Mounting git commits as folders with NFS (2023)

hckrnws

Mounting git commits as folders with NFS (2023)

112

by pvtmert

thewisenerd
32d
> None of these are the most efficient way to do this (you can use git show and git log -S or maybe git grep to accomplish something similar), but personally I always forget the syntax and navigating a filesystem feels easier to me.
i feel like some of the old-school commands will benefit from long args, e.g., '--search'. at the time of writing, the current `git log` documentation[1]'s `-S' has _one_ instance of the word 'search'.
(un)related to the article, author went on to contribute documentation updates to git, which were much needed [2]
[1]: https://git-scm.com/docs/git-log#Documentation/git-log.txt--... [2]: https://jvns.ca/blog/2026/01/08/a-data-model-for-git/
1. js2
  12d
  What, you didn't know to search for pickaxe!? :-)
  Meanwhile, --grep searches the log message. Yeah, the git CLI is an ergonomic nightmare and I've been using it since the very beginning.
  FWIW, I can't think of a single time I've wanted to use -S instead of -G.
  1. masklinn
    01d
    Funny, I use -S routinely and -G rarely: I’m almost never interested in cases where a symbol was moved around, it’s just noise, so always reach for -S first.
2. masklinn
  01d
  -S does not mean “search” tho, it means specifically searching the change history for the symbol being added or removed (but not moved, the number of occurrences has to vary). -G includes the symbol being moved (it will flag commits which both remove and add an occurrence).
  “git grep” is the correct tool for Julia’s grep, however as usual it has the worst defaults: the work tree (so it’s just a slightly better “grep”), you need to give it a list of revisions to search to get a history search (so usually you pipe-xargs a rev-list into it).
chungy
12d
Related: Fossil has a `fusefs` subcommand: https://fossil-scm.org/home/help/fusefs
The DIRECTORY/checkins/ directory doesn't list out anything by itself, but you can look things up by any of the supported checkin names (hash, tag, branch, date...): https://fossil-scm.org/home/doc/trunk/www/checkin_names.wiki
1. valorzard
  02d
dspillett
11d
> But FUSE is pretty annoying to use on Mac – you need to install a kernel extension, and Mac OS seems to be making it harder and harder to install kernel extensions
I'm not a Mac user at all, so there may be reasons what I'm about to suggest is silly beyond the ones I will mention myself, but…
Another way around this is to run the FUSE filesystem in a small VM running a different OS that is more FUSE friendly, then export that filesystem to MacOS using a network filesystem that it natively understands. This may also be NFS so you aren't avoiding NFS if so, but you at least separate the NFS issues from the issues interfacing git (assuming interfacing git with FUSE doesn't have just as many gotchas as using NFS directly).
There are a couple of obvious potential performance issues here. Firstly adding the extra network filesystem layer will likely add a noticeable amount of latency for all operations. You likely have this twice too: if you are reading a repo from the host machine rather than checking out its own copy (which would likely be a significant inconvenience) then the VM will need to access that somehow. Secondly any caching in RAM that the fs->git layer does will mean allocating enough RAM to the VM for that which will be dedicated so not available to other processes on your bare metal. If the amount of memory required is small anyway then this is not a problem, or if letting it swap out to disk (or using a disk based cache in the first place) is significantly less inefficient than constantly rereading+reprocessing the structure that the cache is intended to speed references to, then that is an option too.
tn1
22d
A couple other people mentioned ClearCase which has something similar if you use their NFS based thing, you could see file or directory history and info by accessing something like `foo.c@@/versions/5` (which isn't ordinarily visible when listing its directory). Pretty nifty.
Your workspaces were also copy-on-write from the base file revisions you were using.
1. usr1106
  12d
  We used Clearcase around year 2000 on HP-UX. I found it nice and powerful, but 90% of the developers did not understand it. Well, probably a similar statement holds for git.
IshKebab
02d
> I fixed this by defining an inode(string) function which hashed a string to get the inode number, and using the tree ID / blob ID as the string to hash.
The tree/blob ID is already a hash though. You don't need to hash it again. Just use the first 8 bytes of the tree ID as the inode.
ramses0
02d
This is my favorite cursed finding: https://github.com/zevweiss/booze
FUSE-bindings for "filesystems in bash", eg:
https://github.com/zevweiss/booze/blob/master/cowsayfs.sh#L5...
```
    cs_read()
    {
      if ! [[ "$1" =~ ^/($cowpat)/[^/]+$ ]]; then
        booze_err=-$EINVAL
        return 1
      elif [ "$3" != 0 ]; then
        return 0
      fi

      local msg="${1#/*/}"
      local cow="${1#/}"
      cow="${cow%%/*}"
      cowsay -f "$cow" "$msg"
    }
```
...I think that WebDAV is "the way" compared to FUSE, but I'm always intrigued by the idea of virtual filesystems as an implementation face.
steveBK123
172d
NFS.. stop right there
1. mmh0000
  162d
  You're being downvoted, but, seriously... NFS is a joke for anything outside of an enterprise setup with a bunch of ancillary support services in place.
  The fact that NFSv4 has no concept of true "Authentication" and just blindly accepts whatever the client sends is the craziest network application design ever:
  Client: Hi, NFS server, I'm Bob! UID=1000 Server: Hi Bob! Here's access to all of Bob's files! I trust you and don't need a password or anything! Client: Thanks!!!
  Some of you may nitpick and say, "well ackkkuallyy, NFS supports authentication through GSSAPI/krb."
  And to you, I say, that's crazy! Setting up Kerberos just to authenticate users for access to my Linux ISOs is a crazy large requirement! Sure, it might make sense for an enterprise that already uses Kerberos + LDAP + NFS + certificate management, but for everyone else, that's a lot of infrastructure to set up and maintain for what should be BASIC functionality.
  EDIT
  ALSO!!! Why the fork does NFS run as a kernel module (nfsd)!? Shouldn't that be an external daemon!? Who the heck thought any of this was a good idea!?
  <sarcasm mode> Dev1: Here's a great idea! Let's run an insecure network server in Kernel space! Dev2: OMG! You're so smart! Let's also exclude any encryption!!! </>
  //end rant of an old, bitter Linux sysadmin
pvtmert • OP
04d
Given the advent of LLMs and agentic coding, I believe this article needs re-visiting as it makes it much more discoverable to compare individual files across commits.
Someone
124d
FTA: “problem 1: webdav or NFS?
The two filesystems I could that were natively supported by Mac OS were WebDav and NFS. I couldn’t tell which would be easier to implement so I just tried both”
I might find out that it is incomplete, buggy or a nuisance to use, but FSKit (https://developer.apple.com/documentation/FSKit) would be my first choice.
1. skissane
  12d
  FSKit was released with Sequoia in March 2025. This blog post was written in December 2023—so at the time it was written, FSKit was not yet an option
retrocryptid
32d
Oh man. I was just reminded of ClearCase and Perforce and sort of threw up a little in the back of my mouth. You young whipper-snappers who didn't have to use ClearCase and have only used hg or git don't know how bad it could be. When ClearCase was properly configured, it was fine. But having used it at IBM, DSCCC and Bell Canada, only IBM managed it properly. At DSCCC, we had 40 Sun workstations on a single thin-net segment, each of them trying to mount an NFS share from ClearCase. You had to get there at 6AM to be one of the first five people to log in because if you didn't it was unlikely you COULD even log in. I kept a copy of the part of the code I was working with on a tape and would go into the lab and restore it from tape, do some work, then back it up to tape at the end of the day (the lab machines were reformatted at midnight every day.)
But... yes... this is just using NFS locally to see what's already in GIT, which is perfectly find and as Julia says, allows you to appreciate the structure of the git repo. Ignore this old man yelling at clouds.
1. pjmlp
irusensei
01d
>I don’t know if this is actually a problem or how big of an advantage it would be to use NFSv4.
Of the top of my head only one port is needed for V4.
ulrischa
22d
Nice idea. But when taking commits as folders one should delete, add and remame files in the folder and that is not possible in a commit because it creates another commit. So I think this is nit the right mental model
1. wtallis
  12d
  Files and folders can be read-only, a concept that has been around for about as long as the folders abstraction itself.
deepspace
12d
The dot-com era called. They want ClearCase back.
1. pjmlp
  01d
  I loved the views, you could actually have snapshots git style, and best of all binary caches for distributed compilation of C and C++, something that is still not widely deployed.
  By the way, it is still around.
[deleted]
02d
[deleted]
voidUpdate
01d
Thats awful... I love it and will probably start using it immediately :P
LoganDark
02d
I feel like mounting Jujutsu changes as folders would be more practical since they're stable across rebases?
cyberax
02d
BTW, if you want a simple NFSv4 client in Go, feel free to use mine: https://github.com/Cyberax/go-nfs-client
Making it into an NFSv4 server should also be pretty easy.
everybodyknows
02d
2023.

cs_read() { if ! [[ "$1" =~ ^/($cowpat)/[^/]+$ ]]; then booze_err=-$EINVAL return 1 elif [ "$3" != 0 ]; then return 0 fi local msg="${1#/*/}" local cow="${1#/}" cow="${cow%%/*}" cowsay -f "$cow" "$msg" }