From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Cipher TLSv1:DES-CBC3-SHA:168) (Exim 3.31-VA-mm2 #1 (Debian)) id 19vGtC-00031d-00 for ; Fri, 05 Sep 2003 06:44:38 -0700 Received: from oetest.freeswan.org ([205.150.200.166] helo=noxmail.sandelman.ottawa.on.ca) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.22) id 19vGtA-0006Jk-Ch for user-mode-linux-devel@lists.sourceforge.net; Fri, 05 Sep 2003 06:44:36 -0700 Subject: Re: [uml-devel] hostfs as root In-reply-to: Your message of "Thu, 04 Sep 2003 21:10:50 EDT." <20030905011050.GD16552@alcor.net> Mime-Version: 1.0 (generated by tm-edit 1.8) Content-Type: text/plain; charset=US-ASCII Message-ID: <11307.1062769436@marajade.sandelman.ottawa.on.ca> From: Michael Richardson Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: Date: Fri, 05 Sep 2003 09:43:56 -0400 To: Matt Zimmerman Cc: user-mode-linux-devel@lists.sourceforge.net -----BEGIN PGP SIGNED MESSAGE----- >>>>> "Matt" == Matt Zimmerman writes: >> okay.. Makes sense. But, since they are mode 0, we can't open them as >> the user, which root inside could do. Is there some compromise that we >> can >> do until we have the permissions layer in place? >> Like, forcing u+r on the underlying file maybe? Matt> The problem I ran into which led me to this bug was extracting tar Matt> archives. Matt> When they contain read-only files, tar opens them for writing with Matt> read-only Matt> permissions. Since UML was creating the file and then, subsequently, Matt> attempting to open it for writing, the second open failed. How is this the correct thing to do for the UML then? What bug did you uncover? Matt> I think that in general, having the permissions silently changed Matt> would be Matt> unwise, though I admit that u-r permissions are weird at best. It Well, if the opener is root, you get to ignore the permissions. That means that something has to break. I propose: stat(), save permissions chmod(u+rw) (as appropriate for the open) open() chmod(oldperms) Matt> would Matt> seem better to have mount fixed to stop doing this strange thing, and Matt> eventually to emulate full permission control in hostfs. Well, leaving us in a lurch is decidely not friendly. Your fix has broken debian potato's mount. Being able to run other distros, versions, etc. inside of UML is one of the major features of UML. ] Out and about in Ottawa. hmmm... beer. | firewalls [ ] Michael Richardson, Sandelman Software Works, Ottawa, ON |net architect[ ] mcr@sandelman.ottawa.on.ca http://www.sandelman.ottawa.on.ca/ |device driver[ ] panic("Just another Debian/notebook using, kernel hacking, security guy"); [ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.2 (GNU/Linux) Comment: Finger me for keys - custom hacks make this fully PGP2 compat iQCVAwUBP1iTG4qHRg3pndX9AQFsbQP9FP28wQ6dkztxuLL+No3+3sc/nmh7ZSyC YKmwdPdXBWJ8bMdQUdW2RAnGOXKHUtZ70S4pUOMljQe2pWkRs4aCspAdKpaQwG2c iLmqMabpoH5eACRgxfeuqgHVdDu0ognFJELkT61pAQrN66nAfGIYvN59cRIPjR56 PXZdGyk1/G4= =lErV -----END PGP SIGNATURE----- ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel