Re: [f2fs-dev] [PATCH v3] f2fs: compress: support chksum

[Eric Biggers]

On Thu, Nov 26, 2020 at 06:32:09PM +0800, Chao Yu wrote:
> +	if (!ret && fi->i_compress_flag & 1 << COMPRESS_CHKSUM) {

This really could use some parentheses.  People shouldn't have to look up a
C operator precedence table to understand the code.

> +		u32 provided = le32_to_cpu(dic->cbuf->chksum);
> +		u32 calculated = f2fs_crc32(sbi, dic->cbuf->cdata, dic->clen);
> +
> +		if (provided != calculated) {
> +			if (!is_inode_flag_set(dic->inode, FI_COMPRESS_CORRUPT)) {
> +				set_inode_flag(dic->inode, FI_COMPRESS_CORRUPT);
> +				printk_ratelimited(
> +					"%sF2FS-fs (%s): checksum invalid, nid = %lu, %x vs %x",
> +					KERN_INFO, sbi->sb->s_id, dic->inode->i_ino,
> +					provided, calculated);
> +			}
> +			set_sbi_flag(sbi, SBI_NEED_FSCK);
> +			WARN_ON_ONCE(1);

WARN, WARN_ON_ONCE, BUG, BUG_ON, etc. are only for kernel bugs, not for invalid
inputs from disk or userspace.

There is already a log message printed just above, so it seems this WARN_ON_ONCE
should just be removed.

- Eric