This PR made modification on Lennart Poettering's basis. Fix the LineMax's function failure problem.
Signed-off-by: Yangyang Shen <shenyangyang4@huawei.com>
With some versions of the compiler, the _cleanup_ attr makes it think
the variable might be freed/closed when uninitialized, even though it
cannot happen. The added cost is small enough to be worth the benefit,
and optimized builds will help reduce it even further.
This adds the same line to most of our .conf files.
Not for systemd/user.conf though, since we can't correctly display it right
now:
$ systemd-analyze cat-config --user systemd/user.conf
Option --user is not supported for cat-config right now.
For sysusers.d, tmpfiles.d, rules.d, etc, there is no single file. Maybe
we should short READMEs in /usr/lib/sysusers.d, /usr/lib/tmpfiles.d, etc.?
Inspired by #19118.
Previously, the flag did two things at once: enable support for using
generic partitions as root fs if there were only one/allow use of
partition-table-less images as root fs. And secondly, insist that there
was a rootfs, and fail if not. Let's split these two in two separate
options so that they can be used independently of each other.
There are cases where one wants to use one without the other (i.e. when
inspecting things with systemd-dissect tool it should be OK to do so
even if image has no root fs), and it's cleaner anyway.
To make sd-device properly usable for all programs we need to provide an
API for the "action" field of an event, it's one of the most relevant
ones, and it was so far missing.
This also adds sd_device_get_seqnum(), which isn't that interesting,
except for generating pretty debug output, which we use it ourselves
for.
This also makes device_new_from_stat_rdev() public, as it is truly
useful, as we can see in our own uses of it, and I think is fairly
generic to show up in the public APIs.
This nicely covers the case when optarg is optional. The same parser can be
used when the option string passed to getopt_long() requires a parameter and
when it doesn't.
The error messages are made consistent.
Also fixes a log error c&p in --crash-reboot message.
If the cleanup function returns the appropriate type, use that to reset the
variable. For other functions (usually the foreign ones which return void), add
an explicit value to reset to.
This causes a bit of code churn, but I think it might be worth it. In a
following patch static destructors will be called from a fuzzer, and this
change allows them to be called multiple times. But I think such a change might
help with detecting unitialized code reuse too. We hit various bugs like this,
and things are more obvious when a pointer has been set to NULL.
I was worried whether this change increases text size, but it doesn't seem to:
-Dbuildtype=debug:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494520 Feb 16 15:06 build/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494576 Feb 16 15:10 build/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494640 Feb 16 15:15 build/systemd*
-Dbuildtype=release:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:09 build-rawhide/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:10 build-rawhide/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:16 build-rawhide/systemd*
I would expect that the compiler would be able to elide the setting of a
variable if the variable is never used again. And this seems to be the case:
in optimized builds there is no change in size whatsoever. And the change in
size in unoptimized build is negligible.
Something strange is happening with size of libsystemd: it's bigger in
optimized builds. Something to figure out, but unrelated to this patch.
I started working on this because I wanted to change how
DEFINE_TRIVIAL_CLEANUP_FUNC is defined. Even independently of that change, it's
nice to make make things more consistent and predictable.
As suggested in https://github.com/systemd/systemd/pull/11484#issuecomment-775288617.
This does not touch anything exposed in src/systemd. Changing the defines there
would be a compatibility break.
Note that tests are broken after this commit. They will be fixed in the next one.
I think this formatting was originally used because it simplified
adding new options to the help messages. However, these days, most
tools their help message end with "\nSee the %s for details.\n" so
the final line almost never has to be edited which eliminates the
benefit of the custom formatting used for printf() help messages.
Let's make things more consistent and use the same formatting for
printf() help messages that we use everywhere else.
Prompted by https://github.com/systemd/systemd/pull/18355#discussion_r567241580
Even though many of those scripts are very simple, it is easier to include
the header than to try to say whether each of those files is trivial enough
not to require one.
@keszybz's right on
https://github.com/systemd/systemd/pull/18248#issuecomment-760798473:
swapping out the userdata pointer of a live varlink connection is iffy.
Let's fix this by making the userdata inheritance from VarlinkServer
object to the Varlink connection object optional: we want it for most
cases, but not all, i.e. all those cases where the calls implemented as
varlink methods are stateless and can be answered synchronously. For the
other cases (i.e. where we want per-connection objects that wrap the
asynchronous operation as it goes on) let's not do such inheritance but
initialize the userdata pointer only once we have it. THis means the
original manager object must be manually retrieved from the
VarlinkServer object, which in turn needs to be requested from the
Varlink connection object.
The userdata inheritance is now controlled by the
VARLINK_INHERIT_USERDATA flag passed at VarlinkServer construction.
Alternative-to: #18248
By default, systemd installs various sample configuration files
containing commented-out defaults. Systems seeking to minimize the
number of files in /etc may wish to install directories and
configuration files that have semantic effects, but not install not
commented-out sample configuration files.
Turn install-sysconfdir into a multi-valued option, with a "no-samples"
value to skip installing sample-only configuration files.
Let's clean up hostname_is_valid() a bit: let's turn the second boolean
argument into a more explanatory flags field, and add a flag that
accepts the special name ".host" as valid. This is useful for the
container logic, where the special hostname ".host" refers to the "root
container", i.e. the host system itself, and can be specified at various
places.
let's also get rid of machine_name_is_valid(). It was just an alias,
which is confusing and even more so now that we have the flags param.
The ret_size result is a bit of an awkward optimization that in a
sense enables bypassing the mmap-cache API, while encouraging
duplication of logic it already implements.
It's only utilized in one place; journal_file_move_to_object(),
apparently to avoid the overhead of remapping the whole object
again once its header, and thus its actual size, is known.
With mmap-cache's context cache, the overhead of simply
re-getting the object with the now known size should already be
negligible. So it's not clear what benefit this brings, unless
avoiding some function calls that do very little in the hot
context-cache hit case is of such a priority.
There's value in having all object-sized gets pass through
mmap_cache_get(), as it provides a single entrypoint for
instrumentation in profiling/statistics gathering. When
journal_file_move_to_object() bypasses getting the full object
size, you don't capture the full picture on the mmap-cache side
in terms of object sizes explicitly loaded from a journal file.
I'd like to see additional accounting in mmap_cache_get() in a
future commit, taking advantage of this change.
There are no mmap_cache_get() users that actually deviate prot
from the JournalFile's f->prot.
So there's no point in making this a separate parameter to
mmap_cache_get(), nor is there any need to store it in
JournalFile's f->prot.
Instead just pass it to mmap_cache_add_fd() at MMapFileDescriptor
creation, storing it in there for the mmap() callers, which
already receive MMapFileDescriptor *.
For functions receiving both an MMapFileDescriptor * and prot,
the prot argument has been simply removed and call sites updated.
Formalizing this fd:prot binding at the public API also enables
discarding the prot check in window_matches(), which is a hot
function on long window lists, so a minor CPU efficiency gain
should be had there as seen with the past removal of the fd
check. Unnoticable for uncached journals, but maybe a little
runtime improvement when cached in specific circumstances.
window_matches_fd() has also been simplified to treat the
MMapFileDescrptor * as equivalent to its fd and prot.
Account and log these statistics separately since their overheads
are potentially quite different when the window lists are large.
There should probably be a histogram of window list traversal
counts too.
In preparation for logging more mmap-cache statistics get rid of this
piecemeal stats accessor api and just have a debug log output function
for producing the stats.
Updates the one call site using these accessors, moving what that site
did into the new log function. So the output is unchanged for now,
just a trivial refactor.
Yangyang Shen
Zbigniew Jędrzejewski-Szmek
Luca Boccassi
Lennart Poettering
Yu Watanabe
Daan De Meyer
Susant Sahani
Josh Triplett
Franck Bui
rnhmjoj
Vito Caputo