On 04/21/2016 04:02 AM, Austin S. Hemmelgarn wrote: > On 2016-04-20 16:23, Konstantin Svist wrote: >> Pretty much all commands print out the usage message when no device is >> specified: >> >> [root@host ~]# btrfs scrub start >> btrfs scrub start: too few arguments >> usage: btrfs scrub start [-BdqrRf] [-c ioprio_class -n ioprio_classdata] >> <path>|<device> >> ... >> >> However, balance doesn't >> >> [root@host ~]# btrfs balance start >> ERROR: can't access 'start': No such file or directory > > And this is an example of why backwards comparability can be a pain. > The original balance command was 'btrfs filesystem balance', and had > no start, stop, or similar sub-commands. This got changed to the > current incarnation when the support for filters was added. For > backwards compatibility reasons, we decided to still accept balance > with no arguments other than the path as being the same as running > 'btrfs balance start' on that path, and then made the old name an > alias to the new one, with the restriction that you can't pass in > filters through that interface. What is happening here is that > balance is trying to interpret start as a path, not a command, hence > the message about not being able to access 'start'. >
So since this is still detected as an error, why not print usage info at this point? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
