When hashmap_replace detects no such key exists yet, it calls hashmap_put that
performs the same check again. Avoid that by splitting the core of hashmap_put
into a separate function.
The following hashmap_* and set_* functions/macros have never had any
users in systemd's history:
*_iterate_backwards
*_iterate_skip
*_last
*_FOREACH_BACKWARDS
Remove this dead code.
It is redundant to store 'hash' and 'compare' function pointers in
struct Hashmap separately. The functions always comprise a pair.
Store a single pointer to struct hash_ops instead.
systemd keeps hundreds of hashmaps, so this saves a little bit of
memory.
Functions either should generate error messages for everything they do
themselves, or for nothing and let the caller do it. But they certainly
shouldn't generate errors for some messages but not for others. Since
the function in this case is one that generates messages on its own, it
really should do that for everything, not just for some things, hence.
The check, if the directory/file already exists is only executed, if
there is a symlink target specified. In case of "/root", there is none,
so it is unconditionally tried to create the directory.
In case of a readonly filesystem, errno != EEXIST, but errno == EROFS,
so base_filesystem_create() and switch_root does not succeed.
This patch checks for existance not only in the symlink case.
Similar to container_of(), we now use unique variable names for the bascic
math macros MAX, MIN, CLAMP, LESS_BY. Furthermore, unit tests are added to
verify they work as expected.
For a rationale, see:
commit fb835651af
Author: David Herrmann <dh.herrmann@gmail.com>
Date: Fri Aug 22 14:41:37 2014 +0200
shared: make container_of() use unique variable names
If you stack container_of() macros, you will get warnings due to shadowing
variables of the parent context. To avoid this, use unique names for
variables.
Two new helpers are added:
UNIQ: This evaluates to a truly unique value never returned by any
evaluation of this macro. It's a shortcut for __COUNTER__.
UNIQ_T: Takes two arguments and concatenates them. It is a shortcut for
CONCATENATE, but meant to defined typed local variables.
As you usually want to use variables that you just defined, you need to
reference the same unique value at least two times. However, UNIQ returns
a new value on each evaluation, therefore, you have to pass the unique
values into the macro like this:
#define my_macro(a, b) __max_macro(UNIQ, UNIQ, (a), (b))
#define __my_macro(uniqa, uniqb, a, b) ({
typeof(a) UNIQ_T(A, uniqa) = (a);
typeof(b) UNIQ_T(B, uniqb) = (b);
MY_UNSAFE_MACRO(UNIQ_T(A, uniqa), UNIQ_T(B, uniqb));
})
This way, MY_UNSAFE_MACRO() can safely evaluate it's arguments multiple
times as they are local variables. But you can also stack invocations to
the macro my_macro() without clashing names.
This is the same as if you did:
#define my_macro(a, b) __max_macro(__COUNTER__, __COUNTER__, (a), (b))
#define __my_macro(prefixa, prefixb, a, b) ({
typeof(a) CONCATENATE(A, prefixa) = (a);
typeof(b) CONCATENATE(B, prefixb) = (b);
MY_UNSAFE_MACRO(CONCATENATE(A, prefixa), CONCATENATE(B, prefixb));
})
...but in my opinion, the first macro is easier to write and read.
This patch starts by converting container_of() to use this new helper.
Other macros may follow (like MIN, MAX, CLAMP, ...).
The UNIQUE() macro works fine if used in un-stacked macros. However, once
you stack them like:
MAX(MIN(a, b),
CLAMP(MAX(c, d), e, f))
you will get warnings due to shadowing other variables. gcc uses the last
line of a macro expansion as value for __LINE__, therefore, we cannot even
avoid this by splitting the expressions across lines.
Remove the only user of UNIQUE() so we introduce a new helper in
follow-ups.
If we invoke agents, we should make sure we actually can kill them
again. I mean, it's probably not our job to cleanup the signals if our
tools are invoked in weird contexts, but at least we should make sure,
that the subprocesses we invoke and intend to control work as intended.
Also see:
http://lists.freedesktop.org/archives/systemd-devel/2014-August/022460.html
This patch modifies unit_file_get_list which will now return
hashmap of structures where f->path is *without* root_dir prefix.
This change should be ok, because current code either does not use
root_dir at all or calls basename() on the f->path.
When this system-wide start-up timeout is hit we execute one of the
failure actions already implemented for services that fail.
This should not only be useful on embedded devices, but also on laptops
which have the power-button reachable when the lid is closed. This
devices, when in a backpack might get powered on by accident due to the
easily reachable power button. We want to make sure that the system
turns itself off if it starts up due this after a while.
When the system manages to fully start-up logind will suspend the
machine by default if the lid is closed. However, in some cases we don't
even get as far as logind, and the boot hangs much earlier, for example
because we ask for a LUKS password that nobody ever enters.
Yeah, this is a real-life problem on my Yoga 13, which has one of those
easily accessible power buttons, even if the device is closed.
The MAXSIZE() macro takes two types and returns the size of the larger
one. It is much simpler to use than MAX(sizeof(A), sizeof(B)) and also
avoids any compiler-extensions, unlike CONST_MAX() and MAX() (which are
needed to avoid evaluating arguments more than once). This was suggested
by Daniele Nicolodi <daniele@grinta.net>.
Also make resolved use this macro instead of CONST_MAX(). This enhances
readability quite a bit.
Unlike strv_find_prefix() the new call will return a pointer to the
suffix of the item we found, instead of the whole item. This is more
closer inline with what startswith() does, and allows us to simplify a
couple of invocations.
This way we can use it on non-const strings, and don't end up with a
const'ified result.
This is similar to libc's strstr() which also takes a const string but
returns a non-const one.
Previously systemctl died with message
-bash-4.2# systemctl --root /rawhi list-unit-files
(src/systemctl/systemctl.c:868) Out of memory.
in the case that no unit files were found in the --root
or the directory did not exist.
So lets return ENOENT in the case that --root does not exist
and empty list in the case that there are no unit files.
If a name was passed in as function argument, trust it, and don't do utf-8
encoding for them. Callers are obliged to check the names themselves, and
escape them in case they use anything they got from the outside world.
As memfds are now created by proper kernel API, and not by our functions, we
can't rely on names being escaped/unescaped according to our current logic.
Thus, the only safe way is to remove the escaping and when reading names,
just escape names that are not properly encoded in UTF-8.
Also, remove assert(name) lines from the memfd creation functions, as we
explictly allow name to be NULL.
Now, that the memfd stuff is not exported anymore, we can simplify a few
things:
Use assert() instead of assert_return(), since this is used internally
only, and we should be less permissive then.
No need to pass an allocated fd back by call-by-reference, we can just
directly return it.
This makes possible to spawn service instances triggered by socket with
MLS/MCS SELinux labels which are created based on information provided by
connected peer.
Implementation of label_get_child_label derived from xinetd.
Reviewed-by: Paul Moore <pmoore@redhat.com>
