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Subject: Re: [f2fs-dev] [PATCH 6/7] f2fs: flush quota blocks after turnning it
 off
To:     Jaegeuk Kim <jaegeuk@kernel.org>, linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
References: <20190128234717.77225-1-jaegeuk@kernel.org>
 <20190128234717.77225-6-jaegeuk@kernel.org>
From:   Chao Yu <chao@kernel.org>
Message-ID: <629f4b34-381e-7860-c717-3fe54ee15694@kernel.org>
Date:   Sat, 2 Feb 2019 00:08:27 +0800
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On 2019-1-29 7:47, Jaegeuk Kim wrote:
> After quota_off, we'll get some dirty blocks. If put_super don't have a chance
> to flush them by checkpoint, it causes NULL pointer exception in end_io after
> iput(node_inode). (e.g., by checkpoint=disable)
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>  fs/f2fs/super.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 5e1f8573a17f..7694cb350734 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2026,6 +2026,12 @@ void f2fs_quota_off_umount(struct super_block *sb)
>  			set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
>  		}
>  	}
> +	/*
> +	 * In case of checkpoint=disable, we must flush quota blocks.

checkpoint=disable is one of the cases, right? e.g. IO error can be another case?

So here I guess we need to change the comments a bit for that.

Thanks,

> +	 * This can cause NULL exception for node_inode in end_io, since
> +	 * put_super already dropped it.
> +	 */
> +	sync_filesystem(sb);
>  }
>  
>  static void f2fs_truncate_quota_inode_pages(struct super_block *sb)
>