From e45c9effed903ba3fdbd6ef0498ee8989c35af0a Mon Sep 17 00:00:00 2001 From: Ondrej Zary Date: Wed, 27 Oct 2010 15:33:30 -0700 Subject: [PATCH] isofs: work-around for Rock Ridge+Joliet CDs with empty ISO root directory 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 Cc: Al Viro Cc: Guenter Roeck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/isofs/inode.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c index 60c2b944d762..79cf7f616bbe 100644 --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -543,6 +543,34 @@ static unsigned int isofs_get_last_session(struct super_block *sb, s32 session) return vol_desc_start; } +/* + * 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 = 0, files = 0, de_len; + struct iso_directory_record *de; + struct buffer_head *bh; + + bh = sb_bread(sb, block); + if (!bh) + return true; + while (files < 3) { + de = (struct iso_directory_record *) (bh->b_data + offset); + 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. * @@ -842,6 +870,18 @@ root_found: if (IS_ERR(inode)) 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 -- 2.20.1