This resolves problems with filesystems which do not implement the
aio_write file operation. In this case, the kernel will fall back using
a loop writing technique for each pointer in a received iovec. The
result is strange errors in dmesg such as:
[ 31.855871] elevator: type not found
[ 31.856262] elevator: switch to
[ 31.856262] failed
It does not make sense to implement a synchronous aio_write method for
sysfs as this isn't a real filesystem where a reasonable use case for
using writev exists, nor is there an expectation that tmpfiles will be
used to write more data than can be reasonably written in a single write
syscall.
In addition, some sysfs attrs are currently buggy and will NOT reject
the second write with the newline, causing the sysfs value to be zeroed
out. This of course should be fixed in the kernel regardless of any
wrongdoing in userspace, but this simple change makes us immune to such
a bug.
This change means that we do not write a trailing newline by default, as
the expected use case of 'w' is for sysfs and procfs. In exchange, honor
C-style backslash escapes so that if the newline is really needed, the
user can add it.
Most things seem to function fine without /dev/shm, but it is expected
to be there (quoting linux/Documentation/filesystems/tmpfs.txt:
glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for POSIX
shared memory (shm_open, shm_unlink)).
Since /tmp/ is already mounted as tmpfs, it would be enough to mkdir
/tmp/shm and chmod it. Mounting it separately has the advantage that
it can be easily remounted to change the quota.
When looking for symlinks, it doesn't make sense to error-out if
the directory is missing. The user might delete an empty directory.
This check caused test-unit-file to fail when run before installation.
Before, after the timeout, a session would be timestamped as idle
since 'last activity' + 'idle timeout'. Now, it is timestamped as idle
since 'last activity'.
Before, after all sessions were idle, the seat would be marked with as
idle with the timestamp of the oldest idle session. Now it is
marked with the timestamp of the youngest idle session.
Both changes seem to me to be closer to natural understanding of
idleness: the time since last activity counts.
- Make writing/reading of /etc/timezone dependendent of HAVE_SYSV_COMPAT
- Introduce symlink_atomic() after all, and use it
- Use relative symlink for /etc/localtime
/etc/localtime -> /usr/share/zoneinfo/...
or
/etc/localtime -> ../usr/share/zoneinfo/...
(note, ../usr is not the same if /etc is a symlink, as this isn't
using canonicalize_file_name())
keep other method for now, consider dropping later.
Supporting relative links here are problematic as timezones in
/usr/share/zoneinfo are often themselves symlinks (and symlinks to
symlinks), so this implamentation only supports absolute symlinks
"/usr/share/zoneinfo/" and relative symlinks starting with
"../usr/share/zoneinfo/"
>From TODO (kay sievers):
* kill /etc/timezone handling entirely? What does it provide?
- /etc/localtime carries the same information already:
$ ls -l /etc/localtime; cat /etc/timezone
lrwxrwxrwx 1 root root 33 Jul 27 09:55 /etc/localtime -> /usr/share/zoneinfo/Europe/Berlin
Europe/Berlin
- systemd enforces /usr to be available at bootup, so we can
enforce the use of the symlink
Clang don't treat unknown warnings flags as an error, but rather as a
warning. The result is that the detection for whic CFLAGS are supported
by this compiler will not work, since the compilation will succeed.
With this patch we now successfully detect clang doesn't support
-Wlogical-op, as opposed to previous behavior:
checking if clang supports flag -Wlogical-op in envvar CFLAGS... no
We use this macro only for LDFLAGS and CFLAGS, so it's safe to stash
-Werror there.
Add specifier expansion to Path and String conditions.
Specifier expansion for conditions will help create instance
and user session units by allowing us to template conditions
based on the instance or user session parameters.
An example would be a system-wide user session service file
that conditionally runs based on whether a user has the
service configured through a configuration file in ~/.config/.
This only adds the fields to the D-Bus interfaces but doesn't fill them
in with anything useful yet. Gummiboot exposes the necessary bits of
information to use however and as soon as I get my fingers on a proper
UEFI laptop I'll hook up the remaining bits.
Since we want to stabilize the D-Bus interface soon and include it in
the stability promise we should get the last fixes in, hence this change
now.
Zbigniew Jędrzejewski-Szmek