$ btrfs filesystem show
Label: none uuid: c80a52e3-8f16-4095-bdc2-cc24bd01cf7d
Total devices 1 FS bytes used 144.00KiB
devid 1 size 1022.00MiB used 126.12MiB path /dev/nvme0n1p1
Label: none uuid: 5a0a6628-8cd0-4353-8daf-b01ca254c10d
Total devices 1 FS bytes used 144.00KiB
devid 1 size 1022.00MiB used 126.12MiB path /dev/nvme1n1p1
Label: none uuid: 94b67f81-b51f-479e-9f44-0d33d5cec2d4
Total devices 1 FS bytes used 144.00KiB
devid 1 size 1022.00MiB used 126.12MiB path /dev/nvme1n1p1
It seems to me it's correct "enough" right? It shows the mounted
filesystems according to the temporary fsid.
Also, I've noticed that the real fsid is omitted for device nvme0n1p1,
i.e., the command de-duplicates devices with the same fsid - tested here
without the TEMP_FSID feature and it behaves the same way.
Mounted devices should be fine with those unique temporary fsids in
place. However, my main concern lies with those cloned devices before
they are mounted. Btrfs-progs build the in-memory device list from
the fsid list, and that part requires some fixing.
In the past, we did not handle duplicate fsids. If we had cloned
devices, they had to be fixed with their fsid using 'btrfstune -u|m'
before mounting. Sorting them by fsid worked fine. However, if we want
to allow duplicate fsids, we might need to consider how the end user
will identify the btrfs devices before they are mounted.
I believe that currently, it only displays the last device that was
scanned.
In case you think we could improve such output, I appreciate
suggestions, and I'd be glad if that could be considered an improvement
(i.e., not blocking the patch merge on misc-next) since I might not have
the time to work on this for some weeks...
These commands represent the basic steps users take when trying out
the new feature. We need to make sure it works.
Thanks, Anand
