Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
Function execute_directories logged in a way that was meaningless
without additional context:
systemd[1]: No executables found.
In execute_strv this was partially rectified by extracting the directory
name from one of the directories and using this as the identifier. But
the directory name is not always meaningful, and can also be set from
an environment variable. Let's simplify things by providing a fixed name
that can be used consistently in all log messages. In particular this will
make error messages easier to understand if users report just the error
without additional context.
When switching to another user it's oftentimes desirable to also spawn
the target user's shell. sudo supports this via -i flag, run0 currently
doesn't. We don't want to proactively query NSS ourselves, since
that would fall short when operating remotely. Let's instead teach
the service manager to spawn the command using the user's default shell.
I opted for "|" instead of "." in the end because the latter seems
a bit obscure. But happy to change it to something else if a better option
comes up.
Let's bump the kernel baseline a bit to 4.3 and thus require ambient
caps.
This allows us to remove support for a variety of special casing, most
importantly the ExecStart=!! hack.
Library code should not call freeze(), this is something that should
only be done by "application code", so moving it into shared/ is appropriate.
The fallback to call _exit() is dropped: let's trust that the infinite loop
is infinite.
Currently it's only used in two places in src/shared/, so the function was
already included just once in compiled code. But it seems appropriate to
move it there anyway, because library code should have no need to fork
agents, so it doesn't belong in basic/.
This adds a new bitfield to `execute_directories()` which allows to
configure whether to ignore non-zero exit statuses of binaries run and
whether to allow parallel execution of commands.
In case errors are not ignored, the exit status of the failed script
will now be returned for error reposrting purposes or other further
future use.
This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:
$ du -sb /var/tmp/inst*
54181861 /var/tmp/inst1 (old)
54207441 /var/tmp/inst1s (old split-usr)
54182477 /var/tmp/inst2 (new)
54208041 /var/tmp/inst2s (new split-usr)
(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)
The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
build less stuff for libbasic.a (which wouldn't be used anyway,
so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
synchronization point, possibly allowing better parallelism.
Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Mike Yuan
Lennart Poettering
Yu Watanabe
Lukas Nykryn
Benjamin Robin
Anita Zhang
Matthias Klumpp