We often open the parent directory of a path. Let's add a common helper
for that, that shortens our code a bit and adds some extra safety
checks, for example it will fail if used on the root directory (which
doesn't really have a parent).
The helper is actually generalized from a function in btrfs-util.[ch]
which already existed for this purpose.
These custom macros make the expression go through a function, in order
to prevent ASSERT_SIDE_EFFECT false positives on our macros such as
assert_se() and assert_return() that cannot be disabled and will always
evaluate their expressions.
This technique has been described and recommended in:
https://community.synopsys.com/s/question/0D534000046Yuzb/suppressing-assertsideeffect-for-functions-that-allow-for-sideeffects
Tested by doing a local cov-build and uploading the resulting tarball to
scan.coverity.com, confirmed that the ASSERT_SIDE_EFFECT false positives
were gone.
key_serial_t is defined in keyutil.h, which wasn't included in the header list
in the test, so the test always failed. We were always compiling stuff with
!HAVE_KEY_SERIAL_T.
We could try to add keyutil.h to the test, but then we'd have to first check if
it is available, which just doesn't seem worth the trouble.
key_serial_t should always be defined as int32_t. Let's keep the uncoditional
define, since repeated compatible typedefs are not a problem, and it allows us
to compile even if the header file is missing. If there's ever a change in the
definition, we'll have to adjust the code for the different type anyway, and
our compiler will tell us.
Using _GNU_SOURCE is better because that's how we include the headers in the
actual build, and some headers define different stuff when it is defined.
sys/stat.h for example defines 'struct statx' conditionally.
Unfortunately this needs libshared to link to libkmod. Before it was linked
into systemd-udevd, udevadm, and systemd each seperately. On most systems this
doesn't make much difference, because at least systemd would be installed, but
it might not be in small chroots. It is a small library, so I hope this is not
a big issue.
Starting with glibc 2.27.9000-36.fc29, include file sys/stat.h will have a
definition for struct statx, in which case include file linux/stat.h should be
avoided, in order to prevent a duplicate definition.
In file included from ../src/basic/missing.h:18,
from ../src/basic/util.h:28,
from ../src/basic/hashmap.h:10,
from ../src/shared/bus-util.h:12,
from ../src/libsystemd/sd-bus/bus-creds.c:11:
/usr/include/linux/stat.h:99:8: error: redefinition of ‘struct statx’
struct statx {
^~~~~
In file included from /usr/include/sys/stat.h:446,
from ../src/basic/util.h:19,
from ../src/basic/hashmap.h:10,
from ../src/shared/bus-util.h:12,
from ../src/libsystemd/sd-bus/bus-creds.c:11:
/usr/include/bits/statx.h:36:8: note: originally defined here
struct statx
^~~~~
Extend our meson.build to look for struct statx when only sys/stat.h is
included and, in that case, do not include linux/stat.h anymore.
Tested that systemd builds correctly when using a glibc version that includes a
definition for struct statx.
glibc Fedora RPM update:
28cb5d31fc
glibc upstream commit:
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=fd70af45528d59a00eb3190ef6706cb299488fcd
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.
On overlayfs, FTW_MOUNT causes nftw to not list *any* files because the
condition used by glibc to verify that it's on the same mountpoint doesn't work
on overlayfs, see https://bugzilla.suse.com/show_bug.cgi?id=1096807 for the
details.
However using FTW_MOUNT doesn't seem to be really needed when walking through
the keymap directorie tree. So until the glibc or the kernel is fixed (which
might take some time), let's make localectl works with overlayfs.
There's a small side effect here, by which regular (non-directory) files with
bind mounts will be parsed while they were skipped by the previous logic.
They are not needed, because anything that is non-zero is converted
to true.
C11:
> 6.3.1.2: When any scalar value is converted to _Bool, the result is 0 if the
> value compares equal to 0; otherwise, the result is 1.
https://stackoverflow.com/questions/31551888/casting-int-to-bool-in-c-c
Let's always write "1 << 0", "1 << 1" and so on, except where we need
more than 31 flag bits, where we write "UINT64(1) << 0", and so on to force
64bit values.
