Date: Sat, 13 May 2023 18:00:44 -0500 From: Mike Karels <mike@karels.net> To: rgrimes@freebsd.org Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 36db6b04962a - main - hier(7): document /home/ and /usr/home/ Message-ID: <BDD1210E-EF03-4060-9759-A9A9A3821276@karels.net> In-Reply-To: <202305132248.34DMm3Yu069553@gndrsh.dnsmgr.net> References: <202305132248.34DMm3Yu069553@gndrsh.dnsmgr.net>
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On 13 May 2023, at 17:48, Rodney W. Grimes wrote: >> 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 proposa= l that >>>> we both support. I?ll leave the last message from the list below fo= r >>>> reference. Our consensus is that the main problem is the code in pw= (8) >>>> (used by adduser, and hence bsdinstall) that interprets /home as /us= r/home, >>>> installing a symlink for /home, and similarly for any other home dir= ectory >>>> 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, ho= me >>>> directories really don?t belong in /usr, and the only reason they we= re >>>> there is because of the previous root + /usr partitioning. Now the = default >>>> is one large partition. Of course, people who want to partition dif= ferently >>>> 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 els= ewhere. >>>> >>>> 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 > > Need one more to backout the changes to hier(7)? Two or three more, I see other references too. I=E2=80=99ll make sure th= at these are generally accepted first. 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=3D36db6b04962a= 01ff7b21592def02d >>>>>>>>>>> 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/D4= 0002 >>>>>>>>>>>>> --- >>>>>>>>>>>>> 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 applica= tions" >>>>>>>>>>>> it should not contain home directories. >>>>>>>>>>>>> I do not know when this move to usr came about it was tradi= tionally >>>>>>>>>>> /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 FreeB= SD. >>>>>>>>>>> >>>>>>>>>>> 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/base= dir. >>>>>>>>>>> >>>>>>>>>>> Notes: >>>>>>>>>>> svn path=3D/head/; revision=3D21242 >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> 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 w= as /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 a= nother >>>>>>>>>> headache to deal with should someone fill the filesystem. Fill= ing /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 auto= mount) 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 sys= admin. >>>>>>>>>> >>>>>>>>>> With ZFS the solution is easy. With UFS based systems there ar= e a lot of >>>>>>>>>> other factors that go into how we install the "default" from t= he 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 fig= ure out that >>>>>>>>> the kludge referenced above is in the pw(8) command, which is u= sed as the >>>>>>>>> backend to adduser(8). Neither /home nor /usr/home is in the b= ase package. >>>>>>>>> adduser defaults to /home/user, and creates the parent director= y (e.g. /home) >>>>>>>>> if it does not exist, but if there is no internal slash, pw mov= es the parent >>>>>>>>> to /usr. In this case, it makes the symlink from root. zfs i= s different, >>>>>>>>> in that it includes a usr/home dataset already (created by bsdi= nstall). >>>>> >>>>> I am proposing we fix this. More below. >>>>> >>>>>>>>> In this case, creating a user with /home/user causes the symlin= k 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 dat= asets, in >>>>>>>>> the zfs case). >>>>>>>>> >>>>>>>>> All of this really is a horrible kludge, and it is a house of c= ards. 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 u= sr/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 bsdinstal= l >>>>> 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 po= int? >>>>>> 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/h= ome. >>>>> >>>>>> That doesn?t seem necessary, and I don?t know if it would work fro= m >>>>>> bsdinstall. >>>>> >>>>> No, this has nothing to do with pw directly, this is simply the pat= h >>>>> of the dataset(zfs)/directory(ufs) that bsdinstall should create IF= F >>>>> 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 und= er /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 see= ms sensible), >>>>>>>>> and create a /home directory for ufs installs. I don't know ho= w well known >>>>>>>>> it is that adduser/pw will create parent directories for home d= irectories >>>>>>>>> though. This cleanup would change the default location for hom= e directories >>>>>>>>> to /home, which makes more sense. It would require documentati= on, e.g. in >>>>>>>>> the release notes. The changes would only affect new installat= ions, 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 sh= ould), >>>>>> 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, cha= nge the >>>>>> zfs setup to use a home dataset rather than usr/home (correspondin= g 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@fr= eebsd.org >> >> > > -- = > Rod Grimes rgrimes@free= bsd.org
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