Some discs containing the UDF file system are unable to be mounted,
failing with the following message:

  UDF-fs: error (device sr0): udf_fill_super: minUDFReadRev=260
    (max is 250)

The UDF 2.60 specification [0] states in the section Basic Restrictions
& Requirements (page 10):

  The Minimum UDF Read Revision value shall be at most #0250 for all
  media with a UDF 2.60 file system. This indicates that a UDF 2.50
  implementation can read all UDF 2.60 media. Media that do not have a
  Metadata Partition may use a value lower than #250.

The conclusion is that the discs failing to mount were burned with a
faulty software, which didn't follow the specification. This can be
worked around by increasing UDF_MAX_READ_VERSION to 0x260, to match the
Minimum Read Revision. No other changes are required, as reading UDF
2.60 is backward compatible with UDF 2.50.

[0] http://www.osta.org/specs/pdf/udf260.pdf

Signed-off-by: Bartosz Taudul <wolf@nereid.pl>
---
 fs/udf/
udf_sb.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
index 4fa620543d30..09d62bf1f5fb 100644
--- a/fs/udf/udf_sb.h
+++ b/fs/udf/udf_sb.h
@@ -6,7 +6,7 @@
 #include <linux/bitops.h>
 #include <linux/magic.h>

-#define UDF_MAX_READ_VERSION		0x0250
+#define UDF_MAX_READ_VERSION		0x0260
 #define UDF_MAX_WRITE_VERSION		0x0201

 #define UDF_FLAG_USE_EXTENDED_FE	0
--
2.38.1

On Sat 03-12-22 01:07:24, Bartosz Taudul wrote:
> Some discs containing the UDF file system are unable to be mounted,
> failing with the following message:
> 
>   UDF-fs: error (device sr0): udf_fill_super: minUDFReadRev=260
>     (max is 250)
> 
> The UDF 2.60 specification [0] states in the section Basic Restrictions
> & Requirements (page 10):
> 
>   The Minimum UDF Read Revision value shall be at most #0250 for all
>   media with a UDF 2.60 file system. This indicates that a UDF 2.50
>   implementation can read all UDF 2.60 media. Media that do not have a
>   Metadata Partition may use a value lower than #250.
> 
> The conclusion is that the discs failing to mount were burned with a
> faulty software, which didn't follow the specification. This can be
> worked around by increasing UDF_MAX_READ_VERSION to 0x260, to match the
> Minimum Read Revision. No other changes are required, as reading UDF
> 2.60 is backward compatible with UDF 2.50.
> 
> [0] http://www.osta.org/specs/pdf/udf260.pdf
> 
> Signed-off-by: Bartosz Taudul <wolf@nereid.pl>

Yeah, thanks for the patch. I've merged it into my tree.

								Honza

> ---
>  fs/udf/
> udf_sb.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h
> index 4fa620543d30..09d62bf1f5fb 100644
> --- a/fs/udf/udf_sb.h
> +++ b/fs/udf/udf_sb.h
> @@ -6,7 +6,7 @@
>  #include <linux/bitops.h>
>  #include <linux/magic.h>
> 
> -#define UDF_MAX_READ_VERSION		0x0250
> +#define UDF_MAX_READ_VERSION		0x0260
>  #define UDF_MAX_WRITE_VERSION		0x0201
> 
>  #define UDF_FLAG_USE_EXTENDED_FE	0
> --
> 2.38.1
> 


-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR