On 10/02/2022 21:30, Goldwyn Rodrigues wrote: > On 19:54 10/02, Graham Cobb wrote: >> On 10/02/2022 16:51, Goldwyn Rodrigues wrote: >>> If a read-write root mount is remounted as read-only, the subvolume >>> is also set to read-only. >> >> Errrr... Isn't that exactly what I want? >> >> If I have a btrfs filesystem with hundreds of subvols, some of which may >> be mounted into various places in my filesystem, I would expect that if >> I remount the main mountpoint as RO, that all the subvols become RO as >> well. I actually don't mind if the behaviour went further and remounting >> ANY of the mount points as RO would make them all RO. >> >> My mental model is that mounting a subvol somewhere is rather like a >> bind mount. And a bind mount goes RO if the underlying fs goes RO - >> doesn't it? >> > > If we want bind mount, we would use bind mount. subvolume mounts and bind > mounts are different and should be treated as different features. Yes that's a good point. However, I am still not convinced that this is a change in behaviour that is obvious enough to justify the risk of disruption to existing systems, admin scripts or system managers. > >> Or am I just confused about what this patch is discussing? > > Root can also be considered as a unique subvolume with a unique > subvolume id and a unique name=/ But with an important special property that is different from all other subvolumes: all other subvolumes are reachable from it.
