Arch Linux

cafe

Member

From: Brasil

Registered: 2014-03-20

Posts: 165

POSIX permissions on ZFS

Dear community,

I'm facing a weird behaviour for file and directory creation on a ZFS dataset (/huge/dataset). This pool was imported from a freeNAS device (freeBSD) mainly used for file sharing (smb) on a windows network. It was imported to my archlinux using

# zpoll import -f huge

Now, when I create files with my user (daniel, uid=1000), files are created with mask: 700, but when I create files with another user, they get 000 mask. This is also valid for directories, and is very annoying, because I can't create any folder structure or access files I've just created.

daniel@cafe$ cd /huge/dataset
daniel@cafe$ touch file-daniel
daniel@cafe$ sudo -u fernando touch file-fernando
daniel@cafe$ ls -lha
-rwx------  0 daniel   cafe   file-daniel
----------  0 fernando cafe   file-fernando

Default acl masks seems to be ok

daniel@cafe ~ % getfacl /huge/dataset
# file: huge/dataset
# owner: daniel
# group: cafe
user::rwx
group::rwx
other::---

Also, my zfs acl permissions are not enforcing any type of restrictions, so posix permissions should prevail.

daniel@cafe ~ % zfs get all | grep acl
huge          aclmode                 passthrough             local
huge          aclinherit              passthrough             local
huge          acltype                 off                     default
huge/dataset  aclmode                 passthrough             local
huge/dataset  aclinherit              passthrough             inherited from huge
huge/dataset  acltype                 off                     default

I'm on a dead end. Can you guys help me investigate this problem further and find the culprit?

Last edited by cafe (2026-04-26 13:25:01)

cryptearth

Member

Registered: 2024-02-03

Posts: 2,130

Re: POSIX permissions on ZFS

why you had to force import (using -f)?
if force was required regular import should have given an explicit reason why importing the pool without might be harmful
please post output of

zpool list
zfs list
mount | grep zfs
findmnt /huge/dataset
stat /huge/dataset

Last edited by cryptearth (2026-04-26 13:31:13)

cafe

Member

From: Brasil

Registered: 2014-03-20

Posts: 165

Re: POSIX permissions on ZFS

I forgot to do an export on the previous computer. Here's what you requested:

daniel@cafe ~ % zpool list
NAME   SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
huge  36.4T  9.41T  27.0T        -         -     8%    25%  1.00x    ONLINE  -

daniel@cafe ~ % zfs list
NAME            USED  AVAIL  REFER  MOUNTPOINT
huge           9.41T  26.8T    96K  /huge
huge/dataset   9.41T  26.8T  9.41T  /huge/dataset

daniel@cafe ~ % mount | grep zfs
huge on /huge type zfs (rw,noatime,xattr,noacl,casesensitive)
huge/dataset on /huge/dataset type zfs (rw,noatime,xattr,noacl,casesensitive)

daniel@cafe ~ % findmnt /huge/dataset
TARGET        SOURCE       FSTYPE OPTIONS
/huge/dataset huge/dataset zfs    rw,noatime,xattr,noacl,casesensitive

daniel@cafe ~ % LANG=C stat /huge/dataset
  File: /huge/dataset
  Size: 11        	Blocks: 49         IO Block: 16384  directory
Device: 0,56	Inode: 34          Links: 10
Access: (0770/drwxrwx---)  Uid: ( 1000/  daniel)   Gid: ( 1000/  daniel)
Access: 2023-08-13 22:08:38.974681491 -0300
Modify: 2026-04-26 09:50:09.515654804 -0300
Change: 2026-04-26 10:15:12.013101377 -0300
 Birth: 2023-08-13 22:08:38.974681491 -0300

WorMzy

Administrator

From: Scotland

Registered: 2010-06-16

Posts: 13,493

Website

Re: POSIX permissions on ZFS

Mod note: moving to AUR Issues.

---

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cryptearth

Member

Registered: 2024-02-03

Posts: 2,130

Re: POSIX permissions on ZFS

what does

umask

give?
does this happen only on the zfs pool or also on other partitions with different filesystems?

cafe

Member

From: Brasil

Registered: 2014-03-20

Posts: 165

Re: POSIX permissions on ZFS

umask gives me 022.

This problem only happens inside this old dataset (/huge/dataset). I've created a new dataset inside the same 'huge' pool with

# zfs create huge/fernando

$ zfs list             
NAME            USED  AVAIL  REFER  MOUNTPOINT
huge           9.41T  26.8T    96K  /huge
huge/dataset   9.41T  26.8T  9.41T  /huge/dataset
huge/fernando  5.30G  26.8T  5.30G  /huge/fernando

Within this new folder, posix permissions are working normally. I'll use this as a solution. Thank you for your support cryptearth. I'd still like to dig a little deeper to understand this issue, but luckly, it is a little less critical now.

Last edited by cafe (2026-04-27 10:14:18)

cryptearth

Member

Registered: 2024-02-03

Posts: 2,130

Re: POSIX permissions on ZFS

i would recommend report this as upstream issue - could be more to it: https://github.com/openzfs/zfs/issues

Last edited by cryptearth (2026-04-27 11:40:47)