From mboxrd@z Thu Jan 1 00:00:00 1970 From: sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Subject: Re: [PATCH 11/11][v3]: Enable multiple instances of devpts Date: Sat, 6 Sep 2008 14:45:56 -0700 Message-ID: <20080906214556.GA27373@us.ibm.com> References: <48C00698.8050803@zytor.com> <20080904172542.3ad7bb85@lxorguk.ukuu.org.uk> <48C01163.1050704@zytor.com> <20080904171828.GC11174@us.ibm.com> <48C01B58.2040006@zytor.com> <20080905020131.GA17535@us.ibm.com> <20080905132710.50018aef@lxorguk.ukuu.org.uk> <48C16B42.7030103@zytor.com> <20080905194450.GA18119@us.ibm.com> <48C28E3D.6060404@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <48C28E3D.6060404-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "H. Peter Anvin" Cc: kyle-hoO6YkzgTuCM0SS3m2neIg@public.gmane.org, sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, bastian-yyjItF7Rl6lg9hUCZPvPmw@public.gmane.org, containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org, xemul-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, Alan Cox , ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org List-Id: containers.vger.kernel.org H. Peter Anvin [hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org] wrote: > sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org wrote: >> Agree in general. Not sure if you are implying remount is necessary just >> to change permissions of pts/ptmx. Why not "chmod 0666 /dev/pts/ptmx" ? >> The remount changes the 'ptmxmode' setting, but since the node exists, >> the 'ptmxmode' setting is never used again and we need to chmod. > > A chmod requires bigger changes to existing scripts than an option which > can be set in /etc/fstab. Ok. From implementation pov, we can cache the ptmx dentry in s_fs_info and use it during remount to change the permissions. We could lookup ptmx during remount, but caching is simpler ? > >> ptmx node in multi-instance mounts continue to get PTMX_DEFAULT_MODE >> permissions (not 000) right ? (unless -o ptmxmode is specified) > > It's probably easier to always default it to zero and expect that the mode > is set explicitly. Ok. BTW, I have added CONFIG_DEVPTS_MULTIPLE_INSTANCES and moved the usage info from 11/11 to Documentation/fs/devpts.txt. Will make above ptmx changes, port to recent ttydev tree and send updated patchset in a couple of days. Thanks, suka