Before, when interating over unit files during preset-all, behaviour was the
following:
- if we hit the real unit name first, presets were queried for that name, and
that unit was enabled or disabled accordingly,
- if we hit an alias first (one of the symlinks chaining to the real unit), we
checked the presets using the symlink name, and then proceeded to enable or
disable the real unit.
E.g. for systemd-networkd.service we have the alias dbus-org.freedesktop.network1.service
(/usr/lib/systemd/system/dbus-org.freedesktop.network1.service), but the preset
is only for the systemd-networkd.service name. The service would be enabled or
disabled pseudorandomly depending on the order of iteration.
For "preset", behaviour was analogous: preset on the alias name disabled the
service (following the default disable policy), preset on the "real" name
applied the presets.
With the patch, for "preset" and "preset-all" we silently skip symlinks. This
gives mostly the right behaviour, with the limitation that presets on aliases
are ignored. I think that presets on aliases are not that common (at least my
preset files on Fedora don't exhibit any such usage), and should not be
necessary, since whoever installs the preset can just refer to the real unit
file. It would be possible to overcome this limitation by gathering a list of
names of a unit first, and then checking whether *any* of the names matches the
presets list. That would require a significant redesign of the code, and be
a lot slower (since we would have to fully read all unit directories to preset
one unit) to so I'm not doing that for now.
With this patch, two properties are satisfied:
- preset-all and preset are idempotent, and the second and subsequent invocations
do not produce any changes,
- preset-all and preset for a specific name produce the same state for that unit.
Fixes#3616.
Under NixOS, the config_path /etc/systemd/system is a symlink to
/etc/static/systemd/system. Commands such as `systemctl list-unit-files`
and `systemctl is-enabled` did not work as the symlink was not followed.
This does not affect how symlinks are treated within the config_path
directory.
User expectations are broken when "systemctl enable /some/path/service.service"
behaves differently to "systemctl link ..." followed by "systemctl enable".
From user's POV, "enable" with the full path just combines the two steps into
one.
Fixes#3010.
If for whatever reason the file system is "corrupted", we want
to be resilient and ignore the error, as long as we can load the units
from a different place.
Arch bug https://bugs.archlinux.org/task/49547.
A user had an ntfs symlink (essentially a file) instead of a directory after
restoring from backup. We should just ignore that like we would treat a missing
directory, for general resiliency.
We should treat permission errors similarly. For example an unreadable
/usr/local/lib directory would prevent (user) instances of systemd from
loading any units. It seems better to continue.
That function doesn't draw anything on it's own, just returns a string, which
sometimes is more than one character. Also remove "DRAW_" prefix from character
names, TREE_* and ARROW and BLACK_CIRCLE are unambigous on their own, don't
draw anything, and are always used as an argument to special_glyph().
Rename "DASH" to "MDASH", as there's more than one type of dash.
It's quite a bit shorter and just as readable.
(The full sentence with "pointing to" was added to replace a text that used
"ln -s %s %s". Using the "ln" syntax is indeed unclear, because it's not
obvious which is the source and which is the target, and because symlink(2)
uses the opposite order to ln(1). But with the unicode arrow there should
be no ambiguity.)
Executing 'systemctl enable' on the same unit twice would cause
a warning about a missing [Install] section to be printed. To avoid
this, count all symlinks that "would" be created, and return 1
no matter if we actually created a symlink or skipped creation because
it already exists.
This fixes 'preset-all' with a unit that is a dangling symlink.
$ systemctl --root=/ preset-all
Unit syslog.service is an alias to a unit that is not present, ignoring.
Unit auditd.service is masked, ignoring.
Unit NetworkManager.service is masked, ignoring.
$ systemctl --root=/ preset foobar.service
Cannot find unit foobar.service.
Failed to preset: No such file or directory.
$ systemctl --root=/ preset foobar@.service
Cannot find unit foobar@.service.
Failed to preset: No such file or directory.
$ systemctl --root=/ preset foobar@blah.service
Cannot find unit foobar@blah.service or foobar@.service.
Failed to preset: No such file or directory.
The previous implementation traversed the various config directories,
walking the preset files and parsing each line to determine if a service
should be enabled or disabled. It did this for every service which
resulted in many more file operations than neccessary.
This approach parses each of the preset entries into an array which is
then used to check if each service should be enabled or disabled.
A downside is that a warning about missing [Install] is printed:
$ systemctl --root=/ enable mnt-test.mount
[/etc/systemd/system/mnt-test.mount:5] Aliases are not allowed for mount units, ignoring.
The unit files have no installation config (WantedBy, RequiredBy, Also, Alias
settings in the [Install] section, and DefaultInstance for template units).
This means they are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are:
1) A unit may be statically enabled by being symlinked from another unit's
.wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
4) In case of template units, the unit is meant to be enabled with some
instance name specified.
That's a bit misleading, but I don't see an easy way to fix this. But
the situation is similar for many other parsing errors, so maybe that's
OK.
Before:
$ systemctl preset getty@.service
Failed to preset unit, file /etc/systemd/system/getty.target.wants/getty@tty1.service
already exists and is a symlink to ../../../../usr/lib/systemd/system/getty@.service.
After:
$ systemctl preset getty@.service
Created symlink /etc/systemd/system/getty.target.wants/getty@tty1.service,
pointing to /usr/lib/systemd/system/getty@.service.
We don't really care where the symlink points to. For example, it might point
to /usr/lib or /etc, and systemd will always load the unit from /etc in
preference to /usr/lib. In fact, if we make a symlink like
/etc/systemd/system/multi-user.target.wants/b.service -> ../a.service, pid1
will still start b.service. The name of the symlink is the only thing that
matters, as far as systemd is concerned. For humans it's confusing when the
symlinks points to anything else than the actual unit file. At the very least,
the symlink is supposed to point to a file with the same name in some other
directory. Since we don't care where the symlink points, we can always replace
an existing symlink.
Another option I considered would be to simply leave an existing symlink in
place. That would work too, but replacing the symlink with the expected value
seems more intuitive.
Of course those considerations only apply to .wants and .requires. Symlinks
created with "link" and "alias" are a separate matter.
Fixes#3056.
Fixes#1892.
Previously:
Failed to enable unit: Invalid argument
Now:
Failed to enable unit, file /etc/systemd/system/ssh.service already exists.
It would be nice to include the unit name in the message too. I looked into
this, but it would require major surgery on the whole installation logic,
because we first create a list of things to change, and then try to apply them
in a loop. To transfer the knowledge which unit was the source of each change,
the data structures would have to be extended to carry the unit name over into
the second loop. So I'm skipping this for now.
Fixes#2191:
$ systemctl --root=/ enable sddm
Created symlink /etc/systemd/system/display-manager.service, pointing to /usr/lib/systemd/system/sddm.service.
$ sudo build/systemctl --root=/ enable gdm
Failed to enable unit, file /etc/systemd/system/display-manager.service already exists and is a symlink to /usr/lib/systemd/system/sddm.service.
$ sudo build/systemctl --root= enable sddm
$ sudo build/systemctl --root= enable gdm
Failed to enable unit: File /etc/systemd/system/display-manager.service already exists and is a symlink to /usr/lib/systemd/system/sddm.service.
(I tried a few different approaches to pass the error information back to the
caller. Adding a new parameter to hold the error results in a gigantic patch
and a lot of hassle to pass the args arounds. Adding this information to the
changes array is straightforward and can be more easily extended in the
future.)
In case local installation is performed, the full set of errors can be reported
and we do that. When running over dbus, only the first error is reported.
With any masked unit that would that would be enabled by presets, we'd get:
test@rawhide $ sudo systemctl preset-all
Failed to execute operation: Unit file is masked.
test@rawhide $ sudo systemctl --root=/ preset-all
Operation failed: Cannot send after transport endpoint shutdown
Simply ignore those units:
test@rawhide $ sudo systemctl preset-all
Unit xxx.service is masked, ignoring.
If the error code ever leaks (we print the strerror error instead of providing
our own), the message for ESHUTDOWN is "Cannot send after transport endpoint
shutdown", which can be misleading. In particular it suggest that some
mishandling of the dbus connection occured. Let's change that to ERFKILL which
has the advantage that a) it sounds implausible as actual error, b) has the
connotation of disabling something manually.
This allows dropping all user configuration and reverting back to the vendor
default of a unit file. It basically undoes what "systemctl edit", "systemctl
set-property" and "systemctl mask" do.
The SysV compat code checks whether there's a native unit file before looking
for a SysV init script. Since the newest rework generated units will show up in
the unit path, and hence the checks ended up assuming that there always was a
native unit file for each init script: the generated one.
With this change the generated unit file directory is suppressed from the
search path when this check is done, to avoid the confusion.
Move the search path check from the SysV service compat support into install.c
so that we can reuse the usual algorithm instead of rolling a private loop for
this.
Now, that the search path logic knows the unit path for transient units we also
can introduce an explicit unit file state "transient" that clarifies to the
user what kind of unit file he is encountering.
Previously, we'd execute some operations with the root prefix applied, while
others without (which was a bug). Clean this up: all paths are now prefixed
properly with the root path, and we strip it off when necessary.
(Of course, an alternative option would be to strictly pass around paths
without the prefix prepended and only prepend it right before hitting the disk,
however, I am came to the conclusion this would result in more code.)
We use the root directory parameter while putting together the LookupPaths
structure, hence let's also store it in the structure as-is. That way we can
drop a parameter from half of the functions in install.c
Also, let's move the validation of the root paths into lookup_paths_init() so
that we can drop even more code from install.c
Previously, we had two enums ManagerRunningAs and UnitFileScope, that were
mostly identical and converted from one to the other all the time. The latter
had one more value UNIT_FILE_GLOBAL however.
Let's simplify things, and remove ManagerRunningAs and replace it by
UnitFileScope everywhere, thus making the translation unnecessary. Introduce
two new macros MANAGER_IS_SYSTEM() and MANAGER_IS_USER() to simplify checking
if we are running in one or the user context.
Now that we store the generator directories in LookupPaths we can use this to
intrdouce a new unit file state called "generated", for units in these
directories.
Fixes: #2348
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.
All callers of create_symlink(), such as install_info_symlink_wants(), expect
that to return > 0 if it actually did something, and then return that number.
unit_file_enable() uses that to determine if any action was done
(carries_install_info != 0) and if not, show a "The unit files have no
[Install] section" warning.
Return 1 instead of 0 in the two code paths of create_symlink() when the link
was created or replaced with a new value.
This fixes getting a bogus "No [Install] section" warning when enabling a unit
with full path, like "systemctl enable /some/path/myunit.service".
Previously, the %u, %U, %s and %h specifiers would resolve to the user
name, numeric user ID, shell and home directory of the user configured
in the User= setting of a unit file, or the user of the manager instance
if no User= setting was configured. That at least was the theory. In
real-life this was not ever actually useful:
- For the systemd --user instance it made no sense to ever set User=,
since the instance runs in user context after all, and hence the
privileges to change user IDs don't even exist. The four specifiers
were actually not useful at all in this case.
- For the systemd --system instance we did not allow any resolving that
would require NSS. Hence, %s and %h were not supported, unless
User=root was set, in which case they would be hardcoded to /bin/sh
and /root, to avoid NSS. Then, %u would actually resolve to whatever
was set with User=, but %U would only resolve to the numeric UID of
that setting if the User= was specified in numeric form, or happened
to be root (in which case 0 was hardcoded as mapping). Two of the
specifiers are entirely useless in this case, one is realistically
also useless, and one is pretty pointless.
- Resolving of these settings would only happen if User= was actually
set *before* the specifiers where resolved. This behaviour was
undocumented and is really ugly, as specifiers should actually be
considered something that applies to the whole file equally,
independently of order...
With this change, %u, %U, %s and %h are drastically simplified: they now
always refer to the user that is running the service instance, and the
user configured in the unit file is irrelevant. For the system instance
of systemd this means they always resolve to "root", "0", "/bin/sh" and
"/root", thus avoiding NSS. For the user instance, to the data for the
specific user.
The new behaviour is identical to the old behaviour in all --user cases
and for all units that have no User= set (or set to "0" or "root").
Some distributions use alias unit files via symlinks in /usr to cover
for legacy service names. With this change we'll allow "systemctl
enable" on such aliases.
Previously, our rule was that symlinks are user configuration that
"systemctl enable" + "systemctl disable" creates and removes, while unit
files is where the instructions to do so are store. As a result of the
rule we'd never read install information through symlinks, since that
would mix enablement state with installation instructions.
Now, the new rule is that only symlinks inside of /etc are
configuration. Unit files, and symlinks in /usr are now valid for
installation instructions.
This patch is quite a rework of the whole install logic, and makes the
following addional changes:
- Adds a complete test "test-instal-root" that tests the install logic
pretty comprehensively.
- Never uses canonicalize_file_name(), because that's incompatible with
operation relative to a specific root directory.
- unit_file_get_state() is reworked to return a proper error, and
returns the state in a call-by-ref parameter. This cleans up confusion
between the enum type and errno-like errors.
- The new logic puts a limit on how long to follow unit file symlinks:
it will do so only for 64 steps at max.
- The InstallContext object's fields are renamed to will_process and
has_processed (will_install and has_installed) since they are also
used for deinstallation and all kinds of other operations.
- The root directory is always verified before use.
- install.c is reordered to place the exported functions together.
- Stricter rules are followed when traversing symlinks: the unit suffix
must say identical, and it's not allowed to link between regular units
and templated units.
- Various modernizations
- The "invalid" unit file state has been renamed to "bad", in order to
avoid confusion between UNIT_FILE_INVALID and
_UNIT_FILE_STATE_INVALID. Given that the state should normally not be
seen and is not documented this should not be a problematic change.
The new name is now documented however.
Fixes#1375, #1718, #1706
Instead, let the caller do that. Fix this by moving masked unit messages
into the caller, by returning a clear error code (ESHUTDOWN) by which
this may be detected.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
- Rely everywhere that we use abs() on the error code passed in anyway,
thus don't need to explicitly negate what we pass in
- Never attach synthetic error number information to log messages. Only
log about errors we *receive* with the error number we got there,
don't log any synthetic error, that don#t even propagate, but just eat
up.
- Be more careful with attaching exactly the error we get, instead of
errno or unrelated errors randomly.
- Fix one occasion where the error number and line number got swapped.
- Make sure we never tape over OOM issues, or inability to resolve
specifiers
Commit aedd401 introduced new unit file state, UNIT_FILE_INDIRECT. Unit file is
said to have indirect state if it contains [Install] section which has only
Also= directive. Thus, if enable of such unit file is requested then some other
unit file gets enabled.
Whether or not unit file is in indirect state can be determined by calling
unit_file_can_install. Function unit_file_get_list populates list of unit files
present in given lookup location. So far it did call unit_file_can_install in a
way that would prevent finding out about unit files in indirect state. Such unit
file would be incorrectly marked as static.
Fixes following assertion in test-install,
Assertion 'p->state == s' failed at src/test/test-install.c:59, function main(). Aborting.
[1] 26868 abort (core dumped) ./test-install
Maybe there is some left-over value stored in r from previous function
call. Let's make sure we always return consistent error code when we reach end of
the function body.
Fixes following crash of test-install,
Assertion 'r == 0' failed at src/test/test-install.c:52, function main(). Aborting.
[1] 11703 abort (core dumped) ./test-install
All other types exported from install.h should be namespaces like this,
hence namespace InstallInfo the same way.
Also, remove external forward definition of UnitFileScope type.
A variety of changes:
- Make sure all our calls distuingish OOM from other errors if OOM is
not the only error possible.
- Be much stricter when parsing escaped paths, do not accept trailing or
leading escaped slashes.
- Change unit validation to take a bit mask for allowing plain names,
instance names or template names or an combination thereof.
- Refuse manipulating invalid unit name
like:
src/shared/install.c: In function ‘unit_file_lookup_state’:
src/shared/install.c:1861:16: warning: ‘r’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
return r < 0 ? r : state;
^
src/shared/install.c:1796:13: note: ‘r’ was declared here
int r;
^
With debugging on, sysv-generator would print the full set of
lookup paths for *every* sysv script.
While at it, pass LookupPaths as a pointer in sysv-generator,
and constify it everywhere.
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.
After all it is now much more like strjoin() than strappend(). At the
same time, add support for NULL sentinels, even if they are normally not
necessary.
Using:
find . -name '*.[ch]' | while read f; do perl -i.mmm -e \
'local $/;
local $_=<>;
s/(if\s*\([^\n]+\))\s*{\n(\s*)(log_[a-z_]*_errno\(\s*([->a-zA-Z_]+)\s*,[^;]+);\s*return\s+\g4;\s+}/\1\n\2return \3;/msg;
print;'
$f
done
And a couple of manual whitespace fixups.
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().
f7101b7368 copied some logic to prevent enabling masked units, but
also added a check which causes attempts to enable templated units to
fail. Since we know the logic beyond this check will properly handle
units which truly do not exist, we can rely on the unit file state
comparison to suffice for expressing the intent of f7101b7368.
ref: https://bugs.archlinux.org/task/42616
That hashmap_move_one() currently cannot fail with -ENOMEM is an
implementation detail, which is not possible to guarantee in general.
Hashmap implementations based on anything else than chaining of
individual entries may have to allocate.
hashmap_move_one will not fail with -ENOMEM if a proper reservation has
been made beforehand. Use reservations in install.c.
In cgtop.c simply propagate the error instead of asserting.
This patch adds a transient user unit directory under
`$XDG_RUNTIME_DIR/systemd/user/` and stores transient user-instance
units (such as those created by `systemd-run --user`) under there
instead of putting them in $XDG_CONFIG_HOME/systemd/user/.
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=67331
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.
Zbigniew Jędrzejewski-Szmek