btrfs-progs unable to make snapshots

[Eric]

I have discovered that btrfs from the Raspbian btrfs-progs package can't make snapshots. The result

# btrfs sub snap blue_root blue_root-snap
ERROR: Could not statfs: Value too large for defined data type

seems to indicate that instead of statfs64, the older system calls were inadvertently used. Note that statfs64 has been standard since kernel versions 2.6.

Workaround:

Note that btrfs version v4.20.1 is included with Raspbian Buster. I compiled the latest btrfs version 5.2.1 from source. The problem persisted. Then I copied the old version 4.7.3 binary from Raspbian Stretch to the 4B. Woohoo! The Stretch binary works on Buster!

[Eric (ejolson)]

It appears the bug only affects multi-drive disk pools in mirror mode and not single BTRFS volumes. More information is in the following thread

https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=249873#p1528598

on the Raspberry Pi forum

[at (atrent)]

I confirm this bug, installing (and then pinning) version 4.7.3-1 of btrfs-progs the snapshot can be created

I have a multi disk btrfs volume: 8 disks for a total of 21TB

On raspberry pi 4, 8GB

Linux server 5.4.75-v7l+ #1367 SMP Mon Nov 9 15:07:24 GMT 2020 armv7l GNU/Linux

[at (atrent)]

my btrfs volume is not mirrored, just striped

[Les (lesnewell)]

I'm having the same problem with two striped drives. It only started happening after I added a second drive. The earliest version I appear to be able to downgrade to is 4.20.1-2, which still has the problem.