Re: [PATCH RFC] btrfs: exit scrub and balance early if the fs is being frozen

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2025/10/12 18:53, Askar Safin 写道:
> Qu Wenruo <wqu@suse.com>:
>> There are some reports that btrfs is unable to be frozen if there is a
> 
> I tested your patch on real hardware.
> 
> I applied it to current Linux mainline.
> 
> I have btrfs-raid on two big disks.
> 
> I started "sudo btrfs scrub start -B -d /" and pressed "Suspend" in GUI.
> 
> If /sys/power/freeze_filesystems is 0 (this is default), then your patch doesn't work.
> 
> If /sys/power/freeze_filesystems is 1, then the system stops to respond for a minute
> and then suspends. Here is journalctl:
> https://zerobin.net/?e3376d7d056dcb04#LyzGFYeVdWsbZfgC25G4TuSct6QDyZ278gQlZgCfR94= .
> 
> As well as I understand from journalctl, systemd tries to freeze userspace
> process "btrfs scrub" and fails. Then systemd times out after a minute,
> and then suspend proceeds.
> 
> So, in short, this is not complete solution yet.
> 
> Also I tested Sterba's patch, and it doesn't work either:
> https://lore.kernel.org/linux-btrfs/20250720194803.3661-1-safinaskar@zohomail.com/ .
> 
> I really want this bug to be fixed. Please, CC me with your future attempts.

I'll send you new experimental patch(es) first for test.

In fact I already have some idea how to address it, but unfortunately it 
may take some time.

And it will address scrub first, then addressing balance related operations.

Thanks,
Qu
>