Jun'ichi Nomura
1d086a6e59
When starting a mount unit, systemd invokes mount command and moves the
unit's internal state to "mounting". Then it watches for updates of
/proc/self/mountinfo. When the expected mount entry newly appears in
mountinfo, the unit internal state is changed to "mounting-done".
Finally, when systemd finds the mount command has finished, it checks
whether the unit internal state is "mounting-done" and changes the state
to "mounted".
If the state was not "mounting-done" in the last step though mount command
was successfully finished, the unit is marked as "failed" with following
log messages:
Mount process finished, but there is no mount.
Failed with result 'protocol'.
If daemon-reload is done in parallel with starting mount unit, it is
possible that things happen in following order and result in above failure.
1. the mount unit state changes to "mounting"
2. daemon-reload saves the unit state
3. kernel completes the mount and /proc/self/mountinfo is updated
4. daemon-reload restores the saved unit state, that is "mounting"
5. systemd notices the mount command has finished but the unit state
is still "mounting" though it should be "mounting-done"
mount_setup_existing_unit() should take into account that MOUNT_MOUNTING
is transitional state and set MOUNT_PROC_JUST_MOUNTED flag if the unit
comes from /proc/self/mountinfo so that mount_process_proc_self_mountinfo()
later can make state transition from "mounting" to "mounting-done".
Fixes: #10872
System and Service Manager
Details
General information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list or join our IRC channel.
Stable branches with backported patches are available in the stable repo.