This reverts commit 362c378291.
This commit introduced an ordering loop: remote-cryptsetup.target was both
before and after remote-fs-pre.target. It also globally ordered all cryptsetup
volumes before all mounts. Such global ordering is problematic if people have
stacked storage. Let's look for a different solution.
See https://github.com/systemd/systemd/pull/14378#discussion_r359460109.
Let per-user service managers have user namespaces too.
For unprivileged users, user namespaces are set up much earlier
(before the mount, network, and UTS namespaces vs after) in
order to obtain capbilities in the new user namespace and enable use of
the other listed namespaces. However for privileged users (root), the
set up for the user namspace is still done at the end to avoid any
restrictions with combining namespaces inside a user namespace (see
inline comments).
Closes#10576
PrefixRoute= was added by e63be0847c,
but unfortunately, the meaning of PrefixRoute= is inverted; when true
IFA_F_NOPREFIXROUTE flag is added. This introduces AddPrefixRoute=
setting.
Intermediate Functional Block
The Intermediate Functional Block (ifb) pseudo network interface acts as a QoS concentrator for multiple different sources of traffic. Packets from or to other interfaces have to be redirected to it using the mirred action in order to be handled, regularly routed traffic will be dropped. This way, a single stack of qdiscs, classes and filters can be shared between multiple interfaces.
Here's a simple example to feed incoming traffic from multiple interfaces through a Stochastic Fairness Queue (sfq):
(1) # modprobe ifb
(2) # ip link set ifb0 up
(3) # tc qdisc add dev ifb0 root sfq
This option is an indication for PID1 that the entry in crypttab is handled by
initrd only and therefore it shouldn't interfer during the usual start-up and
shutdown process.
It should be primarily used with the encrypted device containing the root FS as
we want to keep it (and thus its encrypted device) until the very end of the
shutdown process, i.e. when initrd takes over.
This option is the counterpart of "x-initrd.mount" used in fstab.
Note that the slice containing the cryptsetup services also needs to drop the
usual shutdown dependencies as it's required by the cryptsetup services.
Fixes: #14224
Stochastic Fairness Queueing is a classless queueing discipline.
SFQ does not shape traffic but only schedules the transmission of packets, based on 'flows'.
The goal is to ensure fairness so that each flow is able to send data in turn,
thus preventing any single flow from drowning out the rest.
The actual burst limit is modified by the remaining disk space. This
isn't mentioned anywhere in the available documentation and might be a
source of surprise for an end user expecting certain behaviors.
We don't, the signal remains blocked. We use signalfd() to be able to
read the signal events without unblocking the signal.
While we are at it, mention that pthread_sigmask() is fine too.
