Susant Sahani [Tue, 21 Feb 2017 23:16:13 +0000 (04:46 +0530)]
udev: Introduce UDEV_PROPAGATE_LOG macro (#5302)
As per commit 25e773e "udev: switch to systemd logging functions"
Now log_set_max_level() in udev_new() overwites system wide log level.
Propagate the udev.conf setting to log_set_max_level()
only if udev_new() is called from within udevd or one of its helpers.
Introduce a UDEV_PROPAGATE_LOG macro that we set with -D on
the gcc command line for all udev binaries we build, but not
for any others. The log_set_max_level() call is guarded by an
ifdef check for that macro, so that it only effects the various
udev binaries.
If our netlink input buffer overruns the kernel will send us ENOBUFS on
the next recvmsg(). Don't consider this a complete failure resulting in
closing of the netlink socket. Instead, simply continue (after debug
logging).
Of course, ideally we'd have a better strategy for this, and would have
a way to resync if this happens (as well as a scheme for cancelling all
ongoing asynchronous transactions), but for now let's at least not choke
fatally, and simply accept that we lost some messages and continue.
Note that if we lose messages when synchronously waiting for an
operation to complete, we'll still propagate the ENOBUFS up, to make the
individual transaction fail.
See: #5398
(This bug does not properly fix the issue, hence we should leave the bug
open.)
Likewise, it's useful to provide an alternate value during an
environment expansion, if the environment variable isn't already set.
For instance, $LD_LIBRARY_PATH will inadvertently search the current
working directory if it starts or ends with a colon, so the following
is usually wrong:
LD_LIBRARY_PATH=/foo/lib:${LD_LIBRARY_PATH}
To address that, this changes replace_env to support the following
shell compatible alternate value syntax:
We have ./configure switches for various parts of non-essential functionality,
let's add one for this new stuff too. Support for environment generators is
not conditional — if you don't want them, just don't install any.
In the future we might want to allow additional syntax (for example
"unset VAR". But let's check that the data we're getting does not contain
anything unexpected.
We have only basic compatibility with shell syntax, but specifying variables
without using braces is probably more common, and I think a lot of people would
be surprised if this didn't work.
environment-generator: new generator to peruse environment.d
Why the strange name: the prefix is necessary to follow our own advice that
environment generators should have numerical prefixes. I also put -d- in the
name because otherwise the name was very easy to mistake with
systemd.environment-generator. This additional letter clarifies that this
on special generator that supports environment.d files.
Ray Strode [Thu, 4 Aug 2016 16:00:00 +0000 (12:00 -0400)]
basic: add new merge_env_file function
merge_env_file is a new function, that's like load_env_file, but takes a
pre-existing environment as an input argument. New environment entries are
merged. Variable expansion is performed.
Falling back to the process environment is supported (when a flag is set).
Alternatively this could be implemented as passing an additional fallback
environment array, but later on we're adding another flag to allow braceless
expansion, and the two flags can be combined in one arg, so there's less
stuff to pass around.
Ray Strode [Wed, 3 Aug 2016 18:35:50 +0000 (14:35 -0400)]
basic: fix strv_env_get_n for unclean arrays
If an environment array has duplicates, strv_env_get_n returns
the results for the first match. This is wrong, because later
entries in the environment are supposed to replace earlier
entries.
man: add systemd.environment-generator(7) with two examples
v2:
- add example files to EXTRA_DIST
v3:
- rework for the new scheme where nothing is written to disk
v4:
- use separate dirs for system and user env generators
Environment file generators are a lot like unit file generators, but not
exactly:
1. environment file generators are run for each manager instance, and their
output is (or at least can be) individualized.
The generators themselves are system-wide, the same for all users.
2. environment file generators are run sequentially, in priority order.
Thus, the lifetime of those files is tied to lifecycle of the manager
instance. Because generators are run sequentially, later generators can use or
modify the output of earlier generators.
Each generator is run with no arguments, and the whole state is stored in the
environment variables. The generator can echo a set of variable assignments to
standard output:
VAR_A=something
VAR_B=something else
This output is parsed, and the next and subsequent generators run with those
updated variables in the environment. After the last generator is done, the
environment that the manager itself exports is updated.
Each generator must return 0, otherwise the output is ignored.
The generators in */user-env-generator are for the user session managers,
including root, and the ones in */system-env-generator are for pid1.
env-util,fileio: immediately replace variables in load_env_file_push()
strv_env_replace was calling env_match(), which in effect allowed multiple
values for the same key to be inserted into the environment block. That's
pointless, because APIs to access variables only return a single value (the
latest entry), so it's better to keep the block clean, i.e. with just a single
entry for each key.
Add a new helper function that simply tests if the part before '=' is equal in
two strings and use that in strv_env_replace.
In load_env_file_push, use strv_env_replace to immediately replace the previous
assignment with a matching name.
Afaict, none of the callers are materially affected by this change, but it
seems like some pointless work was being done, if the same value was set
multiple times. We'd go through parsing and assigning the value for each
entry. With this change, we handle just the last one.
core/manager: move environment serialization out to basic/env-util.c
This protocol is generally useful, we might just as well reuse it for the
env. generators.
The implementation is changed a bit: instead of making a new strv and freeing
the old one, just mutate the original. This is much faster with larger arrays,
while in fact atomicity is preserved, since we only either insert the new
entry or not, without being in inconsistent state.
basic/exec-util: add support for synchronous (ordered) execution
The output of processes can be gathered, and passed back to the callee.
(This commit just implements the basic functionality and tests.)
After the preparation in previous commits, the change in functionality is
relatively simple. For coding convenience, alarm is prepared *before* any
children are executed, and not before. This shouldn't matter usually, since
just forking of the children should be pretty quick. One could also argue that
this is more correct, because we will also catch the case when (for whatever
reason), forking itself is slow.
Three callback functions and three levels of serialization are used:
- from individual generator processes to the generator forker
- from the forker back to the main process
- deserialization in the main process
v2:
- replace an structure with an indexed array of callbacks
core/manager: split out creation of serialization fd out to a helper
There is a slight change in behaviour: the user manager for root will create a
temporary file in /run/systemd, not /tmp. I don't think this matters, but
simplifies implementation.
sd-device: replace lstat() + open() with open(O_NOFOLLOW)
Coverity was complaining about TOCTOU (CID #745806). Indeed, it seems better
to open the file and avoid the stat altogether:
- O_NOFOLLOW means we'll get ELOOP, which we can translate to EINVAL as before,
- similarly, open(O_WRONLY) on a directory will fail with EISDIR,
- and finally, it makes no sense to check access mode ourselves: just let
the kernel do it and propagate the error.
systemctl: give a hint about --force --force when communication with manager fails
The hint is not too explicit, and just refers to the man page, because this
option is slightly dangereous. This was we don't have to discuss the limitation
in the hint itself.
"systemctl --user edit --force --full tmp.mount" would crash, when we'd do
basename(NULL). Fix this by creating a new unit or a new override even if
not path is found.
journalctl: add reference to sd-id128(3) to output (#5382)
SD_ID128_MAKE is clearly not a standard C macro, so let’s point the user
to its documentation to let them know which header they need and what
they can then do with MESSAGE_XYZ.
nspawn: tweak check whether resolved is around a bit
Let's check D-Bus instead of files in /run to see if resolved is
running. This is a bit nicer as bus names are automatically cleaned up
when resolved dies, which is not the case for files in /run.
Martin Pitt [Fri, 17 Feb 2017 20:29:02 +0000 (21:29 +0100)]
test: re-drop assumption that /run is a mount point (#5377)
Commit 436e916ea introduced the assumption into test-stat-util that /run
is a tmpfs mount point. This is not the case in build chroots such as
Fedora's mock or Debian's sbuild. So only assert that /run is a tmpfs
and not a btrfs if /run is actually a mount point. This will then still
be asserted with installed tests.
udev: fix id_net_name_path for virtio-ccw interfaces (#5357)
The CCW id_net_name_path detection didn't account for virtio
interfaces on the CCW bus. As a result the default interface
names for virtio-ccw interfaces would use the old eth<x>
format instead of enc<busid>.
Since virtio-pci interface naming follows the naming rules
of the parent bus, the names_ccw() logic was changed to apply
the CCW interface naming rules to virtio interfaces as well,
e.g. enc2000 for an interface with a CCW bus id 0.0.2000.
As virtio interfaces are apt to get the otherwise unusual
CCW bus id 0.0.0000, the last '0' is now preserved in this
case.
The virtio subsystem skipping loop has been moved from
names_pci() into a function skip_virtio() that can be reused
for all bus types with virtio network devices.
Since virtio-ccw interfaces use single CCW addresses the ccwgroup
requirement was relaxed and the C definitions were changed
accordingly.
network: change condition in if testing section presence
section_line and filename should be set together or not at all. Change the
if to test filename, since it's the first of the pair and it seems more natural
to test that.
networkd: immediately transfer ownership of route->section
The code was not incorrect previously, but I think it's easier to follow the
ownership (and the code is more likely to remain correct when updated later on),
if freeing of NetworkConfigSection* is immediately made the responsibility of
route_free(), so instead of relying on route_free() not freeing ->section
if adding to the network hashmap failed, make this freeing unconditional.
coredump: when reconstructing original kernel coredump context, chop off trailing zeroes
Our coredump handler operates on a "context" supplied by the kernel via
the core_pattern arguments. When we pass off a coredump for processing
to coredumpd we pass along enough information for this context to be
reconstructed. This information is passed in the usual journal fields,
and that means we extended the 1s granularity timestamp to 1µs
granularity by appending 6 zeroes. We need to chop them off again when
reconstructing the original kernel context.
projects / thirdparty / systemd.git / log
