btrfs filesystem defragment exits with non-zero return code (20) upon success

Hi,

running "btrfs filesystem defrag" somehow always returns a non-zero exit code, even when it succeeds:

[lenz@metis btrfs-progs]% sudo ./btrfs filesystem defrag -v /mnt /mnt
Btrfs v0.19-102-g2482539-dirty
[lenz@metis btrfs-progs]% echo $?
20
[lenz@metis btrfs-progs]% sudo ./btrfs filesystem defrag -v /dev/loop0 /dev/loop0
ERROR: defrag failed on /dev/loop0 - Invalid argument
Btrfs v0.19-102-g2482539-dirty
total 1 failures
[lenz@metis btrfs-progs]% echo $?
1
[lenz@metis btrfs-progs]% sudo ./btrfs filesystem defrag -v /dev/loop0 /dev/loop1 /dev/loop0
ERROR: defrag failed on /dev/loop0 - Invalid argument
/dev/loop1
ERROR: defrag failed on /dev/loop1 - Invalid argument
Btrfs v0.19-102-g2482539-dirty
total 2 failures
[lenz@metis btrfs-progs]% echo $?
1
[lenz@metis btrfs-progs]% sudo ./btrfs filesystem defrag -v /tmp /tmp
ERROR: defrag failed on /tmp - Inappropriate ioctl for device
Btrfs v0.19-102-g2482539-dirty
total 1 failures
[lenz@metis btrfs-progs]% echo $?
1

I'm no C programmer, but looking at the end of the do_defrag function in btrfs_cmds.c, I wonder if the last "return errors + 20" is correct? In case that errors is greater than zero, the function would be left via the exit(1) anyway, wouldn't it? In that case, wouldn't "return 0" at the end be more appropriate?

[SNIP]

  if (errors) {
    fprintf(stderr, "total %d failures\n", errors);
    exit(1);

}

free(av);
return errors + 20;
[SNIP]

Thanks!

  Lenz Grimmer <[email protected]> - http://www.lenzg.net/

Yes, this is a known problem, and one that's on my list of things
to deal with. Thanks for the reminder, though.

Yeah, basically, it's doing something silly and unexpected with
return codes.

Hugo.

=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
       --- Mixing mathematics and alcohol is dangerous.  Don't ---       
                            drink and derive.