We allocated the names set for each unit, but in the majority of cases, we'd
put only one name in the set:
$ systemctl show --value -p Names '*'|grep .|grep -v ' '|wc -l
564
$ systemctl show --value -p Names '*'|grep .|grep ' '|wc -l
16
So let's add a separate .id field, and only store aliases in the set, and only
create the set if there's at least one alias. This requires a bit of gymnastics
in the code, but I think this optimization is worth the trouble, because we
save one object for many loaded units.
In particular set_complete_move() wasn't very useful because the target
unit would always have at least one name defined, i.e. the optimization to
move the whole set over would never fire.
This is a follow-up for 9f83091e3c.
Instead of reading the mtime off the configuration files after reading,
let's do so before reading, but with the fd we read the data from. This
is not only cleaner (as it allows us to save one stat()), but also has
the benefit that we'll detect changes that happen while we read the
files.
This also reworks unit file drop-ins to use the common code for
determining drop-in mtime, instead of reading system clock for that.
If we have a template unit template@.service, it should be allowed to specify a
dependency on a unit without an instance, bar@.service. When the unit is created,
the instance will be propagated into the target, so template@inst.service will
depend on bar@inst.service.
This commit changes unit_dependency_name_compatible(), which makes the manager
accept links like that, and unit_file_verify_alias(), so that the installation
function will agree to create a symlink like that, and finally the tests are
adjusted to pass.
When loading units, sometimes we'd first encounter a unit from .wants or
.requires directory. A typical case would be when multi-user.target.wants/
contains a symlink to some unit. We would prepare to load this unit using
/etc/systemd/system/multi-user.target.wants/foo.service as the fragment
path. This is always wrong. Instead, let's use NULL as the path and let
manager_load_unit() figure out the path on its own.
Fixes#9921.
path=0x5625ed9b01a0 "/usr/lib/systemd/system/local-fs.target.wants/systemd-remount-fs.service", e=0x0,
_ret=0x7ffe64645000) at ../src/core/manager.c:1887
name=0x5625ed9b01ce "systemd-remount-fs.service",
path=0x5625ed9b01a0 "/usr/lib/systemd/system/local-fs.target.wants/systemd-remount-fs.service", e=0x0,
_ret=0x7ffe64645000) at ../src/core/manager.c:1961
name=0x5625ed9b01ce "systemd-remount-fs.service",
path=0x5625ed9b01a0 "/usr/lib/systemd/system/local-fs.target.wants/systemd-remount-fs.service",
add_reference=true, mask=UNIT_DEPENDENCY_FILE) at ../src/core/unit.c:2946
dir_suffix=0x5625ebb179ed ".wants") at ../src/core/load-dropin.c:95
path=0x0, e=0x0, _ret=0x7ffe646452c0) at ../src/core/manager.c:1965
name=0x5625ebb186f8 "local-fs.target", path=0x0, add_reference=true,
mask=UNIT_DEPENDENCY_MOUNTINFO_IMPLICIT) at ../src/core/unit.c:2946
where=0x5625ed9b3cc0 "/tmp", options=0x5625ed947110 "rw,nosuid,nodev,seclabel",
fstype=0x5625ed95be90 "tmpfs", flags=0x7ffe64645395) at ../src/core/mount.c:1439
where=0x5625ed9b3cc0 "/tmp", options=0x5625ed947110 "rw,nosuid,nodev,seclabel",
fstype=0x5625ed95be90 "tmpfs", set_flags=false) at ../src/core/mount.c:1567
at ../src/core/mount.c:1635
ret_retval=0x7ffe64645660, ret_shutdown_verb=0x7ffe646456c0, ret_fds=0x7ffe646456d8,
ret_switch_root_dir=0x7ffe646456b0, ret_switch_root_init=0x7ffe646456b8,
ret_error_message=0x7ffe646456c8) at ../src/core/main.c:1669
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.
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This replaces the dependencies Set* objects by Hashmap* objects, where
the key is the depending Unit, and the value is a bitmask encoding why
the specific dependency was created.
The bitmask contains a number of different, defined bits, that indicate
why dependencies exist, for example whether they are created due to
explicitly configured deps in files, by udev rules or implicitly.
Note that memory usage is not increased by this change, even though we
store more information, as we manage to encode the bit mask inside the
value pointer each Hashmap entry contains.
Why this all? When we know how a dependency came to be, we can update
dependencies correctly when a configuration source changes but others
are left unaltered. Specifically:
1. We can fix UDEV_WANTS dependency generation: so far we kept adding
dependencies configured that way, but if a device lost such a
dependency we couldn't them again as there was no scheme for removing
of dependencies in place.
2. We can implement "pin-pointed" reload of unit files. If we know what
dependencies were created as result of configuration in a unit file,
then we know what to flush out when we want to reload it.
3. It's useful for debugging: "systemd-analyze dump" now shows
this information, helping substantially with understanding how
systemd's dependency tree came to be the way it came to be.
Let's log about this in the caller.
Doesn't really matter, but let's do something about my OCD, and
propagate errors properly, so that the caller can log about them.
unit_name_template returns -EINVAL if the unit name is not a template, but
the code assumed that OOM is the only failure mode. Fix that to emit the warning
if a non-template unit is encountered (because in this case we expect the name
to match exactly), and just skip the warning on other errors (presumably oom).
Fixes#5543.
Feb 04 22:35:42 systemd[1462]: foo.service: Wants dependency dropin /home/zbyszek/.config/systemd/user/foo.service.wants/diffname.service target ../barbar.service has different name
Feb 04 22:35:42 systemd[1462]: foo.service: Wants dependency dropin /home/zbyszek/.config/systemd/user/foo.service.wants/wrongname is not a valid unit name, ignoring
Fixes#1169.
Fixes#4830.
Example log errors:
Feb 04 22:13:28 systemd[1462]: foo.service: Wants dependency on empty_file.service is masked by /home/zbyszek/.config/systemd/user/foo.service.wants/empty_file.service, ignoring
Feb 04 22:13:28 systemd[1462]: foo.service: Wants dependency on masked.service is masked by /home/zbyszek/.config/systemd/user/foo.service.wants/masked.service, ignoring
Essentially, instead of sequentially adding deps based on all symlinks
encountered in .wants and .requires dirs for each name and each unit file load
path, iteratate over the load paths and unit names gathering symlinks, then
order them based on priority, and then iterate over the final list, adding
dependencies.
This patch doesn't change the logic too much, except that the order in which
dependencies are applied might be different. It wasn't defined before, so that
not really a change. Adding filtering on the symlinks is left for later
patches.
The general rule is:
- code in shared/ should take an "original_root" argument (possibly NULL)
and pass it along down to chase_symlinks
- code in core/ should always use specify original_root==NULL, since we
don't support running the manager from non-root directory
- code in systemctl and other tools should pass arg_root.
For any code that is called from tools which support --root, chase_symlinks
must be used to look up paths.
Previously, when creating a transient unit, we'd first add the transient
drop-ins to the unit, and then normally load any other drop-ins later on top of
this, replacing the already loaded drop-ins. Let's not do this, after all the
transient drop-ins area already in effect, let's just add what we find on disk,
but not replace it.
A long time ago – when generators where first introduced – the directories for
them were randomly created via mkdtemp(). This was changed later so that they
use fixed name directories now. Let's make use of this, and add the genrator
dirs to the LookupPaths structure and into the unit file search path maintained
in it. This has the benefit that the generator dirs are now normal part of the
search path for all tools, and thus are shown in "systemctl list-unit-files"
too.
Fixes:
==1== HEAP SUMMARY:
==1== in use at exit: 67,182 bytes in 91 blocks
==1== total heap usage: 70,485 allocs, 70,394 frees, 42,184,635 bytes
allocated
==1==
==1== 5,742 (696 direct, 5,046 indirect) bytes in 29 blocks are
definitely lost in loss record 4 of 7
==1== at 0x4C2DD9F: realloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x21ADDD: realloc_multiply (alloc-util.h:67)
==1== by 0x21BFB0: strv_push (strv.c:448)
==1== by 0x21C245: strv_consume (strv.c:520)
==1== by 0x21C33C: strv_extend (strv.c:559)
==1== by 0x278AD7: unit_write_drop_in (unit.c:3352)
==1== by 0x278EEB: unit_write_drop_in_private (unit.c:3403)
==1== by 0x190C21: bus_service_set_transient_property
(dbus-service.c:254)
==1== by 0x190DBC: bus_service_set_property (dbus-service.c:284)
==1== by 0x18F00E: bus_unit_set_properties (dbus-unit.c:1226)
==1== by 0x186F6A: transient_unit_from_message (dbus-manager.c:683)
==1== by 0x1872B7: method_start_transient_unit (dbus-manager.c:763)
==1==
==1== LEAK SUMMARY:
==1== definitely lost: 696 bytes in 29 blocks
==1== indirectly lost: 5,046 bytes in 58 blocks
==1== possibly lost: 0 bytes in 0 blocks
==1== still reachable: 61,440 bytes in 4 blocks
==1== suppressed: 0 bytes in 0 blocks
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
Special care is needed so that we get an error message if the
file failed to parse, but not when it is missing. To avoid duplicating
the same error check in every caller, add an additional 'warn' boolean
to tell config_parse whether a message should be issued.
This makes things both shorter and more robust wrt. to error reporting.
The information about the unit for which files are being parsed
is passed all the way down. This way messages land in the journal
with proper UNIT=... or USER_UNIT=... attribution.
'systemctl status' and 'journalctl -u' not displaying those messages
has been a source of confusion for users, since the journal entry for
a misspelt setting was often logged quite a bit earlier than the
failure to start a unit.
Based-on-a-patch-by: Oleksii Shevchuk <alxchk@gmail.com>
