From owner-freebsd-bugs@freebsd.org Mon Aug 14 12:06:20 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9994FDC2676 for ; Mon, 14 Aug 2017 12:06:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 867497E25C for ; Mon, 14 Aug 2017 12:06:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v7EC6KXR037948 for ; Mon, 14 Aug 2017 12:06:20 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 221512] Contents of ZFS datasets invisible after being mounted inside a jail with nullfs (Even after a reboot!) Date: Mon, 14 Aug 2017 12:06:20 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.1-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: tsuroerusu@gmail.com X-Bugzilla-Status: Closed X-Bugzilla-Resolution: Not A Bug X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: resolution bug_status Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Aug 2017 12:06:20 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D221512 tsuroerusu@gmail.com changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |Not A Bug Status|New |Closed --- Comment #1 from tsuroerusu@gmail.com --- With a little bit of help, I managed to figure out what the problem was. It turned out that I had run, head first, into the wall of nullfs not operating across file systems. Thus inside the jail, the data was being saved to a regular directory on my "storage/cloud"-dataset (Mountpoint: /storage/cloud= ), whereas outside the jail the child file system "storage/cloud/bc", having b= een left empty, was mounted over the folder "bc" on "storage/cloud", where the files actually resided, thus "hiding" them from view outside the jail. A si= mple "zfs unmount storage/cloud/bc" revealed them. Anybody reading this in the future after a Google search: If you are using = ZFS and want to put a file system and all of its children into a jail then you cannot use nullfs. Instead you need to either change the actual mount point using "zfs set mountpoint=3D/jails/jail1/storage storage/path/to/filesystem= " or to attach the entire dataset to the jail, and allow it to be managed from within the jail using "zfs jail". I would like to propose that the man page for mount_nullfs contain a short sentence about nullfs not crossing file system boundaries. From what I can = tell by, admittedly, giving it a quick look, I didn't see anything about that, so it's possible that I simply missed it if it actually is in there. I apologize for any inconvenience caused by this report. --=20 You are receiving this mail because: You are the assignee for the bug.=