It's useful to be able to combine a regular /usr/ file system with a
tmpfs as root, for an OS that boots up in volatile mode on every single
boot. Let's add explicit support for this via root=tmpfs.
Note the relationship to the existing systemd.volatile= option:
1. The kernel command line "root=/dev/… systemd.volatile=yes" will mount
the specified root fs, and then hide everything at the top by
overmounting it with a tmpfs, except for the /usr subtree.
2. The kernel command line "root=tmpfs mount.usr=/dev/…" otoh will mount
a toot fs at the top (just like the case above), but will then mount
the top-level dir of the fs specified in mount.usr= directly below
it.
Or to say this differently: in the first case /usr/ from the physical
storage fs is going to become /usr/ of the hierarchy ultimately booted,
while in the second case / from the physical storage fs is going to
become /usr of the hierarchy booted.
Philosophically I figure systemd.volatile= is more an option for
"one-off" boots, while root=tmpfs is something to have as default mode
of operation for suitable images.
This is currently hard to test reasonably, since Dracut refuses to
accept root=tmpfs. This needs to be addressed separately though.
Let's fine-tune the path_extract_filename() interface: on succes return
O_DIRECTORY as indicator that the input path was slash-suffixed, and
regular 0 otherwise. This is useful since in many cases it is useful to
filter out paths that must refer to dirs early on.
I opted for O_DIRECTORY instead of the following other ideas:
1. return -EISDIR: I think the function should return an extracted
filename even when referring to an obvious dir, so this is not an
option.
2. S_ISDIR, this was a strong contender, but I think O_DIRECTORY is a
tiny bit nicer since quite likely we will go on and open the thing,
maybe with openat(), and hence it's quite nice to be able to OR in
the return value into the flags argument of openat().
3. A new enum defined with two values "dont-know" and
"definitely-directory". But I figured this was unnecessary, given we
have other options too, that reuse existing definitions for very
similar purposes.
These two together are a lot like dirname() + basename() but have the
benefit that they return clear errors when one passes a special case
path to them where the extraction doesn't make sense, i.e. "", "/",
"foo", "foo/" and so on.
Sooner or later we should probably port all our uses of
dirname()/basename() over to this, to catch these special cases more
safely.
BPF filtering accesses fields in the netlink header that are
only filled in by libudev, never by the kernel. Therefore adding
BPF filters for kernel monitors is pointless. Even false filtering
of kernel events might be possible; at least it's hard to prove that
it can't occur.
We generally operate on the assumption that a source is "gone" as soon
as we unref it. This is generally true because we have the only reference.
But if something else holds the reference, our unref doesn't really stop
the source and it could fire again.
In particular, on_query_timeout() is called with DnsQuery* as userdata, and
it calls dns_query_stop() which invalidates that pointer. If it was ever
called again, we'd be accessing already-freed memory.
I don't see what would hold the reference. sd-event takes a temporary reference,
but on the sd_event object, not on the individual sources. And our sources
are non-floating, so there is no reference from the sd_event object to the
sources.
For #18427.
sockaddr_pretty() is the function that is ultimately called to print
the address, and afaics, it'll always use 0.0.0.0 if family==AF_INET.
So the test must have always been broken on systems with IPv6 support.
Fixes a failure in semaphore debian autopkgtest ci:
"65535" → ✓ 0 → "0.0.0.0:65535" (expect 0 / "[::]:65535") 15:15
Assertion 'streq(out, expected ?: in)' failed at src/test/test-socket-netlink.c:32, function test_socket_address_parse_one(). Aborting. 15:15
It causes a regression in certain running environments (networkd under LXC),
so avoid enabling for now.
Fixes#18795
Suggested-by: Topi Miettinen <toiwoton@gmail.com>
This addresses the issue described in https://lwn.net/Articles/846403/
and makes sure we will be able to stream bytes from procfs/sysfs via
copy_bytes() if people ask us to.
Let's add a special tweak to the btrfs builtin: if /dev/btrfs-control is
not there, let's consider all btrfs file systems as SYSTEMD_READY=0.
This is useful in initrds, where btrfs.ko might be missing. After the
initrd → host transition we can then retigger the device and undo the
SYSTEMD_READY=0 marking.
Prompted by https://bugzilla.redhat.com/show_bug.cgi?id=1930875 in which
I had previously used json_dispatch_unsigned and passed a return variable of
type unsigned when json_dispatch_unsigned writes a uintmax_t.
Yu Watanabe
Lennart Poettering
Xℹ Ruoyao
Luca Boccassi
Martin Wilck
Zbigniew Jędrzejewski-Szmek
Einsler Lee
Anita Zhang