On 2014-11-28 12:55, Gilles Chanteperdrix wrote: > On Fri, Nov 28, 2014 at 12:50:39PM +0100, Jan Kiszka wrote: >> On 2014-11-28 10:57, Gilles Chanteperdrix wrote: >>> On Fri, Nov 28, 2014 at 10:55:56AM +0100, Jan Kiszka wrote: >>>> On 2014-11-28 10:50, Gilles Chanteperdrix wrote: >>>>> On Fri, Nov 28, 2014 at 10:40:27AM +0100, Jan Kiszka wrote: >>>>>> On 2014-11-28 00:15, Gilles Chanteperdrix wrote: >>>>>>> On Thu, Nov 27, 2014 at 09:43:34PM +0100, Jan Kiszka wrote: >>>>>>>> On 2014-11-27 21:34, Gilles Chanteperdrix wrote: >>>>>>>>> On Thu, Nov 27, 2014 at 02:14:38PM -0500, Lennart Sorensen wrote: >>>>>>>>>> On Thu, Nov 27, 2014 at 07:51:27PM +0100, Jan Kiszka wrote: >>>>>>>>>>> On 2014-11-27 19:18, Gilles Chanteperdrix wrote: >>>>>>>>>>>> According to the filesystem hierarchy standard, /mnt is the >>>>>>>>>>>> standard >>>>>>>>>>>> place for "temporarily mounted filesystems". >>>>>>>>>>>> >>>>>>>>>>>> http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard >>>>>>>>>>> >>>>>>>>>>> Right, another reason to NOT mess around with it: if something was >>>>>>>>>>> temporarily mounted there, we will create the mountpoint inside that >>>>>>>>>>> filesystem with unforeseeable side effects. >>>>>>>>>> >>>>>>>>>> I always read that as "temporarily mounted there by the admin or some >>>>>>>>>> other human". Certainly not automatic mounts by software. There is >>>>>>>>>> a >>>>>>>>>> reason /media and such exists on many distributins. >>>>>>>>> >>>>>>>>> I would not venture an "always", autofs for instance, used to mount >>>>>>>>> things under /mnt. and /media has not always existed either, we used >>>>>>>>> /mnt/cdrom. >>>>>>>> >>>>>>>> FHS on /mnt purpose: >>>>>>>> >>>>>>>> "This directory is provided so that the system administrator may >>>>>>>> temporarily mount a filesystem as needed. The content of this directory >>>>>>>> is a local issue and should not affect the manner in which any program >>>>>>>> is run." >>>>>>>> >>>>>>>> I think this makes it crystal clear that Xenomai is not supposed to >>>>>>>> touch it. >>>>>>> >>>>>>> Just to add another argument. I just asked a friend who is a >>>>>>> professional sysadmin. He creates directory under /mnt and mount >>>>>>> things under these directories. So, I am not sure the standard is >>>>>>> even applied by the people who should use it. >>>>>>> >>>>>>> If you read on the last site I sent, under the /media article: >>>>>>> >>>>>>> Amid much controversy and consternation on the part of system and >>>>>>> network administrators a directory containing mount points for >>>>>>> removable media has now been created. Funnily enough, it has been >>>>>>> named /media. >>>>>>> >>>>>>> Are you sure, 100% sure, that every Xenomai user expects to be able >>>>>>> to use /mnt as a mount point? Or that they will create directories >>>>>>> under /mnt like everybody has been doing since Linux exists? >>>>>> >>>>>> I'm both absolutely sure that a) has to be left alone by Xenomai because >>>>>> of requirements of the FHS and the way /mnt is used and b) we should try >>>>>> hard to avoid creating temporary dirs in persistent filesystems. >>>>> >>>>> This is ridiculous. Because the standard changed, and one >>>>> distribution, Debian, decided to follow the new standard, which >>>>> seems to be not widely accepted, and even controversial, you want to >>>>> impose what Debian does to everybody. The distribution I use has >>>>> mount points under /mnt. So, why following Debian and not the >>>>> distribution I use, and what sysadmin have been doing for ages? >>>>> >>>>> You want the mount point to be somewhere else? Fine, put a symbolic >>>>> link. >>>>> >>>>> mkdir /run/xenomai >>>>> ln -s /run/xenomai /mnt/xenomai >>>> >>>> Again, this is not acceptible as /mnt changes all the time and exposes >>>> various remote filesystems which will hide that link. >>> >>> You are missing the point. Yes, Debian does that, but not all >>> distribution. Other distributions do not do that. >>> >> >> SUSE, Ubuntu, Gentoo, Red Hat - it's already standard. But I will change >> my patch to /var/run to avoid surprises with other/older distros. > > Again, using /mnt/xenomai does not break any distribution following > the standard. > > Let us try things another way, the possibilities we have are: > - /mnt/xenomai: a solution that used to be standard but ceased to be > with the FHS which did not provide a standard replacement, but does > not break any distribution
I don't remember that this was ever a standard. My distro (SUSE) never used it like this as long as I can remember (~18 year). > - /run/xenomai: a solution that relies on the existence on the /run > directory, which is not standard, but is going to be, maybe. > - /var/run/xenomai: a solution which does not violate any version of > the standard, but is not standard either, does not make clear that > the directory is a mount point (which /mnt does), breaks the This is how it's used in practice: gvfsd-fuse on /var/run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=100) Just to give one example. > existing documentation, breaks the existing usages of Xenomai 3, and > is longer to type. > > So, I really find that /mnt/xenomai is the best compromise. There is > no standard solution, at least /mnt/xenomai is a solution that used > to be standard. No, it remains a current standard (FHS 2.3) *violation*, it has to be stopped. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
