Re: [PATCH] [RFC] [resend] isofs: work-around for RockRidge+Joliet CDs with empty ISO root directory

[Guenter Roeck]

On Tue, 2010-08-31 at 14:10 -0400, Ondrej Zary wrote:
> If a CD has both Rock Ridge and Joliet extensions and the ISO root directory
> is empty, no files are visible. Disable Rock Ridge extensions in this case and
> use Joliet root directory instead.
> 
> Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
> 
> --- linux-2.6.35-rc2/fs/isofs/inode.c	2010-06-06 05:43:24.000000000 +0200
> +++ linux-2.6.35-rc3/fs/isofs/inode.c	2010-08-24 22:43:26.000000000 +0200
> @@ -549,6 +549,34 @@ static unsigned int isofs_get_last_sessi
>  }
>  
>  /*
> + * Check if root directory is empty (has less than 3 files).
> + *
> + * Used to detect broken CDs where ISO root directory is empty but Joliet root
> + * directory is OK. If such CD has Rock Ridge extensions, they will be disabled
> + * (and Joliet used instead) or else no files would be visible.
> + */
> +static bool rootdir_empty(struct super_block *sb, unsigned long block)
> +{
> +	int offset, files, de_len;
> +	struct iso_directory_record *de;
> +	struct buffer_head *bh;
> +
> +	bh = sb_bread(sb, block);
> +	if (!bh)
> +		return true;
> +	while (files < 3) {

files is uninitialized.

> +		de = (struct iso_directory_record *) (bh->b_data + offset);

offset is uninitialized.

Did you test this patch ?

> +		de_len = *(unsigned char *) de;
> +		if (de_len == 0)
> +			break;
> +		files++;
> +		offset += de_len;
> +	}
> +	brelse(bh);
> +	return files < 3;
> +}
> +
> +/*
>   * Initialize the superblock and read the root inode.
>   *
>   * Note: a check_disk_change() has been done immediately prior
> @@ -842,6 +870,18 @@ root_found:
>  		goto out_no_root;
>  
>  	/*
> +	 * Fix for broken CDs with Rock Ridge and empty ISO root directory but
> +	 * correct Joliet root directory.
> +	 */
> +	if (sbi->s_rock == 1 && joliet_level &&
> +				rootdir_empty(s, sbi->s_firstdatazone)) {
> +		printk(KERN_NOTICE
> +			"ISOFS: primary root directory is empty. "
> +			"Disabling Rock Ridge and switching to Joliet.");
> +		sbi->s_rock = 0;
> +	}
> +
> +	/*
>  	 * If this disk has both Rock Ridge and Joliet on it, then we
>  	 * want to use Rock Ridge by default.  This can be overridden
>  	 * by using the norock mount option.  There is still one other
> 
> 
> 


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