When making ephemeral snapshots of subvolumes whose cleanup depends on
whether they're locked or not, it's necessary to have the lock from the
very beginning, so let's support that with a new BTRFS_SNAPSHOT_LOCK_BSD
flag.
The kernel has had filesystem independent reflink ioctls for a
while now, let's try to use them and fall back to the btrfs specific
ones if they're not supported.
Let's make btrfs_get_block_device_fd() more generic by renaming it
to btrfs_get_block_device_at() so it can operate on only paths, dir_fd
and path, or only on fd by using xopenat().
Let's explicitly let btrfs know when we're done using a loop device.
Otherwise, btrfs will keep the device UUID cached which will result
in mount() failures if we ever generate a device or filesystem with
the same UUID again.
The goal is to move everything that requires selinux or smack
away from src/basic/. This means that src/basic/label.[ch] must move,
which implies btrfs-util.[ch], copy.[ch], and a bunch of other files
which form a cluster of internal use.
This is just moving text around, so there should be no functional difference.
test-blockdev-util is new, because path_is_encrypted() is moved to
blockdev-util.c, and so far we didn't have any tests for code there.
Let's unify the code that checks whether an fd is on btrfs a bit.
(Also, rename btrfs_is_snapshot() to btrfs_is_subvol(), since that's
usually how this is referred to in our code)
If /var/lib/machines is mounted as btrfs loopback file system in
/var/lib/machines.raw with this change we automatically grow the file
system as it fills up. After each 10M we write to it during imports, we
check the free disk space, and if the fill level grows beyond 66% we
increase the size of the file system to 3x the fill level (thus lowering
it to 33%).
When the pool size limit is altered with "machinectl set-limit", then
not only set the subvolume quota of the /var/lib/machine subvolume, but
also resize the backing loop file and the btrfs file system on it
dynamically.
Our write pattern is quite awful for CoW file systems (btrfs...), as we
keep updating file parts in the beginning of the file. This results in
fragmented journal files. Hence: when rotating files, defragment them,
since at that point we know that no further write accesses will be made.
This adds a new bus call to machined that enumerates /var/lib/container
and returns all trees stored in it, distuingishing three types:
- GPT disk images, which are files suffixed with ".gpt"
- directory trees
- btrfs subvolumes
Mike Yuan
Daan De Meyer
Yu Watanabe
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Kay Sievers