFj6w3mGfT6W1JeewjsaRz9EPSW5eA1 uRHw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=in-reply-to:content-disposition:mime-version:list-unsubscribe :list-subscribe:list-id:precedence:references:message-id:subject:cc :to:from:date:dkim-signature:dkim-signature:dkim-signature :dkim-signature; bh=ExYjX0uos6DCU6GHCyPg9wwFspVknw4CNT/cnsm3P7A=; fh=s+QYd/RugIhrPqVes+eeJAI8XyJX7DIs/MdTf2xqmyM=; b=ZFoNHVdo2DC7tJ3WakKkIc/tA/uzFfSUsIWHpTIN/3hlo0Ymz3flPrstZhaJ4YDitP gNrbP4RgO6hwDq3qe9slTRV1pasXD7A5k5RdsU6ZcYvWUmXzxGbooHA3WSWxGVA8+LYy zr/QXVnlabqryE8IRs0v2y6q6nuAxD6bb6v94e3VJRgYIxvBE9Dj5SFLvHg55If5/THG xE3fz/rHMdOosPywJKt73ap49NEJ7ONtk/OUOV4hKK9eoIXkdlv2HtzyXjCoFO/uidRH FUih/JL/oXqsrgcamN+Kpx9v460gTVmrnxqgOANsYp8g8TJbbuu3FZdfSltHRxq7kVod 2ziw==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=QPvj0P87; dkim=neutral (no key) header.i=@suse.cz header.s=susede2_ed25519; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=QPvj0P87; dkim=neutral (no key) header.i=@suse.cz header.s=susede2_ed25519; arc=pass (i=1 spf=pass spfdomain=suse.cz dkim=pass dkdomain=suse.cz dkim=pass dkdomain=suse.cz); spf=pass (google.com: domain of linux-nfs+bounces-3435-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) smtp.mailfrom="linux-nfs+bounces-3435-linux.lists.archive=gmail.com@vger.kernel.org" Return-Path: Received: from ny.mirrors.kernel.org (ny.mirrors.kernel.org. [2604:1380:45d1:ec00::1]) by mx.google.com with ESMTPS id af79cd13be357-794abd4e9bfsi970389585a.645.2024.05.28.03.12.13 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 May 2024 03:12:13 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-nfs+bounces-3435-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1; Authentication-Results: mx.google.com; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=QPvj0P87; dkim=neutral (no key) header.i=@suse.cz header.s=susede2_ed25519; dkim=pass header.i=@suse.cz header.s=susede2_rsa header.b=QPvj0P87; dkim=neutral (no key) header.i=@suse.cz header.s=susede2_ed25519; arc=pass (i=1 spf=pass spfdomain=suse.cz dkim=pass dkdomain=suse.cz dkim=pass dkdomain=suse.cz); spf=pass (google.com: domain of linux-nfs+bounces-3435-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) smtp.mailfrom="linux-nfs+bounces-3435-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ny.mirrors.kernel.org (Postfix) with ESMTPS id 400521C22BFB for ; Tue, 28 May 2024 10:12:13 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 44941161314; Tue, 28 May 2024 10:12:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="QPvj0P87"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="TKTC01+L"; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b="QPvj0P87"; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b="TKTC01+L" X-Original-To: linux-nfs@vger.kernel.org Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (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 89EC617E8F4; Tue, 28 May 2024 10:12:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716891123; cv=none; b=WYByCfCiH1kvsTiYAbd4hL0btgSnpX45Jb9PVj/+CCskzrmS1sy3ZKCkCHN706fJoyFVES5kr53MBItuDsSU1+RRpCAlCJn2q+ntQm22gYI3FZz98bYcolT3RAGhL8nQXXffZY4LHF1SufEEB8tBS2JOu1qpUxFvcmix0g07SxE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716891123; c=relaxed/simple; bh=6ww0aWOR9HDUfIV67S+8vHtHtSWfUePyxXgSYSgpox8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qa9ohIL+TsdXpRkXIeKq8HB6K6n3RMPrAeftWglcIF+CsXeCMEhfmj/bviq6C0ImWgFi3aMmqP3WVG8c1afhJepo0F4IRIAuqjk7lBCf82ctPrbrfrodlqXcZnlRCjXRaXR3ZNO5G+nlj90ct545k5RREyjkYJjwt0bm5eH4TNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=QPvj0P87; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=TKTC01+L; dkim=pass (1024-bit key) header.d=suse.cz header.i=@suse.cz header.b=QPvj0P87; dkim=permerror (0-bit key) header.d=suse.cz header.i=@suse.cz header.b=TKTC01+L; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 65F8222749; Tue, 28 May 2024 10:11:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1716891117; h=from:from:reply-to: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=ExYjX0uos6DCU6GHCyPg9wwFspVknw4CNT/cnsm3P7A=; b=QPvj0P87mJKpCsarWj7GQrCEnpob5RUz/1yS00zF70fdA31q8vQJ2Bq1VC7PoMWnAMHvDQ 55Igr36s4pWfYVXubCEO4dMM6xVrR8U9ZRn1jdUe+fmI01pzM98O303rNjVSlzm2GHpCly 5M0J2K+ObPIRsX6lChXMRqtNP82jrHA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1716891117; h=from:from:reply-to: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=ExYjX0uos6DCU6GHCyPg9wwFspVknw4CNT/cnsm3P7A=; b=TKTC01+LLoOSgAj7Bx3pa6bsQY5wO1AaewNQ2UA2FPcZpvX5+9mHvKjmyFOasscmHgxFp5 ssuPNfrLaoAJssCg== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1716891117; h=from:from:reply-to: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=ExYjX0uos6DCU6GHCyPg9wwFspVknw4CNT/cnsm3P7A=; b=QPvj0P87mJKpCsarWj7GQrCEnpob5RUz/1yS00zF70fdA31q8vQJ2Bq1VC7PoMWnAMHvDQ 55Igr36s4pWfYVXubCEO4dMM6xVrR8U9ZRn1jdUe+fmI01pzM98O303rNjVSlzm2GHpCly 5M0J2K+ObPIRsX6lChXMRqtNP82jrHA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1716891117; h=from:from:reply-to: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=ExYjX0uos6DCU6GHCyPg9wwFspVknw4CNT/cnsm3P7A=; b=TKTC01+LLoOSgAj7Bx3pa6bsQY5wO1AaewNQ2UA2FPcZpvX5+9mHvKjmyFOasscmHgxFp5 ssuPNfrLaoAJssCg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 5482913A5D; Tue, 28 May 2024 10:11:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id a4lYFO2tVWbRZgAAD6G6ig (envelope-from ); Tue, 28 May 2024 10:11:57 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id EDCB1A07D0; Tue, 28 May 2024 12:11:52 +0200 (CEST) Date: Tue, 28 May 2024 12:11:52 +0200 From: Jan Kara To: "hch@infradead.org" Cc: Trond Myklebust , "jack@suse.cz" , "chuck.lever@oracle.com" , "linux-api@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "brauner@kernel.org" , "linux-kernel@vger.kernel.org" , "alex.aring@gmail.com" , "cyphar@cyphar.com" , "viro@zeniv.linux.org.uk" , "jlayton@kernel.org" , "amir73il@gmail.com" , "linux-nfs@vger.kernel.org" Subject: Re: [PATCH RFC v2] fhandle: expose u64 mount id to name_to_handle_at(2) Message-ID: <20240528101152.kyvtx623djnxwonm@quack3> References: <20240523-exportfs-u64-mount-id-v2-1-f9f959f17eb1@cyphar.com> <30137c868039a3ae17f4ae74d07383099bfa4db8.camel@hammerspace.com> <86065f6a4f3d2f3d78f39e7a276a2d6e25bfbc9d.camel@hammerspace.com> Precedence: bulk X-Mailing-List: linux-nfs@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-Spam-Level: X-Spamd-Result: default: False [-2.30 / 50.00]; BAYES_HAM(-3.00)[99.99%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MID_RHS_NOT_FQDN(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MISSING_XM_UA(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCPT_COUNT_TWELVE(0.00)[14]; TAGGED_RCPT(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; FREEMAIL_CC(0.00)[hammerspace.com,suse.cz,oracle.com,vger.kernel.org,kernel.org,gmail.com,cyphar.com,zeniv.linux.org.uk]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_TLS_LAST(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,infradead.org:email,suse.com:email] X-Spam-Score: -2.30 X-Spam-Flag: NO On Mon 27-05-24 09:29:48, hch@infradead.org wrote: > On Mon, May 27, 2024 at 03:38:40PM +0000, Trond Myklebust wrote: > > If your use case isn't NFS servers, then what use case are you > > targeting, and how do you expect those applications to use this API? > > The main user of the open by handle syscalls seems to be fanotify > magic. So some fanotify users may use open_by_handle_at() and name_to_handle_at() but we specifically designed fanotify to not depend on this mount id feature of the API (because it wasn't really usable couple of years ago when we were designing this with Amir). fanotify returns fsid + fhandle in its events and userspace is expected to build a mapping of fsid -> "whatever it needs to identify a filesystem" when placing fanotify marks. If it wants to open file / directory where events happened, then this usually means keeping fsid -> "some open fd on fs" mapping so that it can then use open_by_handle_at() for opening. Honza -- Jan Kara SUSE Labs, CR