[Bug 1978323] Re: cmsfs-fuse fails to mount file systems on Ubuntu 22.04 with error unknown option(s): '-o hard_remove'

[Frank Heimes]

** Changed in: s390-tools-signed (Ubuntu Jammy)
       Status: Fix Committed => Fix Released

** Changed in: s390-tools-signed (Ubuntu Kinetic)
       Status: Fix Committed => Fix Released

** Changed in: ubuntu-z-systems
       Status: Fix Committed => Fix Released

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Title:
  cmsfs-fuse fails to mount file systems on Ubuntu 22.04 with error
  unknown option(s): '-o hard_remove'

Status in Ubuntu on IBM z Systems:
  Fix Released
Status in s390-tools package in Ubuntu:
  Fix Released
Status in s390-tools-signed package in Ubuntu:
  Fix Released
Status in s390-tools source package in Jammy:
  Fix Released
Status in s390-tools-signed source package in Jammy:
  Fix Released
Status in s390-tools source package in Kinetic:
  Fix Released
Status in s390-tools-signed source package in Kinetic:
  Fix Released

Bug description:
  SRU Justification:
  ==================

  [Impact]

   * The cmsfs-fuse utility, that is part of the s390-tools,
     allows to mount z/VM (IBMs commercial hypervisor for IBM Z systems)
     CMS disks.

   * cmsfs-fuse (prior to the migration to fuse3) could use the
     'hard_remove' option without any problem - and it was the default.

   * While migrating to fuse3 all tools were adjusted,
     but it wasn't identified that the 'hard_remove' no longer works
     with fuse3 (only)..

   * Hence if one uses cmsfs-fuse on Ubuntu 22.04, the utility will
     fails  with error "fuse: unknown option(s): '-o hard_remove'".

   * The option '-o hard_remove' is (for whatever reason) hard coded.

  [Fix]

   * upstream commit 0981df62c05e71123bc14483bba347f17aafa59a "cmsfs-
  fuse: fix enabling of hard_remove option"

  [Test Plan]

   * Setup an Ubuntu 22.04 instance on the z/VM hypervisor
     and make sure the guest aware of at least one CMS formatted z/VM disk.

   * The cmsfs-fuse utility is part of the s390-tools package,
     which is mandatory for an Ubuntu on IBM Z Installation,
     so everything is installed and available with a default installation.

   * This disk needs to be defined in the z/VM guests 'user direct',
     which is actually the guest aka virtual machine definition as minidisk,
     like:
     MDISK 1607 3390 0001 10016 LM1607 RR

   * This disk will then be visible from inside the Linux z/VM guest like:
     $ ls -l /dev/disk/by-path/ccw-0.0.1607
     lrwxrwxrwx 1 root root 11 Jun  8 03:18 /dev/disk/by-path/ccw-0.0.1607 -> ../../dasdd
     (or use 'lsdasd')

   * Now just use 'cmsfs-fuse' to mount that disk:
     $ sudo cmsfs-fuse -t /dev/disk/by-path/ccw-0.0.1607 /mnt
     $

   * If the command comes back like above (on a system with the patch included),
     the mount was successful and one may 'ls' that disk.

   * In case of a broken tool one will get the error msg:
     $ sudo cmsfs-fuse -t -o allow_other /dev/disk/by-path/ccw-0.0.1607 /mnt
     fuse: unknown option(s): `-o hard_remove'
     $  
   
  [Where problems could occur]

   * Problem could occur in case this "-o hard_remove" is really
     required, but no longer available.

   * But this is handled by forcing an immediate file removal
     in 'cmsfs_oper_init'.

   * However things could break if cmsfs_oper_init is not properly
     called, but it's done as part of 'fuse_operations cmsfs_oper'.
  __________

  cmsfs-fuse fails to mount any cms file system since it forces the
  hard_remove option and it appears as though that option is no longer
  recognized by fuse 3.

  the recreate is very easy as I cannot yet get it to actually work. So,
  I would make a CMS formatted minidisk available to an Ubuntu 22.04
  z/VM virtual machine. Then, I used the following syntax:

  cmsfs-fuse -t -o allow_other /dev/disk/by-path/ccw-0.0.0291 /mnt. The result of this command will be
  fuse: unknown option(s): `-o hard_remove'

  Similarly: cmsfs-fuse -t /dev/disk/by-path/ccw-0.0.0291 /mnt will result in:
  fuse: unknown option(s): `-o hard_remove'

  At this point, I cannot find an example of the command that will
  actually allow the minidisk to be mounted.

  (originally reported by 'richardflewis')

  Upstream reported as: https://github.com/ibm-s390-linux/s390-tools/issues/131
  Upstream fixed with: https://github.com/ibm-s390-linux/s390-tools/commit/0981df62c05e71123bc14483bba347f17aafa59a

  This but is for getting this included into the Ubuntu package for
  jammy.

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