Like the command-level CommandDescription.argspec, a verb's argspec is now
a nulstr, so that a verb may declare multiple alternative usage lines. The
verbs help table renders one synopsis line per nulstr entry in the
synopsis cell.
All verb argument specifications must gain an explicit NUL suffix. This
is a lot of churn, but I think this needs to be done. For now, there'll
be only one user of the new functionality (i.e. a verb with more than
one argspec), but I think we'll eventually want to use this in other
places too.
Almost all programs are simple and have only a single command. When
printing options, let's just use the first COMMAND block found by default.
This means we can drop the explicit program-name argument and reduce
copy&paste boilerplate.
The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. --help now goes through the pager, like other
commands with --no-pager. The mount.storage helper interface is described
by a second COMMAND(), so that it is exposed by --introspect-cli too.
The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. The abstract is changed from the noun phrase
"Simple file system backed storage provider" to the imperative "Expose
regular files and directories as storage volumes.", following the man
page and consistent with the other commands.
The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. The abstract is changed from the noun phrase
"Simple block device backed storage provider" to the imperative "Expose
local block devices as storage volumes.", following the man page and
consistent with the other commands.
At various places we filter directory enumerations by inode type. Let's
add explicit support for that, so that the "struct dirent" array we
return already suppresses them.
This shortens code and makes things more robust.
This is the util-linux mount-helper interface (mount.storage), so all
options stay hidden via help=NULL — they are not user-facing. The
namespace "mount.storage" is distinct from the storagectl namespace
used for the user-facing CLI.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
We have different help strings for --user/--system in different places, so this
only covers a subset of --system/--user instances. But this particular help
seems to be the most widely used.
(In a few cases, the help string is fixed: it should be "system mode", not
"per-system mode".)
Drop the inline socket-build + sd_varlink_callbo() + reply-dispatch
+ take_fd block from run_as_mount_helper() in favour of the shared
helper. Preserves the type-fallback retry (TypeNotSupported / WrongType
re-tries with requestAs="blk") and the per-error-id message mapping;
the helper just reports the io.systemd.StorageProvider.* error name
back to the caller.
Net effect: ~50 lines of dedup, no functional change.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
The storage backend providers (block, fs) and storagectl currently each
extract storage-util.c into their target. Several upcoming consumers
(machine-util's BindVolume parser, vmspawn's hotplug glue, machinectl's
new bind-volume verbs) need the StorageProvider type/string-table
helpers and a future shared Acquire client helper.
Move storage-util.{c,h} to src/shared so libshared exports the symbols
once and every consumer (storage providers, storagectl, libshared
itself) picks them up by linking libshared. Drop the now-redundant
'extract'/'objects' wiring in src/storage/meson.build.
No code changes; this is purely a relocation.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
The mount.storage helper open-codes the conventional 64K UID/GID
delegation block size as 0x10000 / 0x10000U in four places. Several
other places in the tree do the same (nspawn's arg_uid_range default,
homed's mount setup, …), but with no shared name.
Add USERNS_RANGE_SIZE in user-util.h alongside UID_NOBODY and friends,
and switch storagectl over to it. Other call sites can adopt it
incrementally.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
I am really not a fan of full code lines passed to macros as parameters.
Let's get rid of the 3rd parameter of FOREACH_OPTION() hence:
1. Let's return errors just as a regular value (though a negative one),
that can be handled via a OPTION_ERROR case statement for the switch.
This normalizes handling of the error, just like any other event
returned by the option parser.
2. In order to avoid exploding the amount of boilerplate in each use
(that just propagates the error on OPTION_ERROR), let's then
introduce an explicit FOREACH_OPTION_OR_RETURN(), that returns from
the calling function on its own (and makes that clear in the name).
Together this cleans up, normalizes the logic and shortens the code.
CLI for inspecting and using storage providers. Scans
/run/systemd/io.systemd.StorageProvider/ (or the user-mode equivalent)
for AF_UNIX sockets and talks to each one over Varlink. Verbs:
"volumes" lists volumes across all providers, "templates" lists
supported creation templates, "providers" lists the endpoints
themselves.
Also installed as a mount.storage helper, so
'mount -t storage PROVIDER:VOLUME /mnt' (or 'mount -t storage.<fstype>'
to put a fresh filesystem on a block volume) acquires the volume and
mounts it. Ships with bash/zsh completions and a man page.
Second StorageProvider implementation, exposing regular files and
directories from a backing filesystem. In system mode the backing
directory is /var/lib/storage/, in user mode $XDG_STATE_HOME/storage/;
entries with a .volume suffix are exposed, with the inode type
determining whether the volume is reported as reg, dir or (via
symlinked/bind-mounted device node) blk.
Unlike the block provider, this one supports creating volumes
on-demand from a small set of built-in templates: sparse-file,
allocated-file, directory and subvolume.
First implementation of io.systemd.StorageProvider, exposing all block
devices known to udev (disks, partitions, dm nodes, …) as volumes of
type "blk". Names are picked from stable /dev/mapper and /dev/disk/by-*
symlinks; content-derived identifiers (by-uuid, by-label, …) are
intentionally avoided for security. Volume creation is not supported by
this backend.
Socket-activated via /run/systemd/io.systemd.StorageProvider/block.
Also adds shared storage-util.[ch] (VolumeType / CreateMode helpers)
that subsequent providers reuse.
