tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

core: Add machine-id setting 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.

util-lib: split out allocation calls into alloc-util.[ch]

util-lib: split out umask-related code to umask-util.h

util-lib: split stat()/statfs()/stavfs() related calls into stat-util.[ch]

util-lib: move a number of fs operations into fs-util.[ch]

util-lib: move mount related utility calls to mount-util.[ch]

util-lib: split out hex/dec/oct encoding/decoding into its own file

util-lib: split out IO related calls to io-util.[ch]

util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.

util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] 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.

basic: split out cpu set specific APIs into cpu-set-util.[ch]

basic: rework virtualization detection API 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.

namespace helpers: Allow entering a UID namespace 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.

fileio: consolidate write_string_file*() 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.

path-util: Change path_is_mount_point() symlink arg from bool to flags This makes path_is_mount_point() consistent with fd_is_mount_point() wrt. flags.

shared: add process-util.[ch]

util: rework rm_rf() logic - Move to its own file rm-rf.c - Change parameters into a single flags parameter - Remove "honour sticky" logic, it's unused these days

machine-id-setup: simplifications

Introduce loop_read_exact helper 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.

remove unused includes 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.

util: rework strappenda(), and rename it strjoina() 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.

tree-wide: spelling fixes https://github.com/vlajos/misspell_fixer https://github.com/torstehu/systemd/commit/b6fdeb618cf2f3ce1645b3315f15f482710c7ffa Thanks to Torstein Husebo <torstein@huseboe.net>.

treewide: sanitize loop_write 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.

machine-id-setup: add a machine_id_commit call to commit on disk a transient machine-id If /etc was read only at boot time with an empty /etc/machine-id, the latter will be mounted as a tmpfs and get reset at each boot. If the system becomes rw later, this functionality enables to commit in a race-free manner the transient machine-id to disk.

machine-id-setup: casting const away is ugly, let's not do it if there's no reason to

machine-id-setup: Factorize some machine-id-setup functions to be reused

treewide: another round of simplifications Using the same scripts as in f647962d64e "treewide: yet more log_*_errno + return simplifications".

treewide: use log_*_errno whenever %m is in the format string If the format string contains %m, clearly errno must have a meaningful value, so we might as well use log_*_errno to have ERRNO= logged. Using: find . -name '*.[ch]' | xargs sed -r -i -e \ 's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/' Plus some whitespace, linewrap, and indent adjustments.

treewide: more log_*_errno + return simplifications

treewide: no need to negate errno for log_*_errno() It corrrectly handles both positive and negative errno values.

treewide: auto-convert the simple cases to log_*_errno() As a followup to 086891e5c1 "log: add an "error" parameter to all low-level logging calls and intrdouce log_error_errno() as log calls that take error numbers", use sed to convert the simple cases to use the new macros: find . -name '*.[ch]' | xargs sed -r -i -e \ 's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/' Multi-line log_*() invocations are not covered. And we also should add log_unit_*_errno().

core: improve error message when machine id is missing

machine-id-setup: don't try to read UUID from VM/container manager if we operate on a root directory that's not / This should make sure no UUID from the host systemd-machine-id-setup is running on leaks onto a disk image that is provisioned with the tool.

Always prefer our headers to system headers In practice this shouldn't make much difference, but sometimes our headers might be newer, and we want to test them.

nspawn: create essential base directories at system bootup This allows us to bootup a rootfs with a /usr directory only.

machine-id-setup: allow passing NULL as function argument, for simplicity

machine-id-setup: fix array size of parameters Not that it really would have any effect on the generated code, but let's not confuse people...

machine-id: only look into KVM uuid when we are not running in a container

util: replace close_nointr_nofail() by a more useful safe_close() safe_close() automatically becomes a NOP when a negative fd is passed, and returns -1 unconditionally. This makes it easy to write lines like this: fd = safe_close(fd); Which will close an fd if it is open, and reset the fd variable correctly. By making use of this new scheme we can drop a > 200 lines of code that was required to test for non-negative fds or to reset the closed fd variable afterwards.

machine-id-setup: use path_kill_slashes and modernizations

machine-id: add --root option to operate on an alternate fs tree This makes it possible to initialize the /etc/machine-id file on an arbitrary filesystem hierarchy. This helps systems that wish to run this at image creation time in a subdirectory, or from initramfs before pivot-root is called. [tomegun: converted to using _cleanup_free_ macros]

build-sys: use -Og instead of -O0 to catch warnings $ touch src/core/dbus.c; make CFLAGS=-O0 make --no-print-directory all-recursive Making all in . CC src/core/libsystemd_core_la-dbus.lo CCLD libsystemd-core.la $ touch src/core/dbus.c; make CFLAGS=-Og make --no-print-directory all-recursive Making all in . CC src/core/libsystemd_core_la-dbus.lo src/core/dbus.c: In function 'init_registered_system_bus': src/core/dbus.c:798:18: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized] dbus_free(id); ^ CCLD libsystemd-core.la -Og Optimize debugging experience. -Og enables optimizations that do not interfere with debugging. It should be the optimization level of choice for the standard edit-compile-debug cycle, offering a reasonable level of optimization while maintaining fast compilation and a good debugging experience.

id128: when taking user input for a 128bit ID, validate syntax Also, always accept both our simple hexdump syntax and UUID syntax.

machine-id: fix missing initialization

util: add a bit of syntactic sugar to run short code fragments with a different umask

util: rename write_one_line_file() to write_string_file() You can write much more than just one line with this call (and we frequently do), so let's correct the naming.

nspawn, machine-id-setup: warn if read-only mount call fails They are not crucial, but they shouldn't fail.

honor SELinux labels, when creating and writing config files Also split out some fileio functions to fileio.c and provide a SELinux aware pendant in fileio-label.c see https://bugzilla.redhat.com/show_bug.cgi?id=881577

machine-id: properly mount transient machine ID read-only

machine-id: fix spelling

util: unify getenv() logic for other PID

build-sys: move *-setup out of shared to avoid selinux being pulled in