[LU-14927] osd-zfs could not be loaded on 4.14+ and 5.9+ (gpl issue)

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Affects Version/s: Lustre 2.13.0, Lustre 2.14.0, Lustre 2.12.7
• Severity: 3
• Assignee: James A Simmons
• Reporter: Aurelien Degremont (Inactive)

Description

osd-zfs module is not loading anymore since a kernel commit was merged in 5.9 and is now backported to 4.14 branch. This prevents using ZFS with Lustre, from 2.12 up to master.

This is due to a stronger module license check and EXPORT_SYMBOL_GPL. ZFS is CDDL and as osd-zfs depends on it, it is inheriting is taint, preventing it from using GPL-only symbols.

Here is the original commit: https://github.com/torvalds/linux/commit/262e6ae7081df304fc625cf368d5c2cbba2bb991

Backported to stable branch 4.14, and 5.4 (at least)

 

Reproduced with Lustre master branch and ZFS 2.0.5:

• 4.14.232: OK

• 4.14.238: Error

  $ sudo LOAD=: FSTYPE=zfs ./lustre/tests/llmount.sh
  Loading modules from /home/ec2-user/lustre/lustre/tests/..
  detected 16 online CPUs by sysfs
  libcfs will create CPU partition based on online CPUs
  libkmod: kmod_module_get_holders: could not open '/sys/module/pcc_cpufreq/holders': No such file or directory
  libkmod: kmod_module_get_holders: could not open '/sys/module/amd64_edac_mod/holders': No such file or directory
  quota/lquota options: 'hash_lqs_cur_bits=3'
  $ dmesg | tail -n5
  [ 1844.388948] ZFS: Loaded module v2.0.5-1, ZFS pool version 5000, ZFS filesystem version 5
  [ 1844.400002] osd_zfs: module uses symbols from proprietary module zfs, inheriting taint.
  [ 1844.403770] osd_zfs: Unknown symbol ktime_get_real_seconds (err 0)
  [ 1844.406319] osd_zfs: Unknown symbol init_user_ns (err 0)
  [ 1844.408548] osd_zfs: Unknown symbol ktime_get_seconds (err 0)
  

   

 Not a problem with 2.10, likely because the patch which introduced this symbol was merged in 2.11: https://review.whamcloud.com/#/c/29857/