Network file systems generally do not offer inotify() that would work
across the network. We hence cannot rely on inotify() exclusiely in
those case. Provide an API to determine these cases, and suggest doing
manual regular rechecks.
Note that this is not complete yet, as we need to rescan journal dirs on
network file systems explicitly to find new/removed files
When traversing entry array chains for a bisection or for retrieving an
item by index we previously always started at the beginning of the
chain. Since we tend to look at the same chains repeatedly, let's cache
where we have been the last time, and maybe we can skip ahead with this
the next time.
This turns most bisections and index lookups from O(log(n)*log(n)) into
O(log(n)). More importantly however, we seek around on disk much less,
which is good to reduce buffer cache and seek times on rotational disks.
The new 'unique' API allows listing all unique field values that a field
specified by a field name can take in all entries of the journal. This
allows answering queries such as "What units logged to the journal?",
"What hosts have logged into the journal?", "Which boot IDs have logged
into the journal?".
Ultimately this allows implementation of tools similar to lastlog based
on journal data.
Note that listing these field values will not work for journal files
created with older journald, as the field values are not indexed in
older files.
Much like logind has a client in loginctl, and journald in journalctl
introduce timedatectl, to change the system time (incl. RTC), timezones
and related settings.
As audit is pretty much just a special kind of logging we should treat
it similar, and manage the audit fd in a static variable.
This simplifies the audit fd sharing with the SELinux access checking
code quite a bit.
a) Instead of parsing the bus messages inside of selinux-access.c
simply pass everything pre-parsed in the functions
b) implement the access checking with a macro that resolves to nothing
on non-selinux builds
c) split out the selinux checks into their own sources
selinux-util.[ch]
d) this unifies the job creation code behind the D-Bus calls
Manager.StartUnit() and Unit.Start().
Among other cleanups this introduces a threshold for the size of binary
blobs we serialize as integer arrays in the JSON output. THis can be
disabled via --all.
This requires a little bit of tip-toeing around to explicitly avoid
touching the environment from a sig handler. Instead, simply create a
function to reset the var to its "unset" state, allowing the next call
to columns() to recalculate and cache the new value.