There's a report that a read-only subvolume with a received_uuid set
emits the warning in command 'btrfs subvolume show', which is obviously
wrong.
The reason is that there are different types of root item flags,
depending on how we read them. The check in cmd_subvol_show uses the
ioctl GET_SUBVOL_INFO and the appropriate flag is raw
BTRFS_ROOT_SUBVOL_RDONLY (0x1), while there's another SUBVOL_GETFLAGS that
maps the flags and the raw value is different (BTRFS_SUBVOL_RDONLY, 0x2).
Due to this the warning was issued. Fix that by using the right flag
constant. The test has been extended to check for all combinations of
read-write and received_uuid.
Issue: #419
Signed-off-by: David Sterba <dsterba@suse.com>
dca6b12f0a