There's a report that passing raw device mapper path and -d don't work
together:
yyy@xxx ~ $ sudo btrfs filesystem show /dev/dm-0
Label: none uuid: a7fbb8d6-ec5d-4e88-bd8b-c686553e0dc7
Total devices 1 FS bytes used 144.00KiB
devid 1 size 256.00MiB used 88.00MiB path /dev/mapper/da0972636816-LogVol00
With --all-devices
yyy@xxx ~ $ sudo btrfs filesystem show --all-devices /dev/dm-0
ERROR: not a valid btrfs filesystem: /dev/dm-0
Where dm-0 corresponds to the LogVol00 device from above.
Passing the option -d skips some steps but still uses the real path of
the device that is required for scanning and identification, while
blkid uses the canonicalized path.
The combination of raw device name and -d was not handled as the raw
path is not in cache and thus not recognized. Canonicalization fixes
that although this changes the device name in the output.
Issue: #732
Signed-off-by: David Sterba <dsterba@suse.com>
cb740b3dfb