On Fri, Feb 19, 2021 at 07:01:41PM -0700, Chris Murphy wrote: > Hi, > > systemd does remount ro at reboot/shutdown time, and if free space > tree exists, this is always logged: > > [ 27.476941] systemd-shutdown[1]: Unmounting file systems. > [ 27.479756] [1601]: Remounting '/' read-only in with options > 'seclabel,compress=zstd:1,space_cache=v2,subvolid=258,subvol=/root'. > [ 27.489196] BTRFS info (device vda3): using free space tree > [ 27.492009] BTRFS warning (device vda3): remount supports changing > free space tree only from ro to rw > > Is there a way to better detect that this isn't an attempt to change > to v2? If there's no v1 present, it's not a change. > > -- > Chris Murphy
I am able to reproduce this with: mkfs.btrfs -f dev mount -o space_cache=v2 dev mnt mount -o remount,ro mnt At first I assumed I just completely ignored this case, but reading the code now, it looks like it should have handled it. I assume I messed up the value of the mount option during a remount when it isn't set by the mount command. Apologies for the noise, and I should hopefully have a fix soon. Boris
