This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
When we check the exit status of a subprocess, let's compare it with
EXIT_SUCCESS rather than 0 when looking for success.
This clarifies in code what kind of variable we are looking at and what
we are doing.
This renames wait_for_terminate_and_warn() to
wait_for_terminate_and_check(), and adds a flags parameter, that
controls how much to log: there's one flag that means we log about
abnormal stuff, and another one that controls whether we log about
non-zero exit codes. Finally, there's a shortcut flag value for logging
in both cases, as that's what we usually use.
All callers are accordingly updated. At three occasions duplicate logging
is removed, i.e. where the old function was called but logged in the
caller, too.
This adds a new safe_fork() wrapper around fork() and makes use of it
everywhere. The new wrapper does a couple of things we previously did
manually and separately in a safer, more correct and automatic way:
1. Optionally resets signal handlers/mask in the child
2. Sets a name on all processes we fork off right after forking off (and
the patch assigns useful names for all processes we fork off now,
following a systematic naming scheme: always enclosed in () – in order
to indicate that these are not proper, exec()ed processes, but only
forked off children, and if the process is long-running with only our
own code, without execve()'ing something else, it gets am "sd-" prefix.)
3. Optionally closes all file descriptors in the child
4. Optionally sets a PR_SET_DEATHSIG to SIGTERM in the child, in a safe
way so that the parent dying before this happens being handled
safely.
5. Optionally reopens the logs
6. Optionally connects stdin/stdout/stderr to /dev/null
7. Debug logs about the forked off processes.
We are using the same pattern at various places: call dup2() on an fd,
and close the old fd, usually in combination with some O_CLOEXEC
fiddling. Let's add a little helper for this, and port a few obvious
cases over.
In order to verify a pulled container or disk image, importd only supports
SHA256SUMS files with the detached signature in SHA256SUMS.gpg.
SUSE is using an inline signed file with the name of the image itself and the
suffix .sha256 instead.
This commit adds support for this type of signature files.
It is first attempted to pull the .sha256 file.
If this fails with error 404, the SHA256SUMS and SHA256SUMS.gpg files are
pulled and used for verification.
Given that other file systems (notably: xfs) support reflinks these days, let's
extend the file system snapshotting logic to fall back to plan copies or
reflinks when full btrfs subvolume snapshots are not available.
This essentially makes "systemd-nspawn --ephemeral" and "systemd-nspawn
--template=" available on non-btrfs subvolumes. Of course, both operations will
still be slower on non-btrfs than on btrfs (simply because reflinking each file
individually in a directory tree is still slower than doing this in one step
for a whole subvolume), but it's probably good enough for many cases, and we
should provide the users with the tools, they have to figure out what's good
for them.
Note that "machinectl clone" already had a fallback like this in place, this
patch generalizes this, and adds similar support to our other cases.
Let's make sigkill_wait() take a normal pid_t, and add sigkill_waitp() that
takes a pointer (which is useful for usage in _cleanup_), following the usual
logic we have for this.
Rather than passing a pointer to return the result, return it directly
from the function calls.
Also, return the result in native endianess, and let the callers care
about the conversion. For hash tables and bloom filters, we don't care,
but in order to keep MAC addresses and DHCP client IDs stable, we
explicitly convert to LE.
Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which
enforce pointer alignment this fixes crashes when we previously cast an
unaligned array to uint64_t*, and on others this should at least improve
performance as the compiler now aligns these properly.
This also simplifies the code in most cases by getting rid of typecasts. The
only place which we can't change is struct duid's en.id, as that is _packed_
and public API, so we can't enforce alignment of the "id" field and have to
use memcpy instead.
The files are named too generically, so that they might conflict with
the upstream project headers. Hence, let's add a "-util" suffix, to
clarify that this are just our utility headers and not any official
upstream headers.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
With this change we understand more than just leaf quota groups for
btrfs file systems. Specifically:
- When we create a subvolume we can now optionally add the new subvolume
to all qgroups its parent subvolume was member of too. Alternatively
it is also possible to insert an intermediary quota group between the
parent's qgroups and the subvolume's leaf qgroup, which is useful for
a concept of "subtree" qgroups, that contain a subvolume and all its
children.
- The remove logic for subvolumes has been updated to optionally remove
any leaf qgroups or "subtree" qgroups, following the logic above.
- The snapshot logic for subvolumes has been updated to replicate the
original qgroup setup of the source, if it follows the "subtree"
design described above. It will not cover qgroup setups that introduce
arbitrary qgroups, especially those orthogonal to the subvolume
hierarchy.
This also tries to be more graceful when setting up /var/lib/machines as
btrfs. For example, if mkfs.btrfs is missing we don't even try to set it
up as loopback device.
Fixes#1559Fixes#1129
Also, when the child is potentially long-running make sure to set a
death signal.
Also, ignore the result of the reset operations explicitly by casting
them to (void).
Change cunescape() to return a normal error code, so that we can
distuingish OOM errors from parse errors.
This also adds a flags parameter to control whether "relaxed" or normal
parsing shall be done. If set no parse failures are generated, and the
only reason why cunescape() can fail is OOM.
This also adds "machinectl import-raw" and "machinectl import-tar" to
wrap these new bus calls.
THe commands basically do for local files that "machinectl pull-raw" and
friends do for remote files.
Lennart Poettering