It seems cdrwtool in the udftools has been unusable on "modern" kernels
for some time. A Google search reveals many people with the same issue
but no solution (cdrwtool fails to format the disk). After spending some
time tracking down the issue, it comes down to the following:
The udftools still use the older CDROM_SEND_PACKET interface to send
things like FORMAT_UNIT through to the drive. They should really be
updated, but that's another story. Since most distros are using libata
now, the cd or dvd burner appears as a SCSI device, and we wind up in
block/scsi_ioctl.c. Here, the code tries to take the "struct
cdrom_generic_command" and translate it and stuff it into a "struct
sg_io_hdr" structure so it can pass it to the modern sg_io() routine
instead. Unfortunately, there is one error, or rather an omission in the
translation. The timeout that is passed in in the "struct
cdrom_generic_command" is in HZ=100 units, and this is modified and
correctly converted to jiffies by use of clock_t_to_jiffies(). However,
a little further down, this cgc.timeout value in jiffies is simply
copied into the sg_io_hdr timeout, which should be in milliseconds.
Since most modern x86 kernels seems to be getting build with HZ=250, the
timeout that is passed to sg_io and eventually converted to the
timeout_per_command member of the scsi_cmnd structure is now four times
too small. Since cdrwtool tries to set the timeout to one hour for the
FORMAT_UNIT command, and it takes about 20 minutes to format a 4x CDRW,
the SCSI error-handler kicks in after the FORMAT_UNIT completes because
it took longer than the incorrectly-calculated timeout.
Patch to correct this follows. It fixes the problem on my test system.
Signed-off-by: Tim Wright <[email protected]>
--- linux-2.6.26/block/scsi_ioctl.c.orig 2008-07-27
17:35:49.000000000 -0700
+++ linux-2.6.26/block/scsi_ioctl.c 2008-07-27 17:36:41.000000000 -0700
@@ -629,7 +629,7 @@ int scsi_cmd_ioctl(struct file *file, st
hdr.sbp = cgc.sense;
if (hdr.sbp)
hdr.mx_sb_len = sizeof(struct
request_sense);
- hdr.timeout = cgc.timeout;
+ hdr.timeout = jiffies_to_msecs(cgc.timeout);
hdr.cmdp = ((struct cdrom_generic_command
__user*) arg)->cmd;
hdr.cmd_len = sizeof(cgc.cmd);
On Sun, 2008-07-27 at 17:50 -0700, Tim Wright wrote:
> @@ -629,7 +629,7 @@ int scsi_cmd_ioctl(struct file *file, st
> hdr.sbp = cgc.sense;
> if (hdr.sbp)
> hdr.mx_sb_len = sizeof(struct
> request_sense);
> - hdr.timeout = cgc.timeout;
> + hdr.timeout = jiffies_to_msecs(cgc.timeout);
> hdr.cmdp = ((struct cdrom_generic_command
> __user*) arg)->cmd;
> hdr.cmd_len = sizeof(cgc.cmd);
I'm afraid this patch is completely whitespace damaged: the tabs have
all become spaces and the mailer has broken some of the lines.
Since it's a one liner, I can make the fix directly, but if you look at
Documentation/SubmittingPatches
It has some good advice about how to fix your email tool to prevent this
from happening in future.
James
James Bottomley wrote:
> On Sun, 2008-07-27 at 17:50 -0700, Tim Wright wrote:
>
>> @@ -629,7 +629,7 @@ int scsi_cmd_ioctl(struct file *file, st
>> hdr.sbp = cgc.sense;
>> if (hdr.sbp)
>> hdr.mx_sb_len = sizeof(struct
>> request_sense);
>> - hdr.timeout = cgc.timeout;
>> + hdr.timeout = jiffies_to_msecs(cgc.timeout);
>> hdr.cmdp = ((struct cdrom_generic_command
>> __user*) arg)->cmd;
>> hdr.cmd_len = sizeof(cgc.cmd);
>>
>
> I'm afraid this patch is completely whitespace damaged: the tabs have
> all become spaces and the mailer has broken some of the lines.
>
> Since it's a one liner, I can make the fix directly, but if you look at
>
> Documentation/SubmittingPatches
>
> It has some good advice about how to fix your email tool to prevent this
> from happening in future.
>
> James
>
>
>
Ugh, mea culpa! Thanks James. I haven't submitted anything in a while,
and was using Thunderbird. I will
go off and figure out how to make it leave the contents alone, or I'll
use a less "clever" client in future.
Many thanks for the response and the gentle coaching :-)
Regards,
Tim
On Wed, 30 Jul 2008 08:43:35 -0700 Tim Wright wrote:
> James Bottomley wrote:
> > On Sun, 2008-07-27 at 17:50 -0700, Tim Wright wrote:
> >
> >> @@ -629,7 +629,7 @@ int scsi_cmd_ioctl(struct file *file, st
> >> hdr.sbp = cgc.sense;
> >> if (hdr.sbp)
> >> hdr.mx_sb_len = sizeof(struct
> >> request_sense);
> >> - hdr.timeout = cgc.timeout;
> >> + hdr.timeout = jiffies_to_msecs(cgc.timeout);
> >> hdr.cmdp = ((struct cdrom_generic_command
> >> __user*) arg)->cmd;
> >> hdr.cmd_len = sizeof(cgc.cmd);
> >>
> >
> > I'm afraid this patch is completely whitespace damaged: the tabs have
> > all become spaces and the mailer has broken some of the lines.
> >
> > Since it's a one liner, I can make the fix directly, but if you look at
> >
> > Documentation/SubmittingPatches
> >
> > It has some good advice about how to fix your email tool to prevent this
> > from happening in future.
> >
> > James
> >
> >
> >
> Ugh, mea culpa! Thanks James. I haven't submitted anything in a while,
> and was using Thunderbird. I will
> go off and figure out how to make it leave the contents alone, or I'll
> use a less "clever" client in future.
> Many thanks for the response and the gentle coaching :-)
also see Documentation/email-clients.txt
---
~Randy
Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA
http://linuxplumbersconf.org/