Let's make debugging udev triggering a bit easier, by generating debug
log messages whenever we trigger a device, and also when we see the
event in pid1.
For older kernels that synthetic UUID is not supported, we need to also
check the original device name, as udevd broadcasts uevent with new
sysname.
Fixes#25115.
If the kernel support synthetic UUID in uevent, then let's assume that
the UUID is unique, and check only if the received UUID matches we
specified.
Partially fixes#25115.
If a device is successfully triggered with synthetic UUID, then that means
the kernel support it. Hence, it is not necessary to fallback without UUID
for later devices.
systemd-udev-trigger.service by default triggeres all devices regardless
of whether they were already recognized by systemd-udevd.
There are machines (especially in embedded environments) where
systemd-udev-trigger.service is configured to run at a later stage of
the boot sequence, which can lead to quite a lot of devices being
triggered although they were already recognized by systemd-udevd.
Re-triggering a lot of devices is a relatively expensive operation and
therefore should be avoided if unnecessary.
Therefore this patch introduces --initialized-nomatch, which filters out
devices that are already present in the udev database. For consistance
reasons --initialized-match is implemented as well, which filters out devices
that are *not* already present in the udev database.
Replaces #19949.
In general we almost never hit those asserts in production code, so users see
them very rarely, if ever. But either way, we just need something that users
can pass to the developers.
We have quite a few of those asserts, and some have fairly nice messages, but
many are like "WTF?" or "???" or "unexpected something". The error that is
printed includes the file location, and function name. In almost all functions
there's at most one assert, so the function name alone is enough to identify
the failure for a developer. So we don't get much extra from the message, and
we might just as well drop them.
Dropping them makes our code a tiny bit smaller, and most importantly, improves
development experience by making it easy to insert such an assert in the code
without thinking how to phrase the argument.
This adds two things:
- A new switch --uuid is added to "udevadm trigger". If specified a
random UUID is associated with the synthettic uevent and it is printed
to stdout. It may then be used manually to match up uevents as they
propagate through the system.
- The UUID logic is now implicitly enabled if "udevadm trigger --settle"
is used, in order to wait for precisely the uevents we actually
trigger. Fallback support is kept for pre-4.13 kernels (where the
requests for trigger uevents with uuids results in EINVAL).
This doesn't really change anything, but feels nicer, since it abstracts
away what device_action_from_string()/device_action_to_string() do
internally, and always uses a normalized action string (yes, there's no
ambiguity, but it's nice to stay abstract, maybe one day there is
ambiguity around this)
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.
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
This effectively reverts commit 67acde4869.
After commits 569ad251ad and
67acde4869, -EACCES errors are ignored,
and thus 'udevadm trigger' succeeds even when it is invoked by non-root
users. Moreover, on -EACCES error, log messages are shown in debug
level, so usually we see no message, and users are easily confused
why uevents for devices are not triggered.
If we're using a set with _put_strdup(), most of the time we want to use
string hash ops on the set, and free the strings when done. This defines
the appropriate a new string_hash_ops_free structure to automatically free
the keys when removing the set, and makes set_put_strdup() and set_put_strdupv()
instantiate the set with those hash ops.
hashmap_put_strdup() was already doing something similar.
(It is OK to instantiate the set earlier, possibly with a different hash ops
structure. set_put_strdup() will then use the existing set. It is also OK
to call set_free_free() instead of set_free() on a set with
string_hash_ops_free, the effect is the same, we're just overriding the
override of the cleanup function.)
No functional change intended.
Inside container, writing file returns EACCESS. Moreover, some devices
return ENODEV rather than EACCES. So, let's also ignore these two
error causes.
Closes#13652.
When udevadm trigger is called, the list of devices to trigger is always
generated through enumeration, and devices can come and go, so we should not
treat -ENOENT as a failure. But other types of failure should be logged.
It seems they were logged until baa30fbc2c.
Also, return the first error. (I'm not sure if there are other failure modes
which we want to ignore. If they are, they'll need to be whitelisted like
-ENOENT.).
Checking if we are root on the client side is generally pointless, since the
privileged operation will fail anyway and we can than log what precisly went
wrong.
A check like this makes sense only if:
- we need to do some expensive unprivileged operation before attempting the
privileged operation, and the check allows us avoid wasting resources.
- the privileged operation would fail but in an unclear way.
Neither of those cases applies here.
This fixes calls like 'udevadm control -h' as unprivileged user.
This effectively reverts 2bc54be485
and relevant changes in #9920, as it is used to determine the version
of udev, e.g., dracut.
Fixesdracutdevs/dracut#468.
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
David Tardon
Danilo Krummrich
Daan De Meyer