DVD-RAM media detected with wrong number of blocks (2.4.7)

DVD-RAM media detected with wrong number of blocks (2.4.7)

[David Johnson]

When attempting to create an ext2 partition on a dvd-ram (2.6G/5.2G) 
media the number of blocks is detected wrong causing only half of the 
disk to be usable.  When creating the filesystem with mke2fs only 
609480 2K blocks are allowed instead of 1218960 2K blocks, and I end 
up with a 1.2GB partition instead of 2.4GB one.  The 1.2GB fs works 
fine, it's just a bit small :(

This is with 2.4.7 using a Creative DVD-RAM drive (1216S) on an Adaptec 2940UW.

The correct number of blocks is detected in 2.4.6


[...]
SCSI subsystem driver Revision: 1.00
PCI: Found IRQ 11 for device 00:0c.0
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.1.13
         <Adaptec 2940 Ultra SCSI adapter>
         aic7880: Ultra Wide Channel A, SCSI Id=7, 16/255 SCBs

   Vendor: CREATIVE  Model: DVD-RAM RAM1216S  Rev: 1311
   Type:   CD-ROM                             ANSI SCSI revision: 02
(scsi0:A:4): 10.000MB/s transfers (10.000MHz, offset 15)
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 4, lun 0
sr0: scsi3-mmc drive: 0x/0x dvd-ram cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
[...]


$ mke2fs -b 2048 /dev/scd0
mke2fs 1.18, 11-Nov-1999 for EXT2 FS 0.5b, 95/08/09
/dev/scd0 is entire device, not just one partition!
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=2048 (log=1)
Fragment size=2048 (log=1)
152608 inodes, 609480 blocks
30474 blocks (5.00%) reserved for the super user
First data block=0
38 block groups
16384 blocks per group, 16384 fragments per group
4016 inodes per group
Superblock backups stored on blocks:
         16384, 49152, 81920, 114688, 147456, 409600, 442368

Writing inode tables: done
Writing superblocks and filesystem accounting information: done
$

Re: DVD-RAM media detected with wrong number of blocks (2.4.7)

[Jens Axboe]

[-- Attachment #1: Type: text/plain, Size: 609 bytes --]

On Mon, Jul 23 2001, David Johnson wrote:
> When attempting to create an ext2 partition on a dvd-ram (2.6G/5.2G) 
> media the number of blocks is detected wrong causing only half of the 
> disk to be usable.  When creating the filesystem with mke2fs only 
> 609480 2K blocks are allowed instead of 1218960 2K blocks, and I end 
> up with a 1.2GB partition instead of 2.4GB one.  The 1.2GB fs works 
> fine, it's just a bit small :(
> 
> This is with 2.4.7 using a Creative DVD-RAM drive (1216S) on an Adaptec 
> 2940UW.
> 
> The correct number of blocks is detected in 2.4.6

Does this work?

-- 
Jens Axboe


[-- Attachment #2: sr-cap-1 --]
[-- Type: text/plain, Size: 348 bytes --]

--- drivers/scsi/sr_ioctl.c~	Tue Jul 24 10:24:46 2001
+++ drivers/scsi/sr_ioctl.c	Tue Jul 24 10:24:59 2001
@@ -545,7 +545,7 @@
 
 	switch (cmd) {
 	case BLKGETSIZE:
-		return put_user(scsi_CDs[target].capacity >> 1, (long *) arg);
+		return put_user(scsi_CDs[target].capacity >> 2, (long *) arg);
 	case BLKROSET:
 	case BLKROGET:
 	case BLKRASET:

Re: DVD-RAM media detected with wrong number of blocks (2.4.7)

[David Johnson]

On 7/24/01, Jens Axboe wrote:
>On Mon, Jul 23 2001, David Johnson wrote:
>> When attempting to create an ext2 partition on a dvd-ram (2.6G/5.2G)
>> media the number of blocks is detected wrong causing only half of the
>> disk to be usable.  When creating the filesystem with mke2fs only
>> 609480 2K blocks are allowed instead of 1218960 2K blocks, and I end
>> up with a 1.2GB partition instead of 2.4GB one.  The 1.2GB fs works
>> fine, it's just a bit small :(
>>
>> This is with 2.4.7 using a Creative DVD-RAM drive (1216S) on an Adaptec
>> 2940UW.
>>
>> The correct number of blocks is detected in 2.4.6
>
>Does this work?
>

Shifting another bit causes the size to get cut in half again, not 
shifting at all appears to be the correct thing to do.

Re: DVD-RAM media detected with wrong number of blocks (2.4.7)

[Jens Axboe]

On Tue, Jul 24 2001, David Johnson wrote:
> On 7/24/01, Jens Axboe wrote:
> >On Mon, Jul 23 2001, David Johnson wrote:
> >>When attempting to create an ext2 partition on a dvd-ram (2.6G/5.2G)
> >>media the number of blocks is detected wrong causing only half of the
> >>disk to be usable.  When creating the filesystem with mke2fs only
> >>609480 2K blocks are allowed instead of 1218960 2K blocks, and I end
> >>up with a 1.2GB partition instead of 2.4GB one.  The 1.2GB fs works
> >>fine, it's just a bit small :(
> >>
> >>This is with 2.4.7 using a Creative DVD-RAM drive (1216S) on an Adaptec
> >>2940UW.
> >>
> >>The correct number of blocks is detected in 2.4.6
> >
> >Does this work?
> >
> 
> Shifting another bit causes the size to get cut in half again, not 
> shifting at all appears to be the correct thing to do.

Yes of course, braino. So eliminating the shift gets the right size for
you, correct?

-- 
Jens Axboe