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.
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.
I was debugging stuff during early boot, and was confused that I never
found the logs for it in kmsg. The reason for that was that /proc is
generally not mounted the first time we do log_open() and hence
log_set_target(LOG_TARGET_KMSG) we do when running as PID 1 had not
effect. A lot later during start-up we call log_open() again where this
is fixed (after the point where we close all remaining fds still open),
but in the meantime no logs every got written to kmsg. This patch fixes
that.
This reverts commit 72d967df3e.
Revert this because it broke the `norbind` option of the bind flags
because it does bind-mounts unconditionally recursive.
Let's bring the old logic back.
Fixes: #13170
