[systemd-devel] Hard-coded /bin/mount in systemd
Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? Cheers, Hannes -- Dr. Hannes Reinecke zSeries Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). -- Mantas Mikulėnas graw...@gmail.com ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On 11/27/2013 02:58 PM, Mantas Mikulėnas wrote: On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). Ah. IIRC it was _systemd_ which initiated the move to /usr, so I found it slightly odd to rely on a location which it has just obsoleted ... Or, rather, to have a hard-coded location to start with. Cheers, Hannes -- Dr. Hannes Reinecke zSeries Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
'Twas brillig, and Hannes Reinecke at 27/11/13 14:12 did gyre and gimble: On 11/27/2013 02:58 PM, Mantas Mikulėnas wrote: On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). Ah. IIRC it was _systemd_ which initiated the move to /usr, so I found it slightly odd to rely on a location which it has just obsoleted ... Or, rather, to have a hard-coded location to start with. It's essentially just a practicality thing. Although systemd thinks that a split /usr setup is crack, it *is* still supported (see the --enable-split-usr option to configure) Despite being blamed for the sky falling in because systemd printed a warning message (and that is all!) when it was started when /usr is not available, it does still try and cope and mount it. If all is well then there will be no major ill effects So if it it were not hard coded it would still have to support calling it both as /bin/mount or /usr/bin/mount via some kind of conditional (based on the --enable-split-usr configure switch) which will be uglier in the code. If we know that a properly managed/unified /usr will always have a /bin - /usr/bin symlink, then this conditional is not needed and the filesystem just takes care of it for us. This is how it's done just now. Hope that explains it a bit. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited http://www.tribalogic.net/ Open Source: Mageia Contributor http://www.mageia.org/ PulseAudio Hacker http://www.pulseaudio.org/ Trac Hacker http://trac.edgewall.org/ ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, Nov 27, 2013 at 03:12:02PM +0100, Hannes Reinecke wrote: On 11/27/2013 02:58 PM, Mantas Mikulėnas wrote: On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). Ah. IIRC it was _systemd_ which initiated the move to /usr, so I found it slightly odd to rely on a location which it has just obsoleted ... Or, rather, to have a hard-coded location to start with. It's a pragmatic choice: we know that /bin/mount will work both for separate-/usr and merged-/usr. We *could* introduce a configure time check for the location of mount, but there would be no practical gain. Not having /bin at all is very unlikely, since /bin/sh is hardcoded in many more places. C.f. https://bugs.freedesktop.org/show_bug.cgi?id=55248, where gentoo had kexec in a different place. In that case a practical reason existed. Zbyszek ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, Nov 27, 2013 at 3:12 PM, Hannes Reinecke h...@suse.de wrote: On 11/27/2013 02:58 PM, Mantas Mikulėnas wrote: On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). Ah. IIRC it was _systemd_ which initiated the move to /usr, so I found it slightly odd to rely on a location which it has just obsoleted ... It's not obsoleted, it's still part of the legacy API, which will not go away anytime soon. In a proper system with only one /usr, the location does not matter, everything works the same. Or, rather, to have a hard-coded location to start with. We support exactly two configurations: the (conceptually pointless and confusing) legacy split-/user with /bin/mount, and the one proper single /usr, where /bin must be a symlink to /usr/bin. Nothing else is interesting to support, matters or makes sense in any way. In both supported configurations /bin/mount works just fine. In the very long run, we will get rid of the split-/usr support and at that point just hard-code things like /usr/bin/mount; there is no need really for a configuration switch here. Kay ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, Nov 27, 2013 at 04:41:27PM +0100, Kay Sievers wrote:
We support exactly two configurations:
the (conceptually pointless and confusing) legacy split-/user with
/bin/mount, and the one proper single /usr, where /bin must be a
symlink to /usr/bin.
BTW, it's not about systemd only. The same is valid for
/sbin/{mount,fsck,mkfs}.fs helpers, agetty where we call /bin/login,
etc. etc.
Nothing else is interesting to support, matters or makes sense in any
way. In both supported configurations /bin/mount works just fine.
In the very long run, we will get rid of the split-/usr support and at
that point just hard-code things like /usr/bin/mount; there is no need
really for a configuration switch here.
Yep.
Karel
--
Karel Zak k...@redhat.com
http://karelzak.blogspot.com
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Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, 27.11.13 14:31, Hannes Reinecke (h...@suse.de) wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? Well, /bin/mount is kinda API of Linux, you cannot just change that. All systems must provide that, the same way as /bin/sh, reagrdless whether / and /usr is merged or not. There's really not much point in making this configurable, we don't really want to support systems which move things wildly around into the strangest places. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Hard-coded /bin/mount in systemd
On Wed, 27.11.13 15:12, Hannes Reinecke (h...@suse.de) wrote: On 11/27/2013 02:58 PM, Mantas Mikulėnas wrote: On Wed, Nov 27, 2013 at 3:31 PM, Hannes Reinecke h...@suse.de wrote: Hi all, for some reason systemd has /bin/mount hardcoded in src/core/mount.c:mount_enter_mounting() Which is a bit odd, seeing that everyting moved to /usr/bin. So we always have to do a symlink here, which really is a bit annoying. Is this by design or a simple left-over? If *everything* moved to /usr/bin, then /bin itself has to be a symlink anyway (as many tools expect and some standards require specific commands to be in /bin). Ah. IIRC it was _systemd_ which initiated the move to /usr, so I found it slightly odd to rely on a location which it has just obsoleted ... Or, rather, to have a hard-coded location to start with. systemd supports split /usr just fine really. Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
