There are sometimes users who put unit files in a location that is inaccessible
when systemd starts although they are not found and thus not started because
the corresponding mount units have not activated yet.
There is already a warning for such issue in man 8 systemctl:
link PATH...
...<snip>...
The file system where
the linked unit files are located must be accessible
when systemd is started (e.g. anything underneath /home
or /var is not allowed, unless those directories are
located on the root file system).
However, it looks that it's difficult to find the warning because introductory
users typically doesn't know systemctl link.
Although there is a description in UNIT FILE LOAD PATH pointing to systemctl
link, symlink is now not explicitly mentioned there and thus users doesn't
easily get aware of they should read it.
To deal with this, let's describe "symlink" and "systemctl link" more
explicitly in UNIT FILE LOAD PATH.
We should allow the ones that the [Unit] section of regular unit files
may accet, but no other, in particular not the internal deps we
synthesize as reverse of explicitly configured ones, such was WantedBy=.
Fixes: #14251
It makes sense to filter state changes for some load states that
shouldn't happen, but the common cases should be accepted, because they
might happen during runtime when "systemctl daemon-reload" is issued and
unit files changed state in between. Otherwise we lose events.
Fixes: #4708
When probing partitions, we inherit important information from the parent
disk device such as ID_MODEL, and usage of such properties is seen to
be acceptable and well established.
However, we need to exclude filesystem information from the properties
that get inherited. Information about the device content should not be
passed on in this way.
For example, Linux distro install media commonly uses an ISO filesystem
plus a partition table. The ISO filesystem is detected on the main disk
device, but we should not pass down those details to the partitions,
some or all of which may be pointing at storage areas completely distinct
from the ISO filesystem.
This is particularly problematic when adding new partitions on media
set up in this way (since the new partitions are then reported to contain
the parent device's ISO filesystem), or when dealing with more unusual
hybrid ISO layouts. The inaccuracy of information here inversely affects
users of blkid and udev's persistent storage symlinks.
Exclude ID_FS_* properties from the inheritance chain to avoid these
problems.
Fixes: #14408
Latest meson doesn't work with older python 3.5, which is present on
Ubuntu 16.04. Let's pin in to the latest working version (0.52.1) until
we properly bump all necessary Ubuntu images to 18.04.
See: https://github.com/mesonbuild/meson/issues/6427
The only non-stylistic change is to replace descriptions of how we are
encouraging people to use PrivateTmp= and such, because now they are widely
used.
Build option "link-networkd-shared" to build a statically linked
systemd-networkd by using
-Dlink-udev-shared=false -Dlink-networkd-shared=false
on systems with full systemd stack except systemd-networkd, such
as RHEL/CentOS 8.
To make this easier to understand, let's always log (at debug level)
when we accept or reject each device:
/swapfile: detection of swap file offset on Btrfs is not supported
/swapfile: is a candidate device.
/dev/zram0: ignoring zram swap
/dev/vdb: ignoring device with lower priority
/dev/vdc: ignoring device with lower usable space
...
If we know that hibernation will fail, refuse. This includes cases where
/sys/power/resume is set and doesn't match any device, or
/sys/power/resume_offset is set and we're not on btrfs and it doesn't match.
If /sys/power/resume is not set at all, we still accept the device with the
highest priority (see 6d176522f5 and
88bc86fcf8)
Tested cases:
1. no swap active → refuse
2. just zram swap active → refuse
3. swapfile on btrfs with /sys/power/resume{,_offset} set → OK
4. swapfile on btrfs with /sys/power/resume set, offset not set → refuse
5. swapfile on btrfs with /sys/power/resume set to nonexistent device, offset set → refuse
6. /sys/power/resume not set, offset set, candidate exists → OK (*)
7. /sys/power/resume not set, offset not set, candidate exists → OK
(*) I think this should fail, but I'm leaving that for the next commit.
Let's use uppercase wording in the description string, like we usually
do.
Let's allow using this service in early boot.
If it's pulled into the initial transaction it's better to finish
loading this before sysinit.target.
Don't bother with this in containers that lack CAP_SYS_MODULE
