Re: git: 36db6b04962a - main - hier(7): document /home/ and /usr/home/
Date: Sat, 13 May 2023 00:43:10 UTC
> Rod and I discussed this, and I?m top-posting a summary of a proposal that > we both support. I?ll leave the last message from the list below for > reference. Our consensus is that the main problem is the code in pw(8) > (used by adduser, and hence bsdinstall) that interprets /home as /usr/home, > installing a symlink for /home, and similarly for any other home directory > whose parent has a single component. We propose to remove that code, and > also modify bsdinstall?s zfs script to create a home dataset rather than Small nit, zfs already creates the data set as $POOL/usr/home, this would change to $POOL/home. > usr/home. adduser presents a default home directory using /home, so this > will continue to agree. As Rod said at the start of this thread, home > directories really don?t belong in /usr, and the only reason they were > there is because of the previous root + /usr partitioning. Now the default > is one large partition. Of course, people who want to partition differently > can do whatever they want. > > It will still be possible for admins to create home directories in > /usr/home, they will just have to do so explicitly for pw to create the > directory, and manually create a /home symlink if desired. If they have > a small root file system, they will want to put home directories elsewhere. > > A followup change would be to change various man pages that refer to > /usr/home. > > Mike > > On 11 May 2023, at 12:32, Rodney W. Grimes wrote: > > >> On 11 May 2023, at 9:58, Rodney W. Grimes wrote: > >> > >>>> On Wed, 10 May 2023 16:48:12 -0500 > >>>> Mike Karels <mike@karels.net> wrote: > >>>> > >>>>> On 10 May 2023, at 10:13, Cy Schubert wrote: > >>>>> > >>>>>> In message <ba22a75d-06c0-371e-603e-7ded9d1dca97@freebsd.org>, Mitchell > >>>>>> Horne w > >>>>>> rites: > >>>>>>> On 5/10/23 11:19, Rodney W. Grimes wrote: > >>>>>>>>> The branch main has been updated by mhorne: > >>>>>>>>> > >>>>>>>>> URL: https://cgit.FreeBSD.org/src/commit/?id=36db6b04962a01ff7b21592def02d > >>>>>>> 4c570dac939 > >>>>>>>>> > >>>>>>>>> commit 36db6b04962a01ff7b21592def02d4c570dac939 > >>>>>>>>> Author: Mitchell Horne <mhorne@FreeBSD.org> > >>>>>>>>> AuthorDate: 2023-05-10 12:53:56 +0000 > >>>>>>>>> Commit: Mitchell Horne <mhorne@FreeBSD.org> > >>>>>>>>> CommitDate: 2023-05-10 13:25:17 +0000 > >>>>>>>>> > >>>>>>>>> hier(7): document /home/ and /usr/home/ > >>>>>>>>> > >>>>>>>>> Reviewed by: imp > >>>>>>>>> MFC after: 1 week > >>>>>>>>> Sponsored by: The FreeBSD Foundation > >>>>>>>>> Differential Revision: https://reviews.freebsd.org/D40002 > >>>>>>>>> --- > >>>>>>>>> share/man/man7/hier.7 | 10 ++++++++++ > >>>>>>>>> 1 file changed, 10 insertions(+) > >>>>>>>>> > >>>>>>>>> diff --git a/share/man/man7/hier.7 b/share/man/man7/hier.7 > >>>>>>>>> index ff11289436a1..b6759dd6e65b 100644 > >>>>>>>>> --- a/share/man/man7/hier.7 > >>>>>>>>> +++ b/share/man/man7/hier.7 > >>>>>>>>> @@ -90,6 +90,10 @@ file descriptor files; > >>>>>>>>> see > >>>>>>>>> .Xr \&fd 4 > >>>>>>>>> .El > >>>>>>>>> +.It Pa /home/ > >>>>>>>>> +user HOME directories. > >>>>>>>>> +This is a symlink to > >>>>>>>>> +.Pa /usr/home/ > >>>>>>>> > >>>>>>>> /usr is "contains the majority of user utilities and applications" > >>>>>>>> it should not contain home directories. > >>>>>>>>> I do not know when this move to usr came about it was traditionally > >>>>>>> /home. > >>>>>>>> I do not know why /usr/home even exists, it is not needed by > >>>>>>>> anything I am aware of. If we have a compatible link it > >>>>>>>> should be, usr/home -> ../home and /home should be the > >>>>>>>> directory. > >>>>>>>> > >>>>>>> > >>>>>>> I agree that /usr/home is strange, and is unique (?) to FreeBSD. > >>>>>>> > >>>>>>> The oldest commit in the output of `git log --grep '/usr/home'` is: > >>>>>>> > >>>>>>> commit f2400d465896a8e4f6fdc57eba840cf49b25bbbd > >>>>>>> Author: David Nugent <davidn@FreeBSD.org> > >>>>>>> Date: Fri Jan 3 04:42:18 1997 +0000 > >>>>>>> > >>>>>>> Implemented /home -> /usr/home symlink kludge. > >>>>>>> If home basedir would be created in the root partition, create > >>>>>>> it under /usr instead, and symlink /basedir -> /usr/basedir. > >>>>>>> > >>>>>>> Notes: > >>>>>>> svn path=/head/; revision=21242 > >>>>>>> > >>>>>>> > >>>>>>> So it has been this way for 26 years at least. I do not know what to say > >>>>>>> about whether /usr "should" contain it, but it does. > >>>>>> > >>>>>> Usually history matters. I can understand not changing it. On the flip > >>>>>> side, I cut my UNIX teeth on SunOS 4 and Solaris where /home was /home -- > >>>>>> albeit automounted from /export/home on localhost or some NFS server. In > >>>>>> the Red Hat land at $JOB, /home is its own partition (actually an LVM > >>>>>> volume). In both cases /home is not in /usr because end-users can fill > >>>>>> /usr. This can be problematic operationally because it's yet another > >>>>>> headache to deal with should someone fill the filesystem. Filling /usr is > >>>>>> more serious than filling /home. > >>>>>> > >>>>>> As a point of interest, when I installed my first FreeBSD many moons ago I > >>>>>> used the Solaris standard of /export/home, using amd (now automount) to > >>>>>> serve my /home. I'm not advocating we do this, it's overkill, but /home > >>>>>> should not live in /usr. It's a potential headache for any sysadmin. > >>>>>> > >>>>>> With ZFS the solution is easy. With UFS based systems there are a lot of > >>>>>> other factors that go into how we install the "default" from the get-go. > >>>>> > >>> > >>> First off, thank you Mike for looking at this closer. Add me to any reviews > >>> you might creat. > >>> > >>>>> The situation is a fair mess. It took me a little while to figure out that > >>>>> the kludge referenced above is in the pw(8) command, which is used as the > >>>>> backend to adduser(8). Neither /home nor /usr/home is in the base package. > >>>>> adduser defaults to /home/user, and creates the parent directory (e.g. /home) > >>>>> if it does not exist, but if there is no internal slash, pw moves the parent > >>>>> to /usr. In this case, it makes the symlink from root. zfs is different, > >>>>> in that it includes a usr/home dataset already (created by bsdinstall). > > > > I am proposing we fix this. More below. > > > >>>>> In this case, creating a user with /home/user causes the symlink to be added > >>>>> as a side effect. > >>>>> > >>>>> I?m sure the kludge was originally done when root and /usr were separate > >>>>> file systems by default, root was small, and there was no /home by default. > >>>>> However, we now default to a single large file system (with datasets, in > >>>>> the zfs case). > >>>>> > >>>>> All of this really is a horrible kludge, and it is a house of cards. I'm > >>>>> amazed that it doesn't break more often. I'm tempted to remove the kludge > >>>>> and change the zfs setup to create a home dataset rather than usr/home. > >>> > >>> Or make it a menu option(s): > >>> if (zfs) "Create a user home dataset?" (default yes) > >>> if (ufs) "Create a user home directory?" (default yes) > >> > >> Are you suggesting that bsdinstall should do this? For ufs, there is no > >> need. > > > > Yes I am suggesting that bsdinstall should have a knob to turn > > on (by default) and off the creation of a "home dataset/directory" > > as you well need that if you choose to add users during a bsdinstall > > run, or you may not want a /home at all (currently not possible) as you > > have other mechanisms for dealing with it. > > > > The need for this is just as valid for ufs as it is for zfs. > > > >> > >>> "User home location: /home" (This is default) > >> > >> Are you proposing that the default for pw should be set at this point? > >> From all I read the default for pw is already, and should remain /home. > > Man page bears that out. It has no mention of any symlink or usr/home. > > > >> That doesn?t seem necessary, and I don?t know if it would work from > >> bsdinstall. > > > > No, this has nothing to do with pw directly, this is simply the path > > of the dataset(zfs)/directory(ufs) that bsdinstall should create IFF > > you sayd yes to the create question. At present this is hardcoded > > into bsdinstall as: > > /usr/home > > /home -> /usr/home > > > > I am advocating that this should all be controllable from menu. > > > >> > >>> As far as I am concerned the symlink can just die.... > >> > >> I agree, but that requires a change to pw. It creates the symlink on the > >> first account creation using /home. > > > > I am missing something here, pw creates the symlink yuk. > > As far as I was aware the only think that created a symlink > > /home -> /usr/home was bsdinstall. > > > >> > >>>>> However, if zfs users explicitly configure a home directory under /usr/home, > >>>>> this would end up in the usr dataset. An alternative would be to remove the > >>>>> code from pw to create the parent directory entirely (which seems sensible), > >>>>> and create a /home directory for ufs installs. I don't know how well known > >>>>> it is that adduser/pw will create parent directories for home directories > >>>>> though. This cleanup would change the default location for home directories > >>>>> to /home, which makes more sense. It would require documentation, e.g. in > >>>>> the release notes. The changes would only affect new installations, not > >>>>> upgrades. > >>>>> > >>>>> Thoughts? > >>>>> > >>>> > >>>> Adding home would require a change to BSD.root.dist, since it's not > >>>> currently in there. Only usr is present. > >>> > >>> It should *not* be in the etc/mtree/BSD.*.dist files at all. > >>> And it is not on my 13.1R system. It would not need to be > >>> in BSD.root.dist either, this is a *post distribution* created > >>> directory/dataset. > >> > >> I?m curious why you think this. But if pw retains the ability to create > >> the parent directory for the user directory (and I now think it should), > >> there is no need for a /home by default. > > > > Because there is no need for /home in a base distribution until > > you add a user, and that is a site specific change. What in > > the base system *needs* /home? > > > >>>> IMHO changing pw would be a reasonable approach. > >>> > >>> I am mixed on this.... it more or less does the right > >>> thing, and if a user specifies /tmp/foolishidea/home/$USER > >>> that is on them. No one said all users homes must be > >>> in the same location. > >> > >> Except for moving parent directories with a single component under /usr, > >> and creating a symlink for them... > >> > >> My current plan is to change pw not to move things under /usr, change the > >> zfs setup to use a home dataset rather than usr/home (corresponding to the > >> pw default), and then change the various man pages that refer to /usr/home. > >> Does that seem reasonable? > > > > Yes, then the knobs can easily be added, or scripted install should just > > work to effect the knobs. > > > >> Mike > > > > -- > > Rod Grimes rgrimes@freebsd.org > > -- Rod Grimes rgrimes@freebsd.org