cdrecord dev=ATA cannont scanbus as non-root

cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

Hi all...

I'm trying to get out of the mess that cd burning looks like nowadays in
linux...

As I use a 2.6.x kernel, I folowed this hints:
- no suid cdrecord, it uses capabilities
- make the burner owned by console user (pam)

cdrecord burns ok using dev=/dev/burner, but I can't get GUI tools to
burn using the /dev interface. All of them try to load ide-scsi, and
do a scan based on ATAPI:.
Some tools try to scan with dev=ATA:x:y:z, but that does not work as
normal user.

How can I make 'cdrecord dev=ATA -scanbus' work as non-root ?

TIA

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jan Engelhardt]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: TEXT/PLAIN; charset=UTF-8, Size: 2937 bytes --]

>Hi all...
>
>I'm trying to get out of the mess that cd burning looks like nowadays in
>linux...
>
>As I use a 2.6.x kernel, I folowed this hints:
>- no suid cdrecord, it uses capabilities
>- make the burner owned by console user (pam)
>
>cdrecord burns ok using dev=/dev/burner, but I can't get GUI tools to
>burn using the /dev interface. All of them try to load ide-scsi, and
>do a scan based on ATAPI:.
>Some tools try to scan with dev=ATA:x:y:z, but that does not work as
>normal user.

Maybe because it should have been dev=ATAPI: ?

>How can I make 'cdrecord dev=ATA -scanbus' work as non-root ?

Weird, works for me:

22:49 io:~ > cdrecord -dev=ATAPI: -scanbus
Cdrecord-Clone 2.01 (i686-suse-linux) Copyright (C) 1995-2004 Jörg Schilling
Note: This version is an unofficial (modified) version
Note: and therefore may have bugs that are not present in the original.
Note: Please send bug reports or support requests to
http://www.suse.de/feedbackNote: The author of cdrecord should not be bothered
with problems in this version.
scsidev: 'ATAPI:'
devname: 'ATAPI'
scsibus: -1 target: -1 lun: -1
Warning: Using ATA Packet interface.
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
cdrecord: No such file or directory. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root.
cdrecord: For possible transport specifiers try 'cdrecord dev=help'.
22:50 io:/dev # chmod 666 /dev/hdd
22:50 io:~ > cdrecord -dev=ATAPI: -scanbus
Cdrecord-Clone 2.01 (i686-suse-linux) Copyright (C) 1995-2004 Jörg Schilling
[...]
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
Using libscg version 'schily-0.8'.
scsibus0:
        0,0,0     0) *
        0,1,0     1) 'AOPEN   ' 'CD-RW CRW1232PRO' '1.00' Removable CD-ROM
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *

And further (in addition to above):
22:50 io:/dev # chmod 666 /dev/hdb
22:50 io:~ > cdrecord -dev=ATAPI: -scanbus
scsibus0:
        0,0,0     0) *
cdrecord: Warning: controller returns wrong size for CD capabilities page.
        0,1,0     1) '        ' 'ATAPI CDROM     ' '100H' Removable CD-ROM
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *
scsibus1:
        1,0,0   100) *
        1,1,0   101) 'AOPEN   ' 'CD-RW CRW1232PRO' '1.00' Removable CD-ROM
        1,2,0   102) *
        1,3,0   103) *
        1,4,0   104) *
        1,5,0   105) *
        1,6,0   106) *
        1,7,0   107) *

Apart from the fact that scsibus shifts up by one, Works For Me(TM)


Jan Engelhardt
-- 
Gesellschaft für Wissenschaftliche Datenverarbeitung
Am Fassberg, 37077 Göttingen, www.gwdg.de

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

On 2004.11.29, Jan Engelhardt wrote:
> >Hi all...
> >
> >I'm trying to get out of the mess that cd burning looks like nowadays in
> >linux...
> >
> >As I use a 2.6.x kernel, I folowed this hints:
> >- no suid cdrecord, it uses capabilities
> >- make the burner owned by console user (pam)
> >
> >cdrecord burns ok using dev=/dev/burner, but I can't get GUI tools to
> >burn using the /dev interface. All of them try to load ide-scsi, and
> >do a scan based on ATAPI:.
> >Some tools try to scan with dev=ATA:x:y:z, but that does not work as
> >normal user.
> 
> Maybe because it should have been dev=ATAPI: ?
> 
> >How can I make 'cdrecord dev=ATA -scanbus' work as non-root ?
> 
> Weird, works for me:
> 
> 22:49 io:~ > cdrecord -dev=ATAPI: -scanbus

dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:

> scsibus: -1 target: -1 lun: -1
> Warning: Using ATA Packet interface.
> Warning: The related Linux kernel interface code seems to be unmaintained.
> Warning: There is absolutely NO DMA, operations thus are slow.

dev=ATA uses direct IDE burning. Try that as root. In my box, as root:

werewolf:~# cdrecord dev=ATAPI -scanbus
scsibus0:
        0,0,0     0) *
        0,1,0     1) 'TOSHIBA ' 'DVD-ROM SD-M1712' '1004' Removable CD-ROM
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *
scsibus1:
        1,0,0   100) 'HL-DT-ST' 'DVDRAM GSA-4120B' 'A102' Removable CD-ROM
        1,1,0   101) *
        1,2,0   102) *
        1,3,0   103) *
        1,4,0   104) *
        1,5,0   105) *
        1,6,0   106) *
        1,7,0   107) *

werewolf:~# cdrecord dev=ATA -scanbus
scsidev: 'ATA'
devname: 'ATA'
scsibus: -2 target: -2 lun: -2
#########################################################################################
#
#  Warning: Using ATAPI via /dev/hd* interface. Use dev=ATA:X,Y,Z or dev=/dev/hdX
#
#########################################################################################

scsibus0:
        0,0,0     0) *
        0,1,0     1) 'TOSHIBA ' 'DVD-ROM SD-M1712' '1004' Removable CD-ROM
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *
scsibus1:
        1,0,0   100) 'HL-DT-ST' 'DVDRAM GSA-4120B' 'A102' Removable CD-ROM
        1,1,0   101) *
        1,2,0   102) *
        1,3,0   103) *
        1,4,0   104) *
        1,5,0   105) *
        1,6,0   106) *
        1,7,0   107) *

The scan through ATA lasts much less than with ATAPI, and you can burn with
dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended way.

But as I said, scanning through ATA is not avaliable to normal users, so
it is someway useless.

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jan Engelhardt]

>dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:

I do not have the ide-scsi.ko module even compiled, and it works.
The ATA: scanbus thing works for me as a normal user too (forgot to add that)


-- 
Gesellschaft für Wissenschaftliche Datenverarbeitung
Am Fassberg, 37077 Göttingen, www.gwdg.de

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jens Axboe]

On Mon, Nov 29 2004, J.A. Magallon wrote:
> dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> 
> > scsibus: -1 target: -1 lun: -1
> > Warning: Using ATA Packet interface.
> > Warning: The related Linux kernel interface code seems to be unmaintained.
> > Warning: There is absolutely NO DMA, operations thus are slow.
> 
> dev=ATA uses direct IDE burning. Try that as root. In my box, as root:

Oh no, not this again... Please check the facts: the ATAPI method uses
the SG_IO ioctl, which is direct-to-device. It does _not_ go through
/dev/sgX, unless you actually give /dev/sgX as the device name. It has
nothing to do with ide-scsi. Period.

ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
burning, it's a crippled interface from the CDROM layer that should not
be used for anything.  scsi-linux-ata.c should be ripped from the
cdrecord sources, or at least cdrecord should _never_ select that
transport for 2.6 kernels. For 2.4 you are far better off using
ide-scsi.

> The scan through ATA lasts much less than with ATAPI, and you can burn with
> dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended way.

No! ATAPI is the recommended way.

-- 
Jens Axboe

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

On 2004.11.30, Jens Axboe wrote:
> On Mon, Nov 29 2004, J.A. Magallon wrote:
> > dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > 
> > > scsibus: -1 target: -1 lun: -1
> > > Warning: Using ATA Packet interface.
> > > Warning: The related Linux kernel interface code seems to be unmaintained.
> > > Warning: There is absolutely NO DMA, operations thus are slow.
> > 
> > dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> 
> Oh no, not this again... Please check the facts: the ATAPI method uses
> the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> nothing to do with ide-scsi. Period.
> 
> ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> burning, it's a crippled interface from the CDROM layer that should not
> be used for anything.  scsi-linux-ata.c should be ripped from the
> cdrecord sources, or at least cdrecord should _never_ select that
> transport for 2.6 kernels. For 2.4 you are far better off using
> ide-scsi.
> 
> > The scan through ATA lasts much less than with ATAPI, and you can burn with
> > dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended way.
> 
> No! ATAPI is the recommended way.
> 
> -- 
> Jens Axboe
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 
> 

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

On 2004.11.30, Jens Axboe wrote:
> On Mon, Nov 29 2004, J.A. Magallon wrote:
> > dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > 
> > > scsibus: -1 target: -1 lun: -1
> > > Warning: Using ATA Packet interface.
> > > Warning: The related Linux kernel interface code seems to be unmaintained.
> > > Warning: There is absolutely NO DMA, operations thus are slow.
> > 
> > dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> 
> Oh no, not this again... Please check the facts: the ATAPI method uses
> the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> nothing to do with ide-scsi. Period.
> 
> ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> burning, it's a crippled interface from the CDROM layer that should not
> be used for anything.  scsi-linux-ata.c should be ripped from the
> cdrecord sources, or at least cdrecord should _never_ select that
> transport for 2.6 kernels. For 2.4 you are far better off using
> ide-scsi.
> 
> > The scan through ATA lasts much less than with ATAPI, and you can burn with
> > dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended way.
> 
> No! ATAPI is the recommended way.
> 

Ahh, I think I found the problem....

I tried scanning with dev=ATAPI, and cdrecord did not found anything.
Then I tried in my home box, and it found the burner.
The problem is that in the 'strange' box the burner is hdh, and the
hard drive for system is hde. The previous IDE channels are unused
(an on-board promise with ide[01], hd[abcd]).
I use udev, so there is no hd[a-d] nodes on /dev. And cdrecord
_EXITS_ as soon as it founds a non-existent device !!!

With a quick'n'dirty hack (ln -s hde hd[abcdfg]), cdrecord finally
got the list:

nada:~> cdrecord dev=ATAPI -scanbus
Cdrecord-Clone 2.01-dvd (i686-pc-linux-gnu) Copyright (C) 1995-2004 J�g Schilling
Note: This version is an unofficial (modified) version with DVD support
Note: and therefore may have bugs that are not present in the original.
Note: Please send bug reports or support requests to <warly@mandrakesoft.com>.
Note: The author of cdrecord should not be bothered with problems in this version.
scsidev: 'ATAPI'
devname: 'ATAPI'
scsibus: -2 target: -2 lun: -2
Warning: Using ATA Packet interface.
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
Using libscg version 'schily-0.8'.
scsibus0:
        0,0,0     0) *
        0,1,0     1) 'HL-DT-ST' 'DVDRAM GSA-4040B' 'A300' Removable CD-ROM
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) *
        0,7,0     7) *

I will try to look at the cdrecord sources and make a real patch...
I suppose cdrecord will have a bugzilla or mailing list.

Many things will have to change with udev ;)

Thanks for your time and explanations.

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jan Engelhardt]

>I tried scanning with dev=ATAPI, and cdrecord did not found anything.
>Then I tried in my home box, and it found the burner.
>The problem is that in the 'strange' box the burner is hdh, and the
>hard drive for system is hde. The previous IDE channels are unused
>(an on-board promise with ide[01], hd[abcd]).

IMO that should not worry cdrecord where the burner is.

>I use udev, so there is no hd[a-d] nodes on /dev. And cdrecord
>_EXITS_ as soon as it founds a non-existent device !!!

You can find something that does not exist?

>Many things will have to change with udev ;)

I have udev AND like /dev/hdh, even though I don't have an extra IDE
controller. Yay to static entries.
Try mknod'ding hda and so forth (instead of symlinking) and then scanbus the
thing. Does it show up?



Jan Engelhardt
-- 
ENOSPC

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

On 2004.11.30, Jan Engelhardt wrote:
> 
> >I use udev, so there is no hd[a-d] nodes on /dev. And cdrecord
> >_EXITS_ as soon as it founds a non-existent device !!!
> 
> You can find something that does not exist?

Err, as it tries to open a device and it does not exist.
I tries sequentially
hda, hdb, hdc.. up to 256 until it finds something to open.
If it exists, but has not permissions, it keeps trying on the next.
But if it is not present, cdrecord gives up.

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jan Engelhardt]

>Err, as it tries to open a device and it does not exist.
>I tries sequentially
>hda, hdb, hdc.. up to 256 until it finds something to open.
>If it exists, but has not permissions, it keeps trying on the next.
>But if it is not present, cdrecord gives up.

Reasonable procedure. Albeit, leaky:
Imagine you use devfs... open()ing something like hd* would probably always
create a node. Although there is a max on possible, meaningful, nodes,
someone could use this to fill up /dev with
ridiculuous amounts of nodes, all of which are to my knowledge in kernel space.
"Well then, goodbye".

Luckily, even the very default config does not create arbitrarily nodes, and
cdrecord doesnot probe arbitr. devices.

So I guess, yes, cdrecord should probe harder. Preferably by looking into /sys
when using a 2.6 system.



Jan Engelhardt
-- 
ENOSPC

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

On 2004.11.30, Jan Engelhardt wrote:
> >Err, as it tries to open a device and it does not exist.
> >I tries sequentially
> >hda, hdb, hdc.. up to 256 until it finds something to open.
> >If it exists, but has not permissions, it keeps trying on the next.
> >But if it is not present, cdrecord gives up.
> 
> Reasonable procedure. Albeit, leaky:
> Imagine you use devfs... open()ing something like hd* would probably always
> create a node. Although there is a max on possible, meaningful, nodes,
> someone could use this to fill up /dev with
> ridiculuous amounts of nodes, all of which are to my knowledge in kernel space.
> "Well then, goodbye".
> 
> Luckily, even the very default config does not create arbitrarily nodes, and
> cdrecord doesnot probe arbitr. devices.
> 
> So I guess, yes, cdrecord should probe harder. Preferably by looking into /sys
> when using a 2.6 system.
> 

Patch for cdrecord:

--- cdrtools-2.01/libscg/scsi-linux-ata.c.orig	2004-11-30 19:02:37.929176615 +0100
+++ cdrtools-2.01/libscg/scsi-linux-ata.c	2004-11-30 19:06:11.316213702 +0100
@@ -385,8 +385,6 @@
 						device, f, errno);
 					}
 					return (-2);
-				} else if (errno == ENOENT || errno == ENODEV) {
-					break;
 				}
 			} else {
 				/* ugly hack, make better, when you can. Alex */

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam3 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #1

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Martin Schlemmer [c]]

[-- Attachment #1: Type: text/plain, Size: 3470 bytes --]

On Tue, 2004-11-30 at 08:16 +0100, Jens Axboe wrote:
> On Mon, Nov 29 2004, J.A. Magallon wrote:
> > dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > 
> > > scsibus: -1 target: -1 lun: -1
> > > Warning: Using ATA Packet interface.
> > > Warning: The related Linux kernel interface code seems to be unmaintained.
> > > Warning: There is absolutely NO DMA, operations thus are slow.
> > 
> > dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> 
> Oh no, not this again... Please check the facts: the ATAPI method uses
> the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> nothing to do with ide-scsi. Period.
> 
> ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> burning, it's a crippled interface from the CDROM layer that should not
> be used for anything.  scsi-linux-ata.c should be ripped from the
> cdrecord sources, or at least cdrecord should _never_ select that
> transport for 2.6 kernels. For 2.4 you are far better off using
> ide-scsi.
> 
> > The scan through ATA lasts much less than with ATAPI, and you can burn with
> > dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended way.
> 
> No! ATAPI is the recommended way.
> 

Ok, so I am a bit confused here.  We basically have 3 ways to use
cdrecord on linux-2.6 without ide-scsi:

1) cdrecord dev=/dev/hdx
2) cdrecord dev=ATA
3) cdrecord dev=ATAPI

Now, if I run all three and grep for '^Warning', I get:

-----
 $ cdrecord dev=/dev/cdrw -scanbus 2>&1 | grep '^Warning'
Warning: Open by 'devname' is unintentional and not supported.
 $ cdrecord dev=ATA -scanbus 2>&1 | grep '^Warning'
Warning: Using badly designed ATAPI via /dev/hd* interface.
 $ cdrecord dev=ATAPI -scanbus 2>&1 | grep '^Warning'
Warning: Using ATA Packet interface.
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
 $
-----

Which means:

1) dev=/dev/hdx	- Open by 'devname' is unintentional and not supported.
2) dev=ATA	- Using badly designed ATAPI via /dev/hd* interface.
3) dev=ATAPI	- Using ATA Packet interface.
                  (And some nice things about it not being maintained and
                   slow)

If I check the source for that, I get:

-----
libscg $ grep "Open by 'devname' is unintentional and not supported." *
scsi-linux-sg.c:                        "Warning: Open by 'devname' is unintentional and not supported.\n");
libscg $ grep 'Using badly designed ATAPI via /dev/hd\* interface.' *
scsi-linux-sg.c:                                "Warning: Using badly designed ATAPI via /dev/hd* interface.\n");
libscg $ grep 'Using ATA Packet interface.' *
scsi-linux-ata.c:               error("Warning: Using ATA Packet interface.\n");
libscg #
-----

Which hopefully (without really checking the source) means each are
implemented in these source files:

1) dev=/dev/hdx	- scsi-linux-sg.c
2) dev=ATA	- scsi-linux-sg.c
3) dev=ATAPI	- scsi-linux-ata.c

So if I take note of you comment above about scsi-linux-ata.c (or actually
give a fart about Jorg's warning about unmaintained and slow), should ATA
rather than ATAPI not be the recommended way??

Also, how about having the kernel print a warning when the depreciated
interface (ATAPI??) is used ? 


Thanks,

-- 
Martin Schlemmer


[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Radoslaw Szkodzinski]

On Wednesday 01 of December 2004 22:16, Martin Schlemmer [c] wrote:
> On Tue, 2004-11-30 at 08:16 +0100, Jens Axboe wrote:
> > On Mon, Nov 29 2004, J.A. Magallon wrote:
> > > dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > > > scsibus: -1 target: -1 lun: -1
> > > > Warning: Using ATA Packet interface.
> > > > Warning: The related Linux kernel interface code seems to be
> > > > unmaintained. Warning: There is absolutely NO DMA, operations thus
> > > > are slow.
> > >
> > > dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> >
> > Oh no, not this again... Please check the facts: the ATAPI method uses
> > the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> > /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> > nothing to do with ide-scsi. Period.
> >
> > ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> > burning, it's a crippled interface from the CDROM layer that should not
> > be used for anything.  scsi-linux-ata.c should be ripped from the
> > cdrecord sources, or at least cdrecord should _never_ select that
> > transport for 2.6 kernels. For 2.4 you are far better off using
> > ide-scsi.
> >
> > > The scan through ATA lasts much less than with ATAPI, and you can burn
> > > with dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended
> > > way.
> >
> > No! ATAPI is the recommended way.
>
> Ok, so I am a bit confused here.  We basically have 3 ways to use
> cdrecord on linux-2.6 without ide-scsi:
>
> 1) cdrecord dev=/dev/hdx
> 2) cdrecord dev=ATA
> 3) cdrecord dev=ATAPI
>
> Now, if I run all three and grep for '^Warning', I get:
>
> -----
>  $ cdrecord dev=/dev/cdrw -scanbus 2>&1 | grep '^Warning'
> Warning: Open by 'devname' is unintentional and not supported.
>  $ cdrecord dev=ATA -scanbus 2>&1 | grep '^Warning'
> Warning: Using badly designed ATAPI via /dev/hd* interface.
>  $ cdrecord dev=ATAPI -scanbus 2>&1 | grep '^Warning'
> Warning: Using ATA Packet interface.
> Warning: The related Linux kernel interface code seems to be unmaintained.
> Warning: There is absolutely NO DMA, operations thus are slow.
>  $
> -----
>
> Which means:
>
> 1) dev=/dev/hdx - Open by 'devname' is unintentional and not supported.
> 2) dev=ATA - Using badly designed ATAPI via /dev/hd* interface.
> 3) dev=ATAPI - Using ATA Packet interface.
>                   (And some nice things about it not being maintained and
>                    slow)
>

Well, dev=ATA:nr,nr,nr will not produce any warning and works correctly with 
full performance.
dev=ATAPI:* gives bad performance and as stated above, shouldn't be used.
dev=/dev/hdx is just the same as dev=ATA:/dev/hdx, you can of course replace 
it with correct numbers if you know them or an alias 
in /etc/defaults/cdrecord.dfl (The path's from Gentoo, may be different 
elsewhere.)

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Martin Schlemmer [c]]

[-- Attachment #1: Type: text/plain, Size: 3378 bytes --]

On Thu, 2004-12-02 at 17:23 +0100, Radoslaw Szkodzinski wrote:
> On Wednesday 01 of December 2004 22:16, Martin Schlemmer [c] wrote:
> > On Tue, 2004-11-30 at 08:16 +0100, Jens Axboe wrote:
> > > On Mon, Nov 29 2004, J.A. Magallon wrote:
> > > > dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > > > > scsibus: -1 target: -1 lun: -1
> > > > > Warning: Using ATA Packet interface.
> > > > > Warning: The related Linux kernel interface code seems to be
> > > > > unmaintained. Warning: There is absolutely NO DMA, operations thus
> > > > > are slow.
> > > >
> > > > dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> > >
> > > Oh no, not this again... Please check the facts: the ATAPI method uses
> > > the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> > > /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> > > nothing to do with ide-scsi. Period.
> > >
> > > ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> > > burning, it's a crippled interface from the CDROM layer that should not
> > > be used for anything.  scsi-linux-ata.c should be ripped from the
> > > cdrecord sources, or at least cdrecord should _never_ select that
> > > transport for 2.6 kernels. For 2.4 you are far better off using
> > > ide-scsi.
> > >
> > > > The scan through ATA lasts much less than with ATAPI, and you can burn
> > > > with dev=ATA:1,0,0 or dev=/dev/burner, which is the new recommended
> > > > way.
> > >
> > > No! ATAPI is the recommended way.
> >
> > Ok, so I am a bit confused here.  We basically have 3 ways to use
> > cdrecord on linux-2.6 without ide-scsi:
> >
> > 1) cdrecord dev=/dev/hdx
> > 2) cdrecord dev=ATA
> > 3) cdrecord dev=ATAPI
> >
> > Now, if I run all three and grep for '^Warning', I get:
> >
> > -----
> >  $ cdrecord dev=/dev/cdrw -scanbus 2>&1 | grep '^Warning'
> > Warning: Open by 'devname' is unintentional and not supported.
> >  $ cdrecord dev=ATA -scanbus 2>&1 | grep '^Warning'
> > Warning: Using badly designed ATAPI via /dev/hd* interface.
> >  $ cdrecord dev=ATAPI -scanbus 2>&1 | grep '^Warning'
> > Warning: Using ATA Packet interface.
> > Warning: The related Linux kernel interface code seems to be unmaintained.
> > Warning: There is absolutely NO DMA, operations thus are slow.
> >  $
> > -----
> >
> > Which means:
> >
> > 1) dev=/dev/hdx - Open by 'devname' is unintentional and not supported.
> > 2) dev=ATA - Using badly designed ATAPI via /dev/hd* interface.
> > 3) dev=ATAPI - Using ATA Packet interface.
> >                   (And some nice things about it not being maintained and
> >                    slow)
> >
> 
> Well, dev=ATA:nr,nr,nr will not produce any warning and works correctly with 
> full performance.
> dev=ATAPI:* gives bad performance and as stated above, shouldn't be used.
> dev=/dev/hdx is just the same as dev=ATA:/dev/hdx, you can of course replace 
> it with correct numbers if you know them or an alias 
> in /etc/defaults/cdrecord.dfl (The path's from Gentoo, may be different 
> elsewhere.)

Yes, I know .. its just that I have been under the impression (and also
what experience shows) that 'dev=/dev/hdx' and 'dev=ATA' is the same
thing, with 'dev=ATAPI' the depreciated one, but Jens stated differently
above ...

-- 
Martin Schlemmer


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Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Jan Engelhardt]

> Ok, so I am a bit confused here.  We basically have 3 ways to use
>> cdrecord on linux-2.6 without ide-scsi:
>>
>> 1) cdrecord dev=/dev/hdx
>> 2) cdrecord dev=ATA
>> 3) cdrecord dev=ATAPI
>>
>> Now, if I run all three and grep for '^Warning', I get:

Worse, yet, there is no DMA for any of these three :-(


Jan Engelhardt
-- 
ENOSPC

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Rahul Karnik]

On Fri, 3 Dec 2004 08:35:32 +0100 (MET), Jan Engelhardt
<jengelh@linux01.gwdg.de> wrote:
> > Ok, so I am a bit confused here.  We basically have 3 ways to use
> >> cdrecord on linux-2.6 without ide-scsi:
> >>
> >> 1) cdrecord dev=/dev/hdx
> >> 2) cdrecord dev=ATA
> >> 3) cdrecord dev=ATAPI
> >>
> >> Now, if I run all three and grep for '^Warning', I get:
> 
> Worse, yet, there is no DMA for any of these three :-(

Not true in 2.6. 1 definitely uses DMA now (disregard the damn
warning). And why would anyone use 2 or 3?

-Rahul

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Jan Engelhardt]

>> > Ok, so I am a bit confused here.  We basically have 3 ways to use
>> >> cdrecord on linux-2.6 without ide-scsi:
>> >>
>> >> 1) cdrecord dev=/dev/hdx
>> >> 2) cdrecord dev=ATA
>> >> 3) cdrecord dev=ATAPI
>> >>
>> >> Now, if I run all three and grep for '^Warning', I get:
>>
>> Worse, yet, there is no DMA for any of these three :-(
>
>Not true in 2.6. 1 definitely uses DMA now (disregard the damn
>warning). And why would anyone use 2 or 3?

Right, forgot to add. Read as "no DMA for any that does not give a cdrecord
warning".



Jan Engelhardt
-- 
ENOSPC

Re: cdrecord dev=ATA cannont scanbus as non-root [u]

[Jens Axboe]

On Fri, Dec 03 2004, Jan Engelhardt wrote:
> >> > Ok, so I am a bit confused here.  We basically have 3 ways to use
> >> >> cdrecord on linux-2.6 without ide-scsi:
> >> >>
> >> >> 1) cdrecord dev=/dev/hdx
> >> >> 2) cdrecord dev=ATA
> >> >> 3) cdrecord dev=ATAPI
> >> >>
> >> >> Now, if I run all three and grep for '^Warning', I get:
> >>
> >> Worse, yet, there is no DMA for any of these three :-(
> >
> >Not true in 2.6. 1 definitely uses DMA now (disregard the damn
> >warning). And why would anyone use 2 or 3?
> 
> Right, forgot to add. Read as "no DMA for any that does not give a cdrecord
> warning".

They all use DMA, whenever possible.

-- 
Jens Axboe

Re: cdrecord dev=ATA cannont scanbus as non-root

[Markus Plail]

Jens Axboe <axboe@suse.de> writes:

> On Mon, Nov 29 2004, J.A. Magallon wrote:
>> dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
>> 
>> > scsibus: -1 target: -1 lun: -1
>> > Warning: Using ATA Packet interface.
>> > Warning: The related Linux kernel interface code seems to be unmaintained.
>> > Warning: There is absolutely NO DMA, operations thus are slow.
>> 
>> dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
>
> Oh no, not this again... Please check the facts: the ATAPI method uses
> the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> nothing to do with ide-scsi. Period.
>
> ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> burning, it's a crippled interface from the CDROM layer that should not
> be used for anything.  scsi-linux-ata.c should be ripped from the
> cdrecord sources, or at least cdrecord should _never_ select that
> transport for 2.6 kernels. For 2.4 you are far better off using
> ide-scsi.

Are you sure you don't mix ATA with ATAPI? I think ATA is equivalent to
dev=/dev/hdX. 

regards
Markus

Re: cdrecord dev=ATA cannont scanbus as non-root

[Jens Axboe]

On Wed, Dec 01 2004, Markus Plail wrote:
> Jens Axboe <axboe@suse.de> writes:
> 
> > On Mon, Nov 29 2004, J.A. Magallon wrote:
> >> dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> >> 
> >> > scsibus: -1 target: -1 lun: -1
> >> > Warning: Using ATA Packet interface.
> >> > Warning: The related Linux kernel interface code seems to be unmaintained.
> >> > Warning: There is absolutely NO DMA, operations thus are slow.
> >> 
> >> dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> >
> > Oh no, not this again... Please check the facts: the ATAPI method uses
> > the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> > /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> > nothing to do with ide-scsi. Period.
> >
> > ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> > burning, it's a crippled interface from the CDROM layer that should not
> > be used for anything.  scsi-linux-ata.c should be ripped from the
> > cdrecord sources, or at least cdrecord should _never_ select that
> > transport for 2.6 kernels. For 2.4 you are far better off using
> > ide-scsi.
> 
> Are you sure you don't mix ATA with ATAPI? I think ATA is equivalent to
> dev=/dev/hdX. 

I did mix them up, my apologies til Magallon. As always you should just
use -dev=/dev/hdX and it will work the best, there's no need to give ATA
or ATAPI. They are too easy to mix up as the names don't really give you
any hints on what access method they will utilize. Using -dev also means
there's no reason to run -scanbus at all, since you know where the
device is. If you don't, then you probably should be using k3b or some
other helper to work out things for you.

-- 
Jens Axboe

Re: cdrecord dev=ATA cannont scanbus as non-root

[J.A. Magallon]

[-- Attachment #1: Type: text/plain, Size: 5615 bytes --]


On 2004.12.02, Jens Axboe wrote:
> On Wed, Dec 01 2004, Markus Plail wrote:
> > Jens Axboe <axboe@suse.de> writes:
> > 
> > > On Mon, Nov 29 2004, J.A. Magallon wrote:
> > >> dev=ATAPI uses ide-scsi interface, through /dev/sgX. And:
> > >> 
> > >> > scsibus: -1 target: -1 lun: -1
> > >> > Warning: Using ATA Packet interface.
> > >> > Warning: The related Linux kernel interface code seems to be unmaintained.
> > >> > Warning: There is absolutely NO DMA, operations thus are slow.
> > >> 
> > >> dev=ATA uses direct IDE burning. Try that as root. In my box, as root:
> > >
> > > Oh no, not this again... Please check the facts: the ATAPI method uses
> > > the SG_IO ioctl, which is direct-to-device. It does _not_ go through
> > > /dev/sgX, unless you actually give /dev/sgX as the device name. It has
> > > nothing to do with ide-scsi. Period.
> > >
> > > ATA uses CDROM_SEND_PACKET. This has nothing to do with direct IDE
> > > burning, it's a crippled interface from the CDROM layer that should not
> > > be used for anything.  scsi-linux-ata.c should be ripped from the
> > > cdrecord sources, or at least cdrecord should _never_ select that
> > > transport for 2.6 kernels. For 2.4 you are far better off using
> > > ide-scsi.
> > 
> > Are you sure you don't mix ATA with ATAPI? I think ATA is equivalent to
> > dev=/dev/hdX. 
> 
> I did mix them up, my apologies til Magallon. As always you should just
> use -dev=/dev/hdX and it will work the best, there's no need to give ATA
> or ATAPI. They are too easy to mix up as the names don't really give you
> any hints on what access method they will utilize. Using -dev also means
> there's no reason to run -scanbus at all, since you know where the
> device is. If you don't, then you probably should be using k3b or some
> other helper to work out things for you.
> 

Ahh, I'm going to kick my head on the table...
Well, lets begin again. So:
- for 2.4, use ide-scsi
- for 2.6, use ATA
So cdrecord should stop to scan the ATAPI pseudo bus.

My problem is just that I want to set an easy way to burn for users.
In other systems you just hav an app onto you throw your mp3 and get 
an audio disc, or d'n'd your files and get a cd.
And I don want to tell people to rune mkisofs with a ton of options
(jolliet, rr, long names, etc...). So they must use a GUI tool.
The best I like nowadays is gnomebaker.

The thing is that all frontends use cdrecord. In many you can't specify
the device by hand, they just give you a menu based on cdrecord -scan
output. They should tell cdrecord to scan SCSI and ATA buses, but not ATAPI.

And now, as root:

werewolf:~# cdrecord dev=ATA -scanbus
...
scsibus1:
        1,0,0   100) 'HL-DT-ST' 'DVDRAM GSA-4120B' 'A102' Removable CD-ROM

werewolf:/store/tmp# cdrecord -dev=ATA:1,0,0 -dao -dummy *.iso
Driver flags   : MMC-3 SWABAUDIO BURNFREE 
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
Speed set to 7056 KB/s
Starting to write CD/DVD at speed  40.0 in dummy SAO mode for single session.
...

And as user:

werewolf:~> cdrecord dev=ATA -scanbus
...
cdrecord: Permission denied. Cannot open '/dev/hda'. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root.
cdrecord: For possible transport specifiers try 'cdrecord dev=help'.

werewolf:/store/tmp> cdrecord -dev=ATA:1,0,0 -dummy -dao *.iso
...
cdrecord: Permission denied. Cannot open '/dev/hda'. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root.
cdrecord: For possible transport specifiers try 'cdrecord dev=help'.

But:

werewolf:/store/tmp> cdrecord -dev=/dev/hdc -dummy -dao *.iso
...
cdrecord: Cannot allocate memory. WARNING: Cannot do mlockall(2).
cdrecord: WARNING: This causes a high risk for buffer underruns.
cdrecord: Operation not permitted. WARNING: Cannot set RR-scheduler
cdrecord: Permission denied. WARNING: Cannot set priority using setpriority().
cdrecord: WARNING: This causes a high risk for buffer underruns.
scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
Warning: Open by 'devname' is unintentional and not supported.
Linux sg driver version: 3.5.27
WARNING ! Cannot gain SYS_RAWIO capability ! 
: Operation not permitted
...
Driver flags   : MMC-3 SWABAUDIO BURNFREE 
Supported modes:                                  < EMPTY AGAIN !!!!!
cdrecord: Drive does not support SAO recording.
cdrecord: Illegal write mode for this drive.

werewolf:/store/tmp> ll /dev/hdc
brw-rw-rw-  1 magallon cdwriter 22, 0 2004.12.01 23:27 /dev/hdc

(pam did it for the console ;))

There are some bugs here:
- One in cdrecord, that exits as soon as it can't open a device, instead
  of trying till it gets the cdwriter.
- Other in cdrecord, the system does not behave the same way if I
  give /dev/hdc or ATA:1,0,0.
- Other in the kernel, that does not allow to query capabilities of the
  drive to a normal user.

I can hackpatch cdrecord, but have no idea of what to do with the kernel.
I remember there were some mails time ago about adding allowed commands to
cdrom/cdwiters, but can't find them.

Perhaps, someday, somwhere, I could burn a disc in Linux as plain user.

Thanks for bearing me...

--
J.A. Magallon <jamagallon()able!es>     \               Software is like sex:
werewolf!able!es                         \         It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.10-rc2-jam4 (gcc 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)) #2


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