Re: [PATCH RFC] btrfs: no need to transition to rdonly for ENOSPC error

From: Qu Wenruo <quwenruo.btrfs@gmx.com>
To: Anand Jain <anand.jain@oracle.com>, linux-btrfs@vger.kernel.org
Cc: josef@toxicpanda.com
Subject: Re: [PATCH RFC] btrfs: no need to transition to rdonly for ENOSPC error
Date: Tue, 12 Jan 2021 21:39:58 +0800	[thread overview]
Message-ID: <56e1248e-0956-0446-1c45-d280c396d378@gmx.com> (raw)
In-Reply-To: <169ba15cd316c181042bbe25e7d10c7963e3b7e8.1610444879.git.anand.jain@oracle.com>

On 2021/1/12 下午6:34, Anand Jain wrote:
> In the current kernel both scrub and balance fails due to ENOSPC,
> however there is no reason that it should be transitioned to the
> RDONLY and making free spaces difficult.

This just masks the real problem.

 From all your reports, the problem is the same, we exhausted the
metadata space, but the GlobalRSV is only 100+MiB.

It looks like the problem Josef is working on to make GlobalRSV work as
usual.

Definitely not the proper way to fix it.

Thanks,
Qu
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>   fs/btrfs/super.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 12d7d3be7cd4..8c1b858f55c4 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -172,6 +172,9 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
>   	if (sb_rdonly(sb))
>   		return;
>
> +	if (errno == -ENOSPC)
> +		return;
> +
>   	btrfs_discard_stop(fs_info);
>
>   	/* btrfs handle error by forcing the filesystem readonly */
>