make snappy's /etc/mtab symlink agree to tmpfiles.d/debian.conf
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Snappy |
Fix Released
|
Medium
|
Unassigned | ||
| livecd-rootfs (Ubuntu) |
Fix Released
|
Medium
|
Oliver Grawert | ||
| systemd (Ubuntu) |
Invalid
|
Medium
|
Unassigned | ||
Bug Description
booting a snappy system which comes with a readonly file system that carries /etc/mtab as pre-created link in the readonly area of the fs (pointing to /proc/mounts), we always get an error message on boot when systemd-tmpfiles tries to re-create the mtab link.
systemd-tmpfiles should instead check if /etc/mtab is already there, is a link and points to the desired target. in this case it should just skip the creation attempt gracefully without error.
Feb 17 18:56:51 localhost systemd[1]: Starting Create Volatile Files and Directories...
Feb 17 18:56:51 localhost systemd-
, ignoring.
Feb 17 18:56:51 localhost systemd-
m
Feb 17 18:56:51 localhost systemd[1]: systemd-
URE
| affects: | systemd → snappy |
| Changed in snappy: | |
| importance: | Undecided → Medium |
| Changed in systemd (Ubuntu): | |
| importance: | Undecided → Medium |
| Martin Pitt (pitti) wrote | #1 |
| summary: |
- please allow /etc/mtab to be a pre-existing link on readonly filesystems + make snappy's /etc/mtab symlink agree to tmpfiles.d/debian.conf |
| Changed in systemd (Ubuntu): | |
| status: | New → Incomplete |
| Oliver Grawert (ogra) wrote | #2 |
| Changed in systemd (Ubuntu): | |
| status: | Incomplete → Confirmed |
| Oliver Grawert (ogra) wrote | #3 |
| Martin Pitt (pitti) wrote | #4 |
| Oliver Grawert (ogra) wrote | #5 |
| Oliver Grawert (ogra) wrote | #6 |
| Changed in systemd (Ubuntu): | |
| status: | Confirmed → Invalid |
| Changed in snappy: | |
| status: | New → Fix Released |
| Changed in livecd-rootfs (Ubuntu): | |
| status: | New → Fix Released |
| importance: | Undecided → Medium |
| assignee: | nobody → Oliver Grawert (ogra) |
tmpfiles already checks if the symlink is the same if it already exists. However, in this case it's not literally the same: your's points to /proc/mounts while /usr/lib/
Now, /etc/mtab → /proc/mounts is a waste as /proc/mounts is already a symlink to self/mounts, so you need to resolve symlinks twice. The "../" is so that this works with different --root arguments, i. e. if you want to do things with such an image when you mount it somewhere.
Can I convince you to change the snappy image to have /etc/mtab → ../proc/self/mounts ? If not, could we at least agree to → /proc/self/mounts to avoid the double resolution?