Hi all,
this patch adds support for the raid5/6 profiles in the command
'btrfs filesystem usage'.
Until now the problem was that the value r_{data,metadata}_used is not
easy to get for a RAID5/6, because it depends by the number of disks.
And in a filesystem it is possible to have several raid5/6 chunks with a
different number of disks.
In order to bypass this issue, I compute these values from the
r_{data,metadata,system}_chunks values and the ratio
l_*_used / l_*_chunks.
So now if you run btrfs fi us in a raid6 filesystem you get:
$ sudo btrfs fi us /
Overall:
Device size: 40.00GiB
Device allocated: 8.28GiB
Device unallocated: 31.72GiB
Device missing: 0.00B
Used: 5.00GiB
Free (estimated): 17.36GiB (min: 17.36GiB)
Data ratio: 2.00
Metadata ratio: 0.00
Global reserve: 3.25MiB (used: 0.00B)
Data,RAID6: Size:4.00GiB, Used:2.50GiB (62.53%)
[...]
Instead before:
$ sudo btrfs fi us /
WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
Overall:
Device size: 40.00GiB
Device allocated: 0.00B
Device unallocated: 40.00GiB
Device missing: 0.00B
Used: 0.00B
Free (estimated): 0.00B (min: 8.00EiB)
Data ratio: 0.00
Metadata ratio: 0.00
Global reserve: 3.25MiB (used: 0.00B)
Data,RAID6: Size:4.00GiB, Used:2.50GiB (62.53%)
[...]
I want to point out that this patch should be compatible with my
previous patches set (the ones related to the new ioctl
BTRFS_IOC_GET_CHUNK_INFO). If both are merged we will have a 'btrfs fi us'
commands with full support a raid5/6 filesystem without needing root
capability.
I rewrote the patch after some David's comments about the difficult to
review it because I changed too much code. So this time I tried to be less
intrusive. I leaved the old logic and I computed only the missing
values.
Comments are welcome.
BR
G.Baroncelli
V2:
The patch is completely rewritten to be less intrusive
V1:
First issue
--
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
