C's strerror() function does not return a "const char *" pointer
for the string. That has historic reasons and C99 even comments
that "[t]he array pointed to shall not be modified by the program".
Make the strerror_safe() wrapper correct this and be more strict
in this regard.
https://bugzilla.redhat.com/show_bug.cgi?id=1715699
> /dev/mapper/live-rw 6.4G 5.7G 648M 91% /
> systemd-journald[905]: Fixed min_use=1.0M max_use=648.7M max_size=81.0M min_size=512.0K keep_free=973.1M n_max_files=100
When journald is started, we pick keep_free as 15% of the disk size. When the
fs is almost filled, we will only keep one journal file around and rotate very
often (because min_size is very small).
Let's set min use to something reasonable, so that we get more useful logs that
will cover at least the full boot.
Some cases considered in the PR:
> /dev/mapper/live-rw 6.4G 5.7G 648M 91% /
keep_free→MIN(327,100)→100 MB.
min_use→16MB.
effective range: 16 MB – 548 MB
> /dev/mapper/fedora_krowka-root 78G 69G 5.7G 93% /
keep_free → MIN(4GB, 100MB)→100MB
min_use→16MB
effective range: 16 MB – 5.6 GB
(but then there's the max_use limit, which cuts the range down)
> 4TB, 4GB free
keep_free → MIN(209715, 100) → 100 MB
min_use→16MB
effective range: 16 MB – 4.9 GB
(also effectively limited by max_use)
Also replace unneeded width suffixes with spaces, I think this is more
readable, and drop DEFAULT_ prefixes in cases where this setting is
simply a bound, and cannot be overridden by user config, hence is not
a default.
We'd copy /etc/nsswitch.conf, /etc/pam.d/, and /etc/issue (*) on every
tmpfiles --create run. I think we should only do this at boot, so if
people install systemd.rpm in a larger transaction and want to create those
files at a later step, we don't interfere with that.
(Stuff like /etc/os-release and /etc/mtab is not really configurable,
we might as was create it uncondtionally.)
(Seemingly, the alternative approach might be to not call
systemd-tmpfiles --create in systemd.rpm %post. But this wouldn't have much
effect, because various packages call it anyway, and our
%tmpfiles_create_package macro does too. So we need to change the
configuration instead.)
(*) We don't provide /usr/share/factory/issue, so normally this fails, but
somebody else might provide that file, so it seems useful to keep the
C line.
If the symlink is not present, UTC is the default. There *is* a slight
advantage to it: humans might expect it to be present and look in /etc.
But it might interfere with post-install scripts and it doesn't serve
any technical purpose. Let's not create it. Fixes#13183.
This makes two major changes to the way systemd-random-seed operates:
1. We now optionally credit entropy if this is configured (via an env
var). Previously we never would do that, with this change we still don't
by default, but it's possible to enable this if people acknowledge that
they shouldn't replicate an image with a contained random seed to
multiple systems. Note that in this patch crediting entropy is a boolean
thing (unlike in previous attempts such as #1062), where only a relative
amount of bits was credited. The simpler scheme implemented here should
be OK though as the random seeds saved to disk are now written only with
data from the kernel's entropy pool retrieved after the pool is fully
initialized. Specifically:
2. This makes systemd-random-seed.service a synchronization point for
kernel entropy pool initialization. It was already used like this, for
example by systemd-cryptsetup-generator's /dev/urandom passphrase
handling, with this change it explicitly operates like that (at least
systems which provide getrandom(), where we can support this). This
means services that rely on an initialized random pool should now place
After=systemd-random-seed.service and everything should be fine. Note
that with this change sysinit.target (and thus early boot) is NOT
systematically delayed until the entropy pool is initialized, i.e.
regular services need to add explicit ordering deps on this service if
they require an initialized random pool.
Fixes: #4271
Replaces: #10621#4513
There's no reason why writing should work if reading and writing
doesn't. Let's simplify this hence. /dev/urandom is generally an r/w
device, and everything else would be a serious system misconfiguration.
Lennart Poettering