Re: git: 36db6b04962a - main - hier(7): document /home/ and /usr/home/
- In reply to: Rodney W. Grimes: "Re: git: 36db6b04962a - main - hier(7): document /home/ and /usr/home/"
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Date: Sat, 13 May 2023 20:29:30 UTC
On 12 May 2023, at 19:43, Rodney W. Grimes wrote: >> 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. The changes are now in review: https://reviews.freebsd.org/D40085 pw change to use the specified dir https://reviews.freebsd.org/D40086 bsdinstall change to create /home rather than /usr/home dataset on ZFS 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