Nope, the root partition on btrfs is commonly a subvolume called @ So by mounting btrfs without the subvol option, it will mount the real partition.
Check it:
Yes, There are ton of subvolume that docker created
ID 257 gen 107633 top level 5 path @cache
ID 258 gen 107650 top level 5 path @log
ID 1085 gen 107651 top level 5 path @
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ID 1818 gen 95206 top level 1085 path var/lib/docker/btrfs/subvolumes/230630e584523285e1e337ec36fb5f320e8f6036c2a8ded27d983bcaa7a3b008
ID 1819 gen 107601 top level 1085 path var/lib/docker/btrfs/subvolumes/ff567fc46b0c624d9e88c353a82444b57694ecb5595a613a9462dbe6595c123c
ID 1820 gen 95196 top level 1085 path var/lib/docker/btrfs/subvolumes/de6082ba570922ba17b22aabf2afd816b87a54746b6ed12181ebb92ed8ff6c37-init
ID 1821 gen 95197 top level 1085 path var/lib/docker/btrfs/subvolumes/de6082ba570922ba17b22aabf2afd816b87a54746b6ed12181ebb92ed8ff6c37
ID 1823 gen 107094 top level 5 path timeshift-btrfs/snapshots/2022-05-12_01-00-02/@
ID 1827 gen 107094 top level 5 path timeshift-btrfs/snapshots/2022-05-18_14-05-24/@
ID 1828 gen 107094 top level 5 path timeshift-btrfs/snapshots/2022-05-19_01-00-01/@
ID 1831 gen 107094 top level 5 path timeshift-btrfs/snapshots/2022-05-22_01-25-45/@
ID 1832 gen 107094 top level 5 path timeshift-btrfs/snapshots/2022-05-22_23-36-54/@
ID 1833 gen 107649 top level 1085 path var/lib/systemd-swap/swapfc
Your old reply helped me, moved from zram to systemd… for now…
Thats a bad thing…btw… let me show how it looks on my machine:
subvolume
ID 310 gen 216323 top level 5 path @swap <-- created by me
ID 1383 gen 218505 top level 310 path @swap/swapfc <-- created by systemd-swap
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 223,6G 0 disk
├─sda1 8:1 0 100M 0 part /boot/efi
└─sda2 8:2 0 223,5G 0 part /run/timeshift/backup
/home
/var/lib/systemd-swap
/
ID 1834 gen 107681 top level 5 uuid 550fac1e-bc55-f449-ac83-7dbfdfa76040 path @swap
sudo mount /var/lib/systemd-swap/
mount: /var/lib/systemd-swap/: can't find UUID=550fac1e-bc55-f449-ac83-7dbfdfa76040.