[ale] ISO image from a mounted CDROM

[Doug McNash]

Returning EBUSY is a function of the driver.  Looking at the source
(2.4.x), if the cdrom driver is used it will return EBUSY if opened for
exclusive use or if locked, as in no eject, which the app mount or
whatever may choose to do.  The sonycd535 driver allows only one
exclusive open, the second open will fail with EBUSY returned.

I would bet he has a sony drive.


On Wed, 2004-12-15 at 17:30, Aditya Srinivasan wrote:
> On Wed, 15 Dec 2004, Geoffrey wrote:
> 
> > Geoffrey wrote:
> > > james at sumners.ath.cx wrote:
> > > 
> > >> You, sir, have a weird version of dd. dd works at the device level and
> > >> should not be able to read a device that is busy.
> > 
> > Two processes can access the same device.  Right now I've got the 
> > following running:
> > 
> > dd if=/dev/hdc of=foo.iso
> > dd if=/dev/hdc of=foo1.iso
> 
> In agreement.
> 
> No cdrom drive to test this with, instead ....
> To test this, I tried to read /dev/hda, as well as /dev/hda1 as root.
> dd if=/dev/hda of=/home/sriad/out
> 
> Since I could do this, although it is mounted, I guess dd would also be 
> able to read a mounted cdrom drive.
> The man page describes dd as 
> Copy a file, converting and formatting according to the options.
> 
> I can do this with a regular file
> dd if=foo of=bar
> 
> In addition dd apparently has the ability to read device files. 
> 
> --
> Thanks,
> sriad
> 
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