SEARCH_V2: Inappropriate ioctl for device

[andras-kiss]

I'm not sure if this is the right place to post (possible) bugs. Anyway when I try to run compsize on root or my home folder, I get this error message:

akiss@buster:~$ su
Password:
root@buster:/home/akiss# ./compsize/compsize .
SEARCH_V2: Inappropriate ioctl for device
root@buster:/home/akiss#

When I run it on a subfolder, it works as expected:

root@buster:/home/akiss# ./compsize/compsize .steam
Processed 34050 files, 206016 regular extents (206274 refs), 10770 inline.
Type Perc Disk Usage Uncompressed Referenced
TOTAL 65% 23G 35G 35G
none 100% 12G 12G 12G
zstd 45% 10G 22G 22G
root@buster:/home/akiss#

I have an ext4 boot partition mounted at /boot, and a samba share mounted in my home folder.

root@buster:/home/akiss# uname -a
Linux buster 4.14.0-2-amd64 #1 SMP Debian 4.14.7-1 (2017-12-22) x86_64 GNU/Linux

[kilobyte]

Yeah, the handling of non-btrfs filesystems is not as good as it should be.

"Inappropriate ioctl for device" still sounds better than "Not a typewriter" this ioctl would say a while ago (its #define is still named ENOTTY), but an expected error should provide a more obvious message.

I still think that failing immediately when given a non-btrfs initial directory is a good idea, as most of the time all the recursive traversal would be pointless. Should probably have an override for your use case, though.

Any advice?

[andras-kiss]

Thank you for the response. I'm not a developer at all (at least not programmer). I've unmounted the samba share in my home directory (subfolder in home: /home/akiss/share), and compsize produces a report. Yes, maybe it would be useful if compsize ignored any non-brtfs subfolder, or maybe included that in the report. It would help to get compression stats on root even in the common case when there is a separate ext boot partition mounted.

I think it's really cool to see how much smaller data becomes with compression. I hope it will be in the kernel soon as part of brtfs-progs.

[kilobyte]

The error message is unhelpful enough that it needs fixing.