The method was added with migration of resources in mind (e.g. process's
allocated memory will follow it to the new scope), however, such a
resource migration is not in cgroup semantics. The method may thus have
the intended users and others could be guided to StartTransientUnit().
Since this API was advertised in a regular release, start the removal
with a deprecation message to callers.
Eventually, the goal is to remove the method to clean up DBus API and
simplify code (removal of cgroup_context_copy()).
Part of DBus docs is retained to satisfy build checks.
Catch up with the nice little toys the kernel fs developers have added
for us. Preferably, let's make use of the new F_DUPFD_QUERY fcntl() call
that checks whether two fds are just duplicates of each other
(duplicates as in dup(), not as in open() of the same inode, i.e.
whether they share a single file offset and so on).
This API is much nicer, since it is a core kernel feature, unlike the
kcmp() call we so far used, which is part of the (optional)
checkpoint/restore stuff.
F_DUPFD_QUERY is available since kernel 6.10.
This adds the ExtraFileDescriptor property to StartTransient dbus API
with format "a(hs)" - array of (file descriptor, name) pairs. The FD
will be passed to the unit via sd_notify like Socket and OpenFile.
systemctl show also shows ExtraFileDescriptorName for these transient
units. We only show the name passed to dbus as the FD numbers will
change once passed over the unix socket and are duplicated, so its
confusing to display the numbers.
We do not add this functionality for systemd-run or general systemd
service units as it is not useful for general systemd services.
Arguably, it could be useful for systemd-run in bash scripts but we
prefer to be cautious and not expose the API yet.
Fixes: #34396
The disk/by-diskseq symlink should not be shared with multiple block
devices. Hence, it is not necessary to create stack directory for the
symlink that manages which device owns the symlink.
This is not just a optimization.
If a service unit tries to mount a disk image but the service fails, then
the diskseq of the loop device for the image may be continuously increased
during restart, and inodes in /run may increase rapidly, as the stack
directories are cleaned up only when udev queue is empty.
Fixes#34637.
Previously using file descriptors as input arguments in busctl was
unsupported with "UNIX file descriptor not supported as type."
We fix this by parsing the file descriptor as an integer and verifying
it is an available file descriptor in busctl.
Fixes: #14954
Replaces: #34551
This is the only place where xdg_user_dir() is needed and
makes sense. All other invocations have been replaced with
user_search_dirs() - see previous commits for details.
* Rename user_dirs() -> user_unit_search_dirs() and port to
user_search_dirs()
* Use STRV_IFNOTNULL to guard paths that could be NULL,
assert otherwise
xdg_user_dirs() doesn't seem well-organized currently.
In all other xdg_user_*() funcs we assume /etc/xdg/systemd
to be a symlink to /etc/systemd/, hence it is the odd one out.
Also, when the relevant envvar is unset, it only returns
the global search dirs.
sd_path_lookup() actually covers this nicely with SD_PATH_SEARCH_*,
where the combined search paths (from user home and system) are used.
Therefore, let's introduce a wrapper for that, and deprecate xdg_user_dirs()
(would be removed in later commits).
Note that -ENXIO reported by xdg_user_config_dir() is now properly
propagated rather than ignored, as unlike XDG_RUNTIME_DIR, XDG_CONFIG_HOME
has a default value hence ENXIO is not really expected.
Luca Boccassi
Michal Koutný
Lennart Poettering
Yu Watanabe
Ryan Wilson
Daan De Meyer
Ivan Kruglov
Lukas Nykryn
Benjamin ROBIN
Zbigniew Jędrzejewski-Szmek
Mike Yuan