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Subject: Re: [f2fs-dev] [PATCH 3/6] fs-verity: add FS_IOC_READ_VERITY_METADATA
 ioctl
To:     Eric Biggers <ebiggers@kernel.org>, <linux-fscrypt@vger.kernel.org>
CC:     Theodore Ts'o <tytso@mit.edu>, <linux-api@vger.kernel.org>,
        <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-fsdevel@vger.kernel.org>, Jaegeuk Kim <jaegeuk@kernel.org>,
        <linux-ext4@vger.kernel.org>, Victor Hsieh <victorhsieh@google.com>
References: <20210115181819.34732-1-ebiggers@kernel.org>
 <20210115181819.34732-4-ebiggers@kernel.org>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <107cf2f2-a6fe-57c2-d17d-57679d7c612d@huawei.com>
Date:   Sun, 7 Feb 2021 15:46:43 +0800
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Hi Eric,

On 2021/1/16 2:18, Eric Biggers wrote:
> +static int f2fs_ioc_read_verity_metadata(struct file *filp, unsigned long arg)
> +{
> +	if (!f2fs_sb_has_verity(F2FS_I_SB(file_inode(filp))))
> +		return -EOPNOTSUPP;

One case is after we update kernel image, f2fs module may no longer support
compress algorithm which current file was compressed with, to avoid triggering
IO with empty compress engine (struct f2fs_compress_ops pointer):

It needs to add f2fs_is_compress_backend_ready() check condition here?

Thanks,

> +
> +	return fsverity_ioctl_read_metadata(filp, (const void __user *)arg);
> +}