sync() before committing a transient machine-id to disk. This will
ensure that any filesystem changes made by first-boot units will have
been persisted before the first boot is marked as completed.
Currently, a loss of power after the machine-id was written but before
all units with ConditionFirstBoot=yes ran would lead to the next boot
finding a valid machine-id, thus not being marked first boot and not
re-running these units.
To make the first boot mechanism more robust, instead of writing
/etc/machine-id very early, fill it with a marker value "uninitialized"
and overmount it with a transiently provisioned machine-id. Then, after
the first boots completes (when systemd-machine-id-commit.service runs),
write the real machine-id to disk.
This mechanism is of course only invoked on first boot. If a first boot
is not detected, the machine-id is handled as previously.
Fixes: #4511
(Well, at least the ones where that makes sense. Where it does't make
sense are the ones that re invoked on the root path, which cannot
possibly be a symlink.)
Ideally, coccinelle would strip unnecessary braces too. But I do not see any
option in coccinelle for this, so instead, I edited the patch text using
search&replace to remove the braces. Unfortunately this is not fully automatic,
in particular it didn't deal well with if-else-if-else blocks and ifdefs, so
there is an increased likelikehood be some bugs in such spots.
I also removed part of the patch that coccinelle generated for udev, where we
returns -1 for failure. This should be fixed independently.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Let's use chase_symlinks() everywhere, and stop using GNU
canonicalize_file_name() everywhere. For most cases this should not change
behaviour, however increase exposure of our function to get better tested. Most
importantly in a few cases (most notably nspawn) it can take the correct root
directory into account when chasing symlinks.
We currently have code to read and write files containing UUIDs at various
places. Unify this in id128-util.[ch], and move some other stuff there too.
The new files are located in src/libsystemd/sd-id128/ (instead of src/shared/),
because they are actually the backend of sd_id128_get_machine() and
sd_id128_get_boot().
In follow-up patches we can use this reduce the code in nspawn and
machine-id-setup by adopted the common implementation.
Allow for overriding all other machine-ids which may be present on
the system using a kernel command line systemd.machine_id or
--machine-id= option.
This is especially useful for network booted systems where the
machine-id needs to be static, or for containers where a specific
machine-id is wanted.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Introduce a proper enum, and don't pass around string ids anymore. This
simplifies things quite a bit, and makes virtualization detection more
similar to architecture detection.
To be able to use `systemd-run` or `machinectl login` on a container
that is in a private user namespace, the sub-process must have entered
the user namespace before connecting to the container's D-Bus, otherwise
the UID and GID in the peer credentials are garbage.
So we extend namespace_open and namespace_enter to support UID namespaces,
and we enter the UID namespace in bus_container_connect_{socket,kernel}.
namespace_open will degrade to a no-op if user namespaces are not enabled
in the kernel.
Special handling is required for the setns call in namespace_enter with
a user namespace, since transitioning to your own namespace is forbidden,
as it would result in re-entering your user namespace as root.
Arguably it may be valid to check this at the call site, rather than
inside namespace_enter, but it is less code to do it inside, and if the
intention of calling namespace_enter is to *be* in the target namespace,
rather than to transition to the target namespace, it is a reasonable
approach.
The check for whether the user namespace is the same must happen before
entering namespaces, as we may not be able to access /proc during the
intermediate transition stage.
We can't instead attempt to enter the user namespace and then ignore
the failure from it being the same namespace, since the error code is
not distinct, and we can't compare namespaces while mid-transition.
Merge write_string_file(), write_string_file_no_create() and
write_string_file_atomic() into write_string_file() and provide a flags mask
that allows combinations of atomic writing, newline appending and automatic
file creation. Change all users accordingly.
Usually when using loop_read(), we want to read the full buffer.
Add a helper that mirrors loop_write(), and returns 0 when full buffer
was read, and an error otherwise.
Use -ENODATA for the short read, to distinguish it from a read error.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
After all it is now much more like strjoin() than strappend(). At the
same time, add support for NULL sentinels, even if they are normally not
necessary.
loop_write() didn't follow the usual systemd rules and returned status
partially in errno and required extensive checks from callers. Some of
the callers dealt with this properly, but many did not, treating
partial writes as successful. Simplify things by conforming to usual rules.
