linux-kernel - Re: [f2fs-dev] [PATCH] f2fs: prevent compressed file from being disabled after releasing cblocks

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Date:   Sun, 30 Aug 2020 11:23:49 +0800
From:   Chao Yu <chao@...nel.org>
To:     Daeho Jeong <daeho43@...il.com>, linux-kernel@...r.kernel.org,
        linux-f2fs-devel@...ts.sourceforge.net, kernel-team@...roid.com
Cc:     Daeho Jeong <daehojeong@...gle.com>
Subject: Re: [f2fs-dev] [PATCH] f2fs: prevent compressed file from being
 disabled after releasing cblocks

On 2020-8-28 13:46, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@...gle.com>
>
> After releasing cblocks, the compressed file can be accidentally
> disabled in compression mode, since it has zero cblocks. As we are
> using IMMUTABLE flag to present released cblocks state, we can add
> IMMUTABLE state check when considering the compressed file disabling.
>
> Signed-off-by: Daeho Jeong <daehojeong@...gle.com>
> ---
>  fs/f2fs/f2fs.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 02811ce15059..14d30740ba03 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -3936,6 +3936,8 @@ static inline u64 f2fs_disable_compressed_file(struct inode *inode)
>  	if (!f2fs_compressed_file(inode))
>  		return 0;
>  	if (S_ISREG(inode->i_mode)) {
> +		if (IS_IMMUTABLE(inode))
> +			return 1;

It looks most of callers are from ioctl, should we add immutable check in f2fs 
ioctl interfaces if necessary? or I missed existed check.

Thanks,

>  		if (get_dirty_pages(inode))
>  			return 1;
>  		if (fi->i_compr_blocks)
>