(cache)File names over 85 characters crash growisofs -M

exerceo · 03-12-2025, 02:13 PM

(This is a purely informational post, not a question.)

The disc writing tool "growisofs" was apparently the first Blu-ray recording tool for Linux in existence, and is even today used by K3b. It is based on "genisoimage".

But it was abandoned by its creator Andy Pokalov in 2008 and hasn't been developed since. And it is showing its age.

I have noticed that if you use growisofs -r -M (rock ridge, merge with existing session to add new files), none of the new files must exceed 85 characters. Otherwise, you get a garbage error like:

Code:

# growisofs -r -M /dev/sr1 test_dir
Executing 'genisoimage -r -C 16,7082336 -M /dev/fd/3 test_dir | builtin_dd of=/dev/sr1 obs=32k seek=442646'
I: -input-charset not specified, using utf-8 (detected in locale settings)
Rock Ridge signatures found
BAD RR ATTRIBUTES: 93 51 FB 6D 68 38 0B 27 66 00 26 7B 74 68 88 4F 5E EA 93 37 6C 15 6D 14 7B 96 D2 D2 5B CF 3A 23 89 4D BB B7 85 80 34 09 39 32 97 CB 73 20 BC 67 B3 FE E4 2C B3 8F BF 3D 3B 7C 92 1E 44 FD
BAD RR ATTRIBUTES: .Q.mh8.'f.&{th.O^..7l.m.{...[.:#.M....4.92..s .g...,...=;|..D.
genisoimage: **BAD RRVERSION (109) for �Q
genisoimage: Cannot parse Rock Ridge attributes for 'LONG_FIL.MP3;1'.
:-( genisoimage has failed: 255

And you will not be able to resume the session.

In addition, some unicode characters like emojis break UDF directory listings with growisofs -udf. The directory might not be fully listed if a file contains non-ASCII characters.

By the way, when using -M (merge with existing session to add new files), never forget to specify -r (Rock Ridge) or the existing file names will be downgraded to basic ISO9660 file names. This means they are single-case (they appear all-lowercase on Linux and all-uppercase on Windows) and spaces and other non-alphanumeric characters are replaced with underscores.

Example!.mp3 is turned into "example_.mp3" or "EXAMPLE_.MP3" depending on the OS viewing the file.

scdbackup · 03-15-2025, 03:14 AM

Hi,

the error messages shown stem originally from genisoimage, not from
growisofs (which has its own bugs, especially
https://bugs.debian.org/cgi-bin/bugr...cgi?bug=794868
).

genisoimage is unmaintained nearly as long as growisofs.
The author of mkisofs, which was the origin of the genisoimage fork,
has died a few years ago.

As long as one does not need their options -udf or -hfs it should be
possible to use xorriso and its mkisofs emulation xorrisofs instead.
For use under growisofs one would set these variables:

Code:

  export MKISOFS="xorrisofs"
  export GENISOIMAGE="xorrisofs"

It depends on the Linux distro which one of them is used by growisofs.
Debian based versions use GENISOIMAGE, others use MKISOFS.

But when xorriso is involved, one may also omit growisofs and rather
rely on xorriso's burn capabilities:

Code:

  xorriso -dev /dev/sr1 \
          -map test_dir / \
          -find / -exec mkisofs_r --

xorriso command -dev is like mkisofs option -M. It loads the existing
directory tree of the ISO 9660 filesystem on the medium before adding
or deleting files by subsequent xorriso commands.
Command -map has two parameters: the source path on disk and the target
path in the ISO filesystem.
When all intended manipulations are done, the command

Code:

  -find / -exec mkisofs_r --

performs the changes in permissions and ownerships which are caused by
mkisofs option -r instead of -R.

One may practice with a disk file as pseudo-drive:

Code:

  xorriso -dev "$HOME"/test.iso \
          ...

xorriso and xorrisofs have the effect of option -R enabled by default.
I.e long file names and POSIX attributes will be recorded and shown
when the ISO is mounted on Linux.
The effect of option -r is only suited for situations where the
original permissions and ownerships are cumbersome when mounting and
reading the ISO filesystem.

Have a nice day

Thomas

sundialsvcs · 03-15-2025, 03:57 PM

However, if I may say, if your file-names are more than 85(!) characters, you probably need to invent a brand-new way of organizing your information!

My best guess is that you are attempting to "encode information directly into the filename." Probably a much better way is to employ a (SQLITE?) database. Use a very-simple filing system (such as "uuid"), then use the database (file ...) to make proper sense of it.

exerceo · Today, 04:21 PM

Quote:

Originally Posted by sundialsvcs

However, if I may say, if your file-names are more than 85(!) characters, you probably need to invent a brand-new way of organizing your information!

Many online videos have titles longer than 85 characters.