unable to remove files because of No space left

unable to remove files because of No space left

[Jingyun He]

Hello,
I have a HM-SMR device, and have fill the disk full.
the disk went into read-only when I started a balance process,

Now I'm unable to remove any files nor add files.
Once I mount the device, it will automatically start the balance, and
go into read only immediately.
Then I tried the skip_balance option, I can mount the device, and I
tried to remove some files, but it became read only again.
I got following error message when I tried to remove file.
[435609.942923] BTRFS: error (device sdb) in
__btrfs_update_delayed_inode:995: errno=-28 No space left

Any ideas?
Thanks.

Re: unable to remove files because of No space left

[Qu Wenruo]

On 2021/12/25 18:14, Jingyun He wrote:
> Hello,
> I have a HM-SMR device, and have fill the disk full.
> the disk went into read-only when I started a balance process,

This is already a big problem.

Although btrfs needs extra space to do metadata COW, we should not going
to read-only half way.

This mostly means, the extent allocation and space reservation are not
doing ENOSPC check correctly for HM zoned devices.

Add Johannes to CC list, as I believe it's zoned code causing the
behavior change.

Any extra info like `btrfs fi df` and `btrfs fi usage`?
Also the dmesg for the readonly failure would also help.

Thanks,
Qu
>
> Now I'm unable to remove any files nor add files.
> Once I mount the device, it will automatically start the balance, and
> go into read only immediately.
> Then I tried the skip_balance option, I can mount the device, and I
> tried to remove some files, but it became read only again.
> I got following error message when I tried to remove file.
> [435609.942923] BTRFS: error (device sdb) in
> __btrfs_update_delayed_inode:995: errno=-28 No space left
>
> Any ideas?
> Thanks.