Re: [PATCH v9 06/13] exfat: add exfat entry operations

From: Christoph Hellwig <hch@lst.de>
To: Namjae Jeon <namjae.jeon@samsung.com>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	gregkh@linuxfoundation.org, valdis.kletnieks@vt.edu, hch@lst.de,
	sj1557.seo@samsung.com, linkinjeon@gmail.com,
	pali.rohar@gmail.com
Subject: Re: [PATCH v9 06/13] exfat: add exfat entry operations
Date: Wed, 8 Jan 2020 19:00:40 +0100	[thread overview]
Message-ID: <20200108180040.GB14650@lst.de> (raw)
In-Reply-To: <20200102082036.29643-7-namjae.jeon@samsung.com>

> +int exfat_ent_get(struct super_block *sb, unsigned int loc,
> +		unsigned int *content)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	int err;
> +
> +	if (!is_valid_cluster(sbi, loc)) {
> +		exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)",
> +			loc);
> +		return -EIO;
> +	}
> +
> +	err = __exfat_ent_get(sb, loc, content);
> +	if (err) {
> +		exfat_fs_error(sb,
> +			"failed to access to FAT (entry 0x%08x, err:%d)",
> +			loc, err);
> +		return err;
> +	}
> +
> +	if (!is_reserved_cluster(*content) &&
> +			!is_valid_cluster(sbi, *content)) {
> +		exfat_fs_error(sb,
> +			"invalid access to FAT (entry 0x%08x) bogus content (0x%08x)",
> +			loc, *content);
> +		return -EIO;
> +	}
> +
> +	if (*content == EXFAT_FREE_CLUSTER) {
> +		exfat_fs_error(sb,
> +			"invalid access to FAT free cluster (entry 0x%08x)",
> +			loc);
> +		return -EIO;
> +	}
> +
> +	if (*content == EXFAT_BAD_CLUSTER) {
> +		exfat_fs_error(sb,
> +			"invalid access to FAT bad cluster (entry 0x%08x)",
> +			loc);
> +		return -EIO;
> +	}
> +	return 0;

Maybe these explicit checks should move up, and then is_reserved_cluster
can be replaced with an explicit check just for EXFAT_EOF_CLUSTER?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>