What were you trying to do that didn't work?

Boot a system using command line mount units (systemd.mount-extra=WHAT:WHERE:FSTYPE:OPTIONS) to specify an auxiliary mount. The format of the options field follows the fstab convention: a comma-separated list of file system mount options to apply.

What is the impact of this issue to you?

All file system options after the first comma-separated option are silently discarded. If subsequent mount options are essential for the mount to succeed the mount unit will fail, potentially blocking boot and leading to emergency mode.

Please provide the package NVR for which the bug is seen:

systemd-257-9.el10_0.1.x86_64, systemd-257-11.el10

How reproducible is this bug?:

100%

Steps to reproduce

Steps without breaking boot that demonstrate the problem (x- options are used since they are passed through but ignored by mount):

1. Set up a device with a file system for the test: E.g. on an lvm installation with free space run lvcreate -n mounttest -L1g rhel, mkfs.xfs /dev/rhel/mounttest
2. Append e.g. "systemd.mount-extra=/dev/rhel/mounttest:/mnt:xfs:defaults,x-foo,x-bar,x-baz" to the kernel command line for the next boot (either modify the BLS snippet or use grub2 'e' command and append manually while rebooting)
3. Reboot the system
4. Inspect the resulting mount unit in /run/systemd/generator/mnt.mount

   Expected results

   # Automatically generated by systemd-fstab-generator
   
   [Unit]
   Documentation=man:fstab(5) man:systemd-fstab-generator(8)
   SourcePath=/proc/cmdline
   Before=local-fs.target
   Requires=systemd-fsck@dev-rhel-mounttest.service
   After=systemd-fsck@dev-rhel-mounttest.service
   After=blockdev@dev-rhel-mounttest.target
   
   [Mount]
   What=/dev/rhel/mounttest
   Where=/mnt
   Type=xfs
   Options=defaults,x-foo,x-bar,x-baz
   

Actual results

No Options line present in mount unit:

# grep Options /run/systemd/generator/mnt.mount | wc -l
0

# Automatically generated by systemd-fstab-generator

[Unit]
Documentation=man:fstab(5) man:systemd-fstab-generator(8)
SourcePath=/proc/cmdline
Before=local-fs.target
Requires=systemd-fsck@dev-rhel-mounttest.service
After=systemd-fsck@dev-rhel-mounttest.service
After=blockdev@dev-rhel-mounttest.target

[Mount]
What=/dev/rhel/mounttest
Where=/mnt
Type=xfs

Upstream status

This is fixed upstream since April via https://github.com/systemd/systemd/pull/37037 (commit 06fadc42)

Additional information

This was observed while testing snapshot boot using command line mount units in conjunction with Stratis file system mounts which depend on x-systemd.requires=stratis-fstab-setup@POOL_UUID for boot time set up. The Stratis documentation suggests configuring fstab lines as for e.g.:

/dev/stratis/p1/fs1    /where    xfs    defaults,x-systemd.requires=stratis-fstab-setup@POOL_UUID,... 0 0

When translated to systemd.mount-extra only the defaults is parsed by systemd-fstab-generator, leading to boot failure since the stratis-fstab-setup service is mandatory to pull in the required stratisd(,-min) service.