From owner-freebsd-fs@freebsd.org Wed Nov 20 13:24:48 2019 Return-Path: Delivered-To: freebsd-fs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3627A1B6BBC for ; Wed, 20 Nov 2019 13:24:48 +0000 (UTC) (envelope-from mike@sentex.net) Received: from pyroxene2a.sentex.ca (pyroxene19.sentex.ca [IPv6:2607:f3e0:0:3::19]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "pyroxene2.sentex.ca", Issuer "pyroxene2.sentex.ca" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 47J3MM02Vfz3JjF; Wed, 20 Nov 2019 13:24:46 +0000 (UTC) (envelope-from mike@sentex.net) Received: from [192.168.43.26] (saphire3.sentex.net [192.168.43.26]) by pyroxene2a.sentex.ca (8.15.2/8.15.2) with ESMTP id xAKDOjDP033572; Wed, 20 Nov 2019 08:24:45 -0500 (EST) (envelope-from mike@sentex.net) Subject: Re: ZFS snapdir readability (Crosspost) To: Borja Marcos Cc: Alan Somers , Jan Behrens , freebsd-fs References: <20191107004635.c6d2e7d464d3d556a0d87465@magnetkern.de> <9B22AD46-BE87-4305-9638-74D23AD4C8CA@sarenet.es> <261FE331-EC5C-48C8-9249-9BCBF887CE38@sarenet.es> From: Mike Tancsa Openpgp: preference=signencrypt Autocrypt: addr=mike@sentex.net; prefer-encrypt=mutual; keydata= mQENBEzcA24BCACpwI/iqOrs0GfQSfhA1v6Z8AcXVeGsRyKEKUpxoOYxXWc2z3vndbYlIP6E YJeifzKhS/9E+VjhhICaepLHfw865TDTUPr5D0Ed+edSsKjlnDtb6hfNJC00P7eoiuvi85TW F/gAxRY269A5d856bYrzLbkWp2lKUR3Bg6NnORtflGzx9ZWAltZbjYjjRqegPv0EQNYcHqWo eRpXilEo1ahT6nmOU8V7yEvT2j4wlLcQ6qg7w+N/vcBvyd/weiwHU+vTQ9mT61x5/wUrQhdw 2gJHeQXeDGMJV49RT2EEz+QVxaf477eyWsdQzPVjAKRMT3BVdK8WvpYAEfBAbXmkboOxABEB AAG0HG1pa2UgdGFuY3NhIDxtaWtlQHNlbnRleC5jYT6JATgEEwECACIFAkzcA24CGwMGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEJXHwM2kc8rX+sMH/2V6pTBKsQ5mpWWLgs6wVP2k BC+6r/YKNXv9Rw/PrC6+9hTbgA+sSjJ+8gxsCbJsOQXZrxF0x3l9oYdYfuKcwdwXFX1/FS8p HfBeDkmlH+dI709xT9wgrR4dS5aMmKp0scPrXPIAKiYVOHjOlNItcLYTEEWEFBepheEVsgmk GrNbcrHwOx/u4igUQ8vcpyXPyUki+BsftPw8ZQvBU887igh0OxaCR8AurJppQ5UQd63r81cX E1ZjoFoWCaGK/SjPb/OhpYpu5swoZIhOxQbn7OtakYPsDd5t2A5KhvjI8BMTnd5Go+2xsCmr jlIEq8Bi29gCcfQUvNiClevi13ifmnm5AQ0ETNwDbgEIALWGNJHRAhpd0A4vtd3G0oRqMBcM FGThQr3qORmEBTPPEomTdBaHcn+Xl+3YUvTBD/67/mutWBwgp2R5gQOSqcM7axvgMSHbKqBL 9sd1LsLw0UT2O5AYxv3EwzhG84pwRg3XcUqvWA4lA8tIj/1q4Jzi5qOkg1zxq4W9qr9oiYK5 bBR638JUvr3eHMaz/Nz+sDVFgwHmXZj3M6aE5Ce9reCGbvrae7H5D5PPvtT3r22X8SqfVAiO TFKedCf/6jbSOedPN931FJQYopj9P6b3m0nI3ZiCDVSqeyOAIBLzm+RBUIU3brzoxDhYR8pz CJc2sK8l6YjqivPakrD86bFDff8AEQEAAYkBHwQYAQIACQUCTNwDbgIbDAAKCRCVx8DNpHPK 1+iQB/99aqNtez9ZTBWELj269La8ntuRx6gCpzfPXfn6SDIfTItDxTh1hrdRVP5QNGGF5wus N4EMwXouskva1hbFX3Pv72csYSxxEJXjW16oV8WK4KjKXoskLg2RyRP4uXqL7Mp2ezNtVY5F 9nu3fj4ydpHCSaqKy5xd70A8D50PfZsFgkrsa5gdQhPiGGEdxhq/XSeAAnZ4uVLJKarH+mj5 MEhgZPEBWkGrbDZpezl9qbFcUem/uT9x8FYT/JIztMVh9qDcdP5tzANW5J7nvgXjska+VFGY ryZK4SPDczh74mn6GI/+RBi7OUzXXPgpPBrhS5FByjwCqjjsSpTjTds+NGIY Organization: Sentex Communications Message-ID: <913f7040-6e38-452d-6187-e17fae63b652@sentex.net> Date: Wed, 20 Nov 2019 08:24:43 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <261FE331-EC5C-48C8-9249-9BCBF887CE38@sarenet.es> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US X-Rspamd-Queue-Id: 47J3MM02Vfz3JjF X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of mike@sentex.net designates 2607:f3e0:0:3::19 as permitted sender) smtp.mailfrom=mike@sentex.net X-Spamd-Result: default: False [-2.71 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.997,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; R_SPF_ALLOW(-0.20)[+ptr]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; HFILTER_HELO_IP_A(1.00)[pyroxene2a.sentex.ca]; DMARC_NA(0.00)[sentex.net]; HAS_ORG_HEADER(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; HFILTER_HELO_NORES_A_OR_MX(0.30)[pyroxene2a.sentex.ca]; IP_SCORE(-1.71)[ipnet: 2607:f3e0::/32(-4.93), asn: 11647(-3.55), country: CA(-0.09)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:11647, ipnet:2607:f3e0::/32, country:CA]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Nov 2019 13:24:48 -0000 On 11/20/2019 5:07 AM, Borja Marcos wrote: > The problem is, snapshot access breaks the semantics of chown() and > chmod(). >> As the snapshots are always readonly, I think chown and chmod dont >> really apply in this use case. Also, the fact that the mounts can be set >> to be "visibile" or "invisible" has its own, different convention from >> UFS/NFS who dont have that "invisibility" feature (that I know of anyway). > That’s what I mean with breaking the semantics. > > When you change permissions on a file they apply to open() operations attempted after the > permissions/ownership change. > You could make snapshots not mounted, period, requiring administrator’s actions to mount them. But you > would lose convenience for common users. Actually, thats all I am advocating for-- settings perms on the accessibility of the snapshot. ie instead of the "invisibility" feature, change it to an "inaccessible" feature.     ---Mike -- ------------------- Mike Tancsa, tel +1 519 651 3400 x203 Sentex Communications, mike@sentex.net Providing Internet services since 1994 www.sentex.net Cambridge, Ontario Canada