On Thu, Sep 16, 2021 at 08:38:52PM +0800, Qu Wenruo wrote:

On 2021/9/16 20:32, Eli V wrote:

quoted

I just upgraded one of my btrfs systems from 4.19 kernel to 5.10.46
dmesg is outputing the below messages, I assume because of the
enospc_debug mount option I've had in fstab for quite some time now.
Didn't check all of the numbers, but the first line free value does
seem erroneous, unless that's some sort of theoretical maximum being
displayed. This is a fairly large filesystem at 382TB (btrfs usage
below,) but that's a lot more free then total space:

Thu Sep 16 06:17:55 2021] BTRFS info (device sdb): space_info 4 has
18446743694945091584 free, is not full

This is space info dump, normally meaning you're hitting ENOSPC.

The free value has underflow, we should output it in s64 other than u64.

The free space should be -378764460032.

It's still a bit weird to see a negative number but as you found out
it's due to overcommit so it's possible.